View Full Version : Suspected head gasket fail
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, :thumbs: .. “””Any thoughts views ideas welcome chaps,,
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
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. :smokin:
Just pulled the head off ,As expected gasket gone between 1 and 2. Typical of the perfect design of the s54 engine :whistle: 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 :banghead:
Mike R
15-08-2018, 05:33 PM
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 :smt038
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 :whistle:
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, :whistle:... answering my own question, yes they should be perfectly vertical so to speak,, checked with bmw checking tool .
Today dropped in a couple of ring sets in my csl 69500 block , for a comparison to 100 k Motor project,, oem ring set size 00 new top ring end gap measurements a fairly tight 0.20 ,,,,25 mm down cylinder, central ring 0.45 ,so almost perfect,, Then dropped in the npr set,, apparently same as oem 0 set End gap came out 0.30 top ring. Central ring 0.48 So also really good,, Possibly a safety bet at the top of the cylinder bore, will know more if I was to clean top 10mm of the cylinder,,, I’m going to take a piston out and measure the 70k rings see how they measure up as I’m doing shells anyway,, hopefully useful information regarding motor work,,,:smokin:
Another fun day with csl 69500 mile motor,,rod Shells out ,, 5 out of the six rod side shells showing the copper colour,number six was the worst but still only measured up at just under 0.050,, tangs were ok but shell was a little loose so possibly spinning could have been getting close. ,, as usual cap shells not to bad number six the worst ,, Number 1 “least”worn shells looking ok “”. I’ve plastiguage Number one used shells for reference came,, came out as 0.045 to 0.050 ish.. so even though copper colour shows on some shells, they are still in spec,and not always fooked. ,,,, then I’ve pulled the pistons out of the cylinders,, just measured number one piston rings for now ,, turns out top 69500 ring measurements.. 0.35. Actually bmw spec outer limits end gap. ,, central ring unbelievably 1.30 mm So way past outer bmw spec. :whistle: cylinder condition look really good crank journal look good ,, so my conclusion after these two separate csl motors strip downs’ anything past about 50-60 k miles rings are way past there best ,and shell getting close and probably need renewing to keep within bmw spec,, :banghead: il do oil rings later,,,now done oil rings,end gap 0.75 mm, 0.25 outside spec.ok they are sacrificial. hopefully this won’t upset anybody :smokin:
The big dilemma ,, do I aim for perfect piston ring end gap, use the oem 00 ring and go for min gap of 0.20 top ring and mabe have to ring file the tighter one’s ,,? , or go for std 0 size. And settle for 0.30 to 0.35 outside spec top ring . ??? “”. Update checked bmw oil ring in 00 size gives end gap of 0.10 so not really practical to tight,, end gap oil ring npr gaps up at 0.35 so bang on between spec,, so answered my question,, really have to use either oem 0 size or npr rings are good to go ,, In this 69k motor. Note top ring doesn’t wear that much, it’s the central ring and oil ring that really wears,,
Mike R
20-08-2018, 09:19 AM
Lucky to have caught it in time :).
This thread would be nice with some pictures showing condition of everything :whistle: :blalalala:
Lucky to have caught it in time :).
This thread would be nice with some pictures showing condition of everything :whistle: :blalalala:
Hi mike I’ve tried to include pictures, but for some reason it just keeps saying invalid picture file,, pictures off my iPhone have also worked in the past don’t know why I can’t now :banghead: Csl engine is just the block attached to gearbox in the engine bay at the moment :smokin: all great fun,but I’m really surprised just how the rings and shells wear after 69900 miles :whistle:
Just a thought ,as it’s been mentioned before, link between head gasket and shells. My gasket went between 1and 2, The rod bearings number 1 least worn And ok ,,most worn bearings was number 6 rod bearing , that’s the piston on the opposing stroke , so possibly to do with uneven loading on outer ends of crank ,, Olso noted that it’s a more even wear rate in other inner cylinder rod bearings,,, food for thought chaps ..:banghead:
Mark CSL
21-08-2018, 10:34 AM
How to add pictures here
https://procarkits.imgur.com/
Go to this site register
then upload the pictures
Then click on the picture
copy
BBCode (message boards & forums)
it looks like this https://i.imgur.com/ sICh26f.jpg
But without gaps job done
https://i.imgur.com/sICh26f.jpg?1
Mike R
21-08-2018, 10:49 AM
Photobucket is also back up and running at the moment :).
