First of all thanks to all the tech gurus and their input on my thread concerning my 6.9 running rough and blowing a ton of white smoke. But the source of the problem was not anything mentioned. I had a theory, sprouted from the fact that my exhaust manifold had oil seeping from cylinder #1, and oil was drizzling down my down pipe (ATS 088 slip fit). I pulled the glow plug from #1 and turned the engine over with my finger over the hole. Vacuum. And when the piston came back up it didn't blow my finger off. Valve train issue for sure. So I pulled the valve cover, and lone behold, a bolt had backed out of the rocker arm assembly! So I tightened it back up and the rocker was still loose. Hmmm. I took the rockers out and checked the pushrods on glass and they checked out good. Put a set of 7.3 rockers I had gotten from the junkyard, and they tightened down nicely. Bent rocker arm. Really? This whole time it was that simple?!! Intake valve wasn't functioning so the cylinder was sucking oil through the valve guides, Just like I had thought. Needless to say, I'm pretty stoked that my truck can now be driven!
White smoke/rough idle FIXED!
- Thread starter Koch13351
- Start date
Thank you for the report back on what the problem was. Wish everyone would do that. But, was the oil issue mentioned in your request for help? Never too much info when trying to solve a problem.
Editt: Checked your thread, yes you did.
Editt: Checked your thread, yes you did.
Last edited:
buddaniels
Registered User
My 7.3 is doing the same thing. Ran perfect 1 day and the next white smoke and a miss.i did a compression check and all was well. Could you smell burnt oil ?
A compression check would not reveal to you as to what Koch found I don't believe, as both valves would be closed. Pull the valve covers and look.
Yeah I tried a different injection pump and it didn't change anything. So I decided I'd dig as far into finding the problem as I could without removing the engine. I had no signs of head gasket failure, so I knew it had to be valve train related. Unless the piston or cylinder was completely trashed. So I went from a pending overhaul to just new valve cover gaskets. Now i can move onto other areas of this poor neglected truck. Already pulled 40 feet or so of useless wiring out from under the hood! And countless wires hanging down from under the dash. Definitely a score for $600!
MontanaJack
Full Access Member
Was the white smoke slowly getting worse? I'm thinking I might have a similar issue. There is a bead of burned oil that has seeped out between the block and the exhaust manifold on the passenger side front most cylinder. And my truck is slowly smoking more and more. unreal amounts of smoke when I first start it up, and a rough idle.
So pulling that GP and cranking the motor should produce both vacuum and pressure? And you're saying that if there is only vaccum, then the valve is not letting air in properly?
So pulling that GP and cranking the motor should produce both vacuum and pressure? And you're saying that if there is only vaccum, then the valve is not letting air in properly?
Yes exactly! It got progressively worse from when I first checked out the truck for purchase a months ago til I finally fixed it. I'd pull your valve cover before starting it again. I had the oil seeping on the manifold, and even on the same cylinder as you're describing. Good luck! Hopefully it's as simple for you as it was me. Be sure to use red locktite so it doesn't happen again!
MontanaJack
Full Access Member
Well I pulled the valve cover and didn't see anything out of the ordinary 
Aside from loose or broken rocker arms, is there anything I should check before put the valve cover back on and break the bank to try a new injection pump?
Aside from loose or broken rocker arms, is there anything I should check before put the valve cover back on and break the bank to try a new injection pump?
fsmyth
Full Access Member
Well, a leak-down test will give you a rough idea of rings/valves/leaks.
You can generally narrow the problem area down. Combined with a
compression test, you can get a fairly good idea of the mechanical
condition of the engine. Next thing I would do would be to test the
injectors. Just a little bit harder than changing spark plugs
Generally, the folks that test the injectors can also check the pump.
You can generally narrow the problem area down. Combined with a
compression test, you can get a fairly good idea of the mechanical
condition of the engine. Next thing I would do would be to test the
injectors. Just a little bit harder than changing spark plugs
Generally, the folks that test the injectors can also check the pump.
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