still note that my oil temp is running a little warm

[Vanne]

Car is running great, only thing is I've noticed that the oil temp is running 10 degrees to warm, any ideas, or anything that you guys would do?

inspected the oil cooler, looks good.

next ill change the oil..

[JCF]

When did you notice the difference? What was the temp before vs. now?

Could it just be environmental? In other words, hotter air temp equals hotter oil.

[Sterling Roadster]

If you haven't switched oils, used additives or modified anything recently i'd suspect the weather to some amount. Has the coolant temp changed or perhaps the oil pressure?

[Westersund]

Maybe the thermostat in the oil filter housing is going bad.

[Vanne]

Normally, religiously my oil temp was at 100 degrees c, gauge straight up in the center.. Now on a very hot day it will go to 110-115 degrees.. No idee, and I can't remember it doing this last year in the sweltering heat, which if might add is starting to come down now..

I'll change the oil first and then see what's what..

Also might add I have a oxy sensor that seems to be throwing a code.. Is there possibly a link?

[JCF]

If I remember correctly, the acceptable temp range is up to 250 f (121 c)

[Finnegan]

What's the O2 sensor code? I believe a lean mixture can generate excess heat, and the O2 and EGR are used to monitor and adjust mixture IIRC.

[jdoublehcubed]

Originally Posted by Vanne

Normally, religiously my oil temp was at 100 degrees c, gauge straight up in the center.. Now on a very hot day it will go to 110-115 degrees.. No idee, and I can't remember it doing this last year in the sweltering heat, which if might add is starting to come down now..

I'll change the oil first and then see what's what..

Also might add I have a oxy sensor that seems to be throwing a code.. Is there possibly a link?

I bet its environmental. Mine is normally 1 peg to the left of straight up (i think thats like 85), but in the summer it moves to straight up. On hot days I've seen it go to one peg right of straight up. Hot to me is like 115 F, hot to you is probably a lot hotter than that.

Make sure you get a blackstone sample of that oil. If they see that the viscosity is down more than it should be (or a number of other things), that could be your problem.

If you can't send it blackstone from where you are, mail it to me and I'll resend it for you. For the $25 (I think) they charge, its always been an easy choice for me.

[Huz-Z]

Just going back to first principles for a moment, if one accepts that the oil itself is fine, then anything which causes the oil to flow more slowly around the engine cooling circuit could contribute to this or anything that impairs the effectiveness of that system to reject heat out of the car. Maybe there is a filter obstruction or the rad fins are fouled with bugs. and any of what everyone else said!

[bignosejim]

Have you switched oil brands lately? Some just run hotter than others by a little bit. I've heard that the new Shell oil runs hotter and also a couple of others.

[Vanne]

Thanks guys for trying to help out..

No, haven't changed oil.. Actually when I took my car to my Indi the other day, intent on only an oil change, but left there with doing rod bearings and other engine updates/inspections. Coils, plugs, guides, vanos inspection.. So fingers crossed that all goes well..

The returning engine code is 2C31..

I've also told my Indi to check the exhaust manifold for leaks, as I've read that it's possible for that to throw the same code also, failing that, I guess I need a new O2 sensor..

Not sure if I can still get that oil sample JD, as my engine is already apart mate.. Will be interesting to see what my shells will look like... If I have a day off from work, I am going in there to look/help with the rod bearings.. More like probably getting in the way.. :-)

[Rick F.]

Vanne,

Why did your indy mechanic recommend checking the rod bearings? Usually they should be pretty bulletproof, unless water gets in the oil or the oil itself degrades substantially for some reason. Or high miles on a highly tuned engine (i.e., like yours).

I assume you also checked the regular radiator in addition to the oil cooler. Although the gauge shows the oil temp and not the coolant temp, the oil temp would still be affected by a higher-than-normal coolant temperature. I once found an unfortunate bird spread out across my radiator (on another car).

Your theory about a lean fuel mixture contributing to higher engine temps is correct, so a wacko oxygen sensor could be a factor. Likewise for an intake manifold leak. You'd probably hear an exhaust manifold leak; I'm not sure such a leak would contribute to running lean, however. It might affect the oxygen sensor, as you mentioned, but it seems like the composition of the exhaust gas wouldn't change--just that less of it would get to the O2 sensor.

