GT6 radiator modification. Still some cooling problems. Is this "normal"?

[Pete Lewis]

if you have an infra red or  covid thremometer thingy  when shes hot check the top hose rad stub temp then check the outlet  stub 

there must be a large difference  if its all a bit too close then the rad is blocked or lost its cooling efficiency

and if a tube is blocked at the top ,any air in the tubes will expand with heat and 

you start to overflow when its not really hot 

Pete

[RichardS]

4 hours ago, Pete Lewis said:

if you have an infra red or  covid thremometer thingy  when shes hot check the top hose rad stub temp then check the outlet  stub 

there must be a large difference  if its all a bit too close then the rad is blocked or lost its cooling efficiency

and if a tube is blocked at the top ,any air in the tubes will expand with heat and 

you start to overflow when its not really hot 

Pete

Indeed so. I checked the input hose and the output hose with my hand when the car was idling after my test run and the temperatures are too close which is why the temperature continues to creep upwards.

I've decided to speak to the specialist rad company used by the restorers that my Son works for and see what they can do.

I'll let the forum know what they suggest.

Richard

[Pete Lewis]

thats good  its getting clear it is not at its best   and its a main  basic part of the cooling  

Pete

[avivalasvegas]

I experience the same symptoms on my MK2 GT6. Fortunately, the aux fan appears to work well to keep the thermostat firmly at the halfway mark.

Would switching to a Radtec aluminum radiator remove the need for an additional fan? They do claim "a 40% upgrade in cooling when compared to the original."

[Clive]

20 minutes ago, avivalasvegas said:

I experience the same symptoms on my MK2 GT6. Fortunately, the aux fan appears to work well to keep the thermostat firmly at the halfway mark.

Would switching to a Radtec aluminum radiator remove the need for an additional fan? They do claim "a 40% upgrade in cooling when compared to the original."

I very much doubt the rad will get rid of 40% more heat, maybe it has 40% more cooling fin area or suchlike. But it is not a linear relationship, rather the law of diminishing returns. 

I would get a high quality new core fitted to the existing rad in preference, less than half the cost and works correctly.

Of course, there is the VW rad option. Non-original, but the people I know who have gone that route have been very happy with the results, and the cars are well used. A VW rad is about £40, and about the same again for the bits to fit it.

[Pete Lewis]

its normal that many buy bolt on must haves when the base problem is after 50 years you need a re core and not the faf of adding 

£££s in the wrong direction chasing  the Myths of GT6 or others that have evolved over time , 

the trouble is you cant see the offending problem as its all inside , it looks ok outside it must be everything else but not the radiator 

the engine makes the heat   the radiator disperses   it '  all the bits in between are all very useful and control the cooling but 

if you never start it it stays cold  if the radiator is half blocked  when you run it  it stays Hot

no matter what fan.' thermostat or pump or cowling  you pay  £££s  for will solve the base culprit 

a recore  locally is about £140 can be the cheapest option 

Pete

[Clive]

14 minutes ago, Mathew said:

As pete says, treat the root cause not the symptoms. How can you tell its blocked? Flow and weight or even volume of water held compaired to a known good one. 

I think the only reliable way is to check the flow rate through the rad. Not something you can easily do at home. 

I expect it involves a set volume of water at a set height above the rad, and time how long it takes to empty. Compare to a chart of rad core size or a new rad. 

[Nick Jones]

59 minutes ago, Pete Lewis said:

a recore  locally is about £140 can be the cheapest

You what? I couldn’t get a quote below  £300…… which is was I now have a Golf radiator which cost a 10th of that brand new……

Similar issue with the Vitesse except there’s no squeezing a Golf rad in that.

Nick

[johny]

Yes copper prices have shot up in the last few years and I suppose theres not so many places recoring these days so less competition. I went Honda Civic ally for my Vitesse at under 50 quid delivered..

