Cracked head?

[taftonomos]

Car is a 1984 318i. I searched the site for answers, but didn't really find any. Came here looking for the M10 experts, as most other bimmer sites write off the m10 right away and stuff in a bigger motor (which I may do).

The 40k miles gem of a car has coolant in the oil. When I pop off the valve cover, I see that there has been coolant in the oil for a long time....which is probably why the car was parked back in 2003 or 04 sometime.

I pull the head off tonight, and find a perfect condition headgasket, block doesn't appear to be cracked anywhere (head bolt holes), pistons look fine and are holding water (ring pack isn't blown up or missing that I can tell). I was unable to tell in the failing light if a cylinder wall was cracked, but will look tomorrow AM.

The head looks to be fine as well, headgasket left some marks on the head, and based upon the HG looking like it should (not burned up, melted, or otherwise out of order) and the carbon on the head around the chambers, it's safe to say (IMHO) that the HG wasn't the problem.

The motor is/was full of water, timing chain adjuster was holding plenty of it where the chain guide is.

My first concern is there is a crack or other major failure somewhere in the motor (cracked head perhaps?)

Even if the head is cracked, based upon the amount of water/milkshake I can see, I'm wondering if the bottom end/bearings are any good.

The guy I bought the car from did change the oil, drain the fuel/replace filters, and get it to run (not well), but there was water in the oil he said when I bought the car. My intentions were to replace the HG, and drive it. Turbo in the future, absolutely. But needs to drive first

Ideas, thoughts, and ramblings are all welcome, especially if there is a common problem that I'm overlooking with the water in oil situation....

-Theo

[Arshloch]

I think you need to have it cleaned up nicely and tested at a reputable machine shop for a hair line crack.

The proper way would be is to pull the entire engine and see how bad the bottom end is, or any corrosion that resided there.

[oldguy]

when aluminum heads crack they are usually visible from quite a distance.

thoroughly clean the head or *gasp* take it to a shop and have it checked over.

M10's usually crack near the exhaust seat. Either between the two or from one of the coolant ports over to the chamber. Either can be welded and repaired. Water/oil left in engine for years though is going to probably minimum need new rings and a hone job or a good rebuild. I would expect some pitting.

[taftonomos]

I'll take a better look at it today with some good light on it. I'm unsure why the car was parked/not driven since 04, but when I aquired it there was a good amount of water in the pan. Changed the oil, car fired up, but ran like crap (obviously).

Looking at the cylinders everything looks fairly good. Probably best if I find a core M10 to build instead of rebuilding this one....starting with something that hasn't been watered down/sitting for 6 years.

[jimk]

Was the water on the pistons because the block was not drained prior to pulling the head (drain plug removed) or was it sitting on the pistions for a long time? If the latter, the cylinders will have deep pits that most likely cannot be cleaned up even with max boring the block.

[taftonomos]

Based on the condition of the bores, and no surface rust present, I would say the coolant in the bores was due to me not draining the block prior to head removal.

When the car was running, it wasn't puffing water vapor out the tail pipe.... but it was bubbling the coolant in the rad quite a bit with the cap removed.

I be I'll be looking for a new head after I get home and give a closer inspection to what I have.

What should I expect to pay for a head, 300 ish?

[taftonomos]

Yup, found the crack on #3 cylinder between the valve seat and the water jacket. I'll ask around about repairing....might be cheaper to find a used head to get me by for now though...