Oil and antifreeze mixing
 

Long story short, had the car on the dyno and it started overheating, checked the oil and it was all milky. brand new OEM headgasket, torqued the head back down in the right order and to ARP specs, start it up to idle and bleed the coolant system of air and within 5 minutes temps are at 216* check the oil again, yep. all milky. took the head to a machine shop, not warped. that leaves the block. now before i bought the engine it made 470~ whp and ran fine. only thing i changed was swapping a built GSR head on it. is it possible a sleeve sunk on me in the time it was sitting in the garage? i wouldnt think so but im out of ideas as to what else could cause this. engine is an LSVTEC. i can see no cracks in the sleeves or anywhere in the head. any other ideas would be greatly appreciated.

Re: Oil and antifreeze mixing
 

Check the threads on the block itself where you torqued down the head studs. If its been done (from possibly previous owners) in which you weren't aware, it could easily be the aluminum threads themselves stripped out causing a big leak.. It's RARE that any sleeve sunk but that's from other factors that don't seem to be involved in your case.

Re: Oil and antifreeze mixing
 

How did the original head gasket look between the cylinders? Sometimes you can see where the blow out is. Its likely you cracked a sleeve and haven't located it yet.

Re: Oil and antifreeze mixing
 

i seriously doubt it cracked a sleeve considering he just got it to idle where he wanted it and never even did a full pull before it gave a warning for temp. i couldnt see the where he was rpm wise but couldnt have been more than 4-5k. i looked over all 4 sleeves and couldnt find a crack in any of them. i will check the threads in a bit thanks for the tip shodan

Re: Oil and antifreeze mixing
 

the block surface may be warped. I've had a few engines where the block was warped over 0.005" and never knew it. after discovering that, I shave every single block before assembly to ensure straightness.

Re: Oil and antifreeze mixing
 

If it was a sleeve problem you would be getting coolant in the combustion chamber. If it is just oil and coolant mixing and the head is fine I would check the deck on the block next.

Re: Oil and antifreeze mixing
 

Do you have an oil cooler? Some of the OEM style oil coolers that cool the oil with coolant have a membrane that can fail and mix the two fluids.

I've seen some OEM tranny coolers do the same thing. BIG mess. Cooling system full of ATF.

Re: Oil and antifreeze mixing
 

That wouldn't be the case.the oem ones do not use a membrane.they use a metal piece that's forged as one unit

Re: Oil and antifreeze mixing
 

Whether they're one piece metal or not, in my time working at a Honda dealer, I've seen more than one fail.

I doubt that's his problem, because when they fail, it's catastrophic, not a little milky like is the case here.

Re: Oil and antifreeze mixing
 

No oil cooler here. The tuner said he felt like there was some contamination in the combustion chamber because it would start spitting when they started to do a pull and got into boost. Haven't had time to check the block yet. Work is keeping me from it.

Re: Oil and antifreeze mixing
 

well finally got around to checking it out. none of the sleeves have sunk but i can get a .003 feeler between the straight edge and the actual deck with the edge on the sleeves. that seems like quite a bit to me. its like this on all 4 cylinders. is that my problem?

Re: Oil and antifreeze mixing
 

just called GE, was told that a .003 step is normal for their blocks. at this point im about to go light it on fire lol

Re: Oil and antifreeze mixing
 

They step the block to ensure the sleeves seal against the head.

I you've gone over all of this and still no answer you need to look at the sleeves again because one has to have an issue

You'll be hard pressed to crack a sleeve on a sleeved block but sometimes at the bottom of the sleeve where it meets the castings for the main caps it can leak coolant if an o-ring failed or the sealant failed around that area

You need to get the car in the air, pull the pan and windage tray and check for signs of leaks. Sometimes you'll be able to see coolant beaded up on stuff if the engine hasn't been run for a bit

This would also cause the cooling system to lose pressure causing the overheating issue, as pressure will force more coolant out than when the motor is cold

Re: Oil and antifreeze mixing
 

that was my next step. a buddy mentioned pulling the pan and having the coolant system pressurized to see if i can perhaps see where it is leaking.

Re: Oil and antifreeze mixing
 

that is the only other place it could be coming from unless you've looped a line somewhere

is there coolant in the cylinders? If not then it's not a headgasket issue.

There is a chance the head could be cracked somewhere but that is a very rare scenario

Re: Oil and antifreeze mixing
 

it is getting in the cylinders. but just out of curiousity, what lines would it be possible to loop and cause that? the coolant in the block is still normal, but the oil however is not so lucky. i cant see any cracks anywhere in the cylinder walls, but since the head is all i changed perhaps it is cracked somewhere. is there any way test the head for that?

I do believe theres a way to test heads for cracks like you could possibly have.
Wgat were the results from pressurizing the cooling system

Also, did you swap a gsr head for a gsr head or an ls head for gsr head.

Cause ive read that the ls gaskets have rivets that keep the gasket from sealing properly.

Other than something like that, sounds like a crack in the head somewhere

Re: Oil and antifreeze mixing
 

it had a gsr head on it when i bought it, so i swapped my built gsr head on it. also a brand new oem VTEC HG. car is 90 miles away havent been able to pressurize the coolant system and check it yet

Re: Oil and antifreeze mixing
 

Well as stupid as I feel now I think I've discovered the problem. Wentover the entire head and there a .006 ridge around the oil passage that gets plugged for an lsvtec. Head is straight every where else other than there. Someone can feel free to come smack me now

Re: Oil and antifreeze mixing
 

Hope it works out for ya! I live in Linn. You should come out to dyno day and put it on the heart breaker next year...

Re: Oil and antifreeze mixing
 

I'm usually busy working on the weekends, so that limits my ability to make it out to meets :(