Cyl 2 & 4 misfire
Legend
Joined: May 2005
Posts: 8,658
Likes: 7
From: Central Oklahoma
How many miles on the engine? Maybe do what I did, bite the bullet, and yank the engine. Spend a Saturday tearing it down and make a list of items to repair/replace and spend the winter building it.
Professional
Joined: Nov 2008
Posts: 131
Likes: 0
From: Brussels, Belgium
Is it that sad?? I read in the haynes manual that it should have around 150 psi, i could be wrong ... i'll check it later today.
The fact that the 2 cylinders that are at fault are lower in compression tells me that it's probably a headgasket, they sit next to eachother.
If you do a pressure test, try checking the radiator for air bubbles coming up or check the cylinder next to it for escaping air.
Hope this helps,
Greetz,
Bigster
The fact that the 2 cylinders that are at fault are lower in compression tells me that it's probably a headgasket, they sit next to eachother.
If you do a pressure test, try checking the radiator for air bubbles coming up or check the cylinder next to it for escaping air.
Hope this helps,
Greetz,
Bigster
Captain
Joined: Jul 2008
Posts: 678
Likes: 1
From: Houston, TX
Well, your average cylinder compression pressure is 160.8 when you leave out cylinders 2 and 4. That is not great, but not to bad either, and with the exception of #5, are all pretty even. 2 and 4 on the other hand have 13% less pressure than the average of the remaining cylinders, so yeah, there's definitely something going on with those two. Before you tear into the engine, run a leak down test on 2 and 4. If you hear air escaping the TB, it's an intake valve (my story). If you hear it leaking from the tailpipe, then exhaust valve, and if you hear it leaking from the dipstick tube/crankcase, the the rings. If it leaks out of #2 or #4 plug hole, the it's a blown head gasket.
I honestly think with your mileage and compression pressures shown, you are a good candidate for a complete overhaul. Sucks, I know, but you can't argue with the numbers.
I honestly think with your mileage and compression pressures shown, you are a good candidate for a complete overhaul. Sucks, I know, but you can't argue with the numbers.
Well, your average cylinder compression pressure is 160.8 when you leave out cylinders 2 and 4. That is not great, but not to bad either, and with the exception of #5, are all pretty even. 2 and 4 on the other hand have 13% less pressure than the average of the remaining cylinders, so yeah, there's definitely something going on with those two. Before you tear into the engine, run a leak down test on 2 and 4. If you hear air escaping the TB, it's an intake valve (my story). If you hear it leaking from the tailpipe, then exhaust valve, and if you hear it leaking from the dipstick tube/crankcase, the the rings. If it leaks out of #2 or #4 plug hole, the it's a blown head gasket.
I honestly think with your mileage and compression pressures shown, you are a good candidate for a complete overhaul. Sucks, I know, but you can't argue with the numbers.
I honestly think with your mileage and compression pressures shown, you are a good candidate for a complete overhaul. Sucks, I know, but you can't argue with the numbers.
I had planned on doing this or upgrading my suspension this winter. You know how nothing goes as planned.
After the leak down test, and depending whats wrong, I will drive it up to my uncle's garage(big shop, w/engine building room, he used to be a drag racer) with my engine hoist, and tear the truck down and pull the motor.
Where did you find that in the Haynes manual? I couldnt find it anywhere.
That is what I am going to do. I may start tomorow, or Sunday.