oil temp

does eneyone no how hot a mk1 golf gets with the oil temp when running hot in celsius

should be 90-120 normal use depending on ambient temp and how fast/aggressive you are driving. higher temps likely on track

This is really interesting. I have been worrying for quite a while that I have got something drastically wrong…may be I still have.

I had a Kent 172deg Cam kit and a Janspeed mild-steel 4-branch installed in my '83 1800cc Mk1 GTi,  3 years ago. I only use that car at weekends in summer and clock max. 1500 miles in the year. I had loads of work done in summer 2009 and the chap who did it used to work as part of GTi Engineering way back in the 70's and 80's. Long story short - he recommended only using 'Millers Mineral Oil' for the golf. After the cam kit was put in the car and this chap did full service / tune-up, the GTi has always run brilliantly, with a nice little extra poke - but nothing stupid. Oil gauge always registered 90 deg C - even on long journeys at this stage!

Beginning of each summer I get the car a quick service, then MOT a month later. Last year I took the car to my new local garage - really happy with all work they've done on my other cars / daily. After this service the oil temp regularly hits 130deg C on my VDO gauges every time I drive on a dual carriage way at 70mph+/- 5mph!!!!    for more than about 15mins. Engine temp is reasonable - but will creep up when stopped at traffic lights / roundabouts after motorway / dual carriageway driving! Inside the car is always like an oven (and always was)   !

I've done extensive reading into mineral vs. synthetic oil. A possible change to synthetic or semi-synthetic by the new mechanic shouldn't lead to increased heat???!! - but probably altered viscosity and maybe even sludging? Either way - the oil cooler is relatively new (5yrs) and is free from debris - any ideas?…….Am I worrying unnecessarily??  :dontknow: Is persitantly running engine at 130deg C bad?  :dontknow: (prob!) I don't think that the sender for oil temp is jiggered but could be….?

I had the car out last weekend, it was great (first time this yr) but I was constantly worried it maybe damaging the engine and as such am reluctant to do anything more than a short little spin until I can nail this down! Please help….

What are my options?
? New higher surface-area oil cooler? EMPI do one.
? Basic oil change - keep to mineral oil? - any recommendations?
? Oil change to fully synthetic high-grade i.e. mobile 1?
? Up-grade exhaust from the 4-branch to the back box (as this still original) which could be preventing hot gasses escaping sufficiently? = pseudoscience  :dontknow:

Many Thanks in advance for any advice!!!! As you can see, I'm fresh out of good ideas!!!

Regards

Old-GTI

130 degrees when cruising at 70 is a little excessive, though what rpm are you at?

before you go too mad, try the recommended oil and see what happens. if its still too hot then you know its not that, something else has changed.

the exhaust wont effect the oil temp, so no worries there!

it might just be the sensor isnt reading accurately, check the wire is on the right sensor. it should be a green/black on a white collar sensor. the red/yel on the black sensor is for the water temperature.

feel the oil cooler when the oil temps get to around 90degrees, make sure its starting to get warm. it could just be the thermostat in the filter housing has gone, or a blocked oil line like you say

Many thanks for your reply!

Due to the rubbish weather - the cars under wraps for now. I will see what happens to the cooler if I can get the car out. The wiring all looks ok. Will be testing with a multimeter to check nothings running to earth / giving a dodgy signal. I've also got a digi thermometer and probe - I was going to run it along the dual carriageway, then cross reference the two temperature read outs - hopefully pointing to a dodgy VDO sender / wiring. I was going to use the digi-thermometer to test temp of sump pan - as a-side from some conduction to metal it should be similar temp to oil?!

As for Revs - its a tough call. Not sure my clocks are 100% reliable as the rev counter sometimes zeros then bounces back up - but usually cruises at 3500 -4000rpm ish at 70mph. I now drive a diesel daily - but from memory that doesn't seem ridiculously high! When cam kit was put in, the rev limiter was removed - but as I never use 6000+rpm and the oil temp was completely fine for 2 years after the cam kit was put in - so can't think this would be an issue.

I may take it back to the guy who did the work. He was on the pulse (only he's no-longer 'local' - its not too far from where I work!)

Cheers for the pointers. i will endeavor to keep posting -as it's always frustrating when threads don't come to a complete conclusion (for the next poor old owner with a bad Mk1-habit!)

Old-GTi

id take the reading from the base of the oil temp sensor, you know for sure they should be the same reading then

you can work out your revs based on the wheel size and ratios with the calculator on this page:
Gear Up!

though it would have to be revving really high for that kind of temp and 3-4k should be alright really. plus if it was a problem then it would have been high before!

That's brilliant. Thanks. 4000rpm = 71mph (so the rev counter is roughly right - albeit temperamental).

Ok, will take temp as suggested.

Cheers again.  

Okay…the results:

I got the car out today. I drove on country lanes max 60mph ish ave. 40mph for 20mins. The VDO gauge read 90deg C after this gentle run in. I stopped the car, felt the oil cooler - it was warm but I could happy leave my hand on it - without it getting anywhere close to uncomfortable. I took a digi-thermometer reading off the oil cooler = 38degC - (about right - like the hot water tap in the house). I tried to get a reading off the base of the oil temp sensor = 40degC - tried sump-pan = 38.5degC, then I pulled out the dipstick and dripped a spot of oil onto the prob = 42degC!!!!! I noticed that the wire to the oil temp sender was wobbly - so i pushed it on securely (connection looked ok either way).

Then I decided to go for a buzz up the dual carriageway - I ran it at 70mph for 15mins there and 15 mins back. The VDO gauge never left '90degC'. Repeated digi-reads = the same as before across the board. Then I decided to give it some welly - accelerated harder on the 'on ramp' and did 'approximately the national speed limit' for 10miles - to better replicate modern motorway driving speeds. Finally the temp on VDO gauge left the 90degC mark and rocketed to 100degC…..where it stayed!!!!!!! NO WHERE NEAR PREVIOUS EFFORTS!!! So I dropped back down to 65mph ish and the VDO gauge responded within 2 mins and the oil temp reading came back to 90degC. I then drove another 16 miles on country lanes and the oil temp behaved itself properly!!!!

Only differences between last weekend and today - ambient temp last weekend ~27degC, today = 11degC. Last weekend I drove persistently at 70mph for 1hour dropping to 50mph to try and get temp down - AND oil temp hit 130degC after 15mins. This weekend had to 'try' to get it hotter.

Last summer I drove back to Yorkshire in the evening - ambient temp started at 25degC probably dropped to 15degC during journey - if I remember correctly the VDO gauge stayed at 120-130degC regardless.

So:
1.Can 16degC of ambient temp really = a difference of 20-30degC in oil temp?
2.Was the slightly wobbly temp sender connection to blame?
3.Will be planned trip to the Nurburgring in September lead to a cooked engine or will it be ok?! - Who knows!

I will of course repeat tests if we get a warmer day and report back. Still a bit of a mystery to me!!!

regards

Old-GTI

fingers crossed it was just down to a dodgy connection, 16deg ambient might make the oil a bit warmer but i dont think it would make 30degs difference!