I just bought a 1986 F250HD extended cabXLt lariat 4X4, 4 speed 6.9. The engine runs but has a horrific rod knock. The PO ran it low on oil!!! He even had extra lubeoil in the truck. I am planning to replace this engine with a locally available used one. I have found a few of these engines but they are all out of trucks with automatic transmissions. Any one have experience replacing the flex plate with a flywheel? Some other makes of diesel engines have the crank and flywheel dynamically balanced as a unit. Is this true for the navistar 6.9. I have a copy of the navistar service manual for this engine and find no mention of this. Also, anything specific to watch out for when checking out used engines? Thanks ahead of time for any replies.
new to this forum but not to diesels, questions
- Thread starter oldoiler
- Start date
Welcome to the site!
You have no worries whatsoever in bolting up a manual flywheel to where the auto flywheel used to be. these motors are designed and built to accept anything ford had released for the IDI in the trans dept.
As far as checking a used motor already removed, there isn't much you can do other than take a look at the outside condition. Do pay attention to the lower corners of where the heads mate to the block for water/oil seepage, and pull the oil filler cap to see if there is condensation on the underside of the cap.
BTW.....how did you find us here?
You have no worries whatsoever in bolting up a manual flywheel to where the auto flywheel used to be. these motors are designed and built to accept anything ford had released for the IDI in the trans dept.
As far as checking a used motor already removed, there isn't much you can do other than take a look at the outside condition. Do pay attention to the lower corners of where the heads mate to the block for water/oil seepage, and pull the oil filler cap to see if there is condensation on the underside of the cap.
BTW.....how did you find us here?
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Welcome oldoiler, I cant really do much more in the way of info for you since the guy above me is the IDI guru extraordinare`. But I will give a hearty welcome and hope that you enjoy our site and visit often.
Mike and the staff.
Mike and the staff.
F350camper
BOOST!
A big welcome from Colorado!
I’ll add that the later 7.3 IDI motor (88 through early94) is a fairly easy bolt in affair. Just incase that increases your local motor choices. But someone else would have to comment on possible issues with this as I’ve never done it. The 7.3 suffers from a cavitation problem if the original owner didn’t keep up with the SCAs. Because of this, many here believe that the 6.9 is the way to go on a used motor.
I’ll add that the later 7.3 IDI motor (88 through early94) is a fairly easy bolt in affair. Just incase that increases your local motor choices. But someone else would have to comment on possible issues with this as I’ve never done it. The 7.3 suffers from a cavitation problem if the original owner didn’t keep up with the SCAs. Because of this, many here believe that the 6.9 is the way to go on a used motor.
he's lying....the only reason why I know anything is that I have dissected more of them over the years due to drivers breaking something.95_stroker said:
