Coolant/oil mix after new head and head gasket?!

[tirefryer]

Ok, new to the E30 scene - 1989 325ix 5 speed.

Bought the car from a guy who had removed the head due to a broken rocker arm but lost interest in the car. He included a rebuilt head along with the car.

I bought head gasket kit from pelican parts (got the good Goetz head gasket) along with new torx head bolts, timing belt, water pump, thermostat, all accessory belts. Cleaned up the block and with a couple of buddies, installed the head and buttoned down everything. Car started right up idles AWESOME! However, the is oil seeping into the coolant somehow (or vice versa) - there is coolant in the oil and oil in the coolant. No white smoke at all and doesn't overheat. Bled the cooling system and drove today for about 10 min around my block, max of 35mph - ran good, no stutters or anything. However, checked oil when I got home and green slime on dip stick and oil fill cap and valve cover!!!!! WTH?!?! Also, oil is leaking from somewhere over by the oil filter (but not the oil filter - it is dry) area when the car is running only, nothing while just sitting there. The oil drips at a rate of about a drop every 5 secs @ idle and it does have a slight "green" tint to it.

What do I do from here to analyze this further? Possible cracked block -how do I check for that? How do I flush the oil/coolant mixture out of the engine and cooling system? I was hoping to get her up and running before the MI winters hit us!

TIA for any and all help and assistance.

[paperplane94]

Looks like something went wrong during the HG replacement.

You might have to get back in there and have someone check the head and block for cracks. Also make sure that you followed the bentley manual instructions to a T.

You can flush the system for now by doing the regular thing with the drain petcock at the radiator or by disconnecting the lower hose.
Then you can drain the coolant out of the block by removing a large 19mm bolt on the pass. side of the engine right underneath the exhaust manifolds and directly above the exhaust.

[peter_x]

Maybe the oil was already in the block when you got the car. You said the PO had removed the head... maybe some oil poured into the engine.

edit: I read your post again... you said oil seeping into the coolant but what you describe is the reverse.

[nates 87 325is]

I had this same thing after fixing a broken rocker arm. So I pulled the head again and found that the cam smashed a piece of the arm into the head making a crack that I wouldn't have noticed if I wouldn't have taken out the cam.

Good luck.

[tirefryer]

I did not reuse the head with the broken rocker arm - the prev owner had a rebuilt head which I used as a replacement.

Since I did NOT flush the engine block prior to putting the head on, I am wondering if some oil did spill into the block - what is a good way to flush both the block and the cooling jackets of the block before I take off the head to replace the head gasket again?

Would these steps work:
1) drain oil
2) drain coolant (from petcock @ bottom of radiator and block under the exhaust headers)
3) add new oil with Seafoam (to clean out the green slime)
4) add new coolant and bleed the system (or should I just use plain water here with coolant flush detergent?)
5) run the engine to operating temp
6) drain oil while still hot
7) drain water/flush detergent
8) change oil filter and add new oil
9) add new coolant and bleed system

Thoughts? Should I attempt to re-torque the head bolts or is that asking for trouble? @ install, they were torqued to 22ft-lb per manual (I used the torx head bolts from Pelican) then turn another 90 degrees and then a final 90 degree turn (sequence of head bolts followed as per manual).

If this fails, I am picking up a 120k miles 89 325ix engine to swap. Question: Since the front half-shafts run through the oil pan, would I be able to just unbolt the current oil pan which is in the car, lift out the engine, drop in the replacement engine and rebolt my orig oil pan to the incoming engine? Also, the engine I am getting came from an auto 325ix and mine is a 5 speed - is the bolt pattern the same for both transmission for bolting on to the engine block?

thanks.

[jlevie]

Do you see oil in the coolant in the reservoir? Is there "milkshake" in the oil (drain to find out)? If the answers to either of those questions is yes then it is possible that there is a leak between the cooling and oiling systems. That could be from damage to the gasket when installing the head, a cracked head, or one that wasn't flat.

It is also possible that oil got into the cooling system or vice versa when the PO removed the head. A flush of the cooling system will clean that out (instructions below). You will need to find the source of the dripping oil, which could be from the oil pressure switch or oil filter adapter. If it isn't from the head, flush the cooling system and see if further mixing occurs before you condemn the head job.

1) Get the front of the car 1-2' in the air on jack-stands.

2) Drain the coolant, remove the thermostat, and set the heater controls for
full hot. O-ring sealed thermostats require you to make up a temporary
gasket, which can be made out of pasteboard.

3) Add flush compound and fill with plain water. Then run the engine at normal
temperature as specified by the flush manufacturer (usually about 15
minutes at operating temperature). In cooler weather it may be necessary to
block off some of the air into the radiator to decrease the warmup time.

4) Allow the engine to cool until you can place your hand on the cylinder head
w/o discomfort. Drain the system and refill with plain water.

5) Run the engine for 10-15 minutes or until temp is close to normal.

6) Repeat (4) and (5) until the water drained from the system is clear and
free of debris.

7) Fill with coolant. It is best to dilute anitfreeze with distilled water.
Tap water contains disolved oxygen and may contain minerals. Either of
which will reduce the lifetime of the coolant.

Notes:

You don't absolutely need to remove the thermostat, but doing so will allow
continuous flow through the radiator and will also make draining & filling
faster and easier.

Always allow the engine to cool to the point that you can hold your hand on
the cylinder head without discomfort. That will prevent scalds from hot
coolant and prevent thermally shocking the head when you dump the coolant.

Filling the system with hot water makes the process go faster and keeps from
having to run the engine a lot in a cold condition (rich mixture).