6.4 major problems
Elder User
Joined: Mar 2007
Posts: 620
Likes: 0
From: Canyon Country
don't know if this is the same problem my dad had with his truck but he was towing his boat home and started to here some loud grinding then the truck died and after three weeks the dealer finally found the problem...the gear off the high pressure oil pump broke into pieces and went through the engine, it through off the timing and the valves hit the piston...two weeks later and a visit from a rep for ford he got a new crate motor installed in his truck. truck only had 13k on it!
Modular motor junkie
Joined: May 2009
Posts: 6,190
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From: Texas
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Post Fiend
Joined: Jan 2009
Posts: 6,521
Likes: 11
From: Greenwood, SC
bill11012: I really don't think the 6.4 is going to be a problematic motor. Most people search the internet when we have a problem. Most folks that come here with catastrophic problems are seeking help, and that's a good thing.
I have been told that the 6.4 so far is not anywhere near as problematic as other new powerplants that have been introduced, and I don't just mean the 6.0 when it first came out.
I found this site just out of sheer boredom. Luckily I was not in a desperate search for a solution to a blown motor or something.
The 6.4 is a first generation powerplant that had to meet some serious EPA standards, pretty drastic if you read about it. Absolutely every component on the motor is engineered to reduce emissions first, everything else takes a back seat. It's really a radical engine.
I'm happy with mine. 96,000 miles and running like a champ, tows trailers like nothing I have ever driven.
I have been told that the 6.4 so far is not anywhere near as problematic as other new powerplants that have been introduced, and I don't just mean the 6.0 when it first came out.
I found this site just out of sheer boredom. Luckily I was not in a desperate search for a solution to a blown motor or something.
The 6.4 is a first generation powerplant that had to meet some serious EPA standards, pretty drastic if you read about it. Absolutely every component on the motor is engineered to reduce emissions first, everything else takes a back seat. It's really a radical engine.
I'm happy with mine. 96,000 miles and running like a champ, tows trailers like nothing I have ever driven.
Posting Guru
Joined: Mar 2007
Posts: 1,191
Likes: 1
I maintain my truck very maticulusly... I have One Ford Tech guy touch it, if it needs work...SO far routine Maint. Chris the Ford truck Tech said.
When I asked about the 6.4, his response dont even... He says they are very problematic. Some Problems are stated here.
Gear teeth, Valves, and the biggest culprit is the water pump issues.. The Fix for the water pump issue leaves alot to be desired, but it may be the cause of valve failure.
He said the water pump, pumps more water then the radiator can flow, ultimatly at higher rpms causing the pump to cavitate, then engine over heats, then failures occur.
Ford fix for this was a restrictor in the water pump outlet hose, or the hose going back to the radiator... This causes system to flow less, or slower which also under hard pulls will cause over heating, and failures..
I dont own one, and wont buy one for these reasons, But it stands to reason that a higher flowing or bigger radiator would ultimatly correct these issues. Go figure.
Also you have to pull the hole cab off the frame to R&R the engine...
When I asked about the 6.4, his response dont even... He says they are very problematic. Some Problems are stated here.
Gear teeth, Valves, and the biggest culprit is the water pump issues.. The Fix for the water pump issue leaves alot to be desired, but it may be the cause of valve failure.
He said the water pump, pumps more water then the radiator can flow, ultimatly at higher rpms causing the pump to cavitate, then engine over heats, then failures occur.
Ford fix for this was a restrictor in the water pump outlet hose, or the hose going back to the radiator... This causes system to flow less, or slower which also under hard pulls will cause over heating, and failures..
I dont own one, and wont buy one for these reasons, But it stands to reason that a higher flowing or bigger radiator would ultimatly correct these issues. Go figure.
Also you have to pull the hole cab off the frame to R&R the engine...
