Coolant in Motor Oil

[Jwbmo]

How disheartening!   I finally got time to remove the oil cooler and it checks out too!  I can see no evidence of leakage between the o rings either.

 

Does any one have any other ideas before I button up the top with new AOS, starter, oil cooler, many hoses, waterpump and cooler thermostat and just try it again before I remove the engine and send it off or salvage the car?

 

Please see my post earlier - large dump of coolant in oil after a fresh oil change still on jacks!  - NO oil in coolant --- AOS and cooler hold vacuum, cylinder leak down tests were great - slight leakage on two-one exhaust and one intake.  The intake plenums had lots of clean coolant in them when disassembled - the coolant was clean even in the oil cooler that I just removed - oil was the same chocolate milkshake.   I might need to put a lot more vacuum or pressure on the cooler and AOS to test properly.

 

Only thing I can think of is my leak down tests were done with engine cold and I know cracks can open up when warm, but this fast coolant in oil dump had to have a big leak!  My cooler was obviously tested cold too.    So, do I have some internal case crack?  Not associated with the cylinders?

 

Thank you for your help - this is so baffling.

[JFP in PA]

How disheartening!   I finally got time to remove the oil cooler and it checks out too!  I can see no evidence of leakage between the o rings either.

 

Does any one have any other ideas before I button up the top with new AOS, starter, oil cooler, many hoses, waterpump and cooler thermostat and just try it again before I remove the engine and send it off or salvage the car?

 

Please see my post earlier - large dump of coolant in oil after a fresh oil change still on jacks!  - NO oil in coolant --- AOS and cooler hold vacuum, cylinder leak down tests were great - slight leakage on two-one exhaust and one intake.  The intake plenums had lots of clean coolant in them when disassembled - the coolant was clean even in the oil cooler that I just removed - oil was the same chocolate milkshake.   I might need to put a lot more vacuum or pressure on the cooler and AOS to test properly.

 

Only thing I can think of is my leak down tests were done with engine cold and I know cracks can open up when warm, but this fast coolant in oil dump had to have a big leak!  My cooler was obviously tested cold too.    So, do I have some internal case crack?  Not associated with the cylinders?

 

Thank you for your help - this is so baffling.

 

Have you pressure tested the cooling system?  If it doesn't hold pressure, you could add UV dye to the coolant and try to see where it is coming from by the dye trail.

[Ahsai]

I would at least retest the old AOS with 18PSIG pressure as opposed to vacuum. The are two coolant hoses connected to the AOS. Try to apply pressure on one while blocking the other. Then reverse the two and retest (because I'm not sure which direction the coolant pressure naturally applies).

The coolant puddle in the plenum highly suggests the AOS. It would be nice to confirm it was the old AOS.

[Jwbmo]

Thank you JFP and Ahsai.  

 

JFP -yes, before disassembling, I tried vacuum and pressure on the cooling system.  It would not hold anything and blew out so fast with my little pancake compressor, I could not get a read or location at all.  Now that I know where hoses go, I should have isolated the AOS and pressure tested system again.     I also should have refilled system with some dye, as I was just trying to listen for the air leak location.  I falsely assumed it was the AOS after seeing the puddle of coolant in the plenum and disassembled all.  I did pressurize the AOS finally up to 60 PSI - no leaks -- however, after reading your post Ahsai, I did not reverse the pressure - but I am not sure that would be a factor if it is a simple diaphragm.   I have not built up a good pressure test for the cooler yet except for a simple vacuum test that it passed, but I will.

 

I will finish up everything and pressure test coolant system before I start it and while I still have the oil pan off.

 

Thanks again.

[Ahsai]

I will finish up everything and pressure test coolant system before I start it and while I still have the oil pan off.

I like this approach.

[Jwbmo]

The infamous cracked head .....Finally got all the cooling system repairs finished up (new AOS, oil cooler, water pump, L & N low temp thermostat, multiple hoses, new plastic hose connectors) and pressure checked.  All waterpump vanes were intact on an original pump with 85K+  ---- all looked good with a minimal leak down as I tightened up a few connections.  Re pressurized to 20 and left it for 15 minutes.  Came back to see a nice small stream running out of the right bank exhaust. Must be a small crack that I could not detect with the cylinder leak down test that I did with the cold engine.  There was a slight leak down on one cylinder on the right bank through the exhaust.  I wrongly assumed a slight valve leak or ?    I still have no clue what was allowing my original cooling pressure check to be unreadable with a large loss.  

 

Anyone have any idea how clean coolant was pushed up into the intake plenum by a head crack leaking out the exhaust?   The old AOS pressure checked fine.

