Hey all, I have a 1992 S-10 Blazer 4x4 with the 4.3 litre and auto tranny.
This evening I was changing the front brake pads and decided to spray some
carb cleaner in the intake and let it soak while I changed the pads. When I
went to start the truck it ran rough (no suprise there since I sprayed about
a half can of carb cleaner in the tbi unit) I goosed the throttle to clear
the cleaner. When I goosed it, it started to rattle like I dropped a rod.
The rattle/ thunk/thump was consitent with a blown rod bearing, It would
rise up with the revs and go down with the revs. Now for the wierd stuff.
According to the HIGHLY ACCURATE oil pressure gauge that is in the dash I
never lost any oil pressure ( a nice 40 lbs) and once the truck warmed up
the sound went away. What the hell was that noise. The truck runs fine and
it has no noise now so I am VERY CONFUSED here
Fuel knock due to the carb cleaner dripping into the cylinders
that had open valves? Or maybe some of the oil was washed
away from the cylinder walls perhaps resulting in some piston
Just my guess.
With half a can of carb cleaner in there you likely washed all the oil off
the cylinder walls the first crank of the starter. Took the engine a few
minutes to replace it, hence the knock. Just your pistons stretching their
legs in your cylinders!
Most likely when you sprayed carb cleaner of that amount and you let it soak
it probably broke loose some
carbon. Carbon knock can and will sound likes rods beating around. Hence
after running a few minutes the
carbon made it's way out of the combustion chamber.
what you heard was probably the engine running with no oil in the
sleeves, as Doc said, and maybe a big-assed chunk of carbon rattling
Good thing you didn't do that to a ferd.. you'd be sweeping up pieces
holy smokers....the things you don't think of when trying to do yourself a
favour. man its a good thing that relative mechanical rookies like myself
read these posts!!!
its great when someone (and it never fails) has to learn the hard way....we
can all benefit from the information. i'm glad it wasn't me this time!! ;)
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