f650 Loud knock white smoke
 

So in order to scan this truck i need a 9 pin heavy truck connector. Which i dont have. Any how it aint throwin codes. Just a loud tap tap tap in the top of the motor. I pulled all push rods and rockers of course and none are bent. I turned the motor by hand and watched the valve train do its thing and all seems fine. Before i tear the heads off i figure id get some input from the experts. Broke inj tip? Broke valve layin on top the piston? Btw this is a buddies roll back.wrecker. his son was involved in a wreck and not expected to make it. He had another fella runnin his rollback while he tended to his son. So now on top of the crap that happen to his son his wrecker goes down. Im going to fix this truck for free. Hes a good guy and has always helped when i was in need. Just hope i can get parts during xmass.

So any thoughts before i take the heads off? I beleive i have checked what i can but dont know. Anything i missing?

EGR cooler?

Coolant can MIX with the fuel in the cylinders, and well, coolant doesn't mix well with diesel, and can cause an "injector" knock....

Pull EGR valve and see if its wet or dry.

Egr has been deleted. Sorry 4 not adding that

Fuel KNOCK from bad injector

Do a Bubble test

Does the knock sound like the first few seconds of this video?

This was from a few years ago, with a couple bad injectors...

http://s298.photobucket.com/albums/m...=videos003.mp4

All the inj are new. They were just installed 2 months ago. Of course ive bought brand new junk.... bubble test? Im not familuar dude. Im use to my scanner workin out the prob.i dont have heavyy duty coverage on the scanner. Is ther a wright up on it?

I'm not going to be of much help to be quite honest with you, but I'll do my best. First off, the tests described above apply only to F-Series trucks F-250 to F-550. These engines use a Navistar ECM if I'm not mistaken so the only way you'll be able to read DTCs is to possibly get your hands on a scanner from Navistar. But you knew that already.

I was going to suggest you remove all eight glow plugs and do what I call a "mist test". Meaning to crank the engine over with all eight glow plugs removed and check for fluid (fuel or coolant) exiting the cylinder(s) through the glow plug hole(s) to pinpoint your problem cylinder(s). But since you've already jumped the gun and removed all the valvetrain, I would suggest removing all eight injectors for a look/see.

Is this a Navistar or a Sterling? Also there is relatively low cost scanner that has HD function and adapter cables. Its called autoXray a hand held model. Not really a great scanner but does the job for basic codes. Used one for 5 years, before I could get a decent scanner.

Just for general info there is a laptob based software for Heavy duty thats compareable to A&E called PF-Diagnose several different versions and lately came out with a OBDII version as well. Draw back is to work best you use a Nexiq interface that costs over twice what the software pacage does. Base package last I looked was about $300.00

Didnt hit me at the time but cant do Bubble test with Valve train apart either

But if all valves are In and Closed and Injectors still in there Bores with Fuel system hooked up then yes you can do a Bubble test I am thinking Not shure how the Valves not opening and Closeing will affect things

Usually the Bubble test and Mist test is done before Teardown

Basicaly a Bubble test is done to see if Combustion gas is making its way back into the fuel rail from Bad Injector or Bad inject oring

You would Disable FICM and Fuel Pump pull UPPER Fuel filter lid off and Crank engine over and watch for Bubbles at the Upper fuel filter housing

Funny thing. I kno there tty head bolts. But i removed 1 at a time and put new 1s back that i had layin around. So yes i can start the truck. The reason i had new tty headbolts is becuz wen i buy multi layered steel hg's the bolts come with it. Arp headstuds go in there place. And i throw the tty's in the scrap bin

Are these ^^^Specific Steel HG for 6.0L???????

Ohh yea. There dealer specific as a matter o fact. Bolts and gaskets R the same from 03 to 07 i beleive. Just diffrent dowels. 18mm and 22mm. I beleive. But yea,what were u saying about that bubble test? Ive never done this test. It sounds usefull tho. Gimme the skinny blade.

I dont think there is an electric fuel system on this thing. The pump works off the cam....i think.....i kno its not electric. But this thing is full on 6.0....just a diff ecu and tranny,fuel bowl and intake are diff as well. With it being a tandem lift pump,would the bubble test still be of use?

You can do a bubble test or a balloon test. The purpose of the test is to see if you have a cylinder pushing compression back into the fuel rail/head past an injector, indicating a failed crush washer and/or o-ring. The test might be more difficult on a mechanical fuel pump truck because you need to disable the fuel flow to the heads, but it's basically the same. If you attach a balloon to the fuel line to the head and crank the truck it's "supposed" to inflate IF the leak is bad enough. A bubble test is more sensative as it will show a much smaller leak.

I hope my description of the test procedure at least gives you an idea of what you're trying to achieve. It's not injector specific but it will at least give you a starting point.

mike is the man here. listen to him. white smoke/knock is fuel issues. you can test the ficm with a dvom as well.