356 hot oil temperature and possible cure.

[simon james]

Last summer on the motorway the 356 temperature needle ventured into the red for the first time of my ownership.
I put it down to the outside temperature and my lead boots.
Anyway, I kept a close eye on it and noticed how the car would get hot quickly, as in to halfway across the gauge within 2 or 3 miles.
I was about to pull the trigger on a fancy new oil cooler but the price just seemed astronomical...
So, today I pulled out the dynamo complete with fan and investigated.
The cooler looked clear, save for some bent over fins. I squirted everywhere with brake cleaner and used the airline to blow things out. I thought I'd done.
BUT upon trying to poke a piece of soft wire through the cooler it soon became clear that all was not well. I would say 50% of the airways were blocked. Solid.
It took me about two hours with a round ended 1.8mm Allen key to push out the holes.
I was acutely aware of the possible damage I could do, but battled on.
I built the car back up again and this time corrected a previous owners mis-positioning of the dynamo, it needed turning 90 degrees to the right to relieve the wiring harness.
The result?
Well, early days yet but no leaks (phew) and after a quick thrash about the oil temperature is just out of the lower green area. I'm sure the same caning before would have resulted in halfway.
So, moral is check the easy stuff first!!!

[roy mawbey]

Well done Simon, you were sensible to attend to that. My car has never been near the red. Sounds like you might have sorted it.

Roy

[simon james]

Hi there Roy!
You have been lucky with your car, but I guess it hadn't suffered the same incompetent maintenance that mine had up until I got it.......

Well, today I took the car out again, gave it a good hiding and even managed to overtake a Daewoo Matiz, uphill too!
Seriously though I gave it some and the needle didn't even get halfway on the gauge.
What I did find interesting though was that as I descended the hill, probably not even a mile the needle fell back down the scale, it would never have done that before.
I have a dipstick gauge in the engine bay and that is reading a hell of a lot lower too!!!
I have high hopes for summer now!!!

[Kenyon]

The oil / fuel gauges on my 356 have never worked. I've often wondered what was going on back there in terms of how hot the oil was. Appreciate I should really get them fixed and its on the list.

I wondered though has anybody bought an oil temperature gauge dipstick recently? I had a look on google and saw the one's from Precision Matters in the US but wondered if there's any suppliers in the UK / Europe? Couldn't seem to see anything equivalent online.

Cheers

Phil

[simon james]

Hi Phil.
I bought my dipstick, new, off eBay last year, from the US when the gauge on the dashboard started creeping up. It looks like something you'd stick in a turkey but it gives an accurate read. It is calibrated in Fahrenheit up to 300 degrees. Thankfully I never got up that far....
I wasn't entirely convinced of its oil level markings so keep the original dipstick in the car just in case!

[Kenyon]

Cheers - will take a further look closer to home and failing that go for one from US. Really I should just get the gauges fixed I suppose.

[Hendrik Moulds]

Well done Simon for actually looking at the problem before going for an external oil cooler.
Most of the time it is just years of accumulated crap blocking up the oil cooler, happy driving!

[Kneeslider]

The oil / fuel gauges on my 356 have never worked. I've often wondered what was going on back there in terms of how hot the oil was. Appreciate I should really get them fixed and its on the list.

I wondered though has anybody bought an oil temperature gauge dipstick recently? I had a look on google and saw the one's from Precision Matters in the US but wondered if there's any suppliers in the UK / Europe? Couldn't seem to see anything equivalent online.

Cheers

Phil

I have been looking into my non-operating oil temp gauge. If all is original and un messed with proceed as follows:- See what the resistance of the oil temp sensor is. It should read about 20 Ohms at normal room temperature.

The test for the gauge is to switch the ignition on, and see if the needle moves. If it does, then that is good. Next, take off the wire to the sensor. The needle should not change. Next, ground the sensor wire to the engine case. The needle should read at the minimum end of the scale. If it passes all those tests, then the gauge and the wiring is all good.

I have just bought a new sensor from Ebay in the USA. Not cheap though!

Due to un availability of original sensors, some people have fitted a more modern type of sensor, but you have to modify the gauge to suit. Apparently if you have one of these, then the sensor should read approx. 200 ohms at room temperature.

There is some information on the Registry website about how to do the testing, its not complicated.

[Kenyon]

Thanks for the above - will take a look at the Registry info too and have a go with the meter.

Phil

[neilbardsley]

The oil / fuel gauges on my 356 have never worked. I've often wondered what was going on back there in terms of how hot the oil was. Appreciate I should really get them fixed and its on the list.

I wondered though has anybody bought an oil temperature gauge dipstick recently? I had a look on google and saw the one's from Precision Matters in the US but wondered if there's any suppliers in the UK / Europe? Couldn't seem to see anything equivalent online.

Cheers

Phil

I have 6v on my 356 and I think all of the gauges need to be taken with a pinch of salt. I turned off the lights, after a drive last night, and the rpm dropped by 200! When increased by 200 when I putt the lights back on!