Club 80-90 Forums

I have recently purchased an '86 camper, it was a non-runner and so i have fitted a low milage engine from a 1990 bus (1.9 WBX), so the same DG engine as previously fitted.

Now i have it back on the road i have noticed that both temp and fuel gauges seem to be over reading. I thought she was just running hot initially, but runs fine and fan cuts in and out as you would expect, but it sits at an indicated 2/3rds up the scale. Now turns out that the fuel gauge appears to do the same, as i discovered when spluttered to a halt whilst still appearing to have over a 1/4 of a tank of fuel! Also i fill to the brim and manage nearly 100 miles before the needle moves off the top of the scale, and I'm guessing she isnt that economical!

I have searched through previous posts and can find lots of info about under reading, but nothing about over reading, so i wondered if anyone had any ideas. Its a two fold post this really (a) can anyone suggest a fix, and (b) reassure me that this can be an electrical fault and that im not driving around cooking my new engine!

Cheers
Simon

Possibly the voltage regulator is puting out too high a voltage [it feeds both gauges] should be 9 to 10 volts,its a 3 pin transistor looking thing on the back of the rev counter/clock.

Hi - did you get a fix out of this? I'm seeing a similar problem in my 82 (or she is really running that hot!)

Found that my dash has had the voltage regulator replaced with a piece of wire! Hence the fuel gauge and temperature gauge massively overreading... And hence me pulling every single fecking component of the cooling system out to try and find out what the problem was... I really hope thats it for a while, ive spent ages on this overheating non problem! All because the alternator belt was a bit loose and the gauge never read right.!! Too funny...

Smcknighty wrote:Found that my dash has had the voltage regulator replaced with a piece of wire!.

Easy cheap fix then =

https://club8090.co.uk/wiki/VW ... uel_gauges" onclick="window.open(this.href);return false;

I've finally got around to replacing the regulator on mine (99p from Maplins ) but it has made no difference, both gauges still reading the same i.e. about 1/3 higher than they should! So maybe the van is running hot, but that still wouldnt explain the fuel gauge over-reading, so rather confused?!

Will take the dash apart again later and get a meter on it just in case a got a duff regulator, but it seems unlikely. Any other components that could be the culprit?

Now kind of wishing mine had been replaced by wire too, as Smcknighty had, as it least it would be fixed now

Cheers
Simon

UPDATE
right i've now been out with a multi meter and unfortunately i have 11.8v on the innermost (to the centre of the vehicle) side, and 9.9v on the other leg, so my new voltage regulator is clearly working as it should. So either the engine is running hot and the fuel gauge is also over reading - too big a coincidence? Or some other electrical component is at fault, although i cannot think what that would be.

I was supposed to be going away on Thursday, but not sure its a good idea now if the van really is running at 2/3 up the gauge. I was much happier when i thought it was just over reading! On the overheating front (i know this is the wrong part of the forum) it does come down to just on the high side of the light when i run the heater flat out and fan full on, but otherwise sits at 2/3 but all behaving normally:
after about 8 mins at tickover the stat opens and the rad starts to get warm after 12-15 minuts still sitting at tickover the rad is fully hot and the fan kicks in, runs for about 2 minutes then stops and doesnt kick in again for about another 4-5 minutes and then repeat...

All the above seems pretty correct to me, although i know little specifically about WBX engines, so im now officially confused!

Thanks in advance for any help,
Si

Si, that does all sound about right, BUT, the fuel gauge over reading is a bit odd !

I doubt it is the temp sensor because when they go the usually make the gauge read low or not at all. (but it might be that ?)

Do the coolant levels all remain correct over time ?

the sensors are cheap enough.. why not eliminate it?

Sorry should have said, the sender/sensor and the thermostat have been changed as already thought it could be one of them.

The coolant levels remain constant, so dont think i have any leaks.

Thanks for the advice, i think it must be restricted flow in the radiator, so i will bite the bullett and get a new one, £120 is a lot, but if it means i dont have to constantly worry about a cooking engine, i guess its not really all that much As for the fuel gauge, maybe i just have lots of crap at the bottom of the tank, it has had 26 years to accumulate after all, so maybe thats why it started spluttering at 1/4 that time? i was also going around a roundabout which may have moved the remaining fuel away from the pick up point?

I will soon be back asking for more help if the rad doesnt fix it...

thanks again, so much advice and assistance on this forum, its great!
Si

hi just thort i would add ive just changed my rad at cost of only £90, great quality too EURO CAR PARTS

I might have to go this way as my temp gauge is reading above half way when high speed cruising.
thanks for the heads up

hi,ive got a similar prob,1.9 45k genuine mileage, 88,the old guy i bought it from ,said it had always run like that (showing 3/4 on temp gauge)all runs fine tho,going to try sender and stat first,tho i cant see how it could be rad if its all getting hot,so keep us posted.thanks

Both fuel and temperature gauges are 'vague' indicators anyway, even when new. I'm not sure we can expect much in the way of accuracy from what is very basic technology. Providing you're not actually overheating and you know at what point you're about to run out of petrol, I wouldn't worry.

The Beetle, from which the T25 was descended, was even more basic with everything mounted inside the speedo head but it did the job and unlike modern stuff, has much less to go wrong in terms of sensors and computers. Its good enough I'd say.

I know its been a while but thought i would update.

It turned out to be the thermostat, the van came with a new one when i purchased, but had already replaced that, so must have had two dodgy new ones - its now running the original (marked made in W.Germany!) one which came in a box of old bits and runs perfect and if anything slightly on the cold side.

So note of caution, thats 2 thermostats from VW Heritage (nothing against them, ive found them very helpful) which didnt open until the coolant was hot, very hot! Tried them in a saucepan and the water had started bubbling before they opened so must have been about 95 degrees.