M20 needs help

[StereoInstaller1]

but it is in the E34 I just picked up.

Yeah, I know, M20 AND an auto in an E34 is FTL, STFU, no care.

Back to the issue: The thing spits every drop of water it gets into the block.

No milkshake oil
Coolant looks OK
Runs great, revs fine, drives fine.

If you fill the radiator and bleed it, fire it up and let it run for 10 minutes, only steam will come out of the bleeder screw.

Oddly enough, the exhaust seems fairly clear.

Head was recently replaced by a painter/non-mechanic kind of guy.

IF you had to GUESS, would you say...

1. Shitty job torquing head, lost the gasket
2. Pile of M20 lost its head, cracked somewhere shitty
or
3. Block is cracked, thank god that pile of crap was free.

Oh yeah: '89, Lachs on grey. Fairly decent bod, except for trunk lid that was bashed with no other damage. Ellips, all stock, was decent until lately. Needs some love, but I might have time for that soon.

If this motor is toast, I will find something else to power it with. I will either add 12 valves or maybe a liter or so of displacement.

[dashboardmonkey]

well the coolant is going somewhere, no white smoke out the exhaust i assume. check the autotragic fluid, is it milky? does it leave puddles of coolant?

[StereoInstaller1]

That is the freaky part: no mess anywhere.

[twothrees]

If there is no milkshake, no white smoke and coolant looks ok then it doesn't sound like its going into the block. Little leaks in the coolant system can appear tho and make ur coolant drain out. Check the throttle body gasket or hoses that go in/out: i had a leak there and couldn't see it. Check all the hoses for small leaks at all hoses even around the water pump too.

[mikeedler]

cracked block or head. or if your lucky just a crappy job doing the headgasket. we get them alot at my work-- they loose compresssion into the cooling system and pump all the water out.
I had an M10 like that many years ago- replaced EVERYTHING to find out the block must have been cracked-- was a great time to do a swap to an M20 in that e21 back then

[CorvallisBMW]

How much water have you added? Are you totally sure it's full? I've had cars spit nothing but steam out the bleed screw before, turns out I read the manual wrong and didn't put in enough coolant. Check under your floor mats if you have them, there could be leaks from the heater core going unnoticed. Also check the TB heater, the coolant lines that run in to the firewall for the heater core, and the coolant return line on the back of the head against the firewall. If it's leaking there and traveling down the hot block, it could be evaporating before hitting the ground and leaving a puddle.

[StereoInstaller1]

Guys, keep it coming.

I have added 2 gallons of water, plus it had some already in it.

I wish I knew an easy way to test the block for cracks.

I do know it that it snapped a water pump belt, overheated badly, and THEN it got the head (fresh head, BTW) installed by painter dude (actually, a crossdressing painter dude, so dudette) driven for a couple of days then given to me.

Another thing in the mix is the coolant temp sensor is inaccurate; it says "SHUT THE BITCH DOWN", like buried in hot when measuring 114 degrees, F. It is corroded green, so I can forgive it.

I wonder if a set of SETA pistons in a used B27 block could find its way in there easier?

M20 and M30/S38 motors use radically different wiring, all through the car, in fact.

Maybe I could shove an M30 with the 1.3 wiring I have now...that works, right? Can't I basically swap in a 3.4 where the M20 was? What would I need for an ECU or chip in the 173 that is there now?

Worse than that, I just happen to have a complete M5 I can steal all the damn wiring I want...except the engine harness/ECU wiring, of course.

[CorvallisBMW]

Can you get a hold of a coolant system pressure tester? That may help a lot.

[StereoInstaller1]

yeah, got one.

Would not hold pressure at all.

[oh2fly]

Luke, try jacking up the front of the car a foot higher than the back, then try bleeding it. You should see coolant running out the tiny port going into the reservoir, from the small hose. They get plugged and make bleeding impossible. Ditto on the pressure tester. You can bleed with it as well.

[Aveman]

First thing I'd do is pull the rad hose off the rad going to the block and fill up the block from that hose. From there I'd put it back on the rad and top up the coolant. Start it up and let it idle for 15 mins and keep the bleeder screw open. If I didn't start seeing coolant coming out of the bleeder screw I'd open the housing and remove the therostat for testing purposes. If those two things don't fix the issue I'd look in the coolant resevoir for bubbles while it's running. If it's and M20 and I noticed bubbles constantly coming up out of the coolant bottle I'd be thinking of a swap...

[StereoInstaller1]

First thing I'd do is pull the rad hose off the rad going to the block and fill up the block from that hose. From there I'd put it back on the rad and top up the coolant. Start it up and let it idle for 15 mins and keep the bleeder screw open. If I didn't start seeing coolant coming out of the bleeder screw I'd open the housing and remove the therostat for testing purposes. If those two things don't fix the issue I'd look in the coolant resevoir for bubbles while it's running. If it's and M20 and I noticed bubbles constantly coming up out of the coolant bottle I'd be thinking of a swap...

That would be the very first thing I did.

First thing I noticed was some kind of sludgy crap, in like a solidified puddle in the top radiator hose. I assume it to be "stop leak" type of crap.

Thermostat was literally ripped in half, the bridge broken. It is out, now.

Bleeder valve gunked shut. It now works.

So maybe I didn't draw the scenario clearly enough: Fill, bleed, run, bleed some more, run. Gets to temp, then shoots straight to "hot", but the gauge is known wrong.

Attempt to re-bleed, get only steam.

Anyone know what I have to do to get an M30 in there?

[CorvallisBMW]

Has to be a cracked head/block or bad HG if the system wont hold any pressure at all.

[oh2fly]

I still think the return port is plugged, especially now after what you posted. I would put a known good thermostat back in as well.

[VacMan]

You could ask whatt18yahoo to build you an M20 you could drop in.




Or you can go to http://forums.bimmerforums.com/forum...play.php?f=201 and actually ask people who know the answers to the E34-specific questions you're asking. Tell VacMan I said Hi.