Bit more done today , but rain stopped play for the moment. Bit of a cleanup of pistons, fitted new npr rings I’ve spent a lot of time measured all the ring gaps, ,I’ve got to say they seem perfect in all measurements, as I’ve posted before I believe these are the only direct replacement rings for the mahle pistons afaik ,,if they are not as I believe the oem rings anyway??? Looked at the cost of oem £800 now total ripoff, these npr £170 ,, I’ve also fitted new oem rod shells as I had some ,, or would have used the king race shells ,will keep them another day,, no turning back now as pistons are fitted back in the block ,, hopefully can crack on and fit the head back on soon, not sure if I’m going to lap in valves,, but that may bug me if I don’t :whistle:
Mike R
23-08-2018, 09:31 AM
In for a penny in for a pound - do the valves or your OCD ill mean you won't sleep at night :blalalala: ;).
Should have done a before and after dyno to see how much power is lost / regained :hahaha: (I know it is a bit late now, but hey-hoe :whistle: )
Long day on the old girl, plastiguage and bolted the rod shells , bang on 0.040-0.045 so all good, Npr rings all perfect,, new head gasket bolted in ,, not bothering lapping in the valves as I recon they are all good, that can be done at 100k :smokin: ,,I have to say. Probably would be easier to take the engine OUT especially doing the 3 stage rod bolt installation,, :bigcry:,, as the npr rings look so perfect! I’ve picked up another set of rings from suppliers while stocks are there!.
It would be interesting to know what the lads find,regarding rings gap measurements , who work on csl,s / m3 on a regular basis are finding,,??? Or is this something that just doesn’t get checked if compression test or leak down check’s look ok :whistle: can’t wait to get the old girl going just to see what the difference is.
Just fired the old girl back to life :smokin: Few bits to bolt back on then will take it for a gentle spin :thumbs:
All done :smokin: just had it out for a spin tonight! absolutely worth the the pain motor feels so alive, ok power must have been down with head gasket gone between 1+2. But new rings definitely make the difference. Takes me back to mx race bikes, new rings got you that hole shot, simply puts that punch back in the motor,, I can definitely recommend if you doing the head gasket, chances are you’ll be doing shells ,, just “DO” the rings as well,, :thumbs::thumbs:. .. I’ll redo a compression test the same way and check results when I put a few miles on the old girl..
It would be interesting to know what the lads find,regarding rings gap measurements , who work on csl,s / m3 on a regular basis are finding,,??? Or is this something that just doesn’t get checked if compression test or leak down check’s look ok :whistle: can’t wait to get the old girl going just to see what the difference is.:whistle: anybody got anything to add regarding wear on rings, surely owner’s and tec’s not all in denial,,, :banghead:
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 :smokin:
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 :smokin:::thumbs:,, 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. ?:smokin:
It would be interesting to know what the lads find,regarding rings gap measurements , who work on csl,s / m3 on a regular basis are finding,,??? Or is this something that just doesn’t get checked if compression test or leak down check’s look ok :whistle: can’t wait to get the old girl going just to see what the difference is.
Just having a read through , see if I’ve missed anything ,, “NOPE “.. but I’m still interested to know what the chaps who work on e46 m3 for a living have found regarding piston ring wear:whistle:
Still not able to post pictures ,, is it not possible to go back to the old way of posting pictures directly from my iPhone?? :whistle:
alexk
18-03-2019, 07:51 AM
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 :smokin:::thumbs:,, 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. ?:smokin:
I have 2 air filters and I clean them with the K&N kit.
I install the 'freshly' cleaned air filter.
I have 2 air filters and I clean them with the K&N kit.
I install the 'freshly' cleaned air filter.
Hi Alex Good to know I’m not the only one to do this. As it’s something that seems to get neglected on a regular basis,,””ok they do get changed on a full service “” they do get full of junk so has to be better to do more often ,, :smokin:
alexk
18-03-2019, 10:19 PM
Hi Alex Good to know I’m not the only one to do this. As it’s something that seems to get neglected on a regular basis,,””ok they do get changed on a full service “” they do get full of junk so has to be better to do more often ,, :smokin:
The changing bit is interesting too.
These filters are BMC and perfectly serviceable ;)
I’d like to think the track day lads do filter for ever Trackday , csl even sound better when filter freshly cleaned and oiled ,,:smokin:
khooni
19-03-2019, 11:38 PM
dunno. I simply wash them with water and dry it out. not bothered with oil......
dunno. I simply wash them with water and dry it out. not bothered with oil......
If you’ve not used proper Filter oil ,its super sticky catches all the crap from getting through the filter into the motor ,, used to do filter every race on the bikes ,, surprising amount of crap it catches :smokin:
khooni
21-03-2019, 10:42 PM
i just replace them then. can't be arsed with oiling..... Speaking of which .. maybe time to buy a new one again
i just replace them then. can't be arsed with oiling..... Speaking of which .. maybe time to buy a new one again
Simply spray on from the can that comes with the kit , I just do the outer side , yep easier with new filter already oiled :smokin:
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