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MikFish

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1996 GMC 6.5 3500 2WD. 235,000 miles.
Love my truck. At about 214,000 replaced the water pump with the high output and a Duramax fan after blowing a heater hose. Truck ran for about 5-6 minutes before I could get off highway and temp gauge spiked to the max. Replace heater hose refilled system, truck ran fine. noticed the water pump dripping in my drive way as soon as I got home, hence the new pump and fan.
Fast forward to now, additional 20,000 trouble free miles, but now I am seeing small amount of exhaust smoke as well as blow by out of the oil filler cap.
Reading through some of the similar issue threads, could it be the CDR valve be going/gone bad? There is no 'foamy' oil, I don't feel like it is a head gasket. Still has good get up and go, not sluggish at all, no over heating issues, in fact it runs about 15-20 degrees cooler after the new water pump.

There is also a small amount of oil 'film' inside the front of the turbo. I pulled that assembly to clean and replace the air cleaner.
Thanks.
 
I just didnt want to commit to it being safe to run.
I have a fear of an engine having a run away experience.
I am going to adapt a throttle body from a gasoline powered engine into my intake system.
I want to have the capability of shutting down the source of air/oxygen just in case something like that would ever happen.
 
Yup- just keep running it. You just sped up the process with that overheat issue.
Keep it in check best as possible.
200 is ok
210 watch the gauge more than the road
220 pull over& let it cool back to normal.

Not a bad idea to pull & clean cdr. Clean upper. & lower intake. Take pics as reference point. See how long it take to start smokin & oil up the intake again.
 
Yup- just keep running it. You just sped up the process with that overheat issue.
Keep it in check best as possible.
200 is ok
210 watch the gauge more than the road
220 pull over& let it cool back to normal.

Not a bad idea to pull & clean cdr. Clean upper. & lower intake. Take pics as reference point. See how long it take to start smokin & oil up the intake again.
My old enjun’d oil things up real quick like.
Now I’m searching for a throttle body that would have a 2-5/8ths OD for the hose size.
Most have a square four bolt flange on the other end. I can build an adapter for that.
I just cant have enough going on on my truck.
Just have to create more action, besides, I think it’d be a good safety measure.
 
Yup- just keep running it. You just sped up the process with that overheat issue.
Keep it in check best as possible.
200 is ok
210 watch the gauge more than the road
220 pull over& let it cool back to normal.

Not a bad idea to pull & clean cdr. Clean upper. & lower intake. Take pics as reference point. See how long it take to start smokin & oil up the intake again.
Is the CDR serviceable?
 
Usually a good brand of brake and parts cleaner does nicely.
Before getting too carried away, spray some in rag until it is saturated, then rub some onto an area of the valve that contacts no surfaces and see if the foamy portion disintegrates.
Orielly store brand is good stuff.
I have tried Macs and that might be okay but seems to leave traces of water to contend with.
 
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