hello, I have purchased my first Mini Cooper s but the catch was it had engine issues. Well it has a big engine issue. The water and coolant has mixed - In engine and cooling system. White brown goop all over the inside. At first I think head gasket issue , Easy right... after 5 hours I Pulled the head off and found the head gasket had no tell sign of a blowout. Last owner said it overheated and started to smoke. History- Car has 102000 miles highway and short block was replaced 18000 miles ago. Codes pulled-- p10f6 Control Phase w circuit open, p0303 Cylinder 3 misfire, p0304 4 misfire, p0300 random misfire, p0108 Manifold pressure BARO sensor high input, P0193 Fuel rail high input, P0238 Turbo boost sensor high, P169f Limp Modep007d air cooler, p10f6 control phase open bank 1... Could the head gasket leak with no damage sign.. any idea on what other part that would let the two fluids intermix this bad??? Any help would be great. All the local shops just say put in a new engine at 7000$ ..

 

After looking at some listed posts. I could see that someone found a freeze plug within the center of the head to Cause this issue. I also have this plug and it was out sitting loose in the head.. Would this be the problem ? why would this come out and cause all this trouble if it in fact is the problem... Could anybody confirm this...

 

 

oh dang...that is the issue. and as you said, i read that post of the guy having the freeze plug popping. you could pressure or blow some air in the coolant tank and see where it is escaping.

 

Yes its truly going to take some time to somehow flush all that mess out of the cooling system and engine. Why would such a plug be placed in a way that it falls out so easy.. Causing such issues.

 

Yes, the head gasket can leak without any visible signs of damage. It takes close examination of the head gasket to determine if there was a failure. Over heating could have caused the freeze plug to come out. In my case, the cylinder head was warped and the machine shop had to mill .006" off the get it flat again. Before I pulled the head, I did a leak-down test and found cylinder 1 had a 10% higher leak down rate than the other 3. In your case, the freeze plug may be the problem; it all depends what's on the other side of the freeze plug; I'll need to look at that on my cylinder head.

There is no other location where the oil and coolant from the cooling system can cross contaminate. If you think about it, the coolant enters the cooling pump inlet from the black pipe on the back side under the intake manifold. The water pump flows coolant through the engine block and cylinder head from the front of the engine to the rear where the thermostat is. If you've pulled the head, you notice how close the oil and coolant passages are to one another. Again, this is the only place they can mix (see previous comment about the freeze plug). While the coolant flows all over the place (radiator, heater core etc), the engine oil is isolated to the engine block and cylinder head.

Make sure that while the head is in the shop you have all valve seats replaced!!! It's expensive, but it's less expensive than pulling the head a second time. Please see this link. 500 miles after I had the valve job done, one of the #1 cylinder intake valve seats dropped. The head is back in the shop getting all new and deeper valve seats.

http://www.engineprofessional.com/TB/TB113017-1.pdf

 

Actually, there is...Oil filter housing. There were instances, although minimal, where coolant would mix in that area.

 

not sure why they would make it that way, but it could be how the head cast is made.

 

Which engine? Were is the coolant line that goes to the oil filter housing?

 

Thank the French!

 

N14 and N18 to cool the turbo.

 

I think it is the N18 engine..

 

N18 ? I just posted a picture..

 

yes, 2011 Cooper S is N18

 

 

I personally dont know. But if you have to remove the head (you probably did already) then you could get the head serviced to be on the safe side and extend the life of the engine.

 

Yes!!! With an overheated engine, the seats are more likely to fall out.

 

Just an update... Head plug was a issue but the reason it pushed out was the AC condenser was clogged with dirt and fins all bent in. Not letting air to the radiator to cool down the engine. Car overheated and blew the plug. The head is at the shop to get a threaded plug in its place and for a small low spot between 2nd and 3rd cylinder. Also getting service and valve job while its out. Thanks for the information and help!!