engine troubles

[blown up ford]

i was driving around 50km and accelerated to pass a semi and stepped on it and when i got beside him herd a loud knocking sound from the engine but it was not consistant with the rpms of the motor and was blowing white smoke out the exhaust and from under the hood. i have started it a few times to load and unload it onto trailers to get it home and the knocking noise quit but the smoke is heavy white and there is lots of it the exhaust smells a little sweet but the coolant leval is not down by much and there is no coolant or oil under the truck. the engine starts fine and has enough power to climb a steep beaver tail on a low boy semi where do i start to try and diagnose the problem.

[Marty]

Where do you start?

Pull the codes, run a cyl contribution test, and an injector buzz test.

White smoke at idle... and a knock... I might have your answer already.

[Marty]

[sledhed99]

good call on the contribution test

[blown up ford]

whats the answer? and what is a contribution test where can i get it done

[sledhed99]

a contribution test is a test that you can have done at a repair shop or with someone that has a scantool, It test the contribution of the cyl. to tell you which hole is weak.
example. I had a miss in my truck and did the contribution test 3 times in a row everytime it came up cyl. 4 so I pulled the valve cover and found bent and broken pushrods in that cyl.

let me know what you find

[blown up ford]

all right i dont have time to tear into it till next weekend but i will let you know. do you think thats what it could be?

[sledhed99]

Ill make no assumptions but Ill tell you that when mine broke the noise was in consistant with the rpms. Martys video as you know is possibility. When my turbo broke there was a ton of white/blue smoke but no power at all. White is also antifreeze......... but the banging? Maybe it is a headgasket that is internaly leaking causing the missing and the smoke? The answer liath at the site. Good luck, keep up posted

[blown up ford]

thanks for the advise