Temperature Gauge/ Temp Sender and temperature readings.

[Johnh]

Hi All,

I am having problems with my engine temperature either the sender, the gauge or overheating.

I have just put a new Thermostat in the engine to be sure that at least that is OK. according to the old one it was an 82degree which would be correct for the car which is supposed to me a MK1 however it has been re-built before my time. Until recently the reading was steady just below the red zone which seemed high but nothing seemed to complain.

I have just overhauled my heater, a bit of a nightmare but now fine. I have finally managed to get good pressure and I think no air locks but the temp is now in the red.

I have borrowed an infrared temperature gun and I cannot find any where on the engine over 80 degrees most areas in the region of 65 - 72 with one at 75. The sender is only reading 73.

Anyone got any ideas, is it my sender or the gauge, I am told the gauge's are generally more reliable.

What I do not know is what is the normal running temperature for the cylinder heads as this is of course the critical area.

Any good ideas and advice would be really helpful.

Regards, JohnH

[DJT]

John,

I responded to your post in another thread about this and mentioned the sender and the voltage stabiliser. Both of these can give false temp readings.

[Johnh]

John,

I responded to your post in another thread about this and mentioned the sender and the voltage stabiliser. Both of these can give false temp readings.

Hi Dave,

I saw your reply on the other thread after I wrote this one.

I have ordered a new sender and I will order a new voltage stabiliser just to try to eliminate those problems installing one at a time. where does the stabiliser go on the car?

Many thanks for your help.

Regards, john.

[DJT]

Hi Dave,

I saw your reply on the other thread after I wrote this one.

I have ordered a new sender and I will order a new voltage stabiliser just to try to eliminate those problems installing one at a time. where does the stabiliser go on the car?

Many thanks for your help.

Regards, john.

John,

The voltage stabiliser is attached to the back of the tachometer.

[redstag]

Hi John

I suspect you are not getting your engine up to full working temperature.

I cannot remember the exact temps but I did check temps of several cars after a long motorway run coming back from France. From what I remember we found readings on cylinder heads in the 80's on most of the cars, a couple of cars were higher and all except one had the highest temp on the rh cylinder head at the rear.

Pete

[Johnh]

Hi Pete, Dave,

many thanks for your help and advice I shall have a look at them both and then replace them one at a time to see which help most or if it takes both to solve the problem.

There is no doubt, this is a great forum for the unskilled like me. I will update with the results.

Regards, johnH

[flying farmer]

This look familiar?
DSCF0612 (600 x 450).jpg
First time stuck in traffic today and this happens. Fan didn't come on so switched it on manually, made no difference. I was not far from my destination and the gauge stayed in the same place.

Two hours later I restarted the car to come home and the gauge shot back to the same place. No water was lost and it didn't feel hot. Guessed it was the voltage regulator (Fuel tank had just been filled so couldn't go by the reading of that)

Set about replacing the voltage regulator (attached to the back of the speedo on mine), only to find the earth wire has fallen off the speedo as the spade connector is very loose. Changed the voltage regulator anyway, but haven't thrown the old one away, as I suspect this was the actual fault.

Neil

[flying farmer]

Oh no it wasn't, I have just put the car away and from a cold engine the gauge went straight to normal. Looks like an epic fail of the temperature sender.

I shall have a root through my spares pile and see if I can find another sender unit. Just as well I didn't bin the voltage regulator (unless my brand new one is buggered of course)!

Neil

[Johnh]

Bad Luck Neil, I hope the second fix is successful, waiting for my new Sender and stabiliser to try them out. At least my gauge goes up slowly but does not stop before the top of the red.

I borrowed an infrared temperature gauge and was very happy when I found only 80 degrees buy the exit to the radiator all other spots Heads thermostat, heater connections around 65 - 75.

At least I know the engine is not actually overheating!

I wonder if this is more the case than the engines really overheating!!!!

JohnH

[Knockwurst]

I was amazed to see that infrared thermometers are under £10 on Amazon. Mine arrived yesterday and seems remarkably capable for that price.

[Johnh]

Hi all,

Does anyone know where to buy a suitable solid state stabiliser?

I could only find one on the regular parts suppliers and that was the original type. My approach is to use more modern electronics where it seems to give a better result and this seems to be one of those cases.

JohnH

[Johnh]

Hi Dave,

I have found an original stabiliser but it sounds a better bet to get a solid state one, do you know where I can obtain one.

Thanks for your help. JohnH

[Mike Stevens]

I've seen new regulators on eBay, but they do look like the originals in the same size case, but with some light green printed circuit board on the top rather than the original brown stuff - whatever it was!

Cheers,
Mike.

[V Mad]

The old stuff was probably SRBP (FR-2), a very cheap, low quality electrical board material.

[Mike Stevens]

Uusually known as 'sh1t and bus ticket' here!

Cheers,
Mike.