On inclines when the vehicle gets to 2000 rpm it begins to shudder. The computer picks it up and shows a #5 cylinder problem but when checked it is ok. Checked all injectors and all ok. Help!!

you need to check your plug wires. i had one once that would only missfire going up hill......plug wire was burnt.

do you have a k&n air filter, if so sometimes the mass air flow sensor get covered in oil from the filter, just clean it off and that might do it.

I'm being told from my dealer that the vavle guides are starting to clog and the guides are too small for the valves. They just fixed one last week by taking the heads off and having them machined. I don't know if this is going to work or not. I have faith in them. I think the cost is somewhere $1000.00. I hope to get some assistance from General Motors. Has anyone else had this done. I am thinking about spending the money.

Originally posted by iufaniufan
I'm being told from my dealer that the vavle guides are starting to clog and the guides are too small for the valves. They just fixed one last week by taking the heads off and having them machined. I don't know if this is going to work or not. I have faith in them. I think the cost is somewhere $1000.00. I hope to get some assistance from General Motors. Has anyone else had this done. I am thinking about spending the money.

the only way id do that is to be able to verify that the problem is fixed after they do it, and before i payed them a penny.

and yes, GM should by all means make good on that if it is indeed a guide defect.

If it is truly a defect don't you think it would of shown up sooner? After all it took 5 years to show up!! Usually a miss under load is a ignition related issue. Try swapping the wire and plug to another cylinder!

This began happening to me in early 2002 with 28k miles on the vehicle but somewhat in-frequent. Now it is severe. Swapping of the wires and checking of the cyliders has proved nothing. Distributor and injectors were also changed. Tore the heads down and currently found problem valve guides. Does anyone think this is a GM defect of some sort?:frown:

MikeF did you have the heads off your tahoo? Did maching the valve guides solve the problem? My dealer said GM would pay for half. What about you??