04p0300

Maybe someone can help me...I have a 2004 silerado 1500 crew cab
I purchased the truck on 08/04/04 truck ran great till 07-31-06 with 11,000 miles .I was on vacation check engine light went on loss of power. took it to a dealer while on vac. was told it was intake manifold gasket and there was a tsb on it. they fixed it i left was told the truck would be fine.
Went away 2 weeks later 08-10-06 (12000) miles same thing was told this time it was p0300 code and they changed o2 sensor .... got home from vac2 weeks later same thing this time a different dealer changed the intake manifold.(12144 miles). on 10-24-06 check engine light went on again went to dealer where i purchased truck cleared the code p0300 told me to come back when on again.....12-05-06 (13162 miles) light on again dealer cleaned injectors fuel installed data recorder .. truck ran fine until 02-13-07 (14802 miles) p0300 code again dealer swapped coil and plug from # 7 cylnder to # 3 . light came with in a week.. took truck to dealer on 02-27-07 talked with service manager and head mechanic and AVM from chevy they have no idea whats wrong with truck chevy gave mechanic 3 more things to trie truck is still in shop......
Any suggestions ( other than burn the truck)
Thanks
Pat

Ps anybody know of Gm buying vechiles like this back ????????

shnormo

It's a random multiple cylinder misfire. So it could be a whole slew of things, such as coil packs, spark plugs, ecu, O2 sensors, bad fuel pressure regulartor, timing off, valves not seating all the way, vaccuum leak etc.

04p0300

Yeah they have tried most of them seems the problem is with cylnder #7 always getting most misfires even when they swapped coil and plug ..could it be something major this truck has been babied and only has 14500 miles

shnormo

I would get an injector noid light to see if it's getting a consistant signal and an ignition spark through tool. Check if it's getting a consistant spark and fuel. Use a vaccuum gauge to see if you have a leak some where. If you have access to a Genisis scan tool, you could look at the voltages through the system.

04p0300

Dealer is telling me they found carbon build up in motor .....no they ywant to replace heads.....
this is a nightmare

02HD

I replaced intake this week to solve a cold start / misfire. I was not showing any codes. The problem only showed up in tempsless than30 degrees. With as many shops and mechanics and GM reps looking I will not make suggestions on the fix. I will however encourage you to make it the dealer's problem. I have found hanging around the show room and talking to potential buyers about the problems you're having getting your truck fixed will result in the entire dealership, most esspecially the sales people, doing what's needed to make the problem go away, i.e. make you go away. Being in the way of sales, politely, should at the very least get you a very good price on a replacement. Burn it, no. Make the dealer burn for you.

04p0300

Thanks for the tip my intake was replaced in sept was fine till it got cold ...i filed with bbb... hope that will help they are saying its carbon buildup now and want to change heads in truck...

golfer

It might do you good to get a second opinion.