Colin Lindsay Posted April 19, 2018 Report Share Posted April 19, 2018 Anyone else found this? I bought a replacement sender unit for the GT6 earlier this week, as I'd left the cooling system drained whilst working on other things over the winter and when I rebuilt and refilled the system, the temperature gauge was being intermittent - first there was no heat, then it was normal, then back to zero.... so I fitted the new sensor. On the first drive I brought the car back with the needle in the red, so was quite concerned even though there were no real symptoms of trouble at the actual engine. Took the water pump off, flushed everything, replaced the thermostat, and suspected an airlock so was very careful with the refill, but same result on the second test drive - the needle very close to the red and not in the usual 6 o'clock position. This morning as a test I cleaned up the old sensor and replaced it once I'd sourced another sealing washer - this time the needle stayed in the normal position, no trace of overheating. So: it appears the new sensor is reading too high. As you can see from the photo it's slightly longer than the old one on the left, so must be a different setting even though it's marketed for the GT6. Looks like I'll have to find a NOS spare, to be sure... but if it happens to you, suspect the sensor BEFORE working on the engine. Link to comment Share on other sites More sharing options...
dougbgt6 Posted April 19, 2018 Report Share Posted April 19, 2018 Colin Can't you saw the end off? db Link to comment Share on other sites More sharing options...
Gully Posted April 19, 2018 Report Share Posted April 19, 2018 I found this when my original sender became faulty, but in my case I traced the issue to the previous owner having deleted the voltage stabiliser - when I reinstated it, both the new senders I'd purchased read around halfway on the gauge. Clearly the spec of the old one was different as it had indicated fine on the gauge for years! Gully Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 19, 2018 Report Share Posted April 19, 2018 Mif its nos then from the back of the memory disc you have a two smiths senders Green top is stabilsed gauges current number generic GTR108 And red top is for non stabilised gauges being 121997 I might have the colours mixed up but wrong type sender give hot readings Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 19, 2018 Author Report Share Posted April 19, 2018 Pete - you may be spot on here; I hadn't thought about the stabiliser versions. The one I bought is listed as GTR108; no alternative version is listed, but the red top is the one that arrived in a bag, marked GTR108. All the versions of that number on eBay are black tops. I can't find a photo of the other but it's listed as non-stabilised. I may have been sent the wrong version, then. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 20, 2018 Report Share Posted April 20, 2018 Im sure Red is wrong for stabilised smiths did colour them for easy identification but whats produced these days could be any !! Ie brown was 24v in the hey days wehad the 3 colours on the engine line as all 3 systems were in use in the 60/70s and green brown thro the 70/90 s Had a lot of memebers over the years get the wrong to part number , some from Rb. On the old forum even guys changing engines for over heating ...twas just the wrong sender Pete Link to comment Share on other sites More sharing options...
AidanT Posted April 20, 2018 Report Share Posted April 20, 2018 Would the boiling water test be worthwhile? And if you have a cooking thermometer then you could see what temperature it had to be for half way on the gauge This would confirm all the above Aidan Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 20, 2018 Author Report Share Posted April 20, 2018 That's just tooo much bother for a lazy sod like me ... MOT in three hours anyway so I'll stick with the easy option for now. The car is back on the road for the first time since 2015 and I'm darned if I'll start messing with it so soon! Link to comment Share on other sites More sharing options...
DerekS Posted April 20, 2018 Report Share Posted April 20, 2018 They are colour-coded and my personal experience of e***y is what you order may not be the one that turns up, sellers not being aware of the difference. Early doors in my ownership, I ended up "going down a sidestreet" with this, tried allsorts and it turned out to be the voltage regulator... it was probably you who put me right, Pete! Link to comment Share on other sites More sharing options...
Nautam Mistry Posted April 20, 2018 Report Share Posted April 20, 2018 I'm thinking of get my temperature unit replaced as the reader on the dial doesn't move that much...will compare sizes when I get my replacement and compare it with the old one. Do I need to empty the radiator when taking the old one out?...sorry daft newbie question. Nautam Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 20, 2018 Report Share Posted April 20, 2018 no need to empty , just a quick out and in , leave the cap on but relief any residual pressure first, you will only get a short spillage , then top up when done. apart from a maybe different colour insulators the two types are exactly the same fitting and size its the innards that change . the two senders operate very differently and cannot be mixed up what ever colour the designed resistance and range for a GTR108 for slow bi metal stabilised gauges and that for the much earlier fast wiggle needle moving iron non stabilised gauges has to be a 121997 get them mixed and you get a cold engine reading its much HOTTER ! fuel senders from the same pre stabilised era cannot be mixed either . pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 20, 2018 Author Report Share Posted April 20, 2018 4 hours ago, derekskill said: They are colour-coded and my personal experience of e***y is what you order may not be the one that turns up, sellers not being aware of the difference. Early doors in my ownership, I ended up "going down a sidestreet" with this, tried allsorts and it turned out to be the voltage regulator... it was probably you who put me right, Pete! Sadly it wasn't eBay who I got it from, but I was using eBay as an example simply because they have photos! Went to MOT with normal temperature for the first ten miles, then none on the way home. I have spare sensors in the spares drawer, so will try those and see if they're anyway accurate - they could be Herald versions. Link to comment Share on other sites More sharing options...
