Overheating Vitesse Mk2

[Paul H]

Went on a run today organised by https://www.centre81.co.uk/events/. . We’ll organised and over 100 entries and well worth supporting . We ended up by going in convoy along Gt Yarmouth front but it was nose to tail making very slow progress with frequent stops for close to 30 minutes . The weather was mid 20’s and there were a few casualties with overheating. My Vitesse mk2 has an electric water temp gauge and the normal range is 82 to 92 then back down . Today temp went up to 115c finally went back to 110 as the pace picked up a bit. Arriving at the parking area my Vitesse engine cut out and refused to start probably due to fuel evaporation . I did try using the heater and blower to cool things down but not sure how much this helped 

My newbie question is was 115 safe and what could have happened . I keep the expansion plastic bottle about half full and this will need topping up as it currently about 1inch from the bottom of the bottle, checked when the engine had cooled down 

Paul 

[JohnD]

Temp gauges on small chassis Triumphs are all "electric", and all have minds of their own.    The sensors are unreliable, especially modern repros, so unless you have calibrated your temp sensing system, "115C" could be anything.

What is your radiator cap pressure rated at?  What concentration of antifreeze are you running?  How new/good is your radiator?  All these affect how likely you are to boil over.

John

[Pete Lewis]

Also  very reliant on a stabilised voltage  with a working voltage stabiliser

As john says there are variations in who makes what , generic number is a gtr108 sender

One from ciagauge IE  EX SMITHS caerbont instruments make them  with their own part number 

https://www.caigauge.com

The pressure cap raises the boiling point,  the higher the psi the higher the boil 

What fan do have fitted ???

It may have got hot but hasnt boiled or you would have a bottle of rusty water  so  not so bad 

Pete

 

[Paul H]

31 minutes ago, JohnD said:

Temp gauges on small chassis Triumphs are all "electric", and all have minds of their own.    The sensors are unreliable, especially modern repros, so unless you have calibrated your temp sensing system, "115C" could be anything.

What is your radiator cap pressure rated at?  What concentration of antifreeze are you running?  How new/good is your radiator?  All these affect how likely you are to boil over.

John

Hi John . Radiator , hoses, heater matrix , heater return pipe all replaced 2 years ago. 30% antifreeze , radiator cap 7 lbs 

Paul 

[Paul H]

12 minutes ago, Pete Lewis said:

Also  very reliant on a stabilised voltage  with a working voltage stabiliser

As john says there are variations in who makes what , generic number is a gtr108 sender

One from ciagauge IE  EX SMITHS caerbont instruments make them  with their own part number 

https://www.caigauge.com

The pressure cap raises the boiling point,  the higher the psi the higher the boil 

What fan do have fitted ???

It may have got hot but hasnt boiled or you would have a bottle of rusty water  so  not so bad 

Pete

 

Hi Pete, I’ll check the sender details , though would like to think the gauge is accurate as the normal range is 82 to 92 and when at rest after a run gauge goes to 105 .  Nb the dash gauge is modern 

What happens if the radiator “ boils over “

Paul 

[johny]

Hi Paul, well on boil over the temperature of the water becomes higher than the boiling point of the system as dictated by the pressure rating of the radiator cap. In your case with a 7psi cap the water will have to reach about 111ºc when it starts to turn to steam which, having a greater volume than water, means the rad cap will open to release it (to protect the system from over pressurisation). This steam then leaves the radiator via the overflow pipe to the bottle where it will usually exit to atmosphere producing the usual steam cloud from under the bonnet.  This is all good because its protecting your engine from the damage that could occur if you continue to drive.

You obviously havent reached this temperature , although rad caps ratings arent exact,  however I think this indicates that your cooling system is close to its limit which on a 50 yr old Vitesse isnt anything unusual and is something Ive been fighting for a while. The problem is that if the engine temperature increases too much, apart from poor running, the lubrication of bearings etc can suffer which could result in major damage. Assuming that your system hadnt lost coolant and as the main external components have been replaced recently the cleanliness of the engine internal waterways is more likely to be the issue. You can try to flush these out in situ but I think cleaning during an engine rebuild is probably the definitve solution. Until then, as Pete asked, the type of fan you have fitted affects cooling, especially when stationary, and there are alternative set ups that could be more effective.....  

[Pete Lewis]

Its well known that thermostats that have been 'cooked' can become oit of calibration , any stat thats hadba serious boiling is best replaced

Boiling where the coolant turns to steam and escapes coolant into the bottle and onto the road  can precipitate loads of aged brown sludge into the radiator cores  for more looming problems

You dont seem to have boiled , just got close to it, 

So what  fan is fitted 

Easiest cleaner is cheap washing soda, a couple of cupfulls and run for a day or two then hose flush it out 

Pete

[Paul H]

Hi it’s a yellow plastic fan 

thanks for all input . Will go down the plastic soda route and opt out of parade runs in future 😎

Paul 

[Pete Lewis]

Yellow fan is  good    up the idle speed in summer a few hundred   may just help air flow under the bonnet when stuck in traffic

Yes  drive it like you  stole it no more silly   parades  sounds a plan  

Soda crystals not so popular for washing these days  might have to hunt the  shelves  

 

Pete

 

[Paul H]

Look what I found in Mrs H cupboard 

Paul 

[Pete Lewis]

Blimey,    now that is forward planning.

To flush take bottom hose off and hose up anything  you can    espec  the heater matrix and pipe under manifold    !!!!