[Clive]

I weighed in a few rads in Feb. one GT6, a vitesse and 3 herald/spit. Got just over £100🙂

All were in need of a recore. I had tried giving them away but no takers. 

My cars both have VW rads fitted. Golf one (£27 now) cools a 180bhp engine no worries, fan rarely cuts in. 

[Pete Lewis]

well   last year  £140 this was  a herald rad  but they are not wildly different depends where you go 

this is an old school small what a mess sort of place but the product is good 

yes cost of copper and man hours all come into the £££

a local Stag rad is being recored and thats heading for £300 which includes new supprt brakets and more and thats at a more 'upmarket'  repair centre 

 

 

[avivalasvegas]

7 hours ago, johny said:

Yes copper prices have shot up in the last few years and I suppose theres not so many places recoring these days so less competition. I went Honda Civic ally for my Vitesse at under 50 quid delivered..

Aaron's radiators. I've had one done for my Mercedes. Top class! 

[johny]

yes theres some good places but how much???

[avivalasvegas]

16 minutes ago, johny said:

yes theres some good places but how much???

Cost me £150 a couple years ago for the upgraded core. I did a citric acid flush with the old radiator on (highly recommended to get the gunk and rust out of the cooling system) and then replaced all the hoses, cleaned and polished the housings myself and added a new thermostat. The difference was astounding - the ol' girl warms up the cabin within 5 minutes on the coldest winter day and stays at 90 degrees (it's a diesel) no matter what I throw at it. Even at 88mph (top speed for the 240D)

Who knows what prices are today but I went with it for originality. That said, for the GT6, the reduced weight of the aluminum radiator and improved cooling are attractive.

[Nigel Clark]

I recently fitted an alloy radiator in my Scimitar GTE. The temp gauge has stayed reassuringly low at around 80-85C during recent hot weather, when before it would hit 90-95C in traffic with the old radiator.

That said, the old radiator was in a bad state, not leaking but looked like it had been there since the car was built in 1977!

Nigel

[Jim-GT6]

6 hours ago, Pete Lewis said:

well   last year  £140 this was  a herald rad  but they are not wildly different depends where you go 

this is an old school small what a mess sort of place but the product is good 

yes cost of copper and man hours all come into the £££

a local Stag rad is being recored and thats heading for £300 which includes new supprt brakets and more and thats at a more 'upmarket'  repair centre 

 

 

This topic is so timely for me, as my GT6 has been getting scary hot recently, but there again maybe this topic comes up every year when we break into temps in the high 20's C ? 😄

It's a long time since I owned an old car, and my GT6 is 3 years older than me. This forum is such a blessing.

Reading these last few posts I'm now convinced I was about to do expensive things in the wrong order.

My car normally sits at about 60% hot. I don't know why. It's always been above middle since I bought it. I thought maybe that was fine for an old car. It was pretty stable at 60% or 65%. I didn't know if it was realistic for gauges to sit dead on where they would have done when the car was young (I still don't to be honest). These last weeks it's got to about 80/85% hot at times. Just below the very small 'hot' box on the gauge. And for a good while on a few journeys. I hate the anxiety of looking at the needle every 30 seconds and panicking if there's a jam on the M4! It's not in the danger zone, but I feel it's doing damage to everything under the bonnet. The power also drops off - it becomes gutless.

Regardless of how accurate the gauge may or may not be, when you take off the rad filler cap, and the cap rubber is stuck to the rim, it's clear the engine is running as hot as the gauge might have suggested (or maybe even hotter). It peels off intact if I take it off very carefully, but it's clearly been 'denatured'. That surely means scary hot? I've ordered a new cap.

I overheated my first car shortly after I passed my test (mini clubman estate 998cc - my first love) and melted a spark plug. Nearly killed it. New head gasket. I didn't know what getting 'well into the red' might do to a car when I was 17. Ever since, unsurprisingly perhaps, I hate it when cars run hot. All the rubber and plastic is the first to go, then really scary things happen (I was emotionally scarred by the abuse I inflicted on that car through poor judgement - we had only just finished restoring it from a £150 rusty heap to gleaming - I was so close to the motorway exit! - we fixed it).