DanMi Posted April 20, 2018 Report Share Posted April 20, 2018 I recently put on a new sensor on my mk2 spit during the engine rebuild, It is now reading hot but I have come to the conclusion it is the new sensor. Unfortunately the old one was on the old 1500 when I sold it. Link to comment Share on other sites More sharing options...
Adrian Cooper Posted April 20, 2018 Report Share Posted April 20, 2018 Come on Colin, don't tease us, did it pass the MOT?! Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 20, 2018 Report Share Posted April 20, 2018 herald spit gt6 vit bond 2000 std 8 or whatever the senders are the same its just got to match the gauge design so what one is decided purely on being stabilised or not stabilised stabilised the gauge needle moves slowly after ign. on non stabilised fly up to a reading as soon as ign. on and wag around on bumpy roads Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 20, 2018 Author Report Share Posted April 20, 2018 Here's a test: fill a jar with about four inches of Waxoyl.... now try to see your Triumph chassis through it? Can't? Neither could the MOT tester... so despite the Frankenstein weld on the front outrigger it passed. He did give me an advisory about dust on the bonnet, which had accumulated since it sat outdoors all night; otherwise he wanted to buy it and wanted to make out a cheque on the back of the certificate. We're now road legal again! Our first show is next Saturday. I can't resist a photo just to show off! 3 Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 20, 2018 Report Share Posted April 20, 2018 well done colin Link to comment Share on other sites More sharing options...
Anglefire Posted April 21, 2018 Report Share Posted April 21, 2018 To be fair, I've seen some very pretty welding that wouldn't hold a matchstick - and some pretty ugly ones that you could hang the titanic on. I know which one I'd rather have. (Ok strong and beautiful is the ideal but ...... ) Lovely looking Spitfire too. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 21, 2018 Report Share Posted April 21, 2018 Dont tell colin its spitfire . He's already depressed over the sender units Pete 1 1 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 21, 2018 Author Report Share Posted April 21, 2018 It was scary looking, especially as it was really only on three sides. HOWEVER: and that's worth emphasising in capitals - what is underneath was a small rust bubble where the outrigger overlaps the main rail, only through the outrigger centre and I'd be happy, with my own safety on the road in mind, to say that it was unsightly but not structural. It certainly didn't need a new outrigger, although I've bought one just in case. Previous testers advised to have it repaired, but still passed the car. It's currently under about four inches of Waxoyl so almost invisible, but the car can now be taken to a proper welder and have the entire thing done properly. Link to comment Share on other sites More sharing options...
DanMi Posted April 21, 2018 Report Share Posted April 21, 2018 Just replaced my sender that looked exactly like the one above with a NOS Smiths one now the temperature gauge sits nicely in the middle so there are clearly faulty ones around Link to comment Share on other sites More sharing options...
Anglefire Posted April 21, 2018 Report Share Posted April 21, 2018 6 hours ago, Pete Lewis said: Dont tell colin its spitfire . He's already depressed over the sender units Pete ? oops. Sorry Colin. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 21, 2018 Author Report Share Posted April 21, 2018 Apologies accepted! I knew I should have posted a bigger photo! I hadn't my glasses on either... and I am NOT depressed over the sender units! Hopping a bit, but not depressed. Just bought a laptop that won't run my music recording programme... now THAT's depressing! (I was just about to apologise to the OP for hi-jacking his thread wayyyy off target then realised .. it was ME!) 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 21, 2018 Report Share Posted April 21, 2018 Colin, apologies for thread drift are banned Even your own !!! Pete Link to comment Share on other sites More sharing options...
Anglefire Posted April 21, 2018 Report Share Posted April 21, 2018 That’s a good job otherwise every thread would be full of apologies Link to comment Share on other sites More sharing options...
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