Hey guys,

My wife and I were driving home last night and on the highway the engine started running funny. Go it home and checked everything out today. I discovered it's lost all compression on cylinder 2. It has been burning oil for a while which may or may not be related.

Curious if those more experienced with this engine have a good guess what has happened. I would think it would be top end. But curious how catastrophic whatever happened would be?

This is a 2005 JCW. All stock as far as I know.

Thanks for your help,
Zeff

 

anything, really. Stuck or burnt valve, failed valve seat, a hole in the piston, crack in head or block, failed compression rings (less likely, though, if you don't have other weird noises from the engine).
Start with removal of the valve cover, inspect the valve stems, check if they move freely all the way. You may use a flex cable inspection camera through the spark plug hole, but you'd need the one that can "look back" as well as "front" (i.e. at the head, and at the piston). This way you could inspect if there are any debris on the piston, if the cylinder walls are damaged and if the valves are good or not (by looking back at the head).
But most likely you'd need to remove the head to figure out what happened.

 

You can do a leak down test to get more or less definitive answer what is wrong. You put cyl 2 in TDC, put a compressor into the spark plug hole and apply pressure. Listen where the air is coming from: 1) exhaust - issue with the exhaust valves, 2) intake - intake valves, 3) open the coolant expansion tank, bubbles - issue with the headgasket, 4) from the oil dip stick - rings, piston, block.

 

Update!

Burnt valve was the culprit. And, I discovered the camshaft is in terrible shape. Thankfully the cylinders look great. But man, the camshaft is a bummer.

If anyone out there has a good camshaft collecting dust, please get in touch.

 

Just curious how many miles on this car and what is its history before you owned it, if you know it?

 

It has about 160K.
Three owners as far as I know.
Owner before my wife notoriously bad at maintenance.
Someone installed woofers and an amp in the trunk so I think the first owner was pretty young.

Took the head to the machine shop today. They said it was rebuilt previously based on a tag attached to its side. Maybe that's why some of the exhaust nuts were loose...

 

I have a good used camshaft
I’ll have to figure out what’s what as it’s next to a
r50 cam so hopefully I can tell them apart. It’s cold as fork though in Wisconsin currently

 

FYI; Rock Auto has head gaskets for $16. Or you can get a bigger kit w HG, valve cover gasket, water outlet, valve stem seals, etc.

im in the middle of a new HG install, so I’m replacing every gasket and seal I can. No fun to have to pull stuff apart twice.

but not making much progress. It’s been to cold in Flagstaff. Highs in the 30’s w wind and snow. Yes, it snows in AZ!

 

Aren't the stock R50 and R53 cams the same?

 

Dont think so but would make it easier when I go out to look lol. It has been so long since I have seen a stock unit. I have 6 of various sizes on the shelf for various applications. Current is 300/288 lol

 

They are the same.
https://www.realoem.com/bmw/enUS/par...&q=11311485827

 

[.]

 

Cool OP if you want it pm me

 

while the part number is the same the profile is intact very different. So real oem messed up that one. I checked with digital calipers as well as asked Kurt and Way