6.5 questions

Hi anyone who will answer and give there input, I'm picking up a 93 6.5 Turbo Diesel this week. Has a little less than 180,000 miles, is all original and clean which is very hard to find here in the Northeast. Looking forward to my first diesel truck, so I know blowby can be an issue went to go look at it and there's no blowby im pretty sure so thats good I took the oil cap off while the truck was warm and at good temp there was a little bit of smoke but that's normal right? was no spitting or movement of the oil cap while was off and on top. Did all the 6.5s have an issue with the harmonic balancer also? Im gonna look at it when I go to pick it up to bring home anyways didnt get the chance to when I went this morning but I want to know if its the first thing I should swap out next to my choice of an exhaust i want to get for it? I was thinking about something but wanted to get someones opinion who is familiar with these trucks I dont know if you guys have heard of at-205 but it pretty much helps to bring rubber back to life. I've been using it on my 2nd gen dodge and it does help keep the bushings and everything from cracking along with the weather stripping, is it worth a try on the balancer since theyre all rubber if im correct? I've heard really good things about the early production 6.5s so I was primarily looking for a 93, it is 2wd which is nice. Less to worry about plus better fuel mileage, is there anything else I should worry about? The transmisson was just rebuilt so thats nice, has an unlimited warrantly.

Welcome to TDP :):)

The damper is not a "Standard" failure point at all.... A good look at the serp drive pulley that bolts to the balance'r is a good idea.....

The pulley is rubber mounted and and the rubber does fail over time.

The damper can be examined and if there is signs that the outer ring has moved or the rubber is coming loose definitely replace it.

"Snake SAUCE" for the rubber would not be my choice....the truck in question is 27 years old.....parts wear out


As far as an exhaust goes.....a good 4" system is great.

Sadly the engine bay is tight....and a 4" will not fit all the way to the turbo.

The turbo on 6.5 is basically a big CORK in the flow.

There are several turbo's that flow far better than the GM xxxxx series.

Exhaust temp gauge and boost gauge area must have.

1000 F exhaust temp MAX and no more than 15 psi boost on these engines if you want it to live long.

Exhaust back pressure is an issue with the stock 6.5 systems.....this is between the turbo and the cylinders....and some of the aftermarket setups will help a lot.

Good maintenance is always good...change the oil (Top notch 15-40 diesel rated oil) a new filter, change the fuel filter, air filter and such.

Freshen up the oils in the diffy/s

Just a good going over...

Have fun.....:):)

Thanks so much for the response, that sucks a 4" exhaust won't work. What size exhaust is underneath already? A 2"? Maybe will have 3" pipes put on to a 5-6" cat stack. The truck does already have boost gauge, exhaust temp gauge, and trans temp gauge so thats good. Alright so fuel filter, oil filter, front and rear diff oil, needs an oil change in the next 2 weeks, an air filter, and a turbo will be a little later on down the road or if it does decide to go bad then it will be changed out.

The down pipe can be 3" down to where the pipe is below the frame...then go 4" all the way back to the muffler.

As far as the cat/soot trap goes....be sure you have a good one that is clean.

These are usually junk on the older rigs unless it has been changed.

If you don't need one don't bother with it...1993 should not have one ?????

I think I need a cat but not a muffler, I don't think the truck will pass inspection without it where I'm located at. Was planning on an exhaust without a muffler just a stack and thats it

What's the 8th digit of the VIN? If it wasn't delivered with a cat, it won't need one to pass a smog test. Also, just because there's something in front of a muffler, or something in the place where a cat would be, doesn't mean it was a cat (ever). A turbo with a resonator makes for a better straight-pipe option.

About the balancer, don't try to "fix" it. That's asking for trouble (and a broken crank). If it's dry, hard and cracked, replace it. If you are worried about rubber, install a Fluid-Dampr.

Don't know about Kalifornia, but everywhere else, the '93 6.5 did not have a cat. (VIN "F")

Alright sweet ill take your word for it

I don't think any of the 92-93's had a cat, or EGR, but like you said, Kalifornia. I don't remember, and it's been a while since I've seen one unmolested. Even now in California, Diesels are only tested back to 1998 models, although still 1975 gassers.

Well so much for getting the 93, dude sold it without even telling me or updating the ad on facebook. Went all the way over there and the truck wasn't there☹ they're really hard to find here in Northern Pennsylvania.

Many Craig's list sellers are pukes and are not trustworthy.....

I have seen a couple deals go south....my son in law called on one, told the seller he was on the way with cash....1-1/2 hr drive one way...Gets there and the guy had sold the item a few minutes before......


Definitely these kind are out there.

Sorry to hear the news.

I messaged the guy so many times on Facebook and their head/profile picture pops up on the messenger when they've seen them and he saw every one of my messages but didn't respond. All he had to do was respond yes, I asked him if the other guy purchased it.

I went their on Sunday and looked at the truck and it was really clean but I told him gimme a few days and I'll be over to purchase it.