Missfire No.1 and 3 Cylinder, Car shakes on idle, Oil on Spark Plug Thread

[goodybear]

Hi everyone, I hope you guys can help me fix this before I take it to the shop. Long story short, here's what I did 4 months ago.
1. Replaced valve cover and gaskets
2. Replaced spark plugs and wires
3. Installed Oil Catch Can
4. Big 3 upgrades

A couple of days ago I filled up gas and CEL was blinking once I got to the freeway. It drove just fine until I got to the stop light and felt the shaking. It wasn't too bad and I was able to drive it back home. My OBDII reader posts P030, P0303, P0300, and P1399. Missfire is on Cylinder 1 and 3. I checked all of the spark plugs and found spark plug no.3 had oil on the thread (shiny not gunk). I bought new plugs and wires yesterday and still doing the same thing. I don't have a compression testing tool so I'm hoping to get second opinion as to what other things I need to look at.

Any input would be much appreciated.

Thank you

 

[ThatDesiKid]

Check your coil packs. Turn on the car and slide each coil pack out one by one. If you remove a coil pack and the car runs the same....that coil pack needs to be replaced.

 

[Sil2DrV6]

EGR Valve, too.

 

[goodybear]

Thanks for the recommendation. I took it to a shop and they found a low compression on cylinder no.3 (40 psi). Would checking coil pack and cleaning EGR valve help?. The two shops I called recommending an engine replacement or valve job which is around the same price of the car. Just drove the car today, still runs like a champ dispite the sputtering at the stop light.

 

[INK DEMON]

A valve adjustment would only help if the low compression is due to the valves. The fact that you have oil on the threads is not a good sign. While it could be an issue with the valve guides or seals, the most likely cause, IMO would be worn rings. Usually this is diagnosed by either doing a leak down test or a “wet” compression test.

If you have a 4 cylinder model, your car does not have coil packs and that wouldn’t explain low compression anyways.

EGR valve won’t help in this case.

Based on your car’s symptoms and the low compression diagnosis you already received, you are looking at either an engine replacement or rebuild.

You MAY be able to use some engine restorer just to get by for a bit longer, but this is NOT a solution. Just a bandaid. And if you have a constant misfire and continue to drive the car like that, you will likely fry the catalytic converter.

 

[INK DEMON]

Check your coil packs. Turn on the car and slide each coil pack out one by one. If you remove a coil pack and the car runs the same....that coil pack needs to be replaced.

This is not a good standard to abide by. You can have no change if you have a burnt/broken valve, cracked head or block, bad rings, bad guides, the list goes on.

If swapping parts is the method someone is going to use, they are better off swapping the coil with a coil from a different cylinder to see if the problem transfers over.

 

[goodybear]

Thanks for all the input here, I really appreaciate all suggestions and opinions. I believe INK DEMON sums it up well here. Very helpful information in this thread and I hope it will be helpful for those experiencing the same problem going forward. I am planning to sell the car next week
. As much as I love this car, I have come to realize that it's not worthwhile to keep it, knowing that it will cost more (to replace the motor) than what the car was worth when I bought it.

 

[T.$.Racing]

Thanks for all the input here, I really appreaciate all suggestions and opinions. I believe INK DEMON sums it up well here. Very helpful information in this thread and I hope it will be helpful for those experiencing the same problem going forward. I am planning to sell the car next week
. As much as I love this car, I have come to realize that it's not worthwhile to keep it, knowing that it will cost more (to replace the motor) than what the car was worth when I bought it.

Do you have any experience wrenching on cars? These things are stupid simple to work on as far as modern automobiles. Fix it yourself if you like the car.

I'm not sure if its what you're experiencing but a friend had a similar problem recently on his '92 Civic with 242k on it. Started idling like shit, ran pretty decent while actually driving and cruising on the highway, but compression test revealed #4 cylinder was around 30psi. Ended up being the exhaust valve on that cylinder broke at the seat and a chunk the size of tic-tac had cracked off. O'reileys ended up having it in stock for $12, total job took around 6 hours in his driveway in 20 degree temps using youtube and a factory service manual for reference when needed.

 

[goodybear]

Thanks for the recommendation. I do not have a garage (or place) to work on my car. I mostly do simple things with the tools that I have (oil change, electrical component fix, brakes, etc). I have no experience in motor replacement or fixing motor parts.

 

[INK DEMON]

If you are considering getting this vehicle fixed, I suggest a leak down test as your next step. Any reputable shop can do it and it will narrow down the cause of your low compression.
Given the symptoms, best case scenario would be something on the top end (head gasket, valves, guides, etc).
Worst case scenario would be bottom end (rings).
Or possibly a crack in either the head or the block.

Anything other than a simple top end problem and you’re better off just swapping in a used engine (if you’re wanting to keep the car).