My '04 Z06 has become a nightmare! It was at the dealer for 2 weeks to fix a faulty oil pump. The pressure release valve froze up. While they were working on it, they found the water pump had a weep hole so they replaced that. I got the car back and only had it for one day. They installed the fan belt incorrectly and a piece broke off and whipped around destroying my hodd liner. While it was in for that I told them it felt like it was missing on WOT. It hadn't done that prior to the original oil pressure issue. They replaced the liner and belt and did the CL recall. They said they took it out and hammered it and it ran fine.

I did a couple of WOT accels going home and it was still missing. After it sat for about an hour I checked the plugs and wires and all seems fine. I took it for a test run and I got the blinking check engine light. I shut it down for a couple of minutes and tried it again. The check engine light came on steady and it threw a P0300 code. Engine misfire. I cleared it but it keeps coming back. The car runs like crap. It backfires under low loads in 3rd and 4th gear.

I can't believe they said it ran great. The car has been at the dealer for 17 out of the last 18 days. If it isn't plugs or wires, what could it be? Coil pack? Injector? Valve spring? Anything they could have done replacing the oil and water pumps? Is it safe to drive it back to the dealer AGAIN or should I have it towed?


mark

 

Nobody can even venture a guess? The car is back at the dealer. I had it towed. The check engine light is on with a P0300 code thrown. Now maybe they can determine what cylinder is missfiring. Since this didn't start happening until after the no oil pressure issue, what things could cause a missfire that may have been damaged as a result of no oil pressure? I guess it could be electrical but that would be one hell of a coincidence IMO.

mark

 

i don't have a clue to what might be wron, and i feel for you with your problems, i've had my share of minor ones.
i think you should be considering lemon law issues at this point. jmho
good luck!

 

Wow man that stinks - to say the least. I really cannot help you with your problem, but I can feel your pain.

I first would look for another dealer. Your dealer seems not to know what they are doing.

Maybe you can ask around for a better dealer in your area....

Good luck getting it fixed....

 

Who is your dealer? Sounds like you might need another one. Email me if you want a recommendation - mine is pretty far from you, but excellent.

Best of luck

Lee

 

I would check everything that busted belt could have hit, intake, wires,TB etc. Something whipping around the engine compartment is Good luck

 

Two Words:

New Dealer !

 

I exprienced the missing before the belt broke and after the oil and water pumps were replaced. I've thought about another dealer but many are reluctant to step in to situations like this. This has got to be it for this dealer though. Three strikes and you're out. I may have to get GM involved and the regional rep if I can find out who he is.

mark

 

If this flashing check engine light and misfire code showed up after you checked the plugs and wires like you stated, then you probably didn't get a plug wire on tight.

 

Check your wires again AT THE Coils. Had a similar situation a while back and it ended up being a loose wire on the coil. Good luck.

 

Towed the car to the dealer and it turned out to just be a cracked plug. When I was checking the wires and plugs, I was interrupted and stopped working on the car for about an hour. When I came back I started working on the driver side. I must not have checked the #8 plug. So the Peter principal was at work. The one plug I miss was the one that was bad. I tell you, my short term memory has gone to you know what in my old age.

I put NGK plugs in about a month after I bought the car. The plugs ran fine for 6 months. I ran them for over 25k miles in my '01 Z without incident. When I got the car back from the dealer for the oil pump, it missed. Don't know why they would need to pull plugs for an oil pump repair. I didn't touch the plug after I initially put it in last May. I guess it could be just a coincidence the plug cracked at the same time the dealer had it. Or maybe the crack got worse at that time and started arcing.

Anyway, all is well again and I'm back enjoying my Z!



mark

 

That's good news, Mark. Glad it was an easy fix, though not a quick one!