dead cylinder

[4drboost]

My friend has a 2003 Protege ES. Today it started missfiring in cylinder #4. We checked the spark plug and noticed that it was smashed. We replaced it with a new one, it ran fine for a minute but it started knocking again, so we took the new plug out and notice that one was smashed too!! so W/T/F mate? Could he have lost a valve, what could this be?

thanks,
Ian

[alexlitov]

did you check the coil?

[pdhaudio83]

piston hitting the spark plug...

[4drboost]

I know the piston is hitting the spark plug, I want to know what could cause it. I dont think the timing belt broke, if so, are these interfirence engines?

[Focus]

My friend has a 2003 Protege ES. Today it started missfiring in cylinder #4. We checked the spark plug and noticed that it was smashed. We replaced it with a new one, it ran fine for a minute but it started knocking again, so we took the new plug out and notice that one was smashed too!! so W/T/F mate? Could he have lost a valve, what could this be?

thanks,
Ian
Could be something in the chamber, possibly a rod is stretched. Try looking in with a flashlight while you slowly crank it.

[MPNick]

did you check the coil?
Sounds like he detonated the piston. So small parts of it keep breaking off and hitting the plug.

[MPNick]

did you check the coil?
If a coil was bad it would kill two cylinders at the same time. We have wasted spark coils.

[pdhaudio83]

are you running modifications on the engine?

[4drboost]

No, he just bought it. It is stock now, but I think I had a few bolt ons. It does have the Racing Beat exhaust, and I think it had a CAI on at once. We started it up, and its missing realy bad, and there is a lot of rattling comeing from that cylinder. I still think maybe he broke a valve off, im not sure. I feel bad, I told him to trade in his Jetta for one of these, and now this happened. Sucks. Well thanks for the input, has anyone else heard of this on the 2.0's?

[MPNick]

No, he just bought it. It is stock now, but I think I had a few bolt ons. It does have the Racing Beat exhaust, and I think it had a CAI on at once. We started it up, and its missing realy bad, and there is a lot of rattling comeing from that cylinder. I still think maybe he broke a valve off, im not sure. I feel bad, I told him to trade in his Jetta for one of these, and now this happened. Sucks. Well thanks for the input, has anyone else heard of this on the 2.0's?
Did something get dropped into the motor by mistake when the new parts were installed. It is hard to break a valve. Maybe if you jump the timing belt alot.

[Kooldino]

Do a compression check, at least.

[4drboost]

I dont think anything fell in. We have not touched the car. It just started missing one day, and thats when we found out. But yea, I want to do a compression test, that would tell alot.

[pdhaudio83]

where did you buy it from? Hopefully a dealer....

[4drboost]

Yea, he bought it from a dealer, but they said tuff shit. Its used, and from a hick town

[kcbhiw]

Sounds to me like the wrist pin is probably shot. Regardless of what the problem is, the bottom end has to come apart.

[MPNick]

Sounds to me like the wrist pin is probably shot. Regardless, the bottom end has to come apart.
How do you come up with this? I bad pin may cause a knock. How would it cause a mis or hit the plug?

[BlkZoomZoom]

If the wrist pin was missing the piston would hit the plug. Maybe someone stole your wristpin? lol

Lucky for us you can pick a used motor for 400-500$ complete.

[MPNick]

If the wrist pin was missing the piston would hit the plug. Maybe someone stole your wristpin? lol

Lucky for us you can pick a used motor for 400-500$ complete.
IF the pin was missing the piston would only hit the deck of the head surface. The plug sits up higher then the deck so the top of a piston could never hit the plug. Now if the piston broke into little chunks maybe.

[kcbhiw]

How do you come up with this? I bad pin may cause a knock. How would it cause a mis or hit the plug?The miss is obviously due to the plug electrodes being shorted (smashed) together.

The wrist pin could be cracked (with missing chunks), the piston skirt could be cracked (with missing chunks), etc. The likelihood of the connecting rod being stretched on a stock engine is highly unlikely. If the rod cap was broken, it's unlikely that it will remain connected to the crankshaft. The plug obviously didn't start reaching further into the combustion chamber. Therefore, the problem has to lie within the piston and/or wrist pin area.

