E36 M43 HG -> Low compression?

Discuss Non-E30 BMW's in here - No selling!

Moderator: martauto

Ziggy
E30 Zone Team Member
E30 Zone Team Member
Posts: 11534
Joined: Mon Jan 10, 2005 11:00 pm
Location: floating round my tin can...

Post Mon Apr 18, 2011 8:04 pm

E36 318i (touring) - M43B18.

Typical - the one week the E30 is off the road, the E36 decides to **** up. It's running rough as a badgers ar$e. Seems to not be firing properly (if at all) on 2 & 3 - but no coolant loss, mayo or overheating. Plugs all look fine. Would suspect the coil pack, but a: I think it's unlikely to have gone on 2 cylinders(?) & b: it turns over 'unevenly' with the coil disconnected. It's less obvious once up to speed, but is definitely slower and rougher than it should be.

Anyone heard of an M43 HG going in this manner? Last time (just before Christmas!) it went in the more typical M43 manner - overheated, then chucked all of its coolant out of number 4 in a big cloud of white smoke. The damage to the gasket was obvious so I didn't have it pressure tested, but it was skimmed and has done ~5k miles since then. 4 doesn't seem to be the problem this time anyway (dies when disconnected, unlike 2 & 3). Aaaargh!

I guess a compression test is the obvious next step, but as I don't have a tester (yet), anyone got any good ideas in the mean time?
Do I order a new gasket so that I can pull it apart at the weekend?

Cheers for any thoughts!


I just welded up the bottom of the front wing on the convertible ****ing yesterday, after driving it through the salt and snow while the E36 was last off the road nadgered it. Really not impressed with cars today! :cry:
E30 in need of wiring loom smoke since April '11...
Andyboy
Alpina Colada
Posts: 12576
Joined: Mon Sep 11, 2006 11:00 pm

Post Mon Apr 18, 2011 8:44 pm

M43 heads like to bend in the middle. I just did one on a 2000 X reg Compact (late model!). This one was coughing up coolant but with the head whipped off, no cracks or obvious gasket wrongness. It needed a 10 though cut though to get it straight again.
It may well have blown between cyls 2 and 3 - did you skim it last time?
Ziggy
E30 Zone Team Member
E30 Zone Team Member
Posts: 11534
Joined: Mon Jan 10, 2005 11:00 pm
Location: floating round my tin can...

Post Mon Apr 18, 2011 8:59 pm

Arse. No coolant issues (temp or loss), & yep it was skimmed last time...

Public transport for me tomorrow :cry:
E30 in need of wiring loom smoke since April '11...