6.2L diesel coolant...anything special?

[AJMBLAZER]

I swear I remember someone mentioning there was special coolant for diesels? Am I 'mememberin' things or what?
Maybe it was an additive?
...something about cavitation I think...

The Blazer recently started leaking out of the heater core so I'm fixing that this weekend. Figure a coolant flush is in order while I'm at it.

 

[AJMBLAZER]

Anybody also know the part number for the correct thermostat at NAPA, AutoZone, or Advanced Auto? I normally go to NAPA but am local to all 3 and Advanced's heater core is almost $20 cheaper than anyone else's.

Lastly, how many gallons of coolant, regular or special diesel stuff, do I need?

 

[6.2Blazer]

There is no special "diesel only" coolant that I am aware of. Can't remember how much coolant it took to fill mine back up (after a water pump replacement).

Didn't have any issues just asking for a thermostat for my year and make of truck.

 

[AJMBLAZER]

NAPA seems to list a thermostat separately for the 6.2L than the small blocks. I'm going with it.

I talked to some folks on the 6.2-6.5 forum and it's only with the really big diesels that cavitation is an issue. Regular green stuff for us.

 

[fallout232]

Cavitation can be a problem in the smaller diesels as well but something else on your motor will usually go long before this is an issue. You can buy the additive I believe it is called DCA. Last time I flushed and filled I think it took roughly 4 gallons of 1/2 coolant 1/2 water mix. Buy two gallons of concentrate and 2 gallons of distilled water, you will come out alot cheaper then the premix. I know it is probably over kill but I also but a coolant filter kit from napa the last time i flushed mine. While over time it becomes less effective you should see the crap that it removed from my cooling system. (Mostly sand from the casting process).

Regular green coolant is good for us as long as you have never run dexcool. Green coolant and dex cool like to eat aluminum when mixed.

 

[AJMBLAZER]

Dexcool is da debil. I'd never run it in anything I owned.

Any tricks to filling these up? On my 4.0L Ranger there was a PITA trick to getting the air out of the system due to a flaw in the design of the thermostat housing.

 

[tRustyK5]

6.2's are pretty straight forward for coolant refill. Fill it, fire it up without rad cap and add as needed. With a T-stat you'll likely need to add some rev's to get the T-stat to open (~1000 rpm) Once the T-stat opens add until fuill to the neck, add cap and check it after it's cooled down again.

Rene

 

[AJMBLAZER]

Sounds pretty simple. Thanks.

 

[desertrat67]

I replaced my thermostat last week. I did not use the factory style one since it cost 30 bucks or so. I bought a cheapy for my model, but found out it was not correct. I then asked for one for an 86 sub with a 6.2. Works like a charm. Only cost 7.99 from autozone as well.

 

[AJMBLAZER]

Mine was $12 at NAPA. I generally like NAPA products and the local place is a good bunch of folks. Advanced and AutoZone only get my business if they have parts NAPA doesn't or something is just cheaper there (like the heater core).
I had them check to make sure the part number they were showing wasn't the SBC one. They confirmed that so I bought it.

The '86 FSM I have has a complicated picture for replacing the stat. Looks to me like you just pull that horizontal housing off in front of the power steering reservoir and there it should be...or am I missing something?

 

[desertrat67]

iT IS JUST LIKE A sbc. Undo the two bolts on the housing(15 mm) on the crossover pipe(where the upper radiator hose connects), watch the coolant leak on the ground, pull the upper radiator hose and the housing piece away from the crossover, watch more coolant leak out, yank thermostat, eatch more coolant leak out, clean off old gasket material, install new gasket, install thermostat, replace housing piece and tighten both bolts back up to German torque.

 

[AJMBLAZER]

Cool. I'll do that this morning. The thing never has even gotten to 200 on the gauge and the coolant, while not testing low enough for my needs, looks fairly clean and nothing spooky has come out of the drain. Radiator has been replaced at some point and the interior looks clean with no grunge that I could see. Think I'm just going to refill it with the new coolant and not bother with a flush.