Interesting Situation with a 6.9 liter IDI, seeking advice
- Thread starter DuRolf
- Start date
1989FORDIDI
Registered User
I had my CDR stick and I needed my truck so I took it out and cleaned it with parts cleaner and got it freed up and its been fine since no more oil getting pumped into my intake. As far as oil I have switched to lucas oil. They make a 15w 40 and I get it for 16 a gallon. I was using Ford 15w 40 with half a gallon of lucas oil additive and it was great but the lucas oil has everything in it and since using the lucas additive the truck uses no oil between 6,000 mile changes.
Here's the latest. I went ahead with the Hypermax non wastegated turbo installation. Lots more power, but it started running hot. To the point the radiator cap popped.
This lead to a new radiator, water pump, thermostat, ,and fan clutch. Long story.
It is still running hot, but not as much. The Hypermax tech suggested turning the injector pump back two flats, since we didn't really know if we had started at factory setting or if it had already been turned up. I kind of suspected it had had already been turned up due to the massive black smoke I used to produce.
Now it still runs a little warm. The engine gauge is about 7/10, with the needle covering the "l" in normal.
The pyrometer never gets above 1100F.
The boost meter never gets above 6 psi.
Will my 6.9 have a sweet spot? Or is the overheating causing me to have a ceiling as to how much power I can get?
I want to take it on a trip to Lake Tahoe from Colorado in a few weeks, and am thinking those hot miles across Utah and Nevada are risky given the heating. I am thinking of turning the pump down another half or full flat.
This lead to a new radiator, water pump, thermostat, ,and fan clutch. Long story.
It is still running hot, but not as much. The Hypermax tech suggested turning the injector pump back two flats, since we didn't really know if we had started at factory setting or if it had already been turned up. I kind of suspected it had had already been turned up due to the massive black smoke I used to produce.
Now it still runs a little warm. The engine gauge is about 7/10, with the needle covering the "l" in normal.
The pyrometer never gets above 1100F.
The boost meter never gets above 6 psi.
Will my 6.9 have a sweet spot? Or is the overheating causing me to have a ceiling as to how much power I can get?
I want to take it on a trip to Lake Tahoe from Colorado in a few weeks, and am thinking those hot miles across Utah and Nevada are risky given the heating. I am thinking of turning the pump down another half or full flat.
papastruck
Full Access Member
Can't open the links, but a real, numbered temp gauge should be your next step. The fan coming on at all?
ah1988ford
Full Access Member
It seems like from what you said it is running really hot, the turbo is suppose to cool things down and give you more power.
Idk what type of conditions your driving in with this info you are giving us, are you going up the mountains gunning it or are you you on flat land babying it ?
If you were getting MASSiVE black smoke it has been turned up, going up a steep grade and pushing the throttle your going to get some smoke but nothing
close to a freight train if that is what your saying. You dont really want to go any higher than 1100F because iirc after 1200 you run the risk of melting down the heads they are alumn.
I am pretty sure the "sweet spot" is 2300-2500 rpm range some one correct me if I am wrong. Idk you might want to do a compression check if your getting that much pressure it poped the rad cap off that is extremely exssesive. Check your cdr too as stated above by several people. Something is definetly off. I am sure others will chime in with more info and experience than me, so stay tuned.
Cant open links.
Idk what type of conditions your driving in with this info you are giving us, are you going up the mountains gunning it or are you you on flat land babying it ?
If you were getting MASSiVE black smoke it has been turned up, going up a steep grade and pushing the throttle your going to get some smoke but nothing
close to a freight train if that is what your saying. You dont really want to go any higher than 1100F because iirc after 1200 you run the risk of melting down the heads they are alumn.
I am pretty sure the "sweet spot" is 2300-2500 rpm range some one correct me if I am wrong. Idk you might want to do a compression check if your getting that much pressure it poped the rad cap off that is extremely exssesive. Check your cdr too as stated above by several people. Something is definetly off. I am sure others will chime in with more info and experience than me, so stay tuned.
Cant open links.
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Wish our heads were aluminum. Alot lighter then. I run a max of 1200 degrees but have hit 1500 pulling some hills for a less then 15 seconds
Get a real temp gauge on it.
Get a real temp gauge on it.
