September 27, 2001Alright well i have my lift on and been running it around for about 3months or so and since putting the lift on everytime i go up a mountain and when it gets into the 2-2500rpm range the truck starts to shake and the service engine light blinks a few times and stays on for a day or two and goes off. this happens everytime i go over a mountain. i don`t know if it is related or not but also when in 4x4 it vibrates and i can hear something grinding i assume that it is the front driveshaft at an extreme angle. if anyone knows anything please tell me what you know. thanks
October 5, 2001first off i dont think the 2 are related,get a scan tool to check for codes,second if you need to make sure the vibration is comin from the front driveshaft,take it out and drive it...vibration gone then youll know.
October 5, 2001I`m afraid I`m not helping here, but I tend to agree. A smaller shop will usually tell you what code is coming up for a few bucks. If you figure it out though, let me know. I have a different, but somewhat similar vibration on my truck.
October 6, 2001alright well i think i figured it out. I took it to the shop and got it scanned ($50) and they said the #3 cylinder was missing. said it was either a injector or a plug. well they put a new set of plugs and a bottle of injector cleaner in it.(this was yesterday 10-5-01) i took it up the mountain last night and still felt a lil vibration under heavy acceleration but the engine light didn`t come on. I also heard from a good friend of mine that in 98 gm tried something different with the tranny and put some kind of modulator or something like that and they tend to wear out rather quickly with the hypertech power programming(quicker firmer shifts) as for the fix for this i do not know yet. But will find out.
October 6, 2001oh yeah i forgot to mention i did take out the front driveshaft.