Hey guys. Just registered here last night because I thought this would one of the best places to get my question answered.

What is the biggest problems, issues and or differences in the older 6.9 and the new 7.3.

Reason I ask is I ran across an 87 f250 that has almost 200k on the clock and has the 6.9 in it, it is/ was used as a work truck. I know they are not turbo'd and intercooled like the 7.3 and I have had some ppl tell me there was a coolant issue.

All I want it something that is reliable enought to drive 80 miles a day and pull a car trailor on the weekends, that I do not have to bust the bank on. Right now a new truck is out of the question.

Thanks for your time,
BigEd
Administrator for
www.hardcore50.com

 

This is a good place to start, but the best place to get answers about your truck is www.thedieselstop.com. They have a forum specifically for the 6.9L.

I'm not an expert, but from what I've read, the 6.9 is less prone to the coolant cavitation problems the early 7.3L have. The 7.3L started life as a bored out 6.9. With the thinner cylinder walls and a lack of good instructions on using an aniti-foaming additive for the coolant system. The foaming of the coolant caused cavitation along the cylinder walls which intern would erode the metal causing pinholes in the cylinder walls. The 6.9L can still have this problems, but due to the thicker cylinder walls, it was less of a problem.

That's the short version of the story. Check out the above website for a lot better explanation.

 

I know some people that have the 6.9's, they run for ever...They just dont have the get-up and go that the laters have...smaller injectors, no bolt ons...They are excellent engines however...They will tow well, better then a gasser...still get decent fuel economy... Good luck..

 

Thanks for the info guys. But it looks like someone else got to it before I did.
And the search continues!
BTW - nice site, lots of info.