buying a 94 6.5, need advice!!

[s2gots]

Im looking at a 94 cc dually 4x4 auto. It has 240000 miles, and the truck looks good for its age. There are a few concerns that I would like you guys to help me with...first off, I know off hand that the tierods will need to be replaced, and one of the oil lines is leaking a bit. The test drive was good, but there was a whole lot of black smoke when I got on it, I mean it would blind someone riding close behind me. The test drive was in a hillly area with not much flat land, plus I was punching the pedal quite a bit! It stops and shift real good. It will come with an additional fuel injector, ( I think thats what it is, the current owner said its a $2000 part) and two new front rotors. I noticed it has the heat synk on top of the manifold.
After the test drive, I shut the truck off and waited about 5 minutes, I then opened the hood, and I could smell diesel fuel, not a heavy smell, but definatelly there...is that normal?
I forgot to mention, at the first start up it started fairly quick, Im pretty sure it was a cold start, there was whitish smoke from the tail pipe for a few seconds, and then went away, never came back..
Could these symptoms be fairly simple fixes, or are they hiding a bigger issue I dont want to tackle??
Any help will be appreciated,
TIA

[6.5TDTahoe]

No under hood Diesel smell is the norm. Now a non leaker may have a small detectable Diesel fuel odor. Depends on what the owner does with the small spots that may appear. I have a 96 & 97 & no smell from either. If i change the FF a smell is going to be apparent for some period of time. The odor disapates the fastest on a clean engine.White smoke/vapor is unburned fuel. Leaky fuel injectors can cause it.

[s2gots]

Thanks for the reply. The engine compartment is a bit dirty..after all my research and reading, I'm still not sure if this is a truck worth taking on with all the potential negatives of the 6.5

[neo]

Here is my opinion: the 6.5 and 6.2 are actually quite good engines, for what they were designed to do. They are quite miserly to operate since parts are very cheap (I pay $40 for brand new Bosch injectors, compared to several hundred for a PowerStroke or Duramax) and they get reasonable fuel mileage (my K2500 burb gets roughly 21 on the highway and 15-17 around town) whcih is better than the above mentioned two other engines. However, as many folks have said before, it will not run with those other engines, not designed to. You can do some improvements for both performance and efficiency, but still not going to get you to the big boy level.
I personally like the engines alot. I ahve several in a couple vehicles and find they are reliable (possibly not the DS4, but I digress) efficient and give very reasonable performance. There is also a huge user/enthusiast community that helps support them, this page in particular. If you can work on them yourself, it is reasonably priced, I would say get it, you won't be diapointed.
As for the fuel smell, I would focus on the fuel filter/manager. when I bought my 96 it had the same thing and I found on of the hose clamps on the bottom loose. I also have had some issue with the gasket (little thin steel ring aroudn the gasket actually) that seals the top of the filter to the housing leaking. Good luck!
Neo

[ToddMeister]

Also check the bleeder valve for the fuel filter by the thermostat. Mine was leaking a bit when I smelled fuel under teh hood a time ago.

[Robyn]

Considering the miles on the rig, the issues you speak of are all about normal.

The fuel smell can be coming from a small leak in the filter/manager, one of the fuel return hoses on any one of the 8 injectors.

The Black smoke is likely an issue with the Turbo wastegate system.

Here is my honest opinion.
If the trucks interior and body are in nice shape and the price is decent then its worth considering.

Considering the miles on the clock, you are looking at some work on the thing in the not far off future.

If you consider the cost of a newer rig this can look really good.

As mentioned, the 6.5 is cheap to work on and they get pretty good fuel mileage.

The 6.5 will not run with the newer "Big Boys" mile for mile but with a few mods can sure make them nervous.

Base your decision on the Body and the interior. The engine can be fixed easily even if it means a complete rebuild at some point.

Hope this helps


Robyn

[s2gots]

The body is in damn good shape!! No dents or scratches...It has a painted front bumper, painted mirrors and door handles, has a cowl hood, and a 'roll pan' rear bumper(I think thats what their called..Interior is good also, just will need a good cleaning...has nice aftermarket wheels too!!
So basically were trading trucks...Ihave a 1995 silverade extra cab 4x4 with 206000 miles, 5.7, 2500 with the six lug pattern...

[Robyn]

Hmmmm sounds like a nice rig.

Ok, without trying to be an alarmist and or create hate and discontent.

With a 6.5 with this many miles on the clock, you will be into the engine, likely sooner than later.

