my nephews truck, the one that i had posted a while back that i had changed the water pump on. When i did the water pump at 257k miles, i checked his coolant and it was nothing but rusty water. i told him we should flush it right then and there, but it was dark and all he had time for me to do was change the pump and go. Now the truck has 259k, I dont like the idea of running that new pump with that rusty water and hes finally had some time off where i can flush it. Ill be doing it in the next 2 or 3 days. Im thinking a few flushes with distilled water and then once all the rust is out a final mixture of prestone and distilled water 50/50. am I on the right track here? I also changed his oil a few days ago with Napa 10W30 and a proselect filter, i noticed through the fill cap that it had some sludge, mostly hard buildup on the rocker arms. Would some Rotella T5 10W30 and a napa gold at 4-5k intervals be a good combo to slowly clean all the buildup? truck runs fine otherwise.
1992 Chevy 4.3
- Thread starter mobilaltima
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After 259K miles of neglect, I'd do the bare minimum to keep it running and let it die in peace. No doubt the rest of the truck and been neglected as well.
The heater core and radiator probably are starting to disintegrate. Coolant flush should certainly be done sooner than later.
For oil? I would just do any cheap synthetic (supertech) and change it at a short interval.
The heater core and radiator probably are starting to disintegrate. Coolant flush should certainly be done sooner than later.
For oil? I would just do any cheap synthetic (supertech) and change it at a short interval.
Flush it good and use some sort of rad. cleaner, then flush more then refill with fresh coolant.
For oil I would stick with a proven cleaner like PP,PU,M1 and short intervals.
For oil I would stick with a proven cleaner like PP,PU,M1 and short intervals.
Just change the oil at 3k and flush the rad. Have him watch the for intake water leak . That 4.3 has got lots of life still in her the only thing that will kill it is the salt and overheating it truly bomb proof great engines only thing better in the 4.8 Impo
Watch out for opening up radiator leaks after you flush it. It may be that the only thing keeping the radiator from leaking now is the rust scale. That happened to me once on a '78 Buick with a 3.8 V6. A couple of months after I did the Prestone flush, it developed pinhole leaks in a couple of the radiator tubes.
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VIN W or Z?
The 4.3 is a beast, and a good engine... if you can keep up with it. It likes to indicate "low oil pressure" (the digital dash blinks) on "thin" oils when it fully warms up. This may also be why many use a 30 or perhaps a 40 weight in it. Many use 10W-40.
I like the gradual water flush idea. No need to waste distilled on the flushing.. though you could.
The 4.3 is a beast, and a good engine... if you can keep up with it. It likes to indicate "low oil pressure" (the digital dash blinks) on "thin" oils when it fully warms up. This may also be why many use a 30 or perhaps a 40 weight in it. Many use 10W-40.
I like the gradual water flush idea. No need to waste distilled on the flushing.. though you could.
That thing is toast!
its far from being toast. thanks for all the suggestions guys, ill also change the thermostat in it when i do the flush
The final baseline was a coolant flush. The coolant was brown and yucky looking. I rigged a tee on a heater hose and back flushed the engine until the water ran clear then I drained the block. Then I put things back and started filling with coolant. I took a look at the radiator, there were a dozen pin holes flowing merrily. Like something out of a cartoon
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