• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

2002 GTP cylinder 4 misfire

BRUTEL 1

New member
I just bought tonight a 2002 GTP, really clean car but high miles (150,000) all highway. It is misfiring on cylinder #4 Problem stays on #4 when swapping plugs, wires, coil. No intermix in oil or coolant. Car will drive anywhere, just has a miss. It is blowing oil out of the dip stick tube when driving. Guy i bought it from has it has a piston out of it. I don't this so, but what do you guys think? What tests should i do next?

Thanks for any help
Rich
 


you tried switching the fuel injector on cylinder 4 to another one and see if it moves??

and for the oil, perhaps PCV valve?
 
That's not really what's considered "high miles", insurance averages are around 14k per year.

If it's not in the Plug, Wire, or Coil, its either an injector or Ignition control module. Possibly in a rare case the fuel rail could have something plugging that cylinder.

Oil blowing out the tube is a pcv issue.

The only way to know if it's a piston is to do a borescope or tear the top end off.
 
You can do a compression test, or better yet, a cylinder leak down test. The leak down test would be a good one if you have access to an air compressor.


Jay
 


The guy said the oil blowing out the tube started with the misfire.

Could a rocker stud have pulled out of the head. I heard of that
 
If a rocker stud came out, the rocker would be ticking.

Do you have a check engine light on? If so what are the codes it's on for?
 
could it be a problem with a valve in the head? Seems like the crankcase is being pressurized blowing the oil out. I think its all related
 


Do a cylinder leak down test like I stated above, to help narrow down the possibilities. It will tell you if you have a piston issue. I'm thinking you have a hole in the piston or the ring lands are busted up (know issue) allowing combustion gas's and pressures to enter the crank case and pressurize the crankcase. A cylinder leak down test, or even a boroscope will tell a better tale.


Jay
 
Back
Top