R.J.

Hey Fellas, I have the opportunity to buy a complete light front end hit 944S for $50! I pulled the valve cover off and the cams/tensioner looked good. Timing belt is good as well. I pulled all the plugs and this is what #2 looked like. It almost looks like the piston traveled so far up as to smack the bottom of the plug but that just doesn't seem likely. Has anyone seen this before? Is a compression test in order to see if a valve dropped and that's what smacked the spark plug? I'm hoping to hear solid possible scenarios over random guesses. I'll obviously pick up the whole car regardless as it's a good deal either way but it would be nice to know about the condition of engine.

jstand22

with the way the head and pistons are designed i think it's almost impossible for the piston to hit the plug....the pistons are concave and the cylinder head chamber is concave too, and the plug is right in the middle....But I have no idea what would have caused that..

Eric_Oz_S2

I had a similar thing happen to an Alfa Romeo. The valves and pistons collided and the pistons and valves disintegrated and blew out engine parts through the exhaust. The bits of engine collided with the spark plug at the same time causing the spark plugs to also break. You might be in for a new head and pistons.

Daily944

That's my thought as well. Only thing I can come up with is there must be some debris in that cylinder, maybe even valve pieces.

R.J.

I initially thought the same thing but with the timing belt and cams/tensioner are in good shape. I can't think of a reason why valves would have collided with pistons other than a dropped valve. Are these 16V engines known for dropping valves?

jpk

On the 16-valves, the belt drives the exhaust cam only and there's a chain between the exhaust and intake cams at the middle of the head (between the #2 and 3 pistons) You could have a perfectly fine timing belt, yet have a broken chain which destroyed the intake valves.

R.J.

As first stated above: I pulled the valve cover off and the cams/tensioner looked good.
This would obviously include the chain between the two as when they break the carnage is obvious.

jpk

Sorry; I missed the part about pulling the valve cover off.

dream951

If there was no pistion/debris contact, the only thing i can think of is very severe detonation maybe??

I would run a compress/leak down test since its quick and simple. This way you can have a better idea where to look next.

KuHL 951

A compression test would at least tell you if there is piston damage. Looks to me like it ingested something through the intake or a plug hole. A leakdown test would be even better in case you have a cracked piston or badly scored cylinder from the FOD. I assume the car turns over freely if you are doing a compression test; does it also run?

Rock

If thats a Bosch platinum, I have heard stories where the spark plugs start falling apart.

A 50 dollar 944S is a steal, but its 50 dollars for a reason. You never know if some rim ram decided to beat on the spark plug or stole it out of a lawn mower engine that some kid poured rocks into. Its hard to tell from the picture to me what kind of damage is really done to the plug.

Compression test it the way to go. If the numbers look good across the board, then id throw a new plug in there and drive it. If not then were yellow smiley faces that will continue eating popcorn.

Marajit

Confirmed about Bosch Platinum plugs falling apart.
It has been happening down here with regularity.
The center electrode detaches and wrecks havoc inside the cylinder, sometimes even holing the piston and invariably scoring the cylinder wall.

Stick to copper.

R.J.

Bosch WR7DC is the plug in question...not platinum!

Johnny Player Special

I would be careful spinning that thing over with a damaged plug like that who knows whats in that cylinder. You should see if you can round up a boroscope,Matco Tools, Mac, even Home Depot sells one. They are great for doing inspections. They come with a little right angle mirror that will let you see the valves. Thing comes real handy when you find that cerain lowprice find.

R.J.

EXACTLY what I was planning on doing. I'm going to get a borescope in there after I stick a magnet and see if I can pull anything up.