Wife just called, she's got my truck, and called cause something started knocking and rattling really bad.

She checked for codes, none.

Coolant is good, oil is good and not cloudy, she says it sounds like the noise is coming from the top of the engine, near the widshield.
It only seems to do it over 20 MPH.

Guesses


PS it's loud, I can hear it over her voice on the phone, with the windows up.

 

NOT good, please keep us updated!

 

Rocker Arms.

 

Weather stripping over windshield.
Took all afternoon and multiple mechanics to figure it out.

I wish I would have been there to test drive it, I think I would have known the sound wasn't coming from the bottom.

 

Yeah whats the deal with the rocker arms on these?

Crappy oil from regens and EGR coupled with the fact of tight springs used for high back pressure?

 

Oh dear...

I with senix...what's your mileage again? I know they've (rocker arms) had documented issues on high(-er) mileage trucks that were stock (i.e., non-deleted) IIRC.

Sorry...

Re-reading your post so was it the weather stripping that was causing all the noise then? If so...WHEW!

 

Fuel dillution and extended oil changes will increase the wear rate.

 

Yeah it was the weather stripping.

I don't know how the sound could be confused with a mechanical problem, but I wasn't there.

 

Senix is correct, watch out for rocker arm failures. Glad yours turned out to be nothing serious. I have already been through the rocker arm deal with my '08 F450. Go figure, plastic clips on the rockers with fuel dilution. Not a good idea Ford. But they are working machines!

 

Wouldnt that technically be a bad idea by International?

 

I stand corrected!!! Or at least partially corrected!!

 

What kind of oil change intervals did you have on that failed unit? and was it tuned?

 

It had 88k on the engine when they let go. No the truck is not tuned. It is an '08 F450 ambulance. All service done at 5k intervals. As much as I tried, I know oil dilution was the culprit. We have crews that would just shut the truck down after a call when it was in regen that caused the problem. Even after educating these crews, they just want it to run when they need it to and shut it down when they don't. Only one of the other crews(besides myself) drive diesels. That being said, this truck is the reason I bought my '10 F350. These things are BEASTS. Seeing what that ambulance has been able to take made me want one. The truck now has over 112k on it and is doing fine. Only one other major trouble with it was a leaky gasket in between the turbos that was installed incorrectly when the the turbos were re-installed after an oil line broke at the turbo. The tech went through the turbo to make sure no damage had been done. All in all, I love the 6.4!

 

Thats great that you were able to see past the issues at what great trucks these can be.

 

Glad to the OP it was something simple a lot of the time it is simple stuff.