Hello! New to the forum. Have an 06 S40 with 120k miles. Engine / car OK, riding along 5 minutes into store run and hear a loud "POOF". No metal, no clank clank, nothing else except that. All lights on dash go on, then off. I put her in neutral and float to the side of the street. Shut her down, go to start, and I hear the engine turning but zero combustion. I smell gas, but It doesnt kick over - nothing. The timing belt is still on, and removing the plastic cover, there was a small piece or shred of what I think is the belt. Just a sliver which was removed. Belt seems tight and in tact. my mechanic says blown engine, but what exactly is "blown"?? In listening to it further while cranking it, I hear something when the key is turned off and the engine comes to stop. Sounds like from the OHC toward the right side on top. right under the cover. Its not like a rod or bearing was thrown, just slight which may be normal engine noise for all I know.


I don't think its mechanical, like timing, rods, bearings, head gaskets, etc. I think its electrical.


Any ideas?

 

guessing you blew your timing belt or tensioner. Either way - lots of bent valves. Need to pull the head and send it off the the machine shop.

 

Thanks for the reply. Timing belt is in tact. By blowing it, do you mean it skipped? If the tensioner is on the timing belt, then the belt feels snug. So, unsure its either? how did you come to that conclusion? How was electrical ruled out? Sorry so inquisitive, just trying to cover all bases.
Thanks again

 

no compression - sliver of belt - QID

 

My money is on the AC belt or alternator belt shredded, got caught in the timing and bent valves.

 

If you have good compression, then you can treat it as an electrical problem. If you have no compression, then you wouldn't treat it as an electrical problem.