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Discussion Starter #1 (Edited)
So I bought a truck with a good running 6.0, 325 hp and 575 lbs/ft torque. Naturally I wanted to find out what happens to some of them to give the engine such a bad rap.

Maintenance is crucial to these. The antifreeze that Ford specifies starts to particulate when it gets old. When this happens the oil cooler, heat transfer part gets clogged. After the coolant goes through the oil cooler it is supposed on to the egr cooler and do its job there. If it is blocked at the oil cooler - restricted flow - then the egr cooler gets hot from exhaust gases and cracks. Potential outside leaks and internal leaks into the air intake and burned in the cylinders.

Same is true for the oil. If it is not kept clean it will clog the heat transferer.

You can tell if you have a bad egr cooler by 1. Using excessive coolant. 2. White smoke from exhaust. 3. Pull egr and wet underneath.

Best Fix: Pull egr cooler and weld both ends shut. Use tuning module to eliminate dash light. Pull oil cooler and check for clogging. Flush cooling system and use some other extended life antifreeze with a filter and conditioner pack. Check antifreeze regularly with paper strips to evaluate condition.

If no problems yet, flush cooling system throughly and change fluid.

I think so many trucks blow a head gasket after having the egr "fixed" because the engine has already overheated and it was not detected, or just hoping for the best after an overheating episode.

Nice of Ford to 1. make the holes so small in the oil cooler. 2. recommend an antifreeze that will sediment and clog.

I think I'll flush, add antifreeze filter with conditioner, change to Peak extended life, add external oil cooler, and maybe a remote oil filter using really big Baldwin filters. Also decarbon the egr. I'll also stick with synthetic oil like it has in it now.

Anything to add?
 

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Its not just the oil coolers poor design. That is just one link of the chain that made the 6.0 a grenade. Using engine coolant to cool exhaust gasses was not the smartest design idea. It actually had the opposite effect especially on 6.0's running tuners. The exhaust going through the egr actually would boil the coolant which overheated the block and lead to a lot of stretched head bolts and h/gasket failures. I owned one and liked it very much but I couldn't get over the fact that I was driving a grenade with the pin pulled. Delete the egr and upgrade the oil cooler and its a very fun & fast motor.
Dave
 

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Its not just the oil coolers poor design. That is just one link of the chain that made the 6.0 a grenade. Using engine coolant to cool exhaust gasses was not the smartest design idea. It actually had the opposite effect especially on 6.0's running tuners. The exhaust going through the egr actually would boil the coolant which overheated the block and lead to a lot of stretched head bolts and h/gasket failures. I owned one and liked it very much but I couldn't get over the fact that I was driving a grenade with the pin pulled. Delete the egr and upgrade the oil cooler and its a very fun & fast motor.
Dave
you actually didn't need a tuner...you just had to work them hard.all the 6.0's our company had,were at the dealer at least twice for head gasket failures and blocked/cracked oil coolers.only 4 bolts per cylinder was a serious design flaw. they didn't like pulling 12,000 pound generators all over alberta.we also had trouble with the injection systems and fuel supply issues.

ironically,i told them a full year before they bought them that they were going to be trouble...but they "got a deal" (right).they were simply poorly engineered,fuel gobbling waste's of money,and have pretty much soured me on fords ever since...we'll see what the new ford 6.7 engine brings us.i've driven several in leased trucks and so far i'm not impressed...imhop,the duramax is all over it on the hiway...and much thriftier on fuel.

i still miss my 7.3!
 

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The new 6.7 is junk as well. If ford was proud and confident in it, they would have made it an engine option in their F650/750 line up. The only engine you can get in them is the same cummins found in a 3/4 or 1 ton ram truck.
 

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Its not just the oil coolers poor design. That is just one link of the chain that made the 6.0 a grenade.
OMG! where do i start.... I own an 06 CCLB King ranch.

Injector Stiction

HPOP O-ring Blow outs

Rail plug O-ring Blow outs

FICM that fry

head bolts that strech

oil coolers that clog from poor sand casting

up pipes that leak in to the cab

head gaskets that blow from low coolant caused by EGR cooler boiling it away.

And the powerjoke goes on....
 

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Discussion Starter #9
It's no 300 straight six for sure. Mine runs good right now. No issues. Nice having a swap vehicle that runs for a change.

Nice of Ford to provide all these nice trucks for swappers.
 

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The easiest way to tell if you have a failed EGR cooler is to look at your engine oil temp (EOT) and your engine coolant temp (ECT) while under load. They should be very close to one another (no more than 7*F delta if I remember right). If you have more of a difference than that you have a failed cooler.

You're partially right on head gasket failures. The bolted head design does suck, which is why so many people have gone over to studs, but there is an additional problem that should be addressed. If the head gasket ever fails, the head needs to be sent to a machine shop that deals regularly with 6.0L heads to have the flatness checked, and re-machined if necessary. Its also a good idea to have it inspected for any cracking at the same time. The flatness spec on the 6.0L heads is extremely wide for whatever reason. I'm not sure if this was because the supplier could not hold the original design tolerance, or if it was because thats what Navistar felt was acceptable.

A piece of advice on doing an external oil cooler. The oil cooler is a full flow system, so it needs to handle a pretty substantial amount of flow without alot of pressure drop across the cooler to keep from damaging other parts of the engine. There are few oil coolers that fit this bill that will also fit on the truck, and they are not cheap. Bullet Proof Diesel sells an external kit, but it is not for the faint of heart $$$. Some people have built their own kits that work just fine, but most have stated they spent marginally less than Bullet Proof's kit, and invested way more time.

In addition to flushing the cooling system (Restore and Restore+ are a must for doing this) and going to an extended life antifreeze, you'll also want to check the condition of the water pump. Navistar in their infinite wisdom decided to use a plastic impeller, which over time the fins crack out. This is made worse in the event of the coolant being overheated by failed coolers. If the impeller fails then no coolant can circulate and you can get cooler failure from this as well.

If you hadn't guessed, I own a 6.0L, and I've been lucky enough to NOT have any of the above problems yet. I could keep going on about the other items needed to bulletproof the engine. If you go through and do all the fixes the 6.0L can be just as durable as the old 7.3L was. I used to be a big 6.0L naysayer, but after doing my research, they're not as bad as they once were.
 

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I am glad there are ways to strengthen the 6.0L and make it to be durable. They only made so many 7.3L trucks and only for so many years. Eventually they will be harder to find. So being able to take a 6.0L truck and make it decent enough is a good thing. wthomps if you have more information about 6.0L fixes, please do share, I'm sure there are not only owners of these engines here but also people LOOKING to own a PSD engine or truck and if they can pick up a failed 6.0L and make it right, it would be beneficial for all!
 

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It's sad because the Navistar Defense version of the VT365 (6.0L) is a fantastic engine. They used them in the Husky (MXT-MV) military truck and even at it's bloated curb weight, the truck moved along pretty well. Of course, this engine had zero emissions controls on it which makes ALL the difference in the world.
 
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