i put marvel mystery oil in the fuel and oil as a additive. just wondering if there is anything i can do to make it last longer and is mavel okay for a c6 trannsmision thanks

 

these engines are known for running half a million miles or more with just basic maintenance and repairs. do you have any real clue how many miles are on yours, or are you guessing blind like the rest of us?

from all i've heard and read, the most common failures in our engines relate to the fluids. many 6.9s have died because the operator didn't respond fast enough to a loss of oil pressure, usually caused by just not having enough oil in the engine. i added an idiot light to mine so i had an attention-getter plus a stock gage. i have a thread on the subject in the van forum here. https://www.ford-trucks.com/forums/1...with-pics.html
the other big killer of diesels is cavitation. this can be prevented by running the proper coolant with the required additives. search "SCA" or "supplemental coolant additives" and you'll have plenty to read. note that this problem usually attacks the 7.3s more quickly than the 6.9s, but it can kill any of them.

a wise man once said that the guys who use MMO usually drive like a grandpa, and nobody is sure if their extended engine life is from the MMO or from the gentle driving style.
i have no clue about MMO in a c6, but those things are bulletproof anyway. just make sure the transmission cooler is big enough for the way you use it, and occasionally check the fluid level and color.

 

yeah i was thinking; last longer than what? when i read the title to this one.
oh how a many 6.oh no have been outdone by this one time and time again.

ah well what the heck,here's some more to continue after josh:
if she's what was it,pre-87? swap to the 7.3l rockers.ditch the old water trap and install a good one.keep the ip and injectors fresh every 100k,time it properly every 30k.watch the EGT's.if it's n/a turbo it (but don't get carried away with the fuel/boost,without studs.) lots of things can help.but id skip the snake oils.
flush coolant every 30k miles.
oil change every 5k miles.
fuel filter every 60k miles.
trans flush every 30k miles (more often if you tow heavy a lot)
last but not least,run 'er til the truck falls or rusts apart around it.if she fails before that,toss another one in her for $500 bucks and go for who knows how many more years lol.

 

X2 on updating the rockers! Just did that to my 85 6.9 van.


Everything has already pretty much been covered here, so that's that. Very easy to keep these old pigs going and going


My 7.3 has 377k miles on it, and still ran like a charm, no smoke, didn't burn oil, oil always changed every 3k miles. But I had to park it do to the body gone missing around the perfectly good running drivetrain!

 

Really? I think you're way on the low side for coolant, especially if you have a filter and keep up on testing your SCA's. I agree we should change it more frequently than the typical recommended every 150k, but 30k sounds excessive. On the other hand, I suppose it's cheap insurance, and not a terribly difficult job.

As for fuel filter, 60k seems like an extremely long time to go between changes. Maybe the fuel is better where you live, but I don't think I'd want to go more than six months without changing a filter. For me, that's maybe 3000 miles.

 

i change my fuel filter once a year.

 

i change my fuel filter about every 10k miles, which for me is about 3 months. and ever since i started playing with alternative fuels (WMO), i've been carrying a spare filter with me just in case.

 

well it's not "me" per say.
i say a lot of things "by the book" if you will.then folks can decide to go their own way from that.
sometimes when someone says for example; every 60k or 48 months would be fine for coolant flushes,then some may think that's the actual technical recommended interval and then unknowingly stretch an already stretched interval out lol.

this is according to haynes diesel tech book #10330 and (i don't have it in here right now.i put it back in my truck.kinda silly,as i never read it there,i should keep it inside) my '93 owners manual diesel supplement also concurs iirc.
technically,i believe they both share the info of: every 30k miles or every 24 months,whichever comes first.
in no way do i personally feel anyone can't do anything different.
according the fleetcharge,the modern coolant can last much longer than what was available on the shelf's back in the idi era.in fact they claim you can run it forever with a penray need release filter (this is the combo i run) as long as you follow their correct filter change interval.

7. What is meant by the term Fill-For-Life technology?
The Fill-for-Life alternative provides for easy, low cost monitoring of the coolant inhibitor and freeze protection levels. Fill-For-Life is an extended service maintenance program developed by Fleet Charge and Penray researchers. It is very simple. Users simply install a Penray Need-Release filter on an engine coolant system (up to 30 gallons). Every 18 months the filter is replaced. This practice eliminates scheduled coolant changes.
http://www.fleetchargeantifreeze.com/faq.htm#7

 

i would suggest doing your coolant changes at whatever interval is advised on the bottle your coolant came from. the stuff i buy says 150k, but different brands will differ

 

I do mine when I start seing alot of crap floating around in it.

Never went over 50k between flush.

 

Does anyone else change their oil at 3k? I run lots of short trips and i let the high idle kick off so lots of idling. so i err on the safe side. The visor says i should change it with how i drive every 2500. I only change the oil maybe 3 times a year and oil and filter are cheap. 3 gallons of oil, and a power stroke oil filter for something like $50.


But fuel filter, sca, oil, general truck maintenance stuff. Most say conventional coolant should be changed every 2 years. I run fleetcharge pre charged low silicate conventional in mine with distilled water. Got a bottle of dca-2, and test strips, and test every oil change and add as needed.

 

I do my oil at 3k miles. No matter what kind of use I put on it, I mostly do highway though, witch you can go longer without changing it, but I do anyways.

 

Oil is cheap right? why not?

I do mostly highway too. 20 mile trip one way. Then it sits for a few hours then a 20 mile trip back and usually sits till the next day and repeat.

 

Yea 20 miles each way to work on the highway is what I do with my van right now, err well right now i'm doing it in my straight 6 F150, and I can't wait to get the van back up and running cause this damn 6cyl is costing an arm and leg on gas, diesel is alot cheaper than gas around here, so I hate driving gassers. lol

 

60K on the fuel filter seems way excessive, I do mine every other oil change at the longest.

Tanner and John, you guys make me feel spoiled. Not once in my life has a job been more than 10 miles from home