[Morbo2999]

Greetings everyone, I wanted to get a second opinion on the condition of the block and cylinder head around cylinder 1. It's a 2006 330i N52. A little history can be found here if you are interested https://www.e90post.com/forums/showthread.php?t=1748212

Long story short, I have had coolant entering cylinder 1. It wasn't horrible, occasionally a little white smoke and rough start for the first few minute or so. The car isn't driven regularly so I had been stringing things out for as long as I can. Recently the smoke was more prevalent, starting was rough for longer and the check engine light would come on. So I figured it was time.

I pulled the head off and I am not seeing anything that would indicate a crack. I wanted to get a second option on the condition, mainly because I am only 90% certain of what I am looking for. These pictures were taken right after the head came off with no cleaning incase the residual gave an indication of where a leak or crack could be.

There is one area in the coolant passage near the oil filter housing that I can't tell if it's a crack or from manufacture of the block. These are in the bottom of the passage and it would seem like they are lower in the block than where the piston would be at its lowest point. The one I've marked A seems too far away from the cycling that if it was a crack, I can't imagine it would be able to get into the cylinder. The one I've marked B looks more like a casting flaw but it is at the bottom corner of cylinder 1's wall, so if it is a crack, I guess it is possible.

It seems like everything is sound and the issue most likely was the gasket.

Thank you for the input!


Block






Head






Coolant passage near oil filter housing




Larger Images can be found here
Block
https://cvws.icloud-content.com/B/AT...c56RdTQZI&cd=i
https://cvws.icloud-content.com/B/Ae...CKbZQDpss&cd=i
https://cvws.icloud-content.com/B/AX...k9OUI5ntk&cd=i
https://cvws.icloud-content.com/B/Aa...i87Ub3IKI&cd=i
https://cvws.icloud-content.com/B/AV...yzuHtz1x8&cd=i


Head
https://cvws.icloud-content.com/B/AY...3867wnF9Q&cd=i
https://cvws.icloud-content.com/B/Aa...I6X08weIk&cd=i
https://cvws.icloud-content.com/B/AT...qVZ2ThTKE&cd=i
https://cvws.icloud-content.com/B/AY...hbobouGPM&cd=i

Coolant Passage
https://cvws.icloud-content.com/B/AX...1XY9zIAQpE&cd=
https://cvws.icloud-content.com/B/Ae...nAeCvy22I&cd=i
https://cvws.icloud-content.com/B/AT...zGufBS3aE&cd=i

[AmuroRay]

Those don't look like cracks to me, but are you in a position to get a new block if needed? Can you take this one to a machine shop to have it tested?

[Morbo2999]

Originally Posted by AmuroRay

Those don't look like cracks to me, but are you in a position to get a new block if needed? Can you take this one to a machine shop to have it tested?

Thanks for the response. If I need to, I will pull a motor from a junk yard, but that is down the road. The block is still in the car, so to take it somewhere and have it tested could be done, but would require me to pull it.

I've since cleaned the surfaces and checked it for warpage and it is still in spec according to the Bentley manual, 0.10mm longitude and 0.05mm transverse.