[BlkZoomZoom]

damn you got me on a technicality, lol. His was a special domed piston model.

[MPNick]

The miss is obviously due to the plug electrodes being shorted (smashed) together.

The wrist pin could be cracked (with missing chunks), the piston skirt could be cracked (with missing chunks), etc. The likelihood of the connecting rod being stretched on a stock engine is highly unlikely. If the rod cap was broken, it's unlikely that it will remain connected to the crankshaft. The plug obviously didn't start reaching further into the combustion chamber. Therefore, the problem has to lie within the piston and/or wrist pin area.
If any of this was the case it would be game over for this engine. It does still start and run. I have never seen a pin crack, have you? If a piston skirt cracked it would fall down into the oilpan and the engine would be knocking very load.

If anypart of the piston cause the problem it would be due to detonation breaking a small part of the top of the piston. On a stock NA car it would seem odd for this to happen but you never know.

When the plug was replaced did the car run right even for a short time? I still think a small nut or bolt may have dropped into the engine.

[MPNick]

damn you got me on a technicality, lol. His was a special domed piston model.
12 to 1 pistons, must have missed that option.

[BlkZoomZoom]

lol. It was next to the "yeah, right" box.

[kcbhiw]

If any of this was the case it would be game over for this engine. It does still start and run. I have never seen a pin crack, have you? If a piston skirt cracked it would fall down into the oilpan and the engine would be knocking very load.

If anypart of the piston cause the problem it would be due to detonation breaking a small part of the top of the piston. On a stock NA car it would seem odd for this to happen but you never know.

When the plug was replaced did the car run right even for a short time? I still think a small nut or bolt may have dropped into the engine.That's not necessarily true. If the dislodged peice is large enough, it could just sit in the bottom of the pan. It's unlikely that it will bounce around the engine and it won't be sucked into the oil pump.

Yes, I have had a wrist pin crack on a race motor.

If there was a manufacturing defect in one of the piston skirts or somewhere in the wrist pin (weak spot, bubble, etc), it's possible that it could have broken at that point and the piston is more or less flopping around on top of the rod. It's my impression from the original poster that the car hasn't been driven very far or run very long for any catostrophic results to occur (yet).

I don't see how detonation will be piling molten metel in the center of the piston as to where it will strike the plug (assuming that it would then have enough rigidity to destroy the plug - a cold solder joint is a good analogy). It's unlikely that in a molten state (if such were the case), that it would actually re-bond in the same place repeatedly.



And I think you all got the shaft on your Proteges. Mine came with 15.3:1 CR pistons with an integral phase rotation meter.

[vindication]

blkzoomzoom, are you located on the island? Even if you're not, I would love for you to take me in a ride in the speed when it is complete again.

[4drboost]

Ok, found out what it was. The dealer found a screw for the Throttle plate, it had come unloose and sucked in. Nothing we could have done about it. Well, anyways, the piston is cracked and will have to be replaced. Sad ending to this story, but thanks for everyones help

Ian

[pdhaudio83]

warranty?

[4drboost]

no, car has 54,000 miles

[MPNick]

Did something get dropped into the motor by mistake when the new parts were installed. It is hard to break a valve. Maybe if you jump the timing belt alot.
Do I win something for being right?

[Focus]

Do I win something for being right?
Here you go nick:

http://www.fmsinc.com/f_graphics/awards/99vbpj_large.jpg

[pdhaudio83]

(rlaugh)

for getting it right, you get to pay the bill ;)

[MPNick]

(rlaugh)

for getting it right, you get to pay the bill ;)
Thats fair, I will buy the new throttle body bolt.

[kcbhiw]

Do I win something for being right?
lol.





Ouch on the screw! I don't think that's the first time that's happened either.

[MPNick]

lol.





Ouch on the screw! I don't think that's the first time that's happened either.If it is not you still do not want to be part of that club.