M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: Ryann on February 14, 2011, 11:21:36 PM

Title: Profile gasket? No.
Post by: Ryann on February 14, 2011, 11:21:36 PM: My m42 has had a case of very slowly disappearing coolant since I've owned it. Never a drop in the carport, and never a whiff from under the hood, no coolant crust on the plugs, no abnormal moisture in the exhaust. What it does have is moisture on the dipstick and moisture under the oil cap (this goes away on long trips but accumulates during my short daily commutes). So I thought I'd better yank the head and have a look at the profile gasket. The head turns out to be crack and warp free. I thought the PG was a bit crusty but not too bad, and had obviously been changed by the dealer once before.

So I get the whole thing put back together, and my coolant drops at the exact same very slow rate that it did before. I'm starting to think that the aluminum coolant u-tube under the intake is leaching coolant into the crankcase via the crankcase vent hoses that it shares the 4-port fitting with. Anybody feeling me here? Thoughts?
Title: Profile gasket? No.
Post by: colin86325 on February 15, 2011, 10:19:50 AM: You probably have a slow seep in a place that's not easily visible. The plastic connector under the intake manifold could be a culprit. Or it could be a seam on your radiator, etc.

The moisture you see on your dipstick is normal from driving short distances in colder moist climates. The oil never gets hot enough to drive off the moisture it absorbs from the air.

If you're worried about coolant in the oil, you can send an oil sample to Blackstone Labs and have them test it for $25. This will show whether it contains coolant (and many other chemical measurements as well).
Title: Profile gasket? No.
Post by: mr.vang on February 15, 2011, 05:14:46 PM: check all the water hose, 3 of the water hose on mine m42 small slowly leak. it leak under each hose so you will have to touch it to feel that it is wet. so small that when it drip the hot engine evaporate it quickly
Title: Profile gasket? No.
Post by: Cristian G in Oz on February 15, 2011, 08:27:49 PM: Something else to check is you radiator cap. Do you know when it was last replaced?

My car had a similar problem and when I replaced the radiator cap and thermostat it went away. It now holds the same level nearly perfectly year round.

Caps aren't that much, but I would advise getting an OEM item.

Regards
Title: Profile gasket? No.
Post by: jscribble on February 16, 2011, 05:23:32 PM: Mine had a leak under the tb after bypassing the mess under the intake, and it took me forever to find it. Coolant was running down the engine block and evaporating before it would spill anywhere. A really bright flashlight may help if it's the case.
Title: Profile gasket? No.
Post by: Ryann on February 17, 2011, 10:31:18 PM: Thanks for the input guys. I did take a hard look at all coolant hoses while I was in there and didn't see any signs of leakage. I'm planning on removing the upper/lower intakes again to replace ALL plumbing, vacuum & cooling. I'll let you know what I find.
Title: Profile gasket? No.
Post by: longtallsally on February 18, 2011, 08:10:24 AM: I've been fortunate and not had any leaks, but a good number of hoses (both coolant and intake) are cracked, so I'm planning on replacing them all.

The nice part is that not including the plastic part under the intake, I think it was a total of only $143 from Tischer, so not too expensive for some pretty important parts.