cracked head and oil into coolant intermix
 

Anyone try K-Seal or Blue Devil for an intermix issue? My buddy has a 996 and there's oil in the coolant reservoir tank. The oil in the engine looks clear as it should with no signs of coolant.

The mechanic insists and confirms that he replaced the oil cooler and heater core with new parts, etc. So I am trying to rule out the oil cooler mixing into the coolant or the heater core as well.

You can smell coolant in the cabin when driving.

Would K-Seal or Blue Devil or the like, seal the cracked head issue that a handful of owners have experienced? I'm wondering if the oil leaks into the cooling system through the cracked head if a K-Seal or the like would seal that part of the engine?

If you have a cracked head your best bet is to get the crack welded. A few members have successfully executed on this, and the results (if done properly) should be stronger than the original head (which is prone to this type of failure).

Possibly related question: What color should the coolant mix be in the overfill reservoir? 99 C2 is new to me and I recently had the coolant replaced as part of the 90K service. I remember it being clear but today after a spirited drive there's a light brown color to it. Oil level has remained the same since the work was done about 500 miles ago. I did notice the oil pressure gauge going up and down quite a bit at higher revs during some of the curves I was taking at a pretty good clip yesterday as well. Anything to worry about?

thanks

Rich

pm'ed you.

The strangest thing happened. Crossing fingers...we just put in a bottle of Bar's engine repair below and afterwards drove the 911 around for a couple hundred miles and now we are taking out far less oil/milkshake out of the coolant reservoir tank.

A little recap of what happened. We had a bunch of oil mixed into my cooling system and had the entire cooling system overhauled with all new parts. The mechanic charged about $6,000 for the parts and labor. Afterwards, the oil was still there even after they did their so called 6 hour cooling flush BS, etc...after their repair the 911 still had 2 cooling hoses bust open dumping coolant all over the engine bay. Thanks to some of the forum members the 911 has been driving around with the pressure cap open to help release any built up pressure in the cooling system. So far no more hoses busting open...again crossing fingers.

But the 911 was still having massive amounts of milkshake oil that needed to be taken out of the coolant reservoir using marine engine oil absorbent sheets(This absorbs the oil leaving as much cooling behind as possible). This would need to be done after every drive of 30-40 miles checking and re-checking and pulling out oil every time. Now after putting in the Bar's engine repair the 911 was driven longer to push the Bar's through the engine and found far less oil in the coolant reservoir.

So now my question is where are the weak points of the engine that would allow the oil to get into the coolant but not the coolant into the engine?

http://barsproducts.com/system/pictu...jpg?1328225414

My 2 cents,
FWIW, you can't fix these engines with a "bottle" of something or JB weld type stuff. If you have a cracked head weld it or replace it. Trying to do things on the cheap will in most cases not work, these are thoroughbred engines. Now to your problem, you just paid 6K for cooling system repair? HE is responsible for this and make him repair it! No if ands or buts.

Ditto. Putting. $4 gook into a $10,000 engine is not a recipe for success. I would have it completely flushed (again) properly before you blow the whole thing.

Denver Steve, I get it that your from Colorado but let's keep it above the line when it comes to racial slurs no need to use the word "gook" :rolleyes: on this forum or any where really. We drive Porsche's not beat up pick up trucks we should try to be civilized.

I suspect there was a typo and the word should have been "goop".

I am in agreement that using some goop in the coolant in hopes of fixing the leak is at best a pipe dream.

Where the leak is is hard to say -- if one guesses and is right it is a lucky guess nothing more.

Oil leaking into the coolant and not the other way around or without a corresponding appearance of coolant in the oil suggests the leak is at a place where the oil is under pressure and the coolant is not ever under pressure.

I can't off the top of my head think of where this might be. While the coolant is not under as much pressure as the oil it is under pressure -- when the engine is shut off hot -- when the oil pressure drops to zero.

The other possibility is the coolant is getting into the oil just not in quantities that show up from a visual only inspection. An analysis of the oil might turn up the presence of anti-freeze compounds in the oil.

Regardless, if I understand the situation correctly the cooling system was overhauled and at considerable expense and if the cooling system is still not right and oil getting in the coolant is definitely a sign things are not right you should take the car back to where you had it worked on and let the shop sort this out. They did a poor job or possibly misdiagnosed the cooling system as being at fault when there is something else going on, and a cracked head or block is very possible.

I agree they did a poor job and misdiagnosed. They pressure tested the engine for signs of a cracked head which these are known for but they said and documented that the block was good and went on with overhauling the cooling system saying the engine oil cooler was causing the oil to get into the cooling system.

They need to be checked hot for the intermix to appear. On a cold engine you may get nothing. Some cracks are sealed when cold an only open up with thermal expansion.

The cooling system runs about 10 psi, and the oil system 40 psi or so. Given the pressure differential, the fluid migration is from oil into coolant, and not the other way around.