Still 99 Tahoe problems!!!

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??

My 99 Tahoe is in great shape no leaks doesn't burn oil with 168,000 miles on it . The issue I have is that at times the Tac drops to 0 and the speedometer runs up to 90 mph. When this happens the transmition will not shift automatically out of first gear and my service engine light comes on. Usually if I turn off the engine and restart everything goes back to normal for several days or weeks then for NO apparent reason the same thing happens. Any ideas?????????????

Welcome to AF, try and get the code, many things can cause this, the ignition switch is one common area. BTW, you have tagged onto a 7 year old thread!, in the future start a new one.