Smoke screen from 6.5TD

[Blue85]

I've been toying with the idea of getting a diesel burb as a family hauler. I don't think I would end up with an NA 6.2, probably a 6.5TD. I've never owned one, but logged a lot of miles in a 6.2 Sub back in the day. Anyway, I drove a '93 2500 4x4 today with a 6.5TD transplant. Anytime you step on the pedal it fogs the whole road. Are you supposed to hear the turbo at all? I'm wondering if the wastegate is frozen open or the boost controller is messed up. I don't know what year the engine is, but the transmission only has 3 speeds, so it may be the stock tranny - TH400?

 

[eclipse85k10]

You said it was a transplanted 6.5? If so they could have easily swapped to a th400 then. Not a lot of Turbo noise from a 6.5td. They are not that big of turbos. Fogs when you step on it? White or black smoke? White smoke bad and a lot of black smoke on a 6.5 isn't good. They can't handle excessive fueling like a Cummings.

 

[Blue85]

Black smoke. It starts up nice and drives nice. I remember the 6.2 making some smoke when pulling big hills, but this is much different. Anything over like 1/3 throttle and there's some smoke. Mash it and it's pouring out from low rpm to shift.

 

[K5dreamer]

sounds like serious over fueling or lack of boost, blown turbo maybe? hows it feel power wise?

 

[Blue85]

hows it feel power wise?

It feels weak. I expected to feel a short delay, then the torque pick up a bit, but it doesn't. My thought was that the injection doesn't know the boost level. I suppose it's also possible to have a dead cylinder - bad valves, head gasket, etc. But it only seems to shake at idle.

 

[K5dreamer]

does it have a boost gauge? pyrometer?

those two data points would be invaluable in diagnosing the issue.

it really sounds like a dead turbo to me based on the symptoms.

if theres no boost gauge, you can get a pressure gauge and just hook up to a vacuum port on the intake manifold and see if the engine builds any boost by power braking it in the driveway with the hood up.

if no pyrometer.... well.... not sure how to jerry rig something for that.

 

[Blue85]

No, there's no gauges except the stock cluster (and even on that the tach doesn't work, which I understand). If the body had been clean I probably would have pressed on to see what's wrong, but the bottoms of all 4 doors are bubbling and there's a giant bubble on one of the barn doors. It was cheap for something all set, but too expensive for a donor.

 

[hillbilly deluxe]

I like my diesel Sub as a people mover.

Is it the computer controlled engine or the mechanical? I have one of each and they run way differeent.

The wastgate should be actuated by a vacuum hose one way or the other. Stock they don't make much more than 7 psi.

With the stock air box removed and a Heath turbo master my '96 Suburban's turbo makes a ton of noise, and up to 20 psi (need to adjust it down a bit). My '93 which also has the stock air box removed doesn't make much turbo noise at all but you can hear the turbo above 5 psi, it rarely make more than 7-8 psi (you couldn't hear the turbo at all with the stock air box). The '93 will smoke like crazy if you give it a lot of fuel and the rpms are low, the '96 almost never makes any smoke. The '93 will outrun the '96 going up mountain passes.

x2 on getting a boost gauge, they're cheap on Jegs.