When I bought my GT6 last autumn, the PO told me he had put waterless coolant in it, I guess because it must have been overheating. As the gauge had been reading hot recently, I checked and the coolant was low, with nothing in the expansion tank, so bought some Evans to top it up (ouch) and half filled the expansion tank too. I think I'll stick with the waterless for now, as it's in there, but if I have to drain it, I've not made up my mind what to refill it with. I think the PO did not do the job properly (flushed with water not chemical), and the topic of coolant is maybe somewhat aside (I think the topic of another thread?). The thing of import in this regard is - it's pretty rusty looking - pants to crud and corrosion.

My expensive next steps plan to address the scary hot temps, was:

1. Replace the leaking heater valve that piddles coolant all over the engine when it's shut (so it has to stay open all the time, which is great when it's 28 deg out as it was last week!) The apparent leak is clearly the first thing to fix. Valve is on its way.

2. Buy and fit the missing front radiator cowl (regular fibre board, as aluminium feels, well ... why? It will likely get bent in the post, and aluminium to what benefit?) - this cowl is also on the way - I figure it's supposed to be there, so can't be a wrong decision

3. When they're fitted, test it with the number plate on, and off, on a good run, and if that has an effect, buy a bonnet sticker one instead (which I might do anyway, as the number plate really MUST compromise the air flow where it's mounted, and the sticker would look quite cool on the white bonnet IMO 😎) I would have to hope my best efforts at plate visibility satisfy any officers who take an interest

4. Then, if still not good, buy an electric fan kit - was looking at Kenlow / Revotec - undecided which 

5. Then, aluminium uprated radiator combined with an oil cooler (which I'm not sure where you mount?)

The car would then no doubt run at a stable temp, as it would have a brand new (and by material difference alone), more efficient radiator. And an oil cooler that was never there before. I'd also be around 5 or 6 hundred quid lighter.

50 years of crud, material degradation and oxidation of the internal surfaces of the of rad is, I now see quite clearly, the most likely cause of the issue. My 'number 3' will now be to look for a recore locally ASAP, which was not even on my list.

If the recore doesn't fully bring temps under control, then a leccy fan might be on the cards, or maybe I should be looking for a blockage in the engine before a leccy fan?

The bigger picture question I have is this: If they're running as designed, would these cars be fine if they got stuck in a jam for an hour on a hot day after an hour at 70mph? When these cars were brand new, did they run hot and overheat? Or is it that after 10 or 15 years of use, the cars started running hot, because the rads were end of life? It was Pete's comment "the trouble is you cant see the offending problem as its all inside , it looks ok outside it must be everything else but not the radiator" that struck me.

I didn't have the pleasure of driving these cars new, but I expect members on the forum may have. Does a brand new GT6 sit at dead middle temp in all conditions?

If not, maybe the upgrade in materials to aluminium and the luxury addition of electric fan and oil cooler is a worthwhile step to make these cars run as reliably as they can?

 

 

[Pete Lewis]

dont forget or be misguided but  a 82c thermostat  a new voltage regulator and a new correct sender unit is a heck of a lot cheaper 

start to make the basics right  long before you delve into elec fans and oil coolers 

you can fit all that and find the simples  still plague the gauge readings as  the £5 part is the problem 

Pete

 

 

[johny]

I believe these cars were ok when new but there was never a lot of spare cooling capacity so with the years plus possibly changes in fuel and driving conditions that spare capacity has been used up and in certain conditions they can now overheat. All you can do is work through the list of remedies starting at the easiest/cheapest and working your way up. With a standard engine its perfectly feasible to recuperate the spare capacity and, if you want to, even exceed the original.

