[99silverado]

well its finally happened... my stock 4.3L is finally giving me some serious sounding problems.
leave work soudns fine - goes down the highway fine, get on the off ramp and give it a little gas and its making some weird noises! I really cant describe it well but it kinda like lurches and miss's at the same time (chugs?) while driving. In park it idling weird as well.... put it into drive and release the brake a little and the truck kinda jumps forward a little (not smoothly).

Its not really a huge surprise the engine's got roughly 110-120k ish miles (odometer stopped working around 100k) and its been a work truck for 3 years, been through two crash's and seen plenty of WOT

I been waiting for a reason to finally do a 5.3 or 6.0 swap so this may be it.... (swapping for a built transmission as well, this one wont last much longer i bet)

any ideas what might be wrong with the 4.3 though ? I know its hard to diagnos it without hearing it (hopefully ill get a video tomorrow).


and yes oil is fine (level and color) coolant level is fine and looks good still

 

[Ian]

really cant do much without hearing it. I was going to say maybe your fuel sytem is clogged since it's lurking forward. Pumps really just go out, they dont really gradually die. Since it's making wierd noises though, cant really help.

 

[99silverado]

its not fuel related the pump is rougly 3 months old, same with filter, pressure is fine as well. its not bogging down any, or missing bad like a lean a/f does, its definatly something internal.... ill try and get a vid tomorrow morning while i check it out, im tired of this truck, getting to the point where normal wear items are needing to be replaced. debating between engine and tranny swap, or buying a newer silverado and sell/part this one out :hmm:

 

[Ian]

i've seen you around a few times, it's a good looking truck. What are you looking for in a truck? A 6.0 would wake that thing right up with it being RCSB.

 

[99silverado]

got up early this morning preparing for the worst (i dont go into work till noon) and i couldnt believe what was causing it... the damn spark plug wire on the driver side rear cylinder came out of the plastic holder and must of been sitting on the exhaust manifold for awhile. the outer protective part of the plug wire was gone and the plug was pretty much grounding itself out (explain's the symptoms :crazy: 2 minutes and a new plug wire (had some in the garage too!) and it runs great again!

it must of been resting on the exhaust manifold and going around the exit ramp corner moved it just enough to ground it out. kinda glad its nothing major as I really didnt want to do an engine swap yet, but it would of made a good reason :rofl2:

 

[99silverado]

Good stuff, I was gonna ask when the last tuneup was.

Go ahead with the gen III swap though

i do a tuneup every year, the last tuneup was actually about 6months ago... i must of not snapped the plastic holder into place allow the wire to move and touch the exhaust :nono:

 

[jadaven]

Yeah, I pulled one of the wires apart on mine, it ran like crap too.