Engine/Transmission (1998.5 - 2002) Intake Valve Loose

[RGramlow]

I am wondering if anyone has ever seen this before. I went to adjust the valves on the 01 pickup listed in my sig, and found the number 5 intake valve was loose when the engine is on TDC compression number one cylinder. I haven't checked into it much yet, but this afternoon I am going to look deeper, at first look it didn't appear that the push tube was bent, and all the adjusting screws seem to be about the same so I don't believe that the screw just backed out. Possible that a cam lobe wore off? Any input would be appreciated. The pickup seemed to run fine other than surging when cold which I am thinking has to do with the APPS. The pickup has around 160,000 miles. Thanks

 

[DCreed]

what do mean by "loose"?

 

[B.G. Smith]

Do the valves on #1 have clearance in that position? If not then you are on TDC on the compression stroke of #6 cylinder? I'm sure you already knew that but that can happen. bg

 

[Forrest Nearing]

all valves should have lash on the compression stroke as they are all closed.



now, if there is excessive clearance, that's another thing completely



I don't believe 01's have press-in valve seats, but I recently saw a 3rd gen that dropped a seat and one of the valves had a ton of lash. the seat had dropped and the piston hammered the valve into the seat wedging the seat in crooked, thus hanging the valve a little. when the engine was running, the cross mechanism was simply bowing over and only opening one of the exhaust valves on that hole

 

[RGramlow]

Do the valves on #1 have clearance in that position? If not then you are on TDC on the compression stroke of #6 cylinder? I'm sure you already knew that but that can happen. bg

Like I said in the first post, the engine is on TDC Compression #1 cylinder It seems the clearance is about the same as the exhaust valve which is the valve that should be adjusted with #1 tdc compression.

 

[DCreed]

and found the number 5 intake valve was loose



at first look it didn't appear that the push tube was bent,

and all the adjusting screws seem to be about the same so I don't believe that the screw just backed out. Possible that a cam lobe wore off?

So you meant the rocker arm has excessive lash?

 

[Forrest Nearing]

Like I said in the first post, the engine is on TDC Compression #1 cylinder It seems the clearance is about the same as the exhaust valve which is the valve that should be adjusted with #1 tdc compression.

you realize that when the piston is at TDC on the compression stroke, there is an explosion occuring in there... all valves are closed at that point. so all valves would have lash. If the intake valves were "tight", they'd be open.

 

[AFoulk]

I think what he's getting at is that the intake rocker had just as much lash as the exh. valve which shouldn't be, the exh. valves always have more lash because of the heat they see which causes them to expand more. I don't remember the specs. off hand. How excessive was it?

 

[RGramlow]

you realize that when the piston is at TDC on the compression stroke, there is an explosion occuring in there... all valves are closed at that point. so all valves would have lash. If the intake valves were "tight", they'd be open.

Read what I wrote, the engine is on Top Dead Center Compression #1 cylinder, in this position Intake valves 1,2,4 should have clearance and can be adjusted, and 1,3,5 exhaust valves should have clearance and can be adjusted, well, I found 1,2,4, and 5 intake all have clearance. That is what I am saying. I did word it wrong, the valves aren't loose, and the springs appear to be the same height as the others, the rocker arm clearance is what I found loose.

 

[DCreed]

if you have access to a dial indicator you can measure the lift to see if that lobe is excessively worn.