Interesting Situation with a 6.9 liter IDI, seeking advice

[DuRolf]

Here's the latest.
Compression check at worst cylinder 320 psi. Most of those checked were close to 400. Engine running smoothly.
Here is was done on the injection pump setting.
- At original setting, pre turbo, the rig was belching black smoke. Had decent power on flat terrain. I don't know where the pump was set at that point, if the seller had himself adjusted it from the remanufactured setting.
- turned up two flats upon installation of Hypermax non wastegated turbo. The pyrometer never worked from the beginning. This resulted in lots of power, easy boost to 11 psi, and an overheated engine with the coolant boiling out.
- turned back down two flats. Now boost maxed at six psi. Pyrometer 1100. Engine temp gauge while towing on flat terrain about 8 or 9 on a ten scale. To the right of the word "normal", but short of the right hand limit. Engine temp gauge about 7 when not towing.
- turned down another flat today. No change on engine temp gauge. Boost now slower to climb, and maxed out at five psi. Pyrometer maxed at 1100.

Trying to decide whether to take this beast across Wyoming Utah and Nevada to Lake Tahoe for a reunion. Will I be sitting overheated at Golconda Pass in Nevada?

 

[Silver Burner]

I would turn it back up 2 flats to bring back some power and then run at 2500 or better RPM's so you're well into your powerband. This will help keep your engine from lugging and it will run a little cooler. I usually run about 2800-2900 RPM's going up over Mt. Hood when I'm towing. That keeps me running 8-10 Psi mostly, 12 if I need it, and 5 if I'm backing out a little. Going down a flat road you should only be running 600-800 degrees tops if you're doing 60 at around 1800-2300 RPM's, depending on gearing.

 

[DuRolf]

You must be registered for see images attach

This is a picture from the conversion to 4WD. A Dana 60 front end, and an old transfer case from a local retired ambulance.

 

[DuRolf]

You must be registered for see images attach

This is a picture from the conversion to 4WD. A Dana 60 front end, and an old transfer case from a local retired ambulance.

 

[79jasper]

Did you get it running better?

 

[DuRolf]

We drove out to Lake Tahoe, where reversing became a problem, accompanied by a burning smell. We made it back to SLC and the in laws, where Aamco said: burned out reverse clutch and second gear clutch in poor shape. So I had a new C6 put in. Quickly the motor started to leak fuel. A local Ford dealer put in a new lift pump. But the day I picked it up the fuel leak worsened until the rig was dead on the side of the road.
This left me in a quandry. Dump this unlucky beast and part it out? Follow the Ford guys advice and get a new injection pump? I figured then the cylinder with the compression of 320 would go next.
I had them put in a remanufactured 7.3 IDI. I figured all in, and make a rig that should last for many years. Old on the outside but a young drivetrain.
Driving it home with nearly everything new under the hood an oil leak became apparent. The Ford dealer had ordered a reman'd 7.3 IDI turbo, and swapped out the factory turbo parts that would not fit into my E 350 chassis for my Hypermax system. The Ford factory turbo uses a different oil return line than does the Hypermax, and they left the factory port open. But fixing that didn't end the oil leak. It turned out they also used the Ford factory gasket between the turbo body and the air intake manifold, instead of the necessary Hypermax gasket.
I had been losing a lot of boost past that wrong gasket, and attendant blow by oil. Before that leak was fixed the EGTs were my limit to performance. I would get up to 1300 short of full throttle. But after I finally got the right gasket in the EGTs would max out at 1100 or so.
Two weeks ago I took the rig with the family to camp in Park County Colorado. It worked great driving up US - 285, with power like I had never experienced before.
After three nights of being parked we went to drive home, and the engine rapidly overheated. The NAPA gauge (plugged into the passenger side rear most port) climbed fast to 230 before we pulled over and shut it off. The gauge peaked at 255 before cooling back down. The coolant overflow jug had coolant in it. The coolant return hose was hot. All the V belts were present. And the coolant level was normal. We fired it up and it made it down 285 to Morrison with no further problems.
But when I drove it out the next day on the Eastern Colorado plains, air temp in the 90's, the temp gauge began to climb and I could only keep it below 230 by lugging along at 60 in the slow lane.
The fan even when cold seemed to be moving a lot of air. We got a Ford OEM thermostat, but a test drive up a solid hill sent temps to 230 again.
Take it to a Ford dealer I figured. The engine has a 3 year unlimited mile warranty.
When I drove it back, however, I had no overheating. The coolant temp stayed pegged about 210 while driving and 200 at idle.
A local Ford dealer checked for combustion gasses in the coolant and found none. They did find the radiator cap to only hold 6psi pressure, and replaced it with a Ford OEM cap that holds about 15psi.
I drove it yesterday up steep mountain roads, and the coolant temp got up to 220 at the most difficult section. I dropped the gear down to 1 and that brought the temp down as well.


