My C4 here in the UK has 242000 miles on it, so just a low-mileage example. I've been noticing that engine oil temp as shown on the analogue gauge on the dash has just started creeping up slightly above the 100C mark, where it's been for over a decade. I mean, I know that the bottom end must be getting a bit worn, but it only takes a session in UK traffic and the combination of the theory of allowing the coolant temp to get to 228F or whatever, plus the fact that the oil is cooled by that water is sometimes making the oil light flicker at tickover. (I've checked and changed the oil pressure senders)

Is there any way to otherwise control the oil temp so it is a few degrees lower than 100C? On warm-up, maybe 20 miles or so, before it gets to 100 or above, the oil pressure is doubled. I'm just trying to delay the inevitable really, and pull the motor and rebuild it. I've always disliked that policy of allowing the coolant temp to move that far, I mean I know you don't want fans constantly cutting in and out, but really? 40F bandspread? Any ideas very welcome!

 

Oil temp is 212f and H20 is 228f.
Nothing wrong with that. IMHO

Mine runs 205f H20 & 215f oil. (Original sensors not calibrated)

 

Maybe you should look at replacing the oil temperature sensor (above the oil filter on the side of the block).

 

Oil temp tracks coolant temp rather closely. How is your cooling system, inside & out?
What oil are you using and how fresh?
What is cylinder compression like?

 

Mine runs there too, and on track days, it gets up to 270-280*F (the oil).

 

I read somewhere that there's a spring inside that oil filter housing that can get tired, what you think? I realise the oil and water temps are going to track each other, and like I say it's just putting off the inevitable really, it's just that keeping the oil just a few degrees cooler would probably extend remaining life by a year or more! Oil is Mobil1, always has been from day 1, changed every 7500 miles. Coolant system had a new radiator at 200k, water pump at around 150k, otherwise OK. System flushed not too long ago. Compression no idea, but head gaskets OK, if that's the way you're thinking! Due to major f8ck up by the (Chevy) main dealer when fitting the radiator (they never bled the system), they had the heads off to do gaskets at that time and cylinder bore wear was absolutely minimal.

 

What is the actual PROBLEM?

It's not your oil temps or your coolant temps. They are well w/in "normal ranges". It's not your mileage -engine should be fine for another 100k miles. What is the symptom that you are looking to fix here?

 

Don't really see a big problem here. Oil temps for C4's are typically 10-30 degrees F above coolant temps. Full synthetic oils like Mobil-1 can easily handle oil temps as high as 300 degrees F

What year of Corvette?? IMHO, I would change oil at more frequent intervals, maybe something like 6000 miles and use the Mobil-1 High Mileage oil if that's available in England. Of course use a good quality oil filter too.

 

My 88 ran hot and went above 100 for oil often and sometimes reached 110 ... coolant temp would go to 105 before fans kicked in.

I changed the type of oil for a start (among others things)... I now run Shell Helix HX5 ... 15W-40 ... for months now.

Formulated with cleansing technology
Continuously helps to prevent dirt and sludge from building up
Premium multigrade oil for reduced engine noise
Suitable for fuel injected petrol engines with blow-by-gas recirculation

I use 15W-40 because of the higher temperatures in Australia.

The engine is clean as a whistle now and all the sludge is gone and when you take out of oil stick it still pretty clear after a thousand or more miles of driving. Not that dirty brown look you normally see over time.

The car now runs with cooler oil... very rarely goes over 100c (usually sits on 95c to 97c and the coolant temp sits between 83c and 87c... only goes up in city traffic and the fan now kicks in at 100c not 105c.

Other things I found created higher engine temp was leaking exhaust manifold gaskets... you won't notice you have leaks in the gaskets unless you open the bonnet and start of the car standing outside and look down the left hand and right hand side of the motor on start up... if you see fumes coming out of one or both sides of the engine you need new exhaust manifold gaskets... changing those makes the world of difference to your motor and performance.

