New here, and have some questions about my 1995 6.5TD

[jmpidgeo]

i just bought my first diesel. (college student) its a 1995 chevy extended cab, long box, 4x4 with the 6.5 TD and automatic with 115k on the odometer. i did some research before i bought it, and found out the injector pumps on these things commonly go out. i cross referenced the VIN at a chevy dealer, and it has been replaced 50k miles ago. here are my questions:

1) are these things intercooled? i did not really see any intercooler, but i might be blind or something
2) compared to m dad's 2003 dodge, with the cummins, the torque on the 6.5 is almost non existant. now, i realize its an older diesel, which probably does not put out a whole lot of boost, but i thought it would be a bit better than it is...or maybe i have something wrong. one of my friends also told me that it smokes quite a bit when i get on it, and stay on the throttle. also, in almost every new(er) diesel i have driven (i have driven everything but the old 6.5TD like the one i have) the noise form the turbo can be heard at almost anytime, but not on this one. maybe, once again, i am overreacting, but im not sure. just lookin for some insight.

is this something to be concerned about? if i remember correctly, the older 6.5 TD was rated at 430lb ft. of torque, but it just doesn't seem like that much. i did try towing with it the other day, and it did very well, but i am still not quite sure, and am just looking for info.

can anyone give me some guidance on this issue? im assuming i am over reacting or something, but i'd rather be safe than sorry.

[john8662]

Q1: Nope, no intercooler, you can get one aftermarket though for some $$

Q2: Depends, could be a number of things, but something tells me since you're smokin' you're not getting any turbo boost. Is the smoke black? The turbo whine is harder to hear on these engines, but it's there if you listen for it. Do some searchin' for no boost and you'll likely find many great threads that other's have written about in troubleshooting low or no boost situations.

What is your truck geared?

Feel free to fill out your profile a little bit under the "User CP" and attach a signature with your rig's info, to help us identify your truck year/model in the future (saves you from having to do the write up each time).

[jmpidgeo]

i am not sure what my truck is geared at. i tried lookin at the rear diff, but there was no tag on it. is there any other way to tell what im runnin for gearing?

also, is there a way to measure turbo boost, without installing a boost guage? i want to wait on all of that, because i plan on getting the banks stinger kit for my truck eventually, which comes with the turbo and EGT guages.

i have also heard that smoke is pretty normal for these trucks, but i just was not sure how much is normal. can someone give me an idea, on when you floor it, how much smoke you should see? that would be great.

also, one more thing...when i am driving, and give it some throttle from a dead stop, and let it off, i can hear the turbo then...i dont know what its called, but its not really the normal whine, its just the spool down noise...does that mean my turbo is working, or could it still be not putting out the boost it should.

[Robyn]

HI
A quicky check or two
Pull small vacuum line off the turbo wastegate (right close to the turbo)
and check with a vacuum gauge to see what is there whe idleing.
You should see 20plus inches of vacuum and it should be steady.
No vacuum at the turbo_____ check the vacuum pump directly.
Vacuum at the pump___ replace the wastegate solenoid. (small device at the rear of the left valve cover on a small braket with some vacuum lines and an electric plug.
The vacuum lines are plastic and do break so check them out carefully.
Also the wastegate vacuum can has been known to fail too.
Make these checks and me thinks you will find some anomalies.
Both my 94's had issues in this area and its fairly easy to fix.
If the vacuum is not steady or is low you will need to replace the vacuum pump and then all will fall right into place.
My 94 runs strong and its stock.
You should only see a puff of smoke if you mash it untill the turbo spools and then it should run clean.
Black smoke also means heat and lots of it and these engines cant handle high EGT's.
Hope this helps
Robyn

[john8662]

also, one more thing...when i am driving, and give it some throttle from a dead stop, and let it off, i can hear the turbo then...i dont know what its called, but its not really the normal whine, its just the spool down noise...does that mean my turbo is working, or could it still be not putting out the boost it should.

Sounds like you may have barked the turbo, are you taking full throttle romps then immedialy letting out of it?

If so, don't do that!

As for gearing, there is a method if you jack up the back of the truck and mark and rotate the tires. I've had no luck with that method, I always wound up pulling the pan and counting teeth (fun too). Somewhere on here someone has some instructions on how it's done.

Smoke, well that depends! If you mash on it hard and you get a big ball of black smoke that doesn't clear up (you continue to make near solid black smoke), then I'd say you're not boosting. But, if you just mash on it briefly and get the smoke and then it clears up during acceleration, then you probably are getting boost and would be considered normal.

As robyn said, you'll get a little until the turbo spools.

[JohnC]

Teh RPO codes for your truck should be on the bottom of the glove box (inside).

GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU6 -- AXLE REAR, 3.42 RATIO

If you have the heavy duty engine, likely since you have a long box, (RPO code L65) then your torque is 385. Otherwise (RPO L56) it's 360.

[moondoggie]

Good Day!

If you're getting gray smoke with FFF (footfeed floored), particularly at higher rpm, that's normal. The PCM pulls boost as the r's build, for reasons I will likely never understand. By normal I mean a level of gray smoke that isn't too noticeable during the day, but really shows up in the mirrors at night.

If you're getting black smoke in significant quantities, your short air for some reason. Generally a troubleshoot of the vacuum wastegate control system (as described above) will find the problem, but don't overlook a really dirty air filter.

The vacuum pump produces > 20" vacuum. At idle & low elevations, the Wastegate Actuator Solenoid rapidly switches between vacuum & atmosphere, ~ 75% of the duty cycle on vacuum, allowing ~ 75% of what the vacuum pump produces to go to the Wastegate Actuator, which pulls the wastegate partially shut.

If you've got stock-size tires (245/75R16's) & turn ~ 2000 rpm @ 60 mph, you've almost certainly got 4.10 gears.

Blessings!

[jmpidgeo]

yea, i found out i have 3.73 gears, with the heavy duty model engine (L65 i think the code was?)

yea, i checked it out today, just a bit of gray smoke as i hammered on it from about 35mph to 75 mph up a hill...so i guess im good?

on another note, what kinda options are out there for an intercooler? is there any way of retrofitting a duramax intercooler into one of these trucks? seems like you could make it fit between the radiator and a/c condensor??

[ronniejoe]

Read the articles in my signature for a good overview of 6.5 potential.

[Patrick m.]

upgrade the exhaust, get a free-flow air filter and a boost controller and you will hear the turbo very well.

[jmpidgeo]

upgrade the exhaust, get a free-flow air filter and a boost controller and you will hear the turbo very well.

what does removing the muffler do? does it help any? i got a buddy with a duramax that just took the muffler out, can you do that with these, without any harm? does it help out wiht power gains at all? how easy can the intake systems be swapped out, and can someone "make" their own air intake with cone filter easily?

what kinda places do you go for aftermarket parts for these motors? i have not been able to find a whole lot of aftermarket support for these, but i may not be looking in the right places.

[Patrick m.]

some do run a straight pipe system and no "kitty". it is fairly loud, not as loud as a gasser with a flowmaster. The turbo acts as a muffler somewhat.

you can make your own intake system, for example, a guy here recently made one with silicone boots and pcv pipe. some clamps, black paint and a big K&N....you get it.
you can get silicone "90s" and "45s" all over the internet.

search the vendor section here, or go to www.kennedydiesel.com

[JohnC]

what kinda places do you go for aftermarket parts for these motors? i have not been able to find a whole lot of aftermarket support for these, but i may not be looking in the right places.

Start by looking here:
http://www.thedieselpage.com/vendors/main.htm