Dropping valve seat?

9

95cummins

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Joined
Oct 4, 2007
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19
Well, I adjusted my valves a couple of weeks ago. They were still pretty close, but were just hair off.

Fast forward to this week. I get home from work, and the truck is loping and missing. Also getting a slight tick.

I pulled the injectors and had them checked out and they were fine. While I was pulling the injectors I noticed the rocker arm for the exhaust valves on cyl. number 5 was loose as a goose.

It was about .05" out of spec. Checked pushrods and they were fine.

I guess my question is, what is the more likely scenario..... Dropping a valve seat or eating the lobe on the cam? :nail:

Any way to check without pulling either?

Thanks!
 
Would you go to You Tube and type in JL Welding Tk and see if that is the same lope your having?
I am about to go broke trying to figure what is wrong with mine. I have droped 4k in mine because cant find anything wrong.
Thanks Joe
 
Im right behind JL on this one. Does your truck run smooth as silk in the mornins and as it warms up it goes to missing and loping. Ive dropped alot of money in the electrical thinking thats what it was and now were left with mechanical. I dynoed my truck to see if power maybe would show somethign and nothin. My truck runs like a dream once above idle. Milage has dropped probaly 2-4 mpg.
 
Usually when a valve seat dropps u will hear it out the tailpipe or intake its pretty noticiable.
 
The miss would follow the rpms. The truck was not running smoothly at all. Hopefully gonna tear it apart today, I just don't want to tear the head off and it be the cam or vice versa.

I just find it weird that it was that far out of adjustment in a matter of a couple of weeks. I would think if the cam was wearing down it would gradually getting worse. This seemed to be more of a sudden thing.
 
95Cummins
Did you get a chance to go to you tube and listen to my truck? I dont know what to do ,I think it has to be in the head.
 
My 98 I just bought does same thing as yours jl welding runs smooth when in gear or cold but warm it's got a horrible fast lope that shakes the piss out of the truck
 
Mine is doing it too and i think me and jlwelding are gonna hook them bumper to bumper and light em up! I could have made 700hp by now if you added all the money ive spent trying to figure it out!
 
Just pull the rockers off and measure the valve height on the valve that was loose and compare it to a few of the others.
 
Jlwelding, my truck didn't quite sound like that. Yours sounded a little more erratic than mine did. It had a miss that followed the rpms and wasn't jumpin around so much.

Well, I pulled cam out and there is some definate wear on the lobes on probably 4 of the 6 exhaust lobes. Intake lobes appear to be fine.

Found the one valve on cyl. 5 ( the one I had my original issues with) that is about an eighth of an inch shorter than the rest. So head is coming off tomorrow.

Hope I caught everything in time that it didn't do some serious damage.:doh:
 
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