High Oil Temp... Any Ideas?

[MDonziM]

My oil temp started creeping high lately. Used to run around 190- 200 degrees cruising around and maby 220 after running hard. Now it goes right to 220 cruising and will set the warning light at 230 - 240 running harder over 4,000rpm and I have to back off. Pulled the oil cooler end caps off ( was a little debris and parts of an old impeller ) thought that was it... ran the same. Hmmmm. Water temp is fine ~130, doesnt budge. Engine seems to be running fine. (502 mpi) Mechanic says it might be running lean, ethanol maby? I used to get a little soot on the transom and now there is none.
Any ideas besides going to a bigger oil cooler? Synthetic oil?

Thanks- MM

[Mr X]

There is a thermostat in the oil cooler, it might be stuck. More common in the 525's but I would replace it.

Also check the oil cooler to see if water is flowing normally thru it, it may be clogged.
I would FLUSH out the internals of the cooler with water.
Of course it my be the gauge or the sender malfunctioning as well.

[BigGrizzly]

Did you rod out the oil cooler or just remove the stuff. The tubes may be clogged a little. The lack of soot could be the increased oil temp. It is true that oil cools the engine too, so it really shouldn't change temp unless your cooler or oil filter is restricted. Ethanol Should not have an effect on the oil temp unless you got a lot lower octane rating or ran at an extremely high altitude. If it has had no changes to the engine then the oil cooler should be the right size and doesn't need changing unless it is bad.

[MDonziM]

There is a thermostat in the oil cooler, it might be stuck. More common in the 525's but I would replace it.

Also check the oil cooler to see if water is flowing normally thru it, it may be clogged.
I would FLUSH out the internals of the cooler with water.
Of course it my be the gauge or the sender malfunctioning as well.


Where is the thermostate for the oil cooler? I didn't think there was one. I cleaned out the input side of the cooler and all the holes in the plate inside looked clear. I'm pretty sure the guage is ok, the sender is right by the filter... i guess I could check/ change that.

[MDonziM]

Did you rod out the oil cooler or just remove the stuff. The tubes may be clogged a little. The lack of soot could be the increased oil temp. It is true that oil cools the engine too, so it really shouldn't change temp unless your cooler or oil filter is restricted. Ethanol Should not have an effect on the oil temp unless you got a lot lower octane rating or ran at an extremely high altitude. If it has had no changes to the engine then the oil cooler should be the right size and doesn't need changing unless it is bad.

All the hose fittings were clear, cleaned out what I assume is the input side of the cooler, poked a wire hanger thru all the holes in the plate inside...didn't do the other side. I always run high test. Its weird.

[Cuda]

Take to a transmission shop and have it rodded out.

[MOP]

How fresh is your sea water impeller?

[MDonziM]

Take to a transmission shop and have it rodded out.

That makes sence. I'll give it a shot, thanks

[MDonziM]

How fresh is your sea water impeller?

Hey Phil - I'm pretty sure its ok, the water temp has been steady around 130, prob only have 40hrs or so since it was changed. I'll try Cudas suggestion, then if it persists, look at the impeller. thanks

[The Hedgehog]

Hey Phil - I'm pretty sure its ok, the water temp has been steady around 130, prob only have 40hrs or so since it was changed. I'll try Cudas suggestion, then if it persists, look at the impeller. thanks

I would go less on the hours and more on how long. You can dry one out and shred it in 5 hours. They need to be changed at the beginning of every season unless you run year around. Cuda has a good point. So does Phil, maybe low water pressure.

[MDonziM]

I would go less on the hours and more on how long. You can dry one out and shred it in 5 hours. They need to be changed at the beginning of every season unless you run year around. Cuda has a good point. So does Phil, maybe low water pressure.

I think it was replaced last yr. but definately not this spring. I just figured since my water temp was ok and hasn't changed the impeller was ok ... but its easy enough to change so I guess I'll try that before taking the whole oil cooler off and apart. thanks

[The Hedgehog]

I think it was replaced last yr. but definately not this spring. I just figured since my water temp was ok and hasn't changed the impeller was ok ... but its easy enough to change so I guess I'll try that before taking the whole oil cooler off and apart. thanks

You can have ok water temp and low pressure. I would start there. A cheap solution and it needs to be done.

[BigGrizzly]

Remember you can not run impellers dry. Even the blue ones. At Honda a 30 second dry run will cause early impeller failure. We have proven this time and again. on all of our engines.

[glashole]

not to get off topic but 130 seems a little cold doesn't it?

when was the last time you changes the oil

[MDonziM]

not to get off topic but 130 seems a little cold doesn't it?

when was the last time you changes the oil

I agree 130 is a little cool, i guess 150 or 160 would be better. Oil was changed in the spring, maby 10 hrs on it.

[RickR]

Oil temp of 240 @ WOT does not sound too hot to me.
Are the MPI engines set up to run that cool?
Do you get an oil pressure drop as the temp goes up?

[MOP]

Oil temp of 240 @ WOT does not sound too hot to me.
Are the MPI engines set up to run that cool?
Do you get an oil pressure drop as the temp goes up?


DITTO! I have been looking at this post waiting for Minxguy to pop in and straighten things out. Those temps are very common and normal, maybe the gauge decided to be honest!!

Phil

[maddad]

The thermostat in the Canton unit I use dosen't even send oil to the cooler till the temp gets to 215.

[BigGrizzly]

I agree that the 240 isn't bad, but it depends where you reed it- before or after the cooler. What bothers me is it now is higher then it use to be.

[mphatc]

Grizzly is correct here! and for the temp at 240 , that's OK if you're running synthetic . . conventionals, no . . to high!

Mario L.