 

After all the PITA work with engine in -- out it comes and due to the cost versus value issue of a '99 model - this will become another long term project that I will have to learn to rebuild over the next winter myself I guess.

[Ahsai]

You may want to check this thread. It has lots of relevant info http://rennlist.com/forums/996-forum/923130-my-milkshake-brings-all-the-boys-to-the-yard.html

[Jwbmo]

Thanks Ahsai!  

The more pictures of cracks I look at, I can envision a crack from a water jacket dumping coolant into the valve cover/oil.   So my cylinder leak down might have been good, but I got the coolant stream from the exhaust this time either because I had the coolant test pressure high enough or I had the spark plugs out and coolant found its way into the cylinder through the open plug hole and exhaust from the crack.  None of the spark plugs seemed steam cleaned on that bank, but next time I drive back over to work on it, I will pressurize coolant again and borescope those cylinders to possibly locate before disassembling.  I feel better after seeing that link, knowing if only a head crack I have good options for repair and might not need to split the bottom end.  I have been confident with the completely clean oil/filter changes and that the coolant has been completely oil free. Hopefully the water/oil milkshake that I drained out pretty quick has not allowed any corrosion damage on internals.   I certainly will do an RMS and IMS along with clutch etc. while in there.

 

I still cannot imagine how that clean coolant made its way into the intake plenum!!!

[Ahsai]

Yeah, a cracked head is no longer considered catastrophic and all the repair info is already in that long thread. I also don't see why the coolant will infiltrate the intake plenum. You may also want to call/send an email to Len to get his advice.

[sjmsmart]

On 29/12/2006 at 8:14 PM, Loren said:

If the coolant is not on the ground and the oil level is high - then it does not sound good.

 

Hello Loren

 

I have the below problem, coolant is all over the ground, from what you are saying my issue may not be as bad as it seems?

 

Hello 

I have just bought a 996 911 3.4 tiptronic with a good service history etc, checked it over best I could and as have had 2 x 986 boxtsers and I thought I had checked enough to have found a good one. 

There was some slight white build up in the oil tube but hardly anything on the cap both when I first looked at the car and when I tested it today and paid, but everyone I spoke to advised that this was quite normal. There was no smoking, it did lose a little oil on the way home on a two hour drive but was running correctly with 1.5 pressure on the oil pressure gauge. 

However when I got it home this evening I noticed a dropping of liquid onto the exhaust with a hiss/hissing. And when I looked under the car to my dismay water was literally gushing/dumping somewhere in the top back left of the engine bay. There is a large amount of coolant on the floor, there is oil in the coolant and there is oil on the outside of the water expansion tank/cap (I have not opened it as it is too hot but I can only guess that it is full of oil). This was all happening with the engine off as in water pushing its way out. 

I am gutted, and fear the worse as in head gasket, cracked head, but some people have said on forums if there is water on the floor even with oil in it there can be other causes like oil air separator, pipes and or oil/water cooler. 

I will try to get it to my garage early in the week, and have emailed the garage I bought it from but I would be grateful if someone could offer me some advice please. 

Some pictures attached.

[Loren]

56 minutes ago, sjmsmart said:

 

Hello Loren

 

I have the below problem, coolant is all over the ground, from what you are saying my issue may not be as bad as it seems?

 

Hello 

I have just bought a 996 911 3.4 tiptronic with a good service history etc, checked it over best I could and as have had 2 x 986 boxtsers and I thought I had checked enough to have found a good one. 

There was some slight white build up in the oil tube but hardly anything on the cap both when I first looked at the car and when I tested it today and paid, but everyone I spoke to advised that this was quite normal. There was no smoking, it did lose a little oil on the way home on a two hour drive but was running correctly with 1.5 pressure on the oil pressure gauge. 

However when I got it home this evening I noticed a dropping of liquid onto the exhaust with a hiss/hissing. And when I looked under the car to my dismay water was literally gushing/dumping somewhere in the top back left of the engine bay. There is a large amount of coolant on the floor, there is oil in the coolant and there is oil on the outside of the water expansion tank/cap (I have not opened it as it is too hot but I can only guess that it is full of oil). This was all happening with the engine off as in water pushing its way out. 

I am gutted, and fear the worse as in head gasket, cracked head, but some people have said on forums if there is water on the floor even with oil in it there can be other causes like oil air separator, pipes and or oil/water cooler. 

I will try to get it to my garage early in the week, and have emailed the garage I bought it from but I would be grateful if someone could offer me some advice please. 

Some pictures attached.

 

Please do not double post. You already posted this.