Some observations: I saw a some particles in the coolant return line when I replaced the alternator. About a thimblefull of sands worth. ( I had been joking about the fact that under the hood only the alternator and vacuum pump were not new. And of course the alternator then goes bad! ). I burped the system upon filling the coolant back up after replacing the alternator, and got many miles in before the overheating incident. I don't think I left an air bubble.
I have replaced thermostats more than once in IDIs, and they usually have come out clean. This most recent one, that came with the remann'd engine, was much dirtier. A blackish grit was on it.
A coolant flush maybe, to get out post remanufactuing grit? Shouldn't they come clean from the reman shop?

 

[Silver Burner]

Maybe think about spending a little dough to replace the coolant with some Evans Waterless Coolant? I have heard amazing things about that stuff.

 

[dsltech83]

Sounds like you need to get a coolant filter installed to clean out the system.

 

[Diesile]

For what it is worth I had a similar experience this winter with my 7.3 plow truck. After many attempts at remedy the truck stopped overheating
and soldiered on as if nothing had happened. Nothing learned with no clues if it happens again. Ackk!

Anyone else?

 

[DuRolf]

After the new radiator cap purchase I have driven it around Denver and out to the plains. It is now running cool. Yesterday driving east on I -70, with a headwind but overcast, I saw 210 at about 68mph. On one of the few grades I pushed it, with boost at 9 psi and EGTs at 1200 and the coolant temp gauge climbed to 222. But it very quickly came back down after the crest.

 

[GOOSE]

Sounds like progress. Good luck man.

 

[Knuckledragger]

You say in an earlier post that you have a NAPA radiator. I am going to guess that because they really don't know, you have a gasser radiator, which is not likely to handle the needs of the IDI and would explain the overheating problems. Keep on the lookout for a used or rebuilt stock IDI radiator for your vehicle. I have read the whole thread and am confused. Do you have a 1989, 1985 f250 or E250? I think I missed something somewhere. A stock radiator will help immensely, or pony up for an aluminum one that some members think is the bees knees. I like brass.

 

[Michael Fowler]

Catching up on some old threads.
So how is it running, now--6 months after your last post?

I do not see any mention of IP timing. If you haven't done it, or its was done "by ear", get (beg, borrow, or buy) a timing meter, and set it correctly--timing specs on current fuels are a degree or so advanced from the factory oem setting.

Do you hear the radiator fan engaging?--when it gets hot, you should hear a sound like a freight train coming from under the hood--then the temp should drop, and the noise should diminish. Original radiators can plug up. Coolant still flows bottom to top, but check that the center is actually warm--or hot. Watch out for the fan.

Its always good to "close the loop" on issues so that we can all learn from your experience.

 

[DuRolf]

So far cooling has not been a problem. Though, I took it to Utah and back, and was limited by engine temps going up Parley's Canyon out of Salt Lake, even in cold temps. I had to drop the beast down to second gear.

 

[opusd2]

That's always a fun grade to run. In winter it's like you can play a game of count the tipped trailers/trucks too.

It's a long steep climb going up to the "Sixth Crossing" on I-25 in Wyoming, but a nice coast ride down the other side, little ******* brakes but just shift er down.