Once the on-the-move cooling is working well then stationary cooling with the standard fan should also be greatly improved and any further modifications are only really to give additional confidence....  

[Bob Horner]

I had awful problems re overheating in mk2 Gt6.  I had the right cowl in place and the side valances. Checked sender, gauge etc.  No change. Fitted a new aluminium rad. No change. Fitted a blower electric  fan (don’t believe anyone that this sort causes issues - works brilliantly and gives loads of room). No change.  Suspected the flow through the system wasn’t good through the bottom hose. Flushed with all sorts of products.  There was only a dribble out of the tap at the rear of the block.  In the end,  took the head off, flushed head with phosphoric acid (recommended by an old hand and despite scepticism on here seamed to fizz away and work well). Then, after protecting bores, poked around and flushed block.  Tons of crap at rear of block.  Put it all back together.  Now runs as cool as a cucumber.  Even in the recent heat. No issues at all.  Almost too cool!  Taking off the head well worth the effort.  You need to make sure everything is circulating through the block and head and the system is fine.  I’ve spent ££ upgrading but happy with lighter rad and a couple of extra horses from revotec fan but could have got a cool engine with just a deep clean!! Live and learn. 

Bob

[Jim-GT6]

All wise words. Start from the most likely, and easy.

Bob - I would not be at all unhappy to end with the same outcome you have. I think I'd like the comfort you currently enjoy of cooler than norm, rather than hotter. 

I could start replacing sensors and the full system from sender onwards, to be sure of the root issue from the ground up, but suspect what I need to do is be sure the fluid is flowing where it should be. As for other causes, the fuel gauge appears okay, so I feel like the voltage reg is likely okay. The water flows when it warms up, so the thermostat must be functional at some temp. Feels like it's a rad re-core vs. block / head clear out as the things I need to choose between as the first step ...  

[Jim-GT6]

Johny, I feel you've captured it really well here. Capacity. It might have been a bit marginal back in the day with production costs what they were for different materials at that moment in time, and that capacity gets used with degradation, but it's a question, as you rightly say, of how much extra capacity we want to add now for comfort vs. maintaining original setup. We don't expect to see cars on the hard shoulder anymore. It's going to be the same as one's aversion to all sorts of risk! 😁

[Clive]

6 hours ago, Jim-GT6 said:

This topic is so timely for me, as my GT6 has been getting scary hot recently, but there again maybe this topic comes up every year when we break into temps in the high 20's C ? 😄

It's a long time since I owned an old car, and my GT6 is 3 years older than me. This forum is such a blessing.

Reading these last few posts I'm now convinced I was about to do expensive things in the wrong order.

My car normally sits at about 60% hot. I don't know why. It's always been above middle since I bought it. I thought maybe that was fine for an old car. It was pretty stable at 60% or 65%. I didn't know if it was realistic for gauges to sit dead on where they would have done when the car was young (I still don't to be honest). These last weeks it's got to about 80/85% hot at times. Just below the very small 'hot' box on the gauge. And for a good while on a few journeys. I hate the anxiety of looking at the needle every 30 seconds and panicking if there's a jam on the M4! It's not in the danger zone, but I feel it's doing damage to everything under the bonnet. The power also drops off - it becomes gutless.

Regardless of how accurate the gauge may or may not be, when you take off the rad filler cap, and the cap rubber is stuck to the rim, it's clear the engine is running as hot as the gauge might have suggested (or maybe even hotter). It peels off intact if I take it off very carefully, but it's clearly been 'denatured'. That surely means scary hot? I've ordered a new cap.

I overheated my first car shortly after I passed my test (mini clubman estate 998cc - my first love) and melted a spark plug. Nearly killed it. New head gasket. I didn't know what getting 'well into the red' might do to a car when I was 17. Ever since, unsurprisingly perhaps, I hate it when cars run hot. All the rubber and plastic is the first to go, then really scary things happen (I was emotionally scarred by the abuse I inflicted on that car through poor judgement - we had only just finished restoring it from a £150 rusty heap to gleaming - I was so close to the motorway exit! - we fixed it).