Pete

[johny]

I suspect a lot of sludge build up is in the block waterways low down so opening the drain valve on the lower RH side to flush through is probably a good idea. However the valve can be seized and/or blocked.....

[Clive]

What oil are you using? If a mineral type, I would be inclined to change it as the break down much earlier than synthetic types. 

Has this happened before? I ask as blocked rad tubes won't clear with a flush ( they are blocked, so no flow to clean them) However, a good engine flush never hurts. But if you can, get the creditor tested. Sadly most places have now gone now.

As to 7lb cap, why so low? Should be 13lb if memory serves me. 7 was on the 1600 and early heralds.

 

[Paul H]

4 minutes ago, clive said:

What oil are you using? If a mineral type, I would be inclined to change it as the break down much earlier than synthetic types. 

Has this happened before? I ask as blocked rad tubes won't clear with a flush ( they are blocked, so no flow to clean them) However, a good engine flush never hurts. But if you can, get the creditor tested. Sadly most places have now gone now.

As to 7lb cap, why so low? Should be 13lb if memory serves me. 7 was on the 1600 and early heralds.

 

I’m away from the Vitesse for a while now. Oil is Classic Oils 20/50 did notice oil pressure dropped on tickover when hot maybe below 5 . When re started up to 75 and settled at just below 50 when cruising at 2800 revs in od . I’ll check the rad cap when i get back . Rad shouldn’t be blocked as it’s a recon with 2500 miles . Plan is to use the soda and flush . Where did the cup or so of water go from the plastic bottle , overflow or steam, not that I saw any . 

Paul 

[johny]

Think thats the standard cap pressure (Spitfire went to 13 later on) and anyway 111ºc should be sufficient shouldnt it? Certainly one possible cause I forgot and which made mine run much hotter was the fuel mixture. I had leaking carb spindles which allowed extra air in to give a very lean mixture so the engine ran hot although this of course was worse at higher loads and not when trundling along.

Our cooling system being 'open' does tend to slowly lose a little by evaporation from the overflow bottle especially at higher coolant temperatures.

[Pete Lewis]

the missing cup full may just be that there was some air in there somewhere , the  hot expansion and cooling contraction has removed it 

the pressure is not overly important if everything is ok ?  you should be able to run with the cap right off and still get home without a loss .

 well, unless the cap is much lower than the header.

dont get paranoid about the heating up ,  i guess its all got a bit hot under the collar , not the best driving situation,

 its hot , all goes a bit wooly, , idle slows   fan does less , panic sets in  looking at the gauge . think calm dont panic

change the stat as a cheap start job, fit a new 82c   you have a new radiator, so a flush to help the block and deck chair and a glass or two

pete

 

[NonMember]

19 minutes ago, Pete Lewis said:

the pressure is not overly important if everything is ok ?  you should be able to run with the cap right off and still get home without a loss .

Well, my Spitfire (1500 in a Mk3) boiled within ten miles when the radiator cap was not holding pressure. I wouldn't want to drive any distance without a cap.

[JohnD]

15 hours ago, Paul H said:

Hi John . Radiator , hoses, heater matrix , heater return pipe all replaced 2 years ago. 30% antifreeze , radiator cap 7 lbs 

Paul 

Good news, Paul.  As Pete implied it's the sender that goes AWOL - see my graph!   If the coolant circulation is all good, then the airflow through the rad has to be suspect, and in a slow moving queue that's no surprise.    Try turning up the idle, so the fan runs faster!   Or fitting an electric one, for which there is little space in a Vitesse.

John

[Clive]

Going on from jonys talking mixture, timing that is retarded too much can do the same. Just another simple check...

May be worth keeping an eye on the oil.

 

[Rijidij]

12 hours ago, Pete Lewis said:

Easiest cleaner is cheap washing soda, a couple of cupfulls and run for a day or two then hose flush it out

Is that cup or cap fulls? Asking for a friend

 

[Pete Lewis]

Its definitely  a cup full youre making a solution to shift   old block deposits

not tickling an elephants   backside  with a feather 

Pete

[Paul H]

On 08/07/2019 at 12:31, clive said:

What oil are you using? If a mineral type, I would be inclined to change it as the break down much earlier than synthetic types. 

Has this happened before? I ask as blocked rad tubes won't clear with a flush ( they are blocked, so no flow to clean them) However, a good engine flush never hurts. But if you can, get the creditor tested. Sadly most places have now gone now.

As to 7lb cap, why so low? Should be 13lb if memory serves me. 7 was on the 1600 and early heralds.

 

Hi Clive , back at home and checked the radiator cap , it’s 7lbs and this is what WSM says 13 lbs was fitted to GT6 mk3

Paul

[Colin Lindsay]

I've been running a 13 on my Mk1 GT6 for years with no problems; I always thought 7 was too low. 

[johny]

it doesnt make any difference unless you want to run your engine so hot (up to 119ºC) that a 7lb cap would lift. In fact having a higher pressure cap puts more stress on the head gasket sealing, water pump seal, rad etc as on start up when the coolant expands it has to reach 13psi before it opens to discharge the excess to the overflow bottle.....

[Colin Lindsay]

8 minutes ago, johny said:

it doesnt make any difference unless you want to run your engine so hot (up to 119ºC) that a 7lb cap would lift. In fact having a higher pressure cap puts more stress on the head gasket sealing, water pump seal, rad etc as on start up when the coolant expands it has to reach 13psi before it opens to discharge the excess to the overflow bottle.....

Well it's only been twenty years. I'll give it a while longer before deciding.