86 6.9, What To Be Aware Of ?

[mazembe]

Hi, new to the forum and I'd like some advise on an 86 F350 with a 6.9 that has been sitting for about 6 years.The seller will let me try and start it before making an offer.Are there some common issues with this engine? Any advise would be helpful. Thanks ,Matt

[F350SUPERDUTY]

Originally Posted by mazembe

Hi, new to the forum and I'd like some advise on an 86 F350 with a 6.9 that has been sitting for about 6 years.The seller will let me try and start it before making an offer.Are there some common issues with this engine? Any advise would be helpful. Thanks ,Matt

They were known to have a weak bottom end. Some were fixed with recalls.
I know a guy that never took his in and the thing still runs like a champ.
-Dustin

[pipelayerjdh]

Some 6.9's were great engines, and some were crap! I don't have enough info to tell what ones, but my Dad had an '83 that was good and my friend had an '85 that wasn't.

[straycat]

My Dad has an 83, 278,000 on it, 9' camper that's never been off it and it still runs like new. Nice truck, but like the others, I can't tell you what the problems were with them, sorry.

Gord.

[mazembe]

I got it running , it sounds great and I bought it. Should be picking it up tomorrow.Thanks for the all the input.

[straycat]

Congrats on the truck man, lets see some pics, and let us know what your plans are for it.

Gord.

[overl0rd]

Make sure the coolant has the proper amount of additive in it. The IDIs were notorious for cavitation problems leading to pinholes in the cylinders.

[sldghamr]

6.9's are not Strokers, but they are still kin.................

[Petri317]

Early 6.9's from 83 to 85 (there is a vin # cutoff) were known to crack blocks in the block-heater area if it was used extensively. Some of the earlier 6.9's had head gasket problems as well. And the glow plug controller in trucks through 86 would fail in the "on" position, burning out all of the glow plugs(don't ask me how I found this out!!)

These IDI's aren't powerhouses, but they tend to be reliable, inexpensive to work on(for a diesel), and return reasonable fuel economy numbers when compared to gas trucks of the same era.....plus they just sound cool!!

[Petri317]

And Hi everybody! I'm glad I found this forum. Looks like a wealth of info about Powerstrokes (which I have no clue about) as well as IDI's.