When I bought my GT6 last autumn, the PO told me he had put waterless coolant in it, I guess because it must have been overheating. As the gauge had been reading hot recently, I checked and the coolant was low, with nothing in the expansion tank, so bought some Evans to top it up (ouch) and half filled the expansion tank too. I think I'll stick with the waterless for now, as it's in there, but if I have to drain it, I've not made up my mind what to refill it with. I think the PO did not do the job properly (flushed with water not chemical), and the topic of coolant is maybe somewhat aside (I think the topic of another thread?). The thing of import in this regard is - it's pretty rusty looking - pants to crud and corrosion.

My expensive next steps plan to address the scary hot temps, was:

1. Replace the leaking heater valve that piddles coolant all over the engine when it's shut (so it has to stay open all the time, which is great when it's 28 deg out as it was last week!) The apparent leak is clearly the first thing to fix. Valve is on its way.

2. Buy and fit the missing front radiator cowl (regular fibre board, as aluminium feels, well ... why? It will likely get bent in the post, and aluminium to what benefit?) - this cowl is also on the way - I figure it's supposed to be there, so can't be a wrong decision

3. When they're fitted, test it with the number plate on, and off, on a good run, and if that has an effect, buy a bonnet sticker one instead (which I might do anyway, as the number plate really MUST compromise the air flow where it's mounted, and the sticker would look quite cool on the white bonnet IMO 😎) I would have to hope my best efforts at plate visibility satisfy any officers who take an interest

4. Then, if still not good, buy an electric fan kit - was looking at Kenlow / Revotec - undecided which 

5. Then, aluminium uprated radiator combined with an oil cooler (which I'm not sure where you mount?)

The car would then no doubt run at a stable temp, as it would have a brand new (and by material difference alone), more efficient radiator. And an oil cooler that was never there before. I'd also be around 5 or 6 hundred quid lighter.

50 years of crud, material degradation and oxidation of the internal surfaces of the of rad is, I now see quite clearly, the most likely cause of the issue. My 'number 3' will now be to look for a recore locally ASAP, which was not even on my list.

If the recore doesn't fully bring temps under control, then a leccy fan might be on the cards, or maybe I should be looking for a blockage in the engine before a leccy fan?

The bigger picture question I have is this: If they're running as designed, would these cars be fine if they got stuck in a jam for an hour on a hot day after an hour at 70mph? When these cars were brand new, did they run hot and overheat? Or is it that after 10 or 15 years of use, the cars started running hot, because the rads were end of life? It was Pete's comment "the trouble is you cant see the offending problem as its all inside , it looks ok outside it must be everything else but not the radiator" that struck me.

I didn't have the pleasure of driving these cars new, but I expect members on the forum may have. Does a brand new GT6 sit at dead middle temp in all conditions?

If not, maybe the upgrade in materials to aluminium and the luxury addition of electric fan and oil cooler is a worthwhile step to make these cars run as reliably as they can?

 

 

Of course, you are relying on your temp gauge. They are not always reliable sources of information. Ideally you need a calibrated gauge, the old "bulb" type are easy to check and then fit, even temporarily. Mine ws borrowed some years back and returned broken, which is a shame. But it is important to know precicely where you are starting from. (friend thought his herald was running hot, turns out the gauge/sender combo was the issue as it was actually running in the early/mid 80s. I swapped the gauge and sender for ones I had until it indicated bang in the middle)

The first thing is running the waterless coolant. It means you cannot flush the cooling system with it in. So the simple, first step is to drain it, carefully if yu plan to re-use it, and possibly filter it.

