Suspected head gasket fail

[Chad]

Thought I’d start a new head gasket thread,, 69500 miles so about usual mileage. started to notice motor feeling a little lumpy light burbling I can best describe, also not quite as crispy,, so tonight plugs out, fuel pump fuse out, my cheap leak down tester was knackered,,so in with new compression tester ,number 1 cylinder 110psi, Number 2 110 psi,, 3-4-5-6 cylinders bang on 150psi,, Didn’t do the tee spoon full of oil thing and confuse results ,, so possibly would be higher readings, but I think I can be sure failing between 1and 2,, Ps all the plugs looked nice no oil,no build up carbon, or running lean, all looking good,, if I get time this weekend I might start to stripdown of motor and try to take some decent pictures to post for reference, .. “””Any thoughts views ideas welcome chaps,,

[Chad]

Ok for reference. Anybody doing a compression test. Just done compression test on 10k mile max engine, readings 165 ish psi, across all six cylinders warm engine , I did crank the motor over a couple more on this motor and possibly slightly warmer by a few degrees, but not sure it made much difference in readings!! “””Didn’t put any oil in cylinders,,, used a laser compression tester,, so I’d estimate my 65k motor has lost approx 10psi ish across the cylinders , apart from 1 and 2 ,, that show 110psi. Not sure what the lost 10psi -15 psi ish would equate to regarding HP. Comments welcome chaps. :whistl

[Chad]

Further addition. Let 10k motor cool, did a further check on compression just did about 4 -5 cranks on starter motor got 155psi ,, as compared to 69k motor readings 150 psi readings 4-5 cranks . So probably a lot closer that first thought ,, then took a new reading on 10k motor 1/2 tea spoon oil as some recommend , spun motor over 20 times on starter compression readings 175 psi 10 k motor.

[Chad]

Just pulled the head off ,As expected gasket gone between 1 and 2. Typical of the perfect design of the s54 engine gasket also gone on the centre section of the three layers 2 and 3 possibly torn as I pulled gasket off...hopefully block and head will be ok ,,hard to believe they didn’t do a better job in the reliability design,,,don’t you just love bmw

[Mike R]

It does seem strange that they squashed all the cylinders so close together, which means not much surface area of material on the gasket between the cylinders - way to go BMW

[Chad]

Just had chance to properly check the head and block, all looks ok so I can now breathe again, while it’s head is off ,I’m going to do rod shells,, pull one of the piston out and check end gap on top and central ring,if they within bmw spec they will be staying in, I’ll be disappointed if they are out of spec on a 69500 mile engine, but from what I worked out on 100k motor, I recon they should still be inside spec

[Chad]

Question to them that have done camshaft timing before?? Checked camshaft position before I pulled them out , image engine to be vertical,,, I noted at TDC alignment hole in inlet camshaft prity much vertical,,,but exhaust shaft was a few degrees past vertical approx 5-10 degrees, I’d have thought it should be vertical,, Ps I’ve ordered bmw alignment tool for tomorrow,, Question, is this few degrees past for exhaust correct ?? Or possibly a sticking exhaust vanos gear splined shaft..or holding advanced on hydraulic pressure ?? I was assuming alignment tool “holes”inlet and exhaust would be perfectly vertical so to speak..noted exhaust vanos gear was a bit troublesome coming out, ... answering my own question, yes they should be perfectly vertical so to speak,, checked with bmw checking tool .

[Chad]

Morning all. If it’s of any interest to anybody,, new npr piston rings seem to be all good so far ,, only done a couple of hundred miles with them in , will recheck with a compression test soon! and post up findings.. car really feels like a mad cat after motor rebuild

[Chad]

Hi For anybody interested. I’ve now done over seven hundred miles on these new npr piston rings I fitted in the csl ,, inc first trackday Just re done a compression test I get a good 155 psi on all cylinders using same method a before,, checked oil level on dipstick no oil used :,, On a lessor note while I had air box front off, just thought I’d re oil air filter as they tend to run a bit dry after time. Used K&N red filter spray oil ,, ??? Anybody else bother doing this. ?

[alexk]

Originally Posted by Chad

Hi For anybody interested. I’ve now done over seven hundred miles on these new npr piston rings I fitted in the csl ,, inc first trackday Just re done a compression test I get a good 155 psi on all cylinders using same method a before,, checked oil level on dipstick no oil used :,, On a lessor note while I had air box front off, just thought I’d re oil air filter as they tend to run a bit dry after time. Used K&N red filter spray oil ,, ??? Anybody else bother doing this. ?

I have 2 air filters and I clean them with the K&N kit.
I install the 'freshly' cleaned air filter.