wont start- spark plug mangled!

[bigblue]

I put a new starter in a 1990 525i 5spd I just bought. Never saw it run. Now it cranks but still doesn't start. At first I thought it also had a broken timing belt becuase it doesn't sound to have good compression when cranking, but I see the camshaft spinning through the oil fill hole when cranking.

Pulled the spark plugs and tested spark. Has spark. 1 plug looked great. 4 oil fouled and one of them was smashed! The electrode was flattened and knocked over and the tip was even pushed to the side! Does this mean that my M20 has interfered in the past, has bent valves or somehow shrapnel got in the cylinder?
Thanks
Henry Helfman

[mholbrook]

Did you try a compresson check when you had the plugs out. If you don't have compression, particularly on the cyl with the smashed plug, then you probably have bent valves. Bent valves probably from timing belt. My guess is you are looking at a valve job, some new valves, new timing belt, new water pump while you are in there.

[632 Regal]

smashed plug is a NO GO. sounds like its a little more severe than bad gas over there. Could be anything from a busted valve head to a shrapnel piston. whatever the cause that thing needs to be yanked and replaced or rebuilt as necessary.

Last time I saw a smashed plug a valve head rolled out the header with about 2 gallons of antifreeze.

windows are cool as long as they arent in your block.

Take pictures!

[winfred]

ditto


smashed plug is a NO GO. sounds like its a little more severe than bad gas over there. Could be anything from a busted valve head to a shrapnel piston. whatever the cause that thing needs to be yanked and replaced or rebuilt as necessary.

Last time I saw a smashed plug a valve head rolled out the header with about 2 gallons of antifreeze.

windows are cool as long as they arent in your block.

Take pictures!

[bigblue]

windows are cool as long as they arent in your block.


I dont get it.

But yeah I was worried about that. Didn't have my compression tester handy at the time but I did the ol' "finger compression test" on that that cylinder and didn't feel anything when it was cranking. Didn't bother with the other 5. I just want to see this thing fire. Cant see why it would still have a timing belt if it bent valves previously. Will be away this weekend but pics coming monday!

Looks like I'll be parting the car or selling whole. Where should I advertise? Want this thing out of here ASAP!

[632 Regal]

is a term used when there is a hole through a cylinder wall and the block is unreparable.

[bigblue]

Do these M20 motors crack the block a lot? How can I tell?

[Paul in NZ]

is very obvious...aka leg outa bed...rod out the side.....

[bigblue]

I didn't notice any holes/cracks on the outside of the block. I wouldn't have bought it if I saw something that obvious.

what's the telltale sign? How are you so certain it's not a top-end problem?

[632 Regal]

that would tell a tale

[Paul in NZ]

No you misunderstand..we are just talking extremes..I would say though you must at least pull the head and investigate what has happened .I agree with the others you have at least one damaged valve and if one is damaged its likely the others are too....One possible explanation is that the timing belt has broken......or has been replaed b4 breaking but the valve timing was off and now there is not enough compresson to start due to a set of bent valves

[bigblue]

I know the timing belt currently isn't broken, although when i first installed the starter (and heard it crank for the 1st time) it sounded funny (like a broken belt) which made me check to see rocker movement (through the oil fill hole) when cranking.

So I guess I'll have to pull the head. Joy.

any wise words of advise? tricks? Anything to watch out for? How much is a head gasket kit? I want to keep this as cheap as possible