6.9 comments

[gonecrazyi]

I swapped a 6.9 into my 89 f250 about 2 weeks ago and so far everything is going great. I cant believe how much more power this motor has compared to that worn out 7.3.

With the old motor it struggled to maintain 55 with a loaded trailer in 5th, the 6.9 hates to pull at 55 but cruises comfortably at 65 when pulling about 7k.

The motor was burning some oil when I first put it in, but in the past two weeks I think its only seen 2 days that it wasnt pulling a trailer. I think I averaged between 13000 and 17000 most of the time and she still got up and moved pretty good and maintained speed better then the other motor. The oil usage has dissappeared and its pretty quick when empty know that the beds not loaded and there no trailer on the back.

I think that the only problems that I am having are that the rpm guage isnt working and im not getting enough vacuum to use the ac controls but I have enough for the cruise and the brakes. I think I may have a clog in the line becuase up to where it splits the vacuum lines for the ac I have plenty of vacuum.



One more question, my brakes always work better when its raining or wet out. They are more touchy and can lock up the tires easily. Anyone have a guess as to why this is happening?

 

[Goofyexponent]

wet pavement? lol

 

[gonecrazyi]

It happens even when the roads are dry after it gets done raining. Its kindof an interesting feeling wo lock up the rear tires, but it also feels like it takes less pressure on the pedal to get the truck to stop, its more responsive with less input on the pedal.

 

[Devilish]

When were your rear brakes last adjusted?

 

[Diesel JD]

A couple thoughts Billy:
1) Expect that 6.9 to burn some oil, most folks consider up to a quart every 500 miles perfectly acceptable, maybe more. The oil scraper rings and factory valve stem seals weren't what they are on the 7.3.
2) I agree with Devilish it's something to do with the rear brake adjustment. I'm in over my head beyond that, but if you know what you're doing with them, adjust them like you like them, if not find somebody who does.
3) If the rpm gauge is not working, it's likely that tach sensor bit the dust or the wires got rubbed during the swap. I'd hate to insult your intelligence but I remember you told me your donor engine didn't have a tach so unless you remembered to swap the sender from your old 7.3 and plugged everything in right, your results are quite predictable and certain.
Glad to hear you are enjoying it, they are sweet engines even NA if you drop a turbo on it you'll really love it.

 

[gonecrazyi]

Its been about a month since I adjusted my brakes, the only thing that I can figure is that the shoes that I have may be swelling causing them to grab sooner. That or I have a seal in the brake booster that expands when theres high humidity.

The engine that I put in had the hole for the rpm tach, all I had to do was remove the the plug and put in my sensor. When I swapped the motors I left the sensor in the other motor and swapped it over after I had the 6.9 back in my truck and running. I suppose its possible that it got hit when the other motor was pulled but I really dont remember it hitting anything.

I also figured that it might be a ground but everything else is working. I guess Ill have to pull the sensor and see what it looks like, I suppose I really dont need it, I tend to just listen to motor when it comes to shifting anywho.

Im looking for another turbo and have a lead on one in ocala. The guys selling an 85 6.9 coupled to a c6 that also has a banks turbo with a us gear over drive unit. The guy doesnt want to split anything up and wants 1400 for everything.

 

[6.9poweredscout]

the touchy brake thing is a typical ford thing..... every ford i ever owned did it, i had an '88 grand marquis whenever i'd leave the ex-gfs house and there was ANY humidity in the air the back tires would let out a SCREEEEEEECH all the way down the driveway just tapping them. i've had several broncos that did the same. my 250 is the same way, ANY ANY ANY type of moisture in the air and the first few stops before the brakes get hot the 37's lock and SCREAM like a dog getting ran over.... i tell ya, it sure gets the attention of the people in front of me at a light as i roll up and SCREEEEEEEEEEEEEEECH to a stop....

and i adjusted them everyway possible, loose,tight or inbetween all works the same.

-Jon

 

[Diesel JD]

Yeah man you still have my #, give me a call when you come up here to look. I'm not that far from Ocala. I'd say buy that truck, take what you want and sell it as a N/A 85 work truck. Also that US Gear unit, I don't see why you couldn't adapt it to your ZF5 since the C6 and ZF5 have the same spline count.

 

[david85]

Small amount of overnight flash rust, lower quality brake shoes, or brake drums that are beyond their service limit. My Dad's GMC will do this for the first run of every day during the rainy season, and the dam thing is supposed to be ABS. I suspect flash rust there.

Mine does it too, but not nearly as bad. An our or more driving on the highway in the rain without touching the brakes can also set the sympstom off. Never locks the wheels on me though. Just grabs a little hard for the first split second and is normal after that.

 

[gonecrazyi]

I actually wish the brakes were like that more often, but I cant complain with the way my truck stops. When I weighed in at 17k on really couldnt tell there was that much weight behind me becuase it stopped so well.


When it comes to that motor and overdrive unit, its out of a for rv and he's just selling the drive train as is. 1400's worth it for the enitre package, but I just cant justify spending that right now.

Its nice that my trucks finally enjoyable to drive again, it always seemed to struggle to get up to speed and/or maintain speed while driving. This motor just idles through the gears and very easily keeps up with traffic. The one thing that I do need to do id back the fuel screw off a bit, I enjoy the smoke at times, but it keeps me from running the rpms up when Im loaded with a trailer.