bobgodd

Yes, do a leak-down test. I'm guessing your valve seals are toast, which happens on every car. They're pretty cheap and can be replaced on the car, or of course you can pull the head to do it "easier".

This happened to me, I had white smoke at startup, but not when driving. I thought that was indicative of oil seeping past the valve seals while the car sits. Replaced the seals. After replacing the seals I still had oil on a couple plugs, and a leak-down test showed there was oil getting past the piston. A general compression test was otherwise good. Ended up needing a replacement engine.

Max.H

Looks like You're burning oil and the plugs show signs of oil pushing past the rings. That's your smoke. Swap motor :-(

alexanderfoti

Update (at last)

Unfortunately, I am none the wiser.

It also appears somebody has been into this engine before, the head gaskets have evidence of silicone sealant visible from the outside, as does the rear main seal retainer. So much for full service history.

Firstly, in progress shot, took me ages to get to this point because I'm crap. :



Plenums off:



Rocker covers off:



First indication of where the fault is...

The dark side is very sludgy crusty. Its like a layer of deposits over everything.




Head off and I was expecting to find carnage:





Not great but not horrific







And the head itself:




Soooo, no massive hole in piston, no massive gouged liners, but still this:

[YOUTUBE]J3XUzYSOWn4[/YOUTUBE]

Best bet is still an oil control ring I think.

New engine is going in soon, its from an SL 55 so sumps/oil pumps etc need to be swapped. Suspect I may run into an issue there, but best leave that to later.

alexanderfoti

FYI, people on another engine specific forum (....) are convinced that all the valve stem seals have failed at once, and that is where the oil consumption is coming from.

e55amgrocket

Cracked ringland. Seen it several times on these engines.

alexanderfoti

That's what my money is on too. When I have the engine out, I will remove the no 1 piston and confirm it!

9mil

Search my user name- had the same issue.. Was a cracked ring/ scoring in the cylinder wall... Does it smoke on every start up or only when it's cold? Mine was the #6 cyl and the plugs looked wicked bad right before I decided to swap motors.
Sorry- wish I had better news.

alexanderfoti

Bad plugs, like on the pics.

Before this failure, it used to smoke on startup very very randomly.

Now you get this cloud of smoke on startup.

It's OK, I have a second hand engine to go in, would be interested to see the actual damage when I get the block out.

Max.H

Did you do a leakdown test before you took it apart? That will tell the tale.

9mil

Twin plugs prolong the process... I swapped mine out a few times and prolonged the issue. It actually ran good, just burned oil and you could smell it and see it on initial start up - that's how I got douped into buying it... It was cheap so after I put a new motor in I was still whole- but kind of a dick move. Even put my hand on the headers and they were cold... But it was like every 12 hours it would cool down enough to allow oil on start.
There was a big scratch for sure but something wasn't round anymore was my feeling- cyl or piston.
I've seen oil control ring failures so prolly what it was... Glad I didn't redo the guides like I thought it was and glad for the good people here that helped with the swap... Not as bad as I thought it would be and we got to reseal the engine while it was out so all good now!
Seems like I did a leak down and compression test and it actually passes... There might have been some leakage on #6 though....
What cylinder has the worst plugs? Mine looked melted - quite impressed that it still actually ran on that cylinder for a while really.
I'm still interested in what was the primary cause- neglect would be my bet in my case- too long between oil changes and running the snot out of it prior to me.....