E30 'mystery' coolant loss... any ideas?

[cms206]

Posting for a mate who's too scared to join up...

 

'90 G BMW 318is. M42 lump, recently had cracked head replaced, new head gasket done at the same time, recent themostat, think it's had a header tank and radiator done as well after it went through a spell of running absolutely fine then dumping it's coolant for no apparant reason. It's been running fine since getting all the above work done about two or three months ago, but since then it's had a whine which builds with engine revs. It was checked out by a local 'specialist' who found nothing untoward.

 

Cut to yesterday, in all the bollocks which went on, my mate spent an hour and a half in the Clyde Tunnel sitting in traffic. Just like the last time, the temperature gauge started to climb until it was once more cooking itself. Car was abandoned, collected today, and surprise surprise... it's shat all it's coolant somewhere again. Same as last time it also leaves dregs in the bottom of the header tank, but clearly not enough to circulate the system. BEFORE he goes and throws money at another 'specialist' to rebuild the top of the engine for the second time in under two thousand miles, do you guys have any suggestions? I know they eat HGs and header tanks but surely not again that quickly?

 

He's at the end of his tether and is considering getting rid and buying something called a 1-series, which I think is like a Golf, but not a Golf, but even shitter.

[Tayne]

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[cms206]

He said it was a new head. I know it was about £350, but I never actually saw it before it was fitted...

[The Reverend Bluejeans]

Well, if it's overheating in traffic, the viscous fan isn't doing anything so it boils and shits its coolant out. Refill it (do it through the top hose, ignition on, heater set to hot, adding coolant until it starts to dribble from the rad top hose outlet) and it'll probably be okay but it will need a fan coupling.

The whine is from the cam chain - apparently this happens once the engine's been apart and the timing chain's been disturbed. They just do it for some reason.

If there was something really wrong with it (HG), it would overheat at speed quite rapidly. The head gaskets weren't a very common issue on those - the profile gasket was but that was another issue involving oil and water mixing when a rubber gasket between the water way and the front ting case let go. Most were sorted years ago. Header tanks are also not a known recurring issue on the E30.

 

For £350 it wasn't a new head, but a sodding expensive secondhand one. I don't think I've ever sold one for more than £150.

[cms206]

Cheers guys... will get on the case when it's not quite so far below zero!

[Rocket88]

Try the carrot test on the coupling. When the fan is turning, shove a carrot into the blades. If you it chops it in half, it's fine, if the fan stops. it's borked. Has the water pump been changed?

[Rusty Pelican]

I like the idea of the Carrot test although Id be scared to try it

No mystery on my E30 coolant loss , the rads fooked

[daverapid]

I'd be looking at the viscous fan, water pump and header tank cap.

[peter9000uk]

Do these have the plastic impeller on the water pumps like the M50 lump?

 

Got to be worth whipping it out for a look I would have thought

[Owain-328i]

If its already had all the following work done, then, waterpump, themorstat, viscous fan and header cap would be points of interest to me.

 

HOWEVER, if its cooked itself again theres every chance its done another head gasket, no BMW engine likes getting too hot, and they usually show you their disgust at being allowed to overheat by blowing a head gasket.

 

For future referance, dont bother replacing the head gasket as it cost a fortune, and not many people can do it right (even on the four pots). Its cheaper and easyer to swap the borked engine out for a good 2nd hand unit.

[shite_meister]

I have the same motor, the M42 did have an issue with the profile gaskets leaking (yes I realise its had the head replaced/new gaskets) and heads cracking in a specific area something like betwwen number 1 & 2 ports or something.

 

Is the passenger footwell dry? sill suggestion possibly but the heater valve is located there and is known to leak, what about the mass of hoses under the inlet manifold? as I understand there are water hoses as well as breather hoses in that lot.

 

Had loads of issues with viscous fans on E30s. Does sound like he's had a shite repair/cylinder head but I would say find a specialist who knows his shit.

[johnbaz]

Hi

 

I had a 318is and the head gasket gave out, my mate who has his own garage business told me that it was likely that waterpump had siezed, he said they had a plastic shaft, these sieze then snap leading to overheating then the top end blowing, he did the job, he replaced the waterpump, thermostat and did the head gasket (can't remember if he had the head skimmed) but the car was fine after that for another 18 months or so when i got shut of it and bought a Honda (never had a jot of trouble with the Honda but the beemer was breaking down all the time (worst car i've ever had )

 

I phoned one place first about doing the head gasket (a 'proper' garage too!!) and he asked it had a timing belt or a timing chain, it had a chain, he said he couldn't do it as special tools were needed to remove the chain

 

 

John

[The Reverend Bluejeans]

There's all kinds of bollocks spouted about BMW engines. At the end of the day, it's an engine just like any other - there is no mystery to them at all. I've done a few 318iS head gaskets and not had an issue. The only special tool I use is the one to lock the cams at TDC but you can do without it and use a setsquare.

The only ones I wouldn't touch are the post '95 alloy block sixes. Once the head gasket's let go on one of those, it's fucked.