Valve gasket cover.... a few specific questions

[avguy]

I agree with rancdsk8. I had my timing belt snap at 65k and I'm never letting it go past 50k per belt again.
I am having trouble with oil fouling in the plugs, though. My car ran fine, it sat at the airport (outside) for two days in Oregon rain and when I returned, I had the dreaded flashing engine light and a pretty severe stutter / misfire. The stutter is just as the car gets into a new gear and then feels like it picks up and takes off, but with a nasty misfire.
I removed the plugs and wires to replace them all and serious oil fouling in Cyl. 1, and light in Cyl. 4. 2 and 3 were perfectly dry, but fried. They must have been doing all of the work.

I'm going to try to replace the valve cover gasket and see how that does. I'm also going to get a new spark plug socket wrench (the one that comes as one full assembly) because my other one kept popping off. I REALLY hope the gasket replacement does the trick, because I can't fathom another valve replacement if they installed new ones after I bent them all the first time.

I'm scratching my head about what you wrote, and maybe it's because I'm not understanding it. First off, it sounds like it ran fine after a shop did the timing belt repair. You said "if" they replaced the valves. Was that just a typo, or do you really not know if the valves were bent when the belt broke? It also sounds like you are trying to make a connection between the valve cover gasket, and the timing belt/valves bending? Maybe I'm just not understanding what you're trying to say. What replacing the valve cover gasket will do is stop oil from getting into the plug wells, and also from running down the head. It will keep the oil where it belongs, and stop dirt from coming in,but that's about it.
The oil you saw in the spark plug wells wouldn't normally have anything to do with actual fouling of the plug itself. That oil leak is very common in our engines, and just sits there in the plug well. If it leaked for a long time, then perhaps the oil could get high enough to short out the wiring (speculation - I don't know it that could actually happen). But if you didn't dry up the oil from the wells before removing the plugs, then it could have run down the bottom of the plug as it was coming out. That might make it appear that the plug was fouled with oil. But, as I said, that oil in the well isn't going to get onto the inside of the plug during normal operation. So if the plug was really fouled with oil from operation, then you might be looking at some type of engine damage (likely rings). Hopefully the misfire was just bad wires and/or worn plugs, and you didn't actually have a fouled plug at all.

[Lolo_TWC]

HI AvGuy,
Sorry about the randomness of my post.
Here are the specifics:
- The mechanic did definitely change the valves and valve guides at the 65k point my vehicle had the timing belt snap. I demanded to see the valves to make sure everything checked out, and sure enough, I had a bag full of very bent valves and guides (some had cracked from the pressure at the time of the belt breakage). The car ran fine after this fix. I have some intermittent ticking from the valves but it hasn't caused any performance trouble.

- This most recent episode I had was with the misfire. The car ran fine, no rough idle. I parked it for two days at the airport. It rained while I was away. When I picked up the car, the check-engine light came on within the first few minutes of driving and started flashing. The vehicle hesitated when being engaged into a new gear, going very slow at the outset of the gear, then picking up like it was OK, but with a rough running idle. This happened in all gears. I live a very short distance from the airport so I limped it home and parked it.
- I have changed the plugs and wires. After some research, I found oil in what I have learned is Plug 1 and 4, with 4 having the most oil in the well when I pulled out the wires. I soaked up the oil with a clean rag, made sure the well was clean and dry, and put new plugs (platinum) and wireset on. I made sure to do one wire at a time so I made sure to put the correct wire back into the correct locations.
- I changed the air filter (it was filthy).
- The engine still idles roughly and misfires, but only in idle. At the higher rpm's it's fine. I had done some reading that oil in the well was linked to valve trouble, which is where my previous post came from. After more research I find that I have other troubleshooting to do before valves may be the issue.
- I hooked up a handheld trouble code reader and got a P0300 trouble code. It was the only code given. I can feel and hear the engine misfire. I have not yet tried a test drive after my spark/wireset change to see if it still hesitates, but that's where I am at the moment. Now the check engine light is consistent instead of flashing.

Any ideas? I was going to do the "light show" test some people have posted about in other threads to see if the coil pack needs replacing.
Item of note - I haven't replaced my fuel filter in a while. I am thinking of doing this but I don't think I can do it at home unless someone has a step-by-step guide available.

Open to ideas! Sorry my previous post was not well thought-through.

[avguy]

That all makes much more sense now, but one thing is still not clear. Having dried the oil out of the wells before pulling the plugs, how did the firing end of the plugs look? All of them similar, nice and dry - no gunk on the electrodes?
It's always best to systematically diagnose problems, but I tend to agree about the problem perhaps being the coil. New plugs and wires improves the electrical pathway. So the fact that the misfire improved after the new parts tends to point to either a bad coil, or else some other bad wiring up the line. If it does turn out to be a bad coil (or whatever the outcome), please post it here, and help others down the road

[Lolo_TWC]

That all makes much more sense now, but one thing is still not clear. Having dried the oil out of the wells before pulling the plugs, how did the firing end of the plugs look? All of them similar, nice and dry - no gunk on the electrodes?
It's always best to systematically diagnose problems, but I tend to agree about the problem perhaps being the coil. New plugs and wires improves the electrical pathway. So the fact that the misfire improved after the new parts tends to point to either a bad coil, or else some other bad wiring up the line. If it does turn out to be a bad coil (or whatever the outcome), please post it here, and help others down the road

Thank you so much! All four electrodes were gunk-free, thankfully.
The plugs in wells 2 and 3 were a little toasted. They looked burned, for lack of a better word. The other two (1 and 4) were in good condition though #4 was coated with oil on the non-electrode end. Some had collected pretty far down and I didn't seem to get it all out before removing the plug. I am hoping that any oil that was left didn't drip down and causing my current misfire since the vehicle operation is better but not by much. The hesitation is still present in new gears as I did my test drive (4 blocks only) just now.

I just did the spark test on my coil, and ...no light show.
My next check is to look at the O2 sensor and the fuel filter. I'm calling a local mechanic tomorrow. I have a good recommendation for someone nearby b/c my usual mechanic is near work and almost 20 miles away.
I'll relay the full diagnostic and result as soon as the solution is found so it helps the group.