M1008 throttle smoke

[Troopercooper]

Truck is ‘85 m1008, has 93,000 original miles on it. I’ve replaced injectors, glow plugs, CDR valve, fuel filter and countless fuses. Truck starts just fine when temperatures are cold or hot, looks like an oil field is on fire first 10 minutes but clears up as the motor warms. My issue lies when driving it, seems to have decent power but going down a grade mid throttle or mid throttle in general after it’s at speed (50-55) emits decent clouds of white smoke, more so driver side than passenger. I’ve drove it about 3,000 miles this way.

I recently added power services diesel supplement + cetane boost to a tank and the results were instant, smoke emission is down 80% since I added it, truck runs smooth. I just don’t won’t to have to add a supplement to every tank just to make it run decent. At first I thought valve seals were the issue but unsure annymore. Any and all suggestions are appreciated.

 

[87cr250r]

Run it with the radiator cap off and watch for bubbles in the coolant.

 

[Barrman]

Yep, white smoke usually means a bad head gasket. Blue is oil past the valve seals and black is too much fuel. Kind of unique to indirect injection diesels is oily white smoke which mean bad glow plugs.

 

[Guyfang]

Trooper,

What I am going to do is move this thread to the CUCV forum. You will get much better visibility there.

 

[Troopercooper]

Trooper,

What I am going to do is move this thread to the CUCV forum. You will get much better visibility there.

Thank you.

 

[CenterMass762]

I agree with the others. Time to do some leakdown tests or whatever your preferred methods are for headgasket checks.