|
|
02-19-2008
ok today i finally hooked up a scan tool to look at all my sensors and stuff and just to check on it plus i had what i beleived was a misfire well it is misfiring and its just one cyl, but it only misfires at idle. #4 is the only cyl. misfiring. well i think it might be a manifold gasket. any other ideas would be well appreciated.
02-19-2008
Plug, plug wire, coil pack?Originally Posted by MTXGTP
02-19-2008
nope all tested good plugs new wire is new ive tested the coil pack.
02-19-2008
sure sounds electrical since it is only present at idle and only one cylinder.
02-19-2008
ive seen it where a manifold will not seal and allow unmetered air into the cyl. causing a miss fire.
02-19-2008
sounds like you know what the problem is, yes?
ok let me backup you have a leak at the exhaust manifold gasket, and that would cause a misfire? Wouldn't running open headers cause a misfire on all cylinders then?
02-19-2008
no at the LIM no im not sure cause i did a coolant pressure check and found out that im losing pressure but i have no leaks externally. im wondering if coolant could cause an miss fire.
02-19-2008
yes it can
02-19-2008
^^^ agreed on the coolant since it can kill the spark or combustion.
02-20-2008
I had this problem today actually...on a local's car. A slight coolant seep was killing one cylinder. Bad gasket in his case.
Is your plug wet from coolant?
Test to see if you have any spark at that plug. Pull it, and then put the boot on it and hold it with some insulated pliars. Have someone crank on it while you watch for a spark.
02-20-2008
ok but last time i tried this i got a not so very nice shock.
02-20-2008
insulated pliers and a glove, man
02-20-2008
That's why I said insulated pliars.
But if you said that you pressurized the coolant system, and it's bleeding off....you will need to find the leak. It could be going into the intake, or worse going into the block. If you think that you have it pegged at which cylinder it is, then pressurize the system again, wait for it to bleed off and check that plug. If it is going into the cylinder the plug will be soaking wet, and you have found your problem.
New intake gaskets could be in your future.
02-20-2008
If this much coolant was going into the cylinder and fouling the plug to where it won't spark, I would imagine it would be very difficult to start. Do you find it hard to start at all?
02-20-2008
I'm laying money on a plug going dead. I had the same problem were a plug just went dead all of a sudden. is the car running rich? One sure fire way to tell if your burnning coolant with the car running smell the exhaust gas's if they smell sweet then the cars burnning coolant. Keep us posted on whats going on
02-20-2008
if you're burning coolant, you also may see white smoke from the exhaust...
02-20-2008
but not always (I had a truck came in with a cracked head and no gasket that showed no smoke or smell)
02-20-2008
ok well today on the way home i started to get a miss fire during boost so plug has fouled. so would you say a intake or a head gasket if its an intake ill start on it tomorrow.
02-20-2008
Don't you have to pull the LIM to get to the heads off? My vote is LIM gaskets. But that is just going by historical data.
02-20-2008
yea you do have to casue the LIM bolts to the heads
| « Previous Thread | Next Thread » |
