BMW cooling mystery!

Factual Questions
21

Well, I’m still having a hard time coming to grips with this, but here goes:

I said I installed a cylinder head, right? Well, I pulled this head from the junkyard, spent hours handling it during cleaning, adjusting the rockers, prepping and such, and* yet somehow didn’t notice that the dowel on the forward end managed to remain in the head*, instead of in the block. Like on the car sitting there waiting for this head. :smack: The coming tragedy is now apparent…

Tore it down, and in the block was a smashed and mushroomed dowel. I removed it, cleaned up the thread for that hole then started searching the garage for a replacement. I came up with one, and went to measure how long it should be, flipped the head over on the milk crate and …

What the Hell? There was another dowel, smashed and mushroomed! :eek: Incomprehensible! How did I miss it? How did I get it put together? How did it run at all?

That’s my only reasonable explanation. The Mother of All Oversight. I really don’t know how I managed. I worked with that head for days! Its clean enough to eat off. I took a ScotchBright disk to both the head and the block, and specifically recall what a hassle it was on the block to clean up around the dowels. I didn’t recall that being a problem when I cleaned the head. :confused:

Like I say, I’m having a difficult time understanding how this happened at all.

The stupid part is that I suspected a problem as soon as I started to torque the head bolts, but went right along with the reassembly. Dumbass! Didn’t want to take an extra 10 minutes to do it right, so I spent hours and hours to do it over.

Its all put back together and everything checks out. Ski racks are installed and ready to roll.

22

That was supposed to be “Merry Xmas”

23

Don’t feel too bad, thats the kind of mistake even pros make now and then. One thing to remember when doing something mechanical, if something doesn’t feel quite right instead of thinking well maybe I will get away with whatever it is, always stop and go back, we hardly ever get a break. I give you a lot of credit for sticking with it.

24

Yeah, that’s crazy. I wonder if it was just that that cylinder was getting enough compression to run despite leaking water like sieve through the head gasket or if it’s just a testament to how smooth that engine is that you didn’t even notice it had become a 5-cylinder!

Usually when I’m doing something like a head bolts, I try to make absolutely sure I can get them all the way seated by hand (or a small wrench) before putting ol’ Torque-e-mada to work on it. I don’t think I’ve ever made this particular mistake, but I’ve certainly cross-threaded enough of them to have learned my lesson!

25

I’m amazed it ran on all the cylinders.

26

I am surprised the head wasn’t damaged while torquing.

27

I’m with ya. I drove the thing about 150 miles today up and over mountains, down the freeway at 80 and its fine. I don’t know if its something I did, but it seems real quiet now. This is the car that a guy gave me, after his 2 kids abused it through college and thought it had a bad head gasket when he told me to get it out of his yard. I just started driving it to see what was wrong and I’ve been driving it for years now, with occasion minor repairs. This is by far the biggest job I’ve done on it. Counting Anti-Freeze, I’ve got about $110 in this job. Brings the total over the years to maybe $400-ish. :smiley: Not bad for a BMW e30 daily driver.

I’m glad I’m lucky instead of good.

28

This indeed. I think this M20 engine is damn near stupid-proof!

As long as you change that belt on schedule! :smiley:

29

For those interested in this topic, I have added another BMW engine question here.