Then do teh sensible thing, and the weather is sort of on your side. Get a garden hose, fill the system with water, and run it briefly. Now see what happens when you remove the rear block drain plug (under the manifolds hear the rear of the engine) Water should flow feely out, if not get bits of wire etc and start poking about to clear the blockages. Keep going until you have done all you can. I wonder if something like a bit of handbrake cable or a bit thinner would be good as it is flexible. 

Next, take off as many cooling hoses as possible at one end. You can flush the heater matrix from both sides, several times. Then the radiator, then the block by going round all the water outlets, including pressing the end of the bare garden hose against the block drain. You may get a lot of crud out. And pay attention to the metal bypass pipe under the manifolds, it may need rodding though the main pipe, but be aware the T off it near the rear (I think the GT6 has a T off) has only a small hole where it joins the main tube. This all needs checking with a pokey wire thing.

Fit your new heater valve, 82 degree thermostat etc reconnect the hoses. This should all take an hour or so, and wet feet. Fill with water plus some holts speedflush, take for a good  drive.  and let it get hot. Observe the temp gauge, ideally without changing the sensor. See if there is any improvement. This flushing may help, but is essential before swapping a radiator to prevent it being blocked immediately. Once the speedflush has done its job, drain, flush with clean water, then fill with a 30% blue antifreeze mix. (keep the evans stuff for later as long as you are certain it has not been compromised by water contamination at any point)

If it seems much better, you may be OK. If not, you may need to remove the head to clean the block out, and a new rad. I can remember rebuilding my vitesse engine when I put the car together. It was a bare block and head, and I used a jetwash and wire to clean it out. A load of scale was left over the driveway. Using acid to clean the waterways would have been an obvious thing to do in retrospect. 

[johny]

7 hours ago, Jim-GT6 said:

Johny, I feel you've captured it really well here. Capacity. It might have been a bit marginal back in the day with production costs what they were for different materials at that moment in time, and that capacity gets used with degradation, but it's a question, as you rightly say, of how much extra capacity we want to add now for comfort vs. maintaining original setup. We don't expect to see cars on the hard shoulder anymore. It's going to be the same as one's aversion to all sorts of risk! 😁

The limited spare cooling capacity of the original design was probably because of the space restriction in our cars. The chassis was for a 4 cylinder engine which allowed a relatively large radiator to be used in both the Herald and Spitfire but the extra length of the 6 cylinder pushes the radiator further forward so that it has to be lower in height. The chassis rails are the problem and really a T shaped radiator is needed but as this isnt feasible Triumph used thicker and deeper units to try to increase cooling. This helped but is not as effective as having a large frontal area of cooling surface...

[Jim-GT6]

12 hours ago, clive said:

Of course, you are relying on your temp gauge. They are not always reliable sources of information. Ideally you need a calibrated gauge, the old "bulb" type are easy to check and then fit, even temporarily. Mine ws borrowed some years back and returned broken, which is a shame. But it is important to know precicely where you are starting from. (friend thought his herald was running hot, turns out the gauge/sender combo was the issue as it was actually running in the early/mid 80s. I swapped the gauge and sender for ones I had until it indicated bang in the middle)

The first thing is running the waterless coolant. It means you cannot flush the cooling system with it in. So the simple, first step is to drain it, carefully if yu plan to re-use it, and possibly filter it.

Then do teh sensible thing, and the weather is sort of on your side. Get a garden hose, fill the system with water, and run it briefly. Now see what happens when you remove the rear block drain plug (under the manifolds hear the rear of the engine) Water should flow feely out, if not get bits of wire etc and start poking about to clear the blockages. Keep going until you have done all you can. I wonder if something like a bit of handbrake cable or a bit thinner would be good as it is flexible. 

Next, take off as many cooling hoses as possible at one end. You can flush the heater matrix from both sides, several times. Then the radiator, then the block by going round all the water outlets, including pressing the end of the bare garden hose against the block drain. You may get a lot of crud out. And pay attention to the metal bypass pipe under the manifolds, it may need rodding though the main pipe, but be aware the T off it near the rear (I think the GT6 has a T off) has only a small hole where it joins the main tube. This all needs checking with a pokey wire thing.

