Helped my 16 year old son buy a 2008 6.4 last month. Very nice truck, very little rust and has a lot of extras. 120K miles, truck runs excellent. Deleted. Truck appears to have been taken care of. I am well aware of the terrible reliability of these engines, but the truck was too nice to pass up. Since we bought it we are noticing some engine isues (I did notice some of this before we bought it). The engine is leaking oil from the front and rear. There is a slight valve or lifter tap. We've noticed once or twice a few air bubbles in the de-gas bottle when you shut the truck off. I just took it to a reputable Ford diesel repair shop and they gave me the bad news: Engine needs to come out to fix everything. They claim the head gasket(s) is on the way out, and it will need new rocker assemblies, and the oil leak repairs require the engine to be flipped upside down.

My ask to you guys: should I sell it and try to get my money back, or drive it and wait and see what happens?

I'd like some opinions on how long we have before we are FORCED to perform this work. We can live with oil leaks.

thanks!

 

I'll lean in and say this:

The tapping you hear is common on a 6.4. Possibly nothing terrible or immediately a problem unless it gets very pronounced. My truck taps from time to time but I don't see an alarm going off. That was 60,000 miles ago when I noticed it. Goes away and shortly returns evolution.

Bubbles in the degas bottle may be a sign (and I say maybe) that you have a head gasket on the way out, however, if your not seeing oil contamination in the bottle or a wet exhaust tip and/or a loss of coolant, I wouldn't crap my pants. If you haven't replaced the Caps on the degas bottle or fuel cooler, do it now and throw the old ones as far as you can. They are known defective and can contribute to a myriad of problems disguised as an internal problem such as this. Motor-craft caps ONLY. See your dealer parts counter ONLY. The front covers on these trucks have been known to cause cavitation as the water pump wears. Could be the small amount of bubbles you see, but again, no coolant loss tells me the problem isn't as bad as you think.

As far as the oil leaks go, flipping the engine is only required for the pan gasket. If it is the pan gasket, there are other methods to fix a small leak without complete removal.

I suggest you do the preventative steps and monitor the situation. Take a sharpie and put a mark on the degas bottle when cold. Mine has always sat around an inch below the full line. Use that as your benchmark to see if you do have a true loss, checking it when only cold.

I've always had the same problems you are experiencing except oil leaks, and I sure wouldn't throw in the towel on a worry and not a fact or a direct issue.

Sleep well

Denny

 

Thanks Denny- I was hoping you would reply. We'll watch the coolant level closely, as well as the oil.
You mentioned oil contamination in the bottle. Do you mean oil in the coolant (in the bottle)?
We'll replace both caps ASAP.


thanks-
Jason

 

Sorry it took so long to reply. Working my *** off.

You want to look at directly three things for a head gasket issue.
1. Oil in the Degas bottle. Red alert!
2. Antifreeze in a rising oil level. Check frequently if your down on coolant. I see your on top of that.
3. Your truck may develop mild stumble or rocky idle depending on how bad the seep is into a cylinder/s and **** out the tailpipe. Possible change in exhaust color. But loss of coolant will bird dog you to that.

The terrible irony of thinking you have a head gasket problem or not, is now that it has a symptom and a shop says that's it, the question is is how did they test for it and did they explain the procedure. IE: Compression test? Coolant pressure test? Traces of a leak on a head?

Denny

 

I asked about the air bubbles in the bottle and they said that is probably bad a sign.
When I picked up the truck they said I was getting "pressure" in the coolant system, hence a head gasket going out.
Today after driving the truck a short distance and only getting the coolant temp up to about 150- I removed the degas bottle cap and there was no pressure.
That seemed good and normal to me since the coolant was not hot yet.
Once it reached 190 I did the same thing- there was pressure of course- and I had to remove the cap slowly, but the pressure seemed normal again to me.
I have not noticed the coolant looking oily.
Truck runs and idles perfect.

I am gong to make an audio clip of the valvetrain tap tomorrow, and I'll post it on here.

MUCH appreciate your help.
I spoke to another mechanic today and he said SELL IT yesterday.
His reasoning was the engine is junk, and the parts are now hard to find and 3X the cost.
He was quoting north of 12-13K for the above repairs.

 

One thing to revisit if I might add is the cap.

If they won't vent, where does it go?

I believe there's a Ford TSB on it. I'll look.

BTW, the other mechanic works on everything. I personally don't know any mechanic to like his job and not be rasp toward the 6.4 , but he is right about everything except the unbelievable cost to replace it with a newer truck. I'll give mine a pay raise here and there as long as it's hauling the mail.

Denny

 

There’s a test you can do to check the coolant for combustion gasses in your coolant (testing a bad head gasket pressurizing coolant system) can’t remember what it’s called at the moment..

 

Combustion leak detector. Harbor freight has em probably parts stores too

 

Took the truck by a trusted diesel shop today. He said we definitely need a rocker assembly on the passenger side.
Going in next week for both sides. In his opinion the truck does not need a head gasket at this time.
we'll just keep a close eye on it for now.

Should we delete the EGR cooler(s) while we are in there?

 

Is this the same truck you posted a question about in the other forum, that you said you would sell?

 

Yeap. Not convinced the issues are bad enough to sell this truck for a loss, and then have to start over with another truck that its own set of issues.

 

It's a leap but get new pushrods as well.

If the rockers are knocking that bad, the rods are compromised. As are the lifters and cam lobes.

Just depends how deep you want to go or get some miles out of it.

When it finally breaks you know what happened. My call is to maintain and drive it until something eye popping arises.

Monitor and drive it.

Denny

 

Definitely delete te coolers if it’s deleted anyway. Good way to lose all your coolant on the highway

 

......at which point, it's engine OUT, and engine APART quite literally to repair. Perhaps the OP should get a price quote on a cam and lifters for this just to see how spendy these engines can be, not to mention all the gaskets and other incidental parts needed to get in that deep.

Is this the kind of project a sixteen year old kid needs?

 

The easiest way to tell is to put a pressure gauge on the degas tank and start the engine cold. If there is a head gasket leak or combustion is getting into the cooling system the cooling system will start to pressurize almost immediately. If after 3-5 minutes it's not up high on pressure then you probably don't have a combustion leak. That's one of the first things I do to test a system. After that I go ahead and pressurize the system myself and look for leaks.