Blown Head Gasket... Thoughts?

[audi8844]

Due to being quite busy in a new position at work, I haven't been here very often lately. But I have returned for some assistance and input. I recently completed my timing belt, water pump, and thermostat service. Thanks to Fly's DIY, it went off without much of a hitch. However, after driving the car for approximately 1.5 months (daily 60 miles), I recently had some rough idling, and sluggish running in cold weather. Upon further inspection, there was oil around the valve cover (pressure in crankcase) and oil cap (I have a catch can, so PCV is no longer installed). I then got a low oil level light (I was planning to do my 5k oil change next weekend), so I checked the dipstick and noticed that the oil appears to be quite "muddy." This is indicative of coolant in the oil, pointing me to a blown head gasket... great, right (coolant level had dropped slightly, but no sign of oil in the coolant system). I am thinking is may be on the intake side, due to pressure entering the crankcase, but I figured I should replace all gaskets. The only time that the car was reading a high temperature was just after the timing belt change, when I was working on purging the air out of the cooling system, in which case I immediately shut the car off and continued squeezing lines to make sure that the coolant was flowing as needed in all locations. Is there anything further, dealing with the timing belt change, which could cause this to happen? Any other way in which the coolant may leak into the oil? I am worried that a head gasket failure may mean that I am screwed unless I have the surface machined to be sure that there are no imperfections, which may just allow for further failures. Maybe I should just replace gaskets and sell this. But I hate to put this amount of work in with so much life left, and I am planning to keep her for a while. Also, I have not seen much in the way of good DIY's for replacing head gasket, so any suggestions there would be wonderful.

FYI... my car only has 82k on the clock. With a squeaky tensioner pulley, I decided to replace the timing belt, as the difficulty was not high.

TIA for any assistance. I will try to get some pictures this evening.

Added details: I know there is currently an air pocket in the heater core, but I know that there is no air in the rest of the system, as I bled through the top bolt on the cooling line above the motor. The heater core shouldn't cause hot spots elsewhere.

[PNW Avant]

muddy oil is also indicative of MOISTURE in the oil which could be due to your catch can. If its not set up properly then you are not evacuating gases/vapor (including water vapor) properly. Seaping VC gaskets suggests to me that something is wrong with your catch can set up (could be frozen lines) to cause excess pressure build up. This can also lead to excess oil consumption. You mention above this started in cold weather, which further suggests clogged catch can lines.

I suggest reinstalling the stock PCV, changing your oil, and checking again. You said coolant level has dropped only slightly so maybe not the issue. I am much happier with stock PCV than I was with my catch can.

[FraggyA4]

This could also be caused my the oil cooler gasket. If it failed then it would cause coolant to leak into the oil system. I would start there first since it's cheapest and easy to replace. If it is the head gasket then no big deal, the job is quite easy.

Drain oil
Drain Coolant
Unbolt fuel pump
detach coolant lines to rear flange
unhook timing belt and serpentine
unbolt intake manifold
remove air cleaner box
unbolt turbo manifold studs
unbolt turbo support
Remove lower intercooler boot
attempt to remove turbo with lines attached(may need to remove coolant and oil lines on top.)
remove valve cover.
remove head bolts
pull cylinder head up slowly to help remove electrical connections that you may of missed
remove gasket
clean all surfaces.

Also you should go ahead and replace cam chain and tensioner, clean your valves and replace the coolant flange as it is much easier doing it with the head out.

Install in reverse.

[FraggyA4]

muddy oil is also indicative of MOISTURE in the oil which could be due to your catch can. If its not set up properly then you are not evacuating gases/vapor (including water vapor) properly. Seaping VC gaskets suggests to me that something is wrong with your catch can set up (could be frozen lines) to cause excess pressure build up. This can also lead to excess oil consumption. You mention above this started in cold weather, which further suggests clogged catch can lines.

I suggest reinstalling the stock PCV, changing your oil, and checking again. You said coolant level has dropped only slightly so maybe not the issue. I am much happier with stock PCV than I was with my catch can.

This is also true frozen line will fuck shit up.

[DiertyEuroSpec]

Oil cooler o-ring failure will NOT lead to oil mixing in the coolant. It will only lead to a small oil drip onto your belly pan.

[audi8844]

It's funny you mention that, because I was thinking of changing back to stock PCV. I was thinking that originally, because I have had to replace the valve cover gasket before. However, everyone I have shown pictures to says that it is definitely coolant causing the oil to look that way. Would excessive moisture cause cause the oil to muddy up and somewhat freeze when really cold? I will certainly try that first.

[aluthman]

muddy oil is also indicative of MOISTURE in the oil which could be due to your catch can. If its not set up properly then you are not evacuating gases/vapor (including water vapor) properly. Seaping VC gaskets suggests to me that something is wrong with your catch can set up (could be frozen lines) to cause excess pressure build up. This can also lead to excess oil consumption. You mention above this started in cold weather, which further suggests clogged catch can lines.