The 6.5 from my experience is good for about 200K miles and from then on is anybodies guess.

The radiator on a high miler will also be well used up.

If you decide to do this, and the $$$$$ numbers are good to you, this could be a very good deal.

Just plan on getting under the hood on the beast and doing some work.

If you can do your own work, then the costs can be quite workable.

Been there done that.

Have fun

Robyn

[s2gots]

Yesterday I spent some more time looking over the truck, took the buyer checklist with me, and this is what I found:
1. Checkec turbo on cold enging-no play, and spun freeley. There was some oil in the intake tube, and inside the turbo itself, is that normal?
2.Checked for blow by- seems like its ok. There was a little haze when I took the cap off.
3. checked the lift pump with the T-valve-no stumbling, so checks out good there.
4.Injection pump test was good
5. With engine running, checked waste gate- I could move the rod back and forth very easily.

Everything else looks like it checks out ok. Once the truck is in my hands, Im going to have to figure out what part of the waste gate set up is not woking properly.
Im going to check out the RPO codes a bit later, hope theres some nice goodies on there!!lol

[6.5TDTahoe]

Now you have made the buying decision call th Diese lPage office & get( " The 6.2/6.5 Diesel Trouble Shooting & Repair Guide.") You will be pleased such a publication is available!! It will save your time & money. Carry it in the truck all the time!

[JohnC]

5. With engine running, checked waste gate- I could move the rod back and forth very easily.


This is not good! Make sure the wastegate actuator does not leak (apply vacuum to it ans see if it holds). They are quite pricey. (Or, for about the same $$$ you can go to a mechanical wastegate.)

[s2gots]

I'more concerned about the oil in the turbo housing...

[DmaxMaverick]

I'more concerned about the oil in the turbo housing...
Some, even a generous coating, is normal. The crankcase vents into the intake, before the turbo (the small wrinkled elbow). The CDR prevents too much vapor from entering the intake, but it allows enough to coat it pretty well over time. A failed CDR can allow excessive blow-by and blown (sucked) seals. If you removed the oil filler cap at idle, and didn't see what resembles a locomotive huffing away, blowby is probably within normal specs (a little wisp of vapor is normal).

[s2gots]

Good to know..it's a sigh of relief!!! It wasn't much smoke at all.
When the enginecwss running and I tried to move the rod from the solenoid, it felt pretty wobbly, like it wasn't just moving in and out of the solenoid, but in all directions. From what I've read, I'm 90% sure it's the solenoid.. Is dealer the only place to get this part?

[DmaxMaverick]

Good to know..it's a sigh of relief!!! It wasn't much smoke at all.
When the enginecwss running and I tried to move the rod from the solenoid, it felt pretty wobbly, like it wasn't just moving in and out of the solenoid, but in all directions. From what I've read, I'm 90% sure it's the solenoid.. Is dealer the only place to get this part?

The wastegate actuator and bellcrank linkage can seem loose when there isn't a significant load on it. At engine idle, you shouldn't be able to move it in/out by hand. It should have about 15" of vacuum applied to the WG actuator. If it's loose, a full vacuum and WG systems check is in order. This can be done with a simple hand operated vacuum pump/tester/gage (about $45 for a good one at Autozone). The pump should be providing 22-25" at idle (system vacuum), and you should have this system vacuum to the WG solenoid (attached to the intake manifold). The solenoid is pulse-modulated by the PCM, and should allow about 15" vacuum to the WG actuator (the canister attached to the WG bellcrank). If you have too little or no vacuum to the WG actuator, start the check from the actuator and trace back to the pump. You should be able to pull and hold (as in, no leak) 25" vacuum on the actuator. If you have correct vacuum at the solenoid inlet (from the pump), but it isn't modulating vacuum downstream, often a squirt of WD40 through the solenoid is enough to get it working properly.

The vacuum/WG system, when working properly, does very well, and is better than any other option available. Changing to a mechanical WG controller makes the vacuum system obsolete entirely (unless you have an emission system to operate), allowing removal of the vacuum pump and related plumbing. This is a matter of personal choice. Many folks opt for mechanical control when faced with the expense of a complete vacuum system overhaul (pump, plumbing, solenoid, actuator, etc.). If the 8th digit of the VIN is an S, and your state emission tests Diesels, you may be required to keep the vacuum system, in any case. VIN F requires no vacuum for emission compliance, as it has no EGR. The 3500 should have and F digit, in any case. 2500's can go either way, depending on the GVWR and/or state of delivery.