Posting Guru
Joined: Dec 2006
Posts: 2,498
Likes: 3
From: Windsor, Colorado
I guess I just don't see how that is so big of deal when it was designed to be pulled off. I think it is turning out to be a better motor than first thought, but I can't afford one for a while so be then who knows what will be out, or maybe I'll be buying a used 6.4, who knows. LOL!
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Here is a question for your tech, if the radiator can't flow enough that its creating a restriction, so the pump cavitates from the head pressure, how would putting a restriction in line - also increasing pump head pressure fix this? 
What the tech said just does not make sense, the radiators in these trucks are huge, even the smallest of radiators can flow more water then their hoses/fittings allow, and what is supposed to happen on a cold start when the thermostat is closed?
If water pump failure was as common as your tech said - I'm sure you'd see it a lot more often on here.
What the tech said just does not make sense, the radiators in these trucks are huge, even the smallest of radiators can flow more water then their hoses/fittings allow, and what is supposed to happen on a cold start when the thermostat is closed?If water pump failure was as common as your tech said - I'm sure you'd see it a lot more often on here.
Posting Guru
Joined: Mar 2007
Posts: 1,191
Likes: 1
Actually This was a well known problem... And it was adressed by Ford and Intl. Why they corrected the problem that way is beyond me. My though is, it worked, and it was a cheap fix. I would have recalled the radiators and put bigger ones in, that flow more.
It corrected the problem because it slowed the water pumps output, to the point ofthe radiator flow capacity. He showed me the restricter piece and the Ford Update in the dealer computer. Originally, the return line to the radiator and the inlet side would acctually build preassure to the point that it would cavitate the water pump on the suction side causing the over heating problem.
Hey what do I know. My feeling is if you asked a Ford tech he would also tell you. I agree I found it odd
It corrected the problem because it slowed the water pumps output, to the point ofthe radiator flow capacity. He showed me the restricter piece and the Ford Update in the dealer computer. Originally, the return line to the radiator and the inlet side would acctually build preassure to the point that it would cavitate the water pump on the suction side causing the over heating problem.
Hey what do I know. My feeling is if you asked a Ford tech he would also tell you. I agree I found it odd
Elder User
Joined: Mar 2006
Posts: 516
Likes: 1
Actually This was a well known problem... And it was adressed by Ford and Intl. Why they corrected the problem that way is beyond me. My though is, it worked, and it was a cheap fix. I would have recalled the radiators and put bigger ones in, that flow more.
It corrected the problem because it slowed the water pumps output, to the point ofthe radiator flow capacity. He showed me the restricter piece and the Ford Update in the dealer computer. Originally, the return line to the radiator and the inlet side would acctually build preassure to the point that it would cavitate the water pump on the suction side causing the over heating problem.
Hey what do I know. My feeling is if you asked a Ford tech he would also tell you. I agree I found it odd
It corrected the problem because it slowed the water pumps output, to the point ofthe radiator flow capacity. He showed me the restricter piece and the Ford Update in the dealer computer. Originally, the return line to the radiator and the inlet side would acctually build preassure to the point that it would cavitate the water pump on the suction side causing the over heating problem.
Hey what do I know. My feeling is if you asked a Ford tech he would also tell you. I agree I found it odd
First: If it is a "well known" problem how come it has never been mentioned on here before?
Second: These trucks have the biggest radiator I have ever seen on a pickup. If there was a problem it was that the radiator was not restricting flow enough, hence adding a flow restriction.
Posting Guru
Joined: Mar 2007
Posts: 1,191
Likes: 1
Dont shoot the messenger.
I was delivering a 6.4 liter to another dealer, I have pictures of the cab in the air as they replace an engine for the exact same reason. That teck said. we doum all the time for the same reason. ??? DOnt ask me
I was lookin at the 6.4 originally but was steered away.
It was supposed to be a great engine. I think it will ultimatly lead to the divorce of Ford and Navistar.
My son says at the truck night he goes to. the 6.4's pull everything out there, Duraturds... Cummins. even the 6.0's and 7.3's.