Coolant in Oil and Oil in Coolant

Post Wed Nov 26, 2014 3:09 pm

Hi Guys,

I currently having some troubles with my E30 318i.
Long story short, due to recent revving issues I ended up replacing camshaft, rocker arms and tappets, oil pipe, etc.

As I was doing that, I thought I will take the head out, have it pressure tested (I didnt have any problems with it, nor I had the head gasket failure), cleaned, skimmed and all valves replaced with new ones (both exhaust and inlet) and have them resitted. The company that did all the cylinder head work for me said the cylinder head is in good condition and now, obviously, with all the new parts. It looked good and I was really pleased.

I got home, put new head gasket, new head bolts and have put everything back together. The car started fine. There was a bit of a white smoke coming out of the exhaust but I just presumed it's the coolant residue from me removing the head in the first place.
Around 10 minutes into the engine idling, I noticed that it gets louder and louder. I stopped the car and noticed that coolant got into oil and oil into coolant. My first thought was me messing up the head gasket installation.

So I took it all apart and replaced the head gasket and head bolts with new ones again. I have then put it all back together, started the car... 10 minutes later - same thing. There's coolant in the oil and oil in the coolant.

So again, I took it all apart, replaced the head gasket and the head bolts. Again put it all back together and the results were the same!

I then called in for my mate mechanic who came over and installed the 3rd new head gasket for me - in case I keep messing it up somehow. I put the rest back together, but again the same.

To add, each time I have been replacing the head gasket and the bolts:
- I ensured the mating surface is clean and dry,
- I ensured that the gasket is position correctly (label on the gasket)
- I drained any coolant from the block, radiator and hoses l and replaced it with a clean one.
- I drained the oil and replaced with new fresh one and a new fresh oil filter.
- I poured some fresh oil (like 1l) down the oil channels to flush out any coolant/oil mix residue.

I accept that some residue will still remain in the system and I might see some coolant in oil, but not as much as I did get which makes me think there's still an issue. When I was draining oil it was brown and very water'y

And this is where I need your advise guys.
What else could be causing my problems? Is it possible that my cylinder head wasn't skimmed properly and is now not mating with the block evenly.
Are there any pipes/hoses that may have failed and now are causing these two to mix?

Like I said, I didn't have a problem with the head in the first place and it was pressure tested while it was being skimmed. There are no, at least visible, cracks.
Any advise would be much appreciated. Thanks,

Post Wed Nov 26, 2014 3:58 pm

You may find that the block has a crack in it. Not unusual, but they normally are visable due to comonlly splitting on the face that the head gasket sits on and normally around cylinders 2 and 3. The only way to check this would be to completly drain the oil from the engine. Remove the sump. Get the car in the air and pressurize the water system and see where it'is comming from. also have the rocker off as it's not unheard of fro a head to crack after testing and work done.

Post Wed Nov 26, 2014 4:00 pm

Cheers Zaust,
Sounds like I got some job on my hands then. Thanks,

Post Wed Nov 26, 2014 5:21 pm

How you getting on with this, please?

Post Wed Nov 26, 2014 5:34 pm

are you replacing the O RING that sits between the head and the block above the water pump? Also did you run a straight edge across the block? And are you torquing then 90' then 90' again? (all of this assuming you have the M40 engine.)

Post Wed Nov 26, 2014 6:24 pm

Hi. I have replaced the o ring above the water pump and each time I torqued the bolts to 30Nn then 90degress and another 90. I have not run a straight edge across the block. Its a good catch cheers.

Post Wed Nov 26, 2014 6:30 pm

This is what I have been thinking of doing.... Before I remove the head for the 4th time.
Drain all coolant, put new oil and filter and run the car for about 2,3min idling.
Then drain the oil. If the oil is fine then it does definitely mixing with the coolant.
If its brown and milky then there is a residue of coolant somewhere in my oil system.
Would that be a safe thing to do?

Other idea is to leave the coolant as it is. Put new oil and filter.
Run the car and watch the coolant level.

What do you guys reckon?

Post Wed Nov 26, 2014 6:31 pm

And yes... I do have the M40

Post Wed Nov 26, 2014 6:32 pm

if you have a Haynes manual it should tell you the tolerances. get a feeler gauge to check for any damage and also if it was skimmed find out how much they took off as i believe you can only safely skim once on the M40 head. (again I think it's in the Haynes manual)
good luck

Post Wed Nov 26, 2014 6:34 pm

get some engine flush in there or better get some cheap oil from ASDA ect. and flush the whole lot.

Post Wed Nov 26, 2014 6:40 pm

Thanks.I just got some 10w40 oil from Asda and just poured it in with no oil filter and the drain screw off. It comes out relatively clean with some bubbles so I hope to get as much coolant out as I can. Its cold so its draining for ages.
I do have Haynes and will check the tolerance shortly. Cheers

Can I run the car safety for like two minutes with no coolant in the system?

The block and the head look, visually, fine. I have not checked the tolerances but when I prefitted it last time, the head seemed to be fitting perfectly well on the block. No movement.

Post Wed Nov 26, 2014 9:40 pm

just do the pressure check and then go from there fella. will save you allot of ball ache and wasting cash on cheap stuff. a new old m40 can be had for beer money or better still fit a known working 6 pot. action not typing.

Post Wed Nov 26, 2014 9:59 pm

Cheers guys. Will dismantle it again and have pressure tested. Will report back, but it seems like its going to be early next week till I get any decent feedback.

Post Thu Nov 27, 2014 8:18 am

Thanks Will. Good advise. Sounds like a good idea to try before I take it apart again.

Regards,

Post Tue Dec 09, 2014 3:02 pm

Hi Guys,

Just a bit of an update....
I have performed the test that Will suggested above on my cooling system, but I was not able to find any leaks.

I have removed the cylinder head again! I stripped the camshaft, tappets, rocker arms and just left the valves in, then I took it to the same garage that skimmed it originally to re pressure test and re check if it got is warped or something.
When I removed the spark plugs, I noticed that 3 out of 4 were wet... strange... then I noticed a slight oil residue in the holes where the spark plugs go in the head, then some more oil residue in the inlet manifold holes and more oil in the valves. I'm no expert, but I don't think I should find oil in these places. If anything, I should find fuel?
I run the square down the cylinder head and it looked fine, I did the same on the block - again it seemed fine. I don't think this was a very accurate test as the difference might be in millimeters, not noticeable to me and the square I used.

Either way,.... the head is off the car, stripped down and at the garage. Hopefully I will have a feedback on its condition tomorrow.

Regards,