Newb with '87 6.9L

[Brian VT]

I got fed up with the cost of maintaining all the electronics and "green" crap of modern vehicles and just bought a 1987 F-250 4wd 6.9 IDI with 128k on it.
Aside from my "modern" vehicles I've had a 1985 Benz 280SE for a while as my backup/summer ride. It's been the best car I ever bought. Anything that's failed so far I have been able to fix myself. I appreciate that a lot.
That's what got me to decide to sell my "modern" truck and get this old Ford.
This is my first diesel and I've been reading through lots of great info. that you guys have posted here and now I have a list of things to do to this truck to make her happy and, hopefully, last for a long time.
I just wanted to introduce myself and thank you all for this great resource that I'm sure I'll be using a lot in the future.
I hope I can contribute in some way here in the near future.
Cheers!
Brian in Maine, USA

 

[Mikey89014]

Hello Brian

yes, the 6.9 is a wonderful engine to work on. It's not the most powerful , but gets the job done at some point..

 

[Knuckledragger]

Welcome to OB!

As stated before, the 6.9 is no power wagon, but it will get you there eventually. 87 was the last year of the 6.9, but the good news is that you will not have to contend with block worm (cavitation) and the late engines have upgraded rocker arms. Depending on the dedication of the PO, you may need oil cooler O rings, front and/or rear seals and several other minor features to make it comfy and leak resistant.

Do not hesitate to ask questions here. This forum is like no other (I have been on lots of them) in that the answers help you with your problems and nobody is looking to give you a hard time.

 

[Brian VT]

"...the good news is that you will not have to contend with block worm (cavitation)..."

I did read that the 7.3 has thinner cylinder walls but I was still planning to get test strips make sure my coolant was up to spec. against cavitation.
Are you saying I'm fine to run plain green stuff with no SCA?

 

[Knuckledragger]

I did read that the 7.3 has thinner cylinder walls but I was still planning to get test strips make sure my coolant was up to spec. against cavitation.
Are you saying I'm fine to run plain green stuff with no SCA?

Yep. It is the thin casting that allows cavitation to happen, due to the Diesel pulses. The 7.3 uses the same casting tooling as the 6.9 but has a larger bore, resulting in very thin walls. A cheap upgrade with predicable results. Fortunately, the owners figured out how to make their engines survive with special (SCA) coolant and Ph strips. All that being said, if you feel more secure using the better coolant and checking Ph, it certainly will not hurt.

 

[Brian VT]

Good to know. I have other things I'd rather spend the $ on right now than test strips and SCA.
Thanks.

 

[Cubey]

Good to know. I have other things I'd rather spend the $ on right now than test strips and SCA.
Thanks.

I run Zerex G05 in my 6.9 RV because it says it protects against cavitation without adding anything to it, and it's fairly low priced and easily available.

You must be registered for see images attach

 

[ih8minimumwage]

I've always run SCAs and used test strips on my 6.9; doesn't hurt to do it right especially after it's been running for 35 years. Doesn't need to be number one priority, but worth checking on when funds allow.

That said; check over what you need and do it in order of necessity. Might be dumping some money/time up front but these engines do last forever. EGT probe would be an early add on that can save you from blowing a head gasket. Putting a little money away to put toward injectors and injection pump would be a good plan.

Truck a manual or auto? Turbo or NA? Welcome to the club, these trucks are easy to work on and may not be the power houses that the modern toys are, but can hold up to a stock 7.3 Powerstroke (today, haha) with some bolt on mods.

 

[Brian VT]

It's an auto. No turbo.
I will be getting an EGT probe. Thanks. Which one do you guys prefer?
The whole fuel system has been replaced, I was told. Including injectors and pump.
How long should I expect those to last?

 

[Big Bart]

Figure a cheap IP rebuild with rebuilt injectors would be $1,000-1,200. If they did the lines, tanks, and sending units another $500-700. That’s just the parts, labor on top of that.

In theory you are supposed to do the pump and injectors every 100,000mi.(Do them together at the same time.) However results vary on new or rebuilt and who does the work. Some have bought new injectors that did make it 10,000 miles before some started failing. Some have had premature issues with IP’s. Bottom line research the topic on this site. There are 3-4 recommended on this site who do it right and stand behind their work.

On EGT 1,800 works, you should not go past 1,100 to be safe, most try to keep it under 1,000.

 

[quickster]

I have the same truck basically. 100k is the area for replacement like Bart says. For peace of mind I would do the o rings on the oil cooler. Do the axle seals. Repack the bearings,etc. Put a trans cooler on it. Every time you fill up put some kind of sulpher juice in it. For lubricity- the pump will last a little longer. I haven't put an EGT gauge in mine. Non turbo - I don't think you need it.
If you plan on keeping it for a while I would do a ZF5 swap. The C-6 is good, but you're looking at 65-70 max on the highway. Eliminate the pos rabs valve.

 

[quickster]

I also had a 1987 MB 300D. Best damn car I ever had. Wish I never sold it, but had to thin the herd.

 

[Jim993]

In my view it is unwise to not monitor coolant condition. Diesel engines, because of their very high compression and combustion pressure are much more prone to allowing a few molecules of combustion gasses past the head gasket on the power stroke at high throttle settings. Combustion gasses contain carbon dioxide. Carbon dioxide and water make carbonic acid and the coolant gets acidic over time. Acidic coolant attacks headgaskets, the oil cooler and cylinder walls. Use coolant test strips and coolant additive to keep from losing an engine.

Amazon.com: Fleetguard Coolant Analysis Test Kit CC2602A : Automotive

Buy Fleetguard Coolant Analysis Test Kit CC2602A: Coolant - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Amazon.com

 

[Old Goat]

I also had a 1987 MB 300D. Best damn car I ever had. Wish I never sold it, but had to thin the herd.

I have 7 MB from 80 - 85. 80 240D is our baby.
These old Benz`s and the IDI will run for ever, simple, long lasting, and will get you there.
Not the fastest things on the road, but reliable.


Goat

 

[david85]

1987 is the best year IDI in my opinion. The 6.9 IDI has thicker cylinder walls than the 7.3 IDI, but 1987 was a bit of a transition year. That's when better glow plug and fuel filter systems were first installed. I read they also came with the later 7.3 style rocker arms, but haven't been able to confirm this.

The C6 automatic transmission is not going to save you any fuel, but its cheap to rebuild and very reliable. ZF-5 speed swaps are common on these, if you want a relatively cheap overdrive upgrade.

If you do end up turbocharging, I'd keep the max boost to 7psi unless you stud the heads. Most of the time I rarely exceed 5 and that's plenty for daily driving.

I disagree with not running SCA's though. I run that in any diesel I'm responsible for, whether I own it or not. The 7.3's were most prone to cavitation of the block but that doesn't mean it can't happen to other diesels.

Overall, a good buy. Only complaint is the lack of photos (hint hint...)