For a long time I did nothing because the previous owner said it was normal for the engine oil and coolant to run very hot... no it's not... I am just lucky that I decided to change my thinking because if I had not the motor would be stuffed by now... it was starting to really struggle under the high temps.

Anyway that's my two bobs worth.

 

The fact that standing in good (bad) old UK traffic on a warm-ish day can get the oil light dimly flickering. That makes me nervous!

 

Yes, that would make me nervous too.

Never had that happen...

When I first got my C4 I went crazy, drove it all the time and 2 interstate trips within the first six months of owning it.

Well the car probably wasn't used much over the last seven or eight years before I got it... think the previous owner did as many miles in seven or eight years as I have done in 1 year.

So things started to go wrong and I have changed my whole thinking of how I use the car... one thing is it looks brand new inside and outside... I tackle each mechanical problem one by one... and I only use it now to cruise down the road to the coffee shop... or a close country town (not more than 50 kms away).

I don't want an engine rebuild and I know if I don't flog the life out of it as I did for the first 12 months I will keep it ticking over for many years to come.

The reason I am saying all this is many C4 owners will have at least one problem with their car which can be catastrophic in engine failure... it's a numbers game... the more you drive it the sooner it's coming.

Like you, I have had an issue with my motor that got me looking at the price of a crate motor... just replace the damn thing... then I realised the 88 c4 motor will just keep on going and going as long as you listen to it and watch everything... You're red light is basically saying something's not right... it could be anything... I had a coolant leak in my motor and for the life of me I couldn't find it... every day for a month I looked and finally found it was coming from the intake manifold but it was in such a place that it looked like it was coming from the water pump...

Gee that was long winded... Anyway... the solution to your flickering red light is there but sometimes it takes ages to work it out...

 

So when that happens, what does your digital display show for oil pressure?

 

Sorry, man, but regular driving and "2 interstate trips" is in NO WAY, "flogging the life out of it". No way. Properly maintained, that motor could go over 300,000 miles (483,000 km) with no problems at all. If you think that "drove it all the time and 2 interstate trips" is bad, you should see how my vehicles get used. Don't scare someone away from driving their car. Car should be able to be driven...a lot.

 

That light indicates low oil pressure. Nothing to do with oil temperature.

 

That's my opinion and I live in a different country to you... my car is also RHD and I paid big money for it... if I lived in the USA I could have one for the fraction of the cost of mine... If I lived in the USA for the money I paid for mine I could have one to flog, one to take to the shopping centre, one for each of my 3 kids... it's all relative really - no-one can scare anyone into anything...

 

I understand that, don't think I said anything about the light indicating temp.

 

digital display on mine scrolls between water temp, oil temp, tranny oil temp and volts, not oil pressure, sorry.

 

Well, you can see how I made that assumption, based on what was posted.

You said you had an issue with oil temps.
Everyone has pointed out that your temps are normal.

Tom then asked "What the real problem was", and you stated that the flickering light made you nervous.

So, your actual problem isn't your oil temps.
It is your low oil pressure at idle, which causes the light to flicker.

 

What year is the car??

 

Well, I'd say your opinion is wrong. Highway trips in NO WAY, "flog the life out of it" That just ain't true, regardless of your "opinion". Car can go right past 300k doing highway trips. As for scaring people; you've gone and scared yourself right out of driving it, and now you're posting misinformation about how highway driving is detrimental, which just ain't true, man.



W'regard to the issues in this thread, RollaMo-LT4 is right. The actaul problems here is a possible oil pressure issue. steveleakeC4, you're saying that no where on your digital display, does your car show oil pressure? That can't be right... This shows OIl Pressure in the top left of the center information area...


As does this video...



What ever the case, If that is true, then you need to acquire a mechanical gauge, and check your oil pressure so you know what it is, and if your light is erroneous. You need to know what your oil pressure is, bottom line.