Frothy coolant! Help :(

[Reck]

More M10 issues!

Slight overheating at idle, and I normally have to drive about with the blower on a low heat setting to keep the needle around the halfway mark. I've changed the thermostat and the rad cap, reverse flushed the rad and cooling system with a garden hose. The water pump looks fairly new. I've bled it and bled it again.

Today, I decided to try bleeding it again. I noticed that if I rev the engine hard with the rad cap off, the water level drops and a white foam starts to form in the neck of the rad. I've got a feeling that it's the same exact issue I had last time - combustion gases blowing into the coolant, making it brown and frothy and causing a slow overheat that gets worse with time. I'm hoping it's just a bad head gasket and not a cracked head. I don't have a hydrocarbon testing kit and they're like 60 quid online. Is there any way I can diagnose my problem quickly?

[Reck]

P.S. Does anyone know if the 1.6 and 1.8 M10 head gaskets are the same? Seller says they aren't but I'm not sure.. I thought all 4-cyl M10 head gaskets were the same? :S

[Jeroen]

Let the engine cool down and take out the spark plugs, one or two are likely to show discoloration from burning coolant as well. It's most likely the head gasket indeed, M10 heads are pretty strong thought as long as you don't run her too hot. If the gaskets are the same depends on the build (year) and as shape and thickness vary, don't get a crappy one just get one from a decent parts store or dealership that's guaranteed to fit on your engine.

[Reck]

Thanks. The head looks to have been refurbed at some point as it's much cleaner than the block, but I can't be sure it's the original head. Will I need to identify it properly first - or if it's on the factory block, then I can just choose the headgasket for my cars year?

It's also been ported and polished, and as I run twin 40's - do you think it's better to go for the 'heavy duty' head gasket that W+N sell? item #8 on this page http://www.wallothnesch.com/e/eng/enge21.htm#315e

[drjim]

M10 HG's all the same. I used the W&N heavy duty/motorsport version on the slug. If your engine has been worked on it may have higher compression which is abusing the standard HG.

Hope this goes OK, after the saga of the engine swap in the other car I am worried!

Jim

[alschux]

I put the heavy duty one in my 2.0l M10 build and its been OK, but a standard good quality one would also be fine I wouldve thought - from what Ive seen there are some shoddy head gaskets about without the red rubbery sealing lines you see on the OEM ones. Make sure you do the torquing of the head bolts in the right sequence and then angle tighten afterwards. Can anyone say whether the head bolts can be reused on the M10? Ive heard differing stories...

[mr edd]

P.S. Does anyone know if the 1.6 and 1.8 M10 head gaskets are the same? Seller says they aren't but I'm not sure.. I thought all 4-cyl M10 head gaskets were the same? :S

1.6 ltr engines have a smaller bore than 1.8 ltr so the head gaskets are different..edd..

if you get stuck finding a good head gasket this place could help
http://www.jaymic.com/shop/parts_02_pro ... 2EN&page=7

[Reck]

Right, so I'll go for the heavy duty version and a new set of head bolts (I've seen conflicting information on whether they stretch or not).

It's my own fault really. I have been ragging her a bit! I'll probably get the head tested for cracks while it is off though - I do have a good spare if needed.

[Reck]

http://www.e30tech.com/forum/showthread.php?t=82138

Comparison of aftermarket BMW HG's with photos. I'll be avoiding Reinz - who manufactures that heavy duty HG we were discussing? [edit] W+N answered.. Elring. Apparently they manufacture the gaskets for BMW?

Also, RealOEM list two gaskets made by BMW;

02 Cylinder Head Gasket Asbestos-Free 1,50MM 1 09/1980 11121734279 $109.50
02 Cylinder Head Gasket Asbestos-Free 1,80MM(+0,3) 1 09/1980 11121734280 $108.76

Is the second one oversized (+0.3mm) in case you need to have the head skimmed? Or is it just BMW's 'heavy duty' version? Called the dealer and they want £85, and another £35 for the head bolts. :s

[Reck]

To keep costs down I'm going to get my old M10 head (cam and rockers etc. in better condition than the current head) reconditioned myself here;

http://www.impulsedevelopments.co.uk/cy ... tAodpGq7Wg

They've quoted £50+ VAT for pressure/crack test and skim. If it passes, they'll clean it all up, repaint and fit the new valve stem seals for ~£100. Possibly more if valves need grinding etc. Guy on the phone seemed to know what he was talking about, he knew the engine.

It sounds like they skim regardless of whether the head appears warped, just to be safe. In this case - can this mess up the timing? Will I need to get the cam sprocket cover/timing chain cover skimmed by the same amount? Can I still use the heavy duty gasket or do I need to go for the +0.3mm gasket from BMW?

Thanks in advance.

[mr edd]

HI reck ...i feel your headgasket pain i have recently bought a +0.3mm headgasket to fit my skimmed head to my block as the one in my bmw dealer headgasket set is only a standard thickness .....the +0.3mm gasket is packed as payen brand but both this and the factory bmw gasket are both made by the same maker ...goetze!. work that out if you can!!!...edd..

[Jeroen]

Some slight skimming should not cause any problems. Cam and rockers are ok? And grinding the valves is a must imho, try to get a price for all work beforehand and all is fresh again.

[Reck]

the +0.3mm gasket is packed as payen brand but both this and the factory bmw gasket are both made by the same maker ...goetze!. work that out if you can!!!...edd..

Hmm, interesting! Where did you get that 0.3mm+ Payen/Goetze gasket? Is the quality similar to that of the 'factory' gasket - e.g. same thickness of rubber sealing lines, gasket face coating material etc? If it's comparable then I might aswell save myself some money. W+N claimed that factory M10 gaskets are manufactured by Reinz though.

Some slight skimming should not cause any problems. Cam and rockers are ok? And grinding the valves is a must imho, try to get a price for all work beforehand and all is fresh again.

OK, so no need for adjustment to the covers too? Cam and rockers appear good. Don't really want to get into replacing those as a new cam will cost £££'s unless the old one can be remachined somehow.. Not sure if this is a common process. Do you think the W+N heavy duty gasket will be good to use even after skimming? I'm pretty sure the head hasn't been skimmed before, but cannot be certain.

I'll get a price on sprucing the valves and seats up too - expecting this to cost a fair bit more though as it obviously involves disassembling the head.

[Jeroen]

on a head that's not likely to have been skimmed before that gasket would be ok I guess even though I'd always prefer oem instead of the cheap rubbish WN is supplying more and more often (mind you I did not check out the previous messages about different gaskets tho)

its good to supply the head's timing cover for skimming as well just to be sure

grinding the valves shouldn't take up too much time but makes one hell of a difference, should not be $$$

[mr edd]

reck said
Hmm, interesting! Where did you get that 0.3mm+ Payen/Goetze gasket? Is the quality similar to that of the 'factory' gasket - e.g. same thickness of rubber sealing lines, gasket face coating material etc? If it's comparable then I might aswell save myself some money. W+N claimed that factory M10 gaskets are manufactured by Reinz though.
The truth is that the bmw head gasket has no sealing lines on it at all but the payen /goetze one has..a couple of years ago i bought a victor reinz gasket from gsf in swinton and i don't remember it being expensive That one had the sealing lines you asked about...
There is a standard thickness payen gasket for sale on ebay here
http://www.ebay.co.uk/itm/BMW-1766CC-E1 ... 3f121ec43b