I have a 1992 GMC Sonoma - 4.3l v6. This morning it ran fine. This afternoon at lunch it ran fine. This evening on the way home from work, it starts knocking, it never knocked before, and about a minute later began to run very rough and stalled. I was able to restart it after a lot of gas pumping (rough start) but was able to get home.
Came out later to try to locate the knocking - couldn't isolate it. Drove it around the parking lot and it stalled again after a brief period of VERY HEAVY knocking and no power. Pushed it into a parking spot and was not able to restart it.
Just had the oil changed about a week ago. Oil pressure seems normal (on the gauge). Plenty of coolant in the radiator.
Noticed that during the failed attempt to start it that the exhaust smelled really bad, almost like varnish - never smelled exhaust like it before.
Dont know what to do.
Sounds like an engine sensor, EGR valve or O2 sensor has failed. First thing to do is to look at the engine trouble codes to pin down the failure. You can usually borrow an OBD1 code checker from your local parts store.
SOURCE: me again with the1997 gmc stalling,run fuel pump test,
So what IS the fuel pressure. Saying its good, is not enough, what is it. What is the pressure when it stalls.
SOURCE: 1990 GMC Sierra lifters knocking. Oil pressure
I doubt it....It could be a totally worn out engine.
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SOURCE: 1998 gmc 1500, 192000 km.
most likely the knock is a valve lifter, could be caused by a few things but lets start with trying to add some seafome to the engine oil and see if the knock goes away in a day or so,if it does change the oil and continue with the seefome with each oil change, if the knock does not go away then things get a little more complicated, the first thing would be to get an oil pressure reading at the oil pump. if low or no pressure then you will need to at the least replace the oil pump at the worst replace the engine, i think the smoke is only at start up? if it is then it is valve seals, and the seafome will also help with this. if the engine has good oil pressure then you will most likely have to replace the valve lifters.....
let me know if there is any thing else i can do for you.
SOURCE: 89 gmc c2500 5.7 tbi had oil changed at well known
Hi, this is not the first time i've heard of this problem..I have repaired engines with rod knock, crank bearing knock and piston slap after these treatments. These products can clean so much carbon and varnish from the engine that it brings the real internal problems to the surface. Try using thicker oil
Testimonial: "Thanks for the prompt reply, i will give it a try....."
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Well, we figured out wat it was - the rotor was eaten away quite badly so that the rotor was only intermittently delivering the spark to the cap. Change cap and rotor - problem solved.
The timing chain could have jumped.
Check for plugged exhaust specifically catalytic converter.
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