I've noticed my coolant reservoir low and my oil level higher than it should be. I think coolant is obviously leaching into my oil somewhere but the weird thing is the damn system will hold pressure for literally weeks. For example my car has been parked since the 3rd of June. It is now June 15th which is 2 days short of two weeks later and when I opened up the reservoir today it was still as pressurized as it ever is. I'm running a LSJ block with a L61 head. Where is the most likely place for a leak?


I plan on sending my oil in to Blackstone labs for analysis. I just don't see how it can be leaking as it would obviously pass a typical pressure test. Maybe my head is lifting and I should re-torque my head studs? As far as I know the LSJ's never had issues with porous blocks so I don't really know anywhere else in the block where there is likely to be a leak.

 

How will an oil analysis help with finding the leak?

 

It will verify if there is or isn't coolant in my oil.

 

You can figure that out easy enough... especially if the oil level is rising. What's the bottom of your oil fill cap look like? How much condensation after running it is on the bottom of the oil fill.
Pull the valve cover and look at the underside toward the cap side after a good run.
It there any yellow foamy mix on the dip stick at all?

I don't trust any of the lost foam blocks with what we are doing to them. That's why I decked the block and surfaced the head this time and had the head pressure checked.

 

I plan on changing oil later today and will post up pictures. To this point I have seen no evidence of moisture in the oil.

 

Are you running the factory oil cooler?

 

If you crack open you oil drain and the liquid that comes out looks like this, you're hosed.

 

Yes I am running LSJ stock oil cooler. No milky oil or signs of coolant.

 

take a sample when you open the drain. oil floats, so coolant would be the first that comes out if it's just oozing into the oil pan. Mine didn't really have a milkiness at first.

 

I took a sample of oil when draining. No sing of coolant although I did drain the oil after running it and the oil was warm. Where was your leak?

 

The oem coolers have been known to turn out to be the source of rogue coolant/oil contamination when they couldn't find an obvious source. Not saying that's what it is, but if you drain coolant out of the pan, it's something to check.

 

No clue. Took it to the stealership after that and they said my block was toast. I filled the water jacket after pulling the motor but nothing dripped. I never thought of checking the oil cooler, just took the stealership's word (in hindsight, pretty dumb). If the block was cracked it must've closed up when it cooled. It was leaking really bad though, like a quart after 10 miles.

 

Did your cooling system hold pressure?

 

For mine I pulled the pan and used a pump to pressurize the system and watched inside where the coolant was coming from.

 

don't know, i'm not sure what they tested. i just know they put the dye in it and that stuff got everywhere when I took it apart

 

and i can't remember if the cap was pressurized after sitting. i just know that the level dropped significantly overnight from when i pulled into the garage.

after the car cools off i don't have much if any pressure in the expansion tank