Otherwise, there are the usual candidates: low water (or oil) level, radiator fan or water-temp sensor acting up, thermostat going bad, or a problem with the water pump.

Good luck, and let us know what you find!

Rick

[Vanne]

Thanks Rick,

(mech didn't recommend that, i took it in for an oil change, and had been planning to do the bearings as my ///M is very high milage, with a few spirited days chucked in there for good measure, so left it with them to do the bearings, preventative only, engine was running as smooth as a new baby's bottom..

I just got the car back yesterday, new oil etc.. driving home.. seems to be a little better, not quite 100 degrees, but floating around 105-110. so needle a bee's-sting past middle. My tech cleaned both O2 sensors (2C31 Finn), and will see if the error returns. if it does, il swap the oxy sensor.. (the heat here is still substantial, during drive home yesterday 47 degrees..) so kinda hoping its also still possible to be environmental.

looking at pulling the front bumper off, (yeah yeah, I've been talking about that for months, but just need a few cool days for installing a /LOT/ of stuff.. and was thinking about the section behind the front air dam.. and possibly thinking of installing an extra oil cooler in there...

first things first though.. gonna see if the temp comes down / see if error returns, then swap out the sensor.. and for piece of mind maybe obtain an extra oil cooler..

[Vanne]

Couple of quick pics this morning doung some kms. All below 3k as running in the new bearings..






Oat up at 40 degrees, what do you guy's think, is it something to worry about?
Is it possible the thermostat (water) is mis behavibg?

[chickdr]

Originally Posted by Rick F.

Vanne,

Why did your indy mechanic recommend checking the rod bearings? Usually they should be pretty bulletproof, unless water gets in the oil or the oil itself degrades substantially for some reason. Or high miles on a highly tuned engine (i.e., like yours).

I assume you also checked the regular radiator in addition to the oil cooler. Although the gauge shows the oil temp and not the coolant temp, the oil temp would still be affected by a higher-than-normal coolant temperature. I once found an unfortunate bird spread out across my radiator (on another car).

Your theory about a lean fuel mixture contributing to higher engine temps is correct, so a wacko oxygen sensor could be a factor. Likewise for an intake manifold leak. You'd probably hear an exhaust manifold leak; I'm not sure such a leak would contribute to running lean, however. It might affect the oxygen sensor, as you mentioned, but it seems like the composition of the exhaust gas wouldn't change--just that less of it would get to the O2 sensor.

Otherwise, there are the usual candidates: low water (or oil) level, radiator fan or water-temp sensor acting up, thermostat going bad, or a problem with the water pump.

Good luck, and let us know what you find!

Rick

The S54 rod bearings are not known to be bulletproof. Many are finding they need replacement between 60-100k. They are a wear item on the S54....

See this thread for an example(59k replacement...) http://www.zpost.com/forums/showthread.php?t=607732

[StickMon]

Originally Posted by Vanne

Couple of quick pics this morning doung some kms. All below 3k as running in the new bearings..Oat up at 40 degrees, what do you guy's think, is it something to worry about?
Is it possible the thermostat (water) is mis behavibg?

That's about where mine runs in stop-go traffic in 90°F ish ambient.
Cools back down once I get in free air for about 5 minutes.

I'll probably change my oil this weekend. We'll see what Blackstone says.
I think I'll be the next one under the knife for rod bearings.
Coming up on 127k miles.

[RADRACR]

FWIW

I used to be at 11:30 in Seattle with Castrol oil.

Then I was at 12:00 when I switched to Redline.

Now I'm at 12:30 in Miami with Redline.

[inTgr8r]

^

[RADRACR]

Originally Posted by inTgr8r

^

Like the dial of a clock. I don't know the exact temps when the needle is a little below or a little above the 210-degree mark.

[inTgr8r]

Got the 12:00 but Wasn't sure about the 11:30 & 12:30

[Vanne]

210, is that where my 100 deg C mark is?

recon i should check my water thermostat ?

[StickMon]

Originally Posted by Vanne

210, is that where my 100 deg C mark is?

Yep.

Originally Posted by Vanne

recon i should check my water thermostat?

I'm not convinced the 2 are closely related.
Separate liquid to air coolers.

Just for more data, when my oil is up to "12:30" my water is right about 200°F.
On cool days and/or not in stop-go traffic, oil at "11:30" and water just under 180°F.