Fit your new heater valve, 82 degree thermostat etc reconnect the hoses. This should all take an hour or so, and wet feet. Fill with water plus some holts speedflush, take for a good  drive.  and let it get hot. Observe the temp gauge, ideally without changing the sensor. See if there is any improvement. This flushing may help, but is essential before swapping a radiator to prevent it being blocked immediately. Once the speedflush has done its job, drain, flush with clean water, then fill with a 30% blue antifreeze mix. (keep the evans stuff for later as long as you are certain it has not been compromised by water contamination at any point)

If it seems much better, you may be OK. If not, you may need to remove the head to clean the block out, and a new rad. I can remember rebuilding my vitesse engine when I put the car together. It was a bare block and head, and I used a jetwash and wire to clean it out. A load of scale was left over the driveway. Using acid to clean the waterways would have been an obvious thing to do in retrospect. 

Thanks Clive. Your breakdown of how to do this job is super helpful. Makes great sense. Really appreciate the step by step. Not sure I have the wherewithal or kit to ensure the gauge and sender are calibrated. Really wish I did.

I've added a new temp. sender, thermostat and voltage regulator (in addition to what was on it's way) so I can do my best to rule all those out. I think the regulator is worth a check as my fuel gauge hits the top end-stop when I fill it, way off the scale, and I imagine there can be a few causes for this, but I've been reading that the OEM voltage regulators can become poor with age and be thrown off by temperature. It certainly gets toasty under my dash! May as well change the regulator as it could easily be causing or confusing an issue, what with the whole 'always at 60% hot' thing too. I've ordered an OEM one from ANG, and I've also got a solid state regulator in my basket on eBay, as I'm tempted to try both. Are these any good? https://www.ebay.co.uk/itm/254122537915 More stable than the standard ones?

I've looked through the history, and found everything cooling related:

1991: Rebuild Radiator (Guildford Radiators Ltd £95 + VAT), Thermostat 88 degree, Hose set

2003: Recon exchange radiator assy (Six Spares, Teddington £120 + VAT), Radiator cap 13lb, Heater water valve, Thermostat 82 degree, Hose set

2014: Voltage stabiliser, Hose set

These jobs coincide with burst of receipts for all sorts of work, and there are big gaps in between.

Mileage I have references for: 1999: 85,627. 2002: 95,138. 2014: 95,145. 2015: 96,378. 2016: 96,652. 2017: 97,122. 2019: 97,267. late 2020: 98,249 (when I bought it) 2021: 00,118 (now)

If this is correct, it last had a last proper cooling overhaul in 2003, then barely moved for 11 years. It did 3k miles between 2014 and 2020.

Last rad overhaul 18 years ago, hoses 7 yrs ago, and 5k miles over the whole period.

Current plan:

1. Drain and discard the waterless coolant (no confidence it's <3% water, and it looks quite rusty)

2. Flush everything as described above, poke until everything is flowing, taking particular note of flow through the rear block drain

4. Once cleared, fit heater valve, front radiator cowl, 82 degree thermostat and 13lb filler cap (but keep voltage regulator and temp sender change in hand until after the test run to measure the flush effect using the same kit)

5. Fill with water+speedflush, run, check for improvement on the readings

6. Drain, refill with 30% antifreeze and water, fit voltage regulator and temp sender, go on another run, if it's changed, it due to the sender or regulator

If it's all not happy and stable after that, It either needs a clear-through of the block with the head off, or a recore of the rad., or both.

I know I've just repeated back everything you've collectively told me, but I can now print this as my to do list! 😄

Cheers,

Jim

 

 

[johny]

I imagine waterless coolant with water still in it wouldnt be a good combination because you still got the corrosion potential of water without the protection of inhibitor in normal coolant☹️