OK, WHO put your thermostat in, and WHERE did they get it? This is critical. If ANYTHING other than a Ford or IH sourced genuine part was put in, you're walking on thin ice. What coolant did they use? And what Radiator? 6.9's by and large DO NOT overheat or run hot. Let's look at what's been done closely. Oil consumption could be what was mentioned. Or your umbrella seals on the exhaust valves could be shot. This can be remedied easily without a major tear down.
ah1988ford
Full Access Member
Really, this whole time I thought our heads were alum. ......... Please excuse my ignorance
Listen to them not me lol.
icanfixall
Official GMM hand model
I have made aluminum heads many times in my dreams but.. Never got one done either... They really are not the answer either. As Mel posted... The 6.9 engines usually never overheat because they have a better open cooling system than the 7.3 does. The 7.3 has 4 plugs in the lower corners of the heads and block preventing coolant flow.... Why you might ask.... Nobody really knows why but I feel its to create more heat so the engines passed smog tests before reaching our trucks. There is no reason to cut off coolant flow in these 7.3 engines either. Also we can use the 6.9 head gaskets on the 7.3 if we open up the plugs. Then I'll bet not one clean cooling system in a 7.3 will cause overheating issues. Throw in an aluminum radiator and bring on the heavy loads thru the 115 dgress summers...
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.
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Black dawg
Registered User
are we talking over heating at a sustained 1100 degrees? With my truck, anything over 1000 is when you have to start watching the temp gauge. Do you know what your coolant temps were. Also, your boost seems low for 1100 deg. The loads I pull put me at 5lbs and 900deg at 2k cruise.
What t-stat??
Lots of years ago I had an NA 6.9 that would run hot even with light loads. Cooling system was 110%, but would easily get 230 if you worked it. Never got it fixed, but found a ford TSB years later that described a casting flaw in the 84 blocks that would cause overheating.
Silver Burner
Burnin' Oil&Rubber
You ever want to sell that Born Free, look me up...
Those links were what I got when I hit the insert image icon to add pictures. Is there a way to get pix in the message body?
I have a 1985 6.9 IDI that was remanufactured by Jasper sometime over ten years ago.
Thermostat is a NAPA one, with the little valve. Not an OEM part. The radiator is a plastic and aluminum NAPA version.
Getting a compression check tomorrow. The Hypermax tech said if the injection pump was at factory setting, then even turning it up two flats should never cause over heating, especially with a new cooling system. He wondered if I caused damage with the overheating incident when I popped the radiator cap.
When I bought the rig last October it belched black exhaust like a fiend. I didn't know enough at the time to ask the seller if he had adjusted the injection pump.
Right after the Hypermax turbo install and turning the pump up two flats, I could get a lot of power, up to ten psi boost, and pyrometer around 1100. But the engine temp ran really hot. This was on the Eastern Colorado plains, not up in the mountains. Since the new cooling system and turning the pump back down two flats it has never been able to get over 6 psi boost. To be honest now it, on the plains, has only a touch more power than pre turbo. The engine temp gauge is running a little cooler, maybe a 7/10. I'd like it to be midline.
The Hypermax tech also suggested getting the injection pump recalibrated.
Agreed that a real engine temp gauge with numbers would be a good next step.
I have a 1985 6.9 IDI that was remanufactured by Jasper sometime over ten years ago.
Thermostat is a NAPA one, with the little valve. Not an OEM part. The radiator is a plastic and aluminum NAPA version.
Getting a compression check tomorrow. The Hypermax tech said if the injection pump was at factory setting, then even turning it up two flats should never cause over heating, especially with a new cooling system. He wondered if I caused damage with the overheating incident when I popped the radiator cap.
When I bought the rig last October it belched black exhaust like a fiend. I didn't know enough at the time to ask the seller if he had adjusted the injection pump.
Right after the Hypermax turbo install and turning the pump up two flats, I could get a lot of power, up to ten psi boost, and pyrometer around 1100. But the engine temp ran really hot. This was on the Eastern Colorado plains, not up in the mountains. Since the new cooling system and turning the pump back down two flats it has never been able to get over 6 psi boost. To be honest now it, on the plains, has only a touch more power than pre turbo. The engine temp gauge is running a little cooler, maybe a 7/10. I'd like it to be midline.
The Hypermax tech also suggested getting the injection pump recalibrated.
Agreed that a real engine temp gauge with numbers would be a good next step.
