Temp Gauge

[ccjnr]

Hello everyone,
busy getting the mk3 back on the road, just one or two issues now to resolve before the MOT. One problem which has recently occured over the last few months is the temperature gauge. The car had developed a starting problem which coincided with the rev counter not working :- had the screens out so removed the dash top & checked all earth wires running back to chassis.
A few loose connections here & there (rev counter), sorted that out now the car & all other instrumentation working correctly.
Not the temp gauge though, that seems to reach a high level immediately after starting the engine.
Never had any overheating problems with the car, will sit on tickover for hours temp normally around 75.
Have rechecked all connections & cleaned the terminals. The gauge is actually showing varying readings but still all above 100, also with just ignition switched on.
So what are the options? Have been looking out for a new gauge, no luck so far may try Roger spares. Or is it likely the problem lies elsewhere?
Thanks for any ideas,
Chris
UWP 811L

[Tony Hayward]

Chris

Check the voltage regulator, screwed to the back of the dasboard. Ensure the wiring is correct and it is earthed. Replace if necessary. I assume you have checked the connection onto the sender.

Tony

[ccjnr]

Thanks Tony,
will check it out tommorrow.
Want to get all the niggles sorted out now before replacing the screen as access is alot easier as you know.
Have had to redesign rear seats to suit after fitting of roll cage, complete.
Modifying subframes to fit front recaro's from Ford. Installed driver's side, pretty much a tight squeeze to recline back with the upright from the roll hoop but happy with the results. (My apologies to all purists )
Electric fuel pump / pressure regulator fitted, wired it though fused switch on dash.
Changed to compomotive alloys, 6"x13" 's although the clearance to arch at the front of the car is very tight no problems.
Overall in good shape now, it's amazing how much additional wiring has been added over the years. This is now removed, i have followed the original colour codes from the mk3 handbook, i guess there'll still be one or two rogue wires but without completely changing the loom....
Chris

[Waylison]

Hi Chris

I'm running 6x13 compomotives on my MkII with 205's fitted and they are very tight to the arches! Do you find that when you jack up a corner of the front of the car, the opposing rear tyre can be heard scraping the rear wheel arch! Mine does, it's that tight

Just another thought on your engine temp gauge problem.....if changing the voltage regulator or sorting out the earths doesn't cure it, then try taking out the sender unit screwed into the intake manifold, attaching an earth wire ( because now it's not touching the engine it has no earth) and keeping the live wire connected, boil a kettle of water and lower the cylinder part of the sender into the boiling water, must be as near to boiling as possible, and read what the gauge says. Should be as close to 100 deg as possible. If not, change the sender unit, very cheap to buy.

Wayne.

[Greybags]

The guage gets a resistive earth from the sender, the lower the resistance the higher the temp reading, so if your guage reads high when its cold, then it must be recieving an earth from somewhere...

Disconnect the wire from the sender and if the guage still reads a high (it should be zero) then the sender wire is getting an earth from somewhere else, possibly a short or contact somewhere.

If the guage now reads zero with the sender disconnected which it should, then it is probably the sender at fault...

Hope this helps...


Grahame

[ccjnr]

Okay Guys,
thanks for the comments & advice. Have ordered a new voltage stabilizer from Merlin, will try that along with testing the sender. I always try to source through Roger spares, on this occassion Merlin Motorsport seem to have a good range of switches & classic spares to suit at very reasonable cost. Not too many of the mk3 spares in circulation a good sign i guess.
Wayne the tyres i fitted were the vredestein sprint classic which are 205 60 r13, not close on the mk3 with the flared arches it's more an issue with full lock on the front but it just about clears.
Regards,
Chris,
UWP 811L

[Reddi-Eng]

Hey Chris, sound like you're making good progress on your restoration.

Any chance of some pics before we see it at National Day

[ccjnr]

Hello Derek,
progress has been slow, one job seems to lead on to another but getting there slowly. Not easy to devote alot of time to the mk3, working offshore long trips but i hope to make it to National Day this year. Repaint on the car will have to wait until next year though,
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sorry the youngster had to get in on the act, i'll get some decent shots once safely through mot. Have left the roof & door pillars in primer for the time being, a result of removing the vinyl & rebonding roof section in place.
Regards,
Chris