I suggest reinstalling the stock PCV, changing your oil, and checking again. You said coolant level has dropped only slightly so maybe not the issue. I am much happier with stock PCV than I was with my catch can.

This. The drop in coolant is probably just from left over air pickets being evacuated.

[audi8844]

Thanks everyone. I will replace valve cover gasket, install stock PCV, and change oil and report back. I was thinking this might be the only issue, but I had some skeptics when I was discussing with buddies of mine.

[GodFatherMav03]

Dude, I'm from the MD area too and I have the catch can as well... same thing happened to my car the other day and also had more smoke out the exhaust then usual. I ended up popping the valve cover gasket. This is what I did to fix my issue. Removed catch can....The can was full of water and oil mixture and it was frozen solid. I took the can inside wrapped it in a heating blanket or element and that was thawed within 30 mins. I replaced the valve cover gasket, drained catch can and re-installed it. took it out for a drive and problem was solved. This arctic cold weather is doing a number on our cars...just need to take that extra care.

[FraggyA4]

Oil cooler o-ring failure will NOT lead to oil mixing in the coolant. It will only lead to a small oil drip onto your belly pan.

If the gasket fails somewhere on the back of the oil cooler it could most definitely cause the oil and coolant to mix. Is it likely only if for some reason the coolant system plug right near the cooler and caused access pressure.

[PNW Avant]

I wouldnt even replace the VC yet. Once you fix the PCV then the pressure will be relieved and it probably won't seep anymore.

[DiertyEuroSpec]

If the gasket fails somewhere on the back of the oil cooler it could most definitely cause the oil and coolant to mix. Is it likely only if for some reason the coolant system plug right near the cooler and caused access pressure.

That is not a B6 1.8t oil cooler sorry for confusion. Wait a minute does OP have a B6 or B7?

[p0isin]

B7

[trj]

As others have said, your catch can lines might be frozen resulting a build up.
Switch to stock PCV. Don't even change the VC or VC gasket if you don't see any oil leaks around.

In BMW world, there are two versions of PCV. One is normal and another is for cold climate. Essentially, same PCV and lines covered with insulating foam. I am planning on insulating the PCV lines with foam when I do the PCV on B7. I installed the normal version in my BMW and its working just fine but next time I will go with cold climate version because I am still experiencing oil loss between the oil changes. Right now, I do not have any oil burn/leak issue with the B7, so I do not like poking a sleeping giant.

As to your head gasket speculation, its highly unlikely. A leaky head gasket would lead to a lot more problems, unless you have a minute (very) leak. CEL, misfires, overheating, sweet smelling smoke(coolant smell) from tail pipe, loss of power are some of the things I can think of.

[B72011]

This could also be caused my the oil cooler gasket. If it failed then it would cause coolant to leak into the oil system. I would start there first since it's cheapest and easy to replace. If it is the head gasket then no big deal, the job is quite easy.

Drain oil
Drain Coolant
Unbolt fuel pump
detach coolant lines to rear flange
unhook timing belt and serpentine
unbolt intake manifold
remove air cleaner box
unbolt turbo manifold studs
unbolt turbo support
Remove lower intercooler boot
attempt to remove turbo with lines attached(may need to remove coolant and oil lines on top.)
remove valve cover.
remove head bolts
pull cylinder head up slowly to help remove electrical connections that you may of missed
remove gasket
clean all surfaces.

Also you should go ahead and replace cam chain and tensioner, clean your valves and replace the coolant flange as it is much easier doing it with the head out.

Install in reverse.

Um yeah, no problem----easy stuff! Hahahhahah

[PNW Avant]

As others have said, your catch can lines might be frozen resulting a build up.
Switch to stock PCV. Don't even change the VC or VC gasket if you don't see any oil leaks around.

In BMW world, there are two versions of PCV. One is normal and another is for cold climate. Essentially, same PCV and lines covered with insulating foam. I am planning on insulating the PCV lines with foam when I do the PCV on B7. I installed the normal version in my BMW and its working just fine but next time I will go with cold climate version because I am still experiencing oil loss between the oil changes. Right now, I do not have any oil burn/leak issue with the B7, so I do not like poking a sleeping giant.

As to your head gasket speculation, its highly unlikely. A leaky head gasket would lead to a lot more problems, unless you have a minute (very) leak. CEL, misfires, overheating, sweet smelling smoke(coolant smell) from tail pipe, loss of power are some of the things I can think of.

There's no need for any insulation on the OEM set up. The OEM set up is designed to combust any and all vapor pretty much immediately whereas the catchcan is designed to catch and store vapor/fluid. Once the vapor is stored as fluid in the catch can, it is then subject to freezing.

[CleverA4Name]

You could always just vent your catch can to atmosphere, and by that I mean just leave the drain open on the bottom

[vtwinjunkie]

So this is not a head gasket issue? I saw the title and skimmed through it.....did I miss something?
I am confused.

[PNW Avant]

Not likely. His only indication was "muddy" oil. Which just means moisture, not necessarily coolant. Then he started talking about cold temps and his catchcan. Probably clogged or frozen catch can. Tell-tale signs.