Worn Pushrods causing hard cold start?

[Fordtoughranger]

So I am planning on replacing my pushrods as I have excessive valve train noise and they appear to be the commonly worn part on the 4.0L OHV. Question I have is could worn out push rods cause the cold start to act as if the valves aren't opening completely in a few cyl. causing it to crank over hesitantly and then idle rough? Or would this symtom be more of a lifter bleeding off after sitting for a long time?

I have searched the forum and could find anyone with this same situation, just noisy pushrods.

Also searched for OEM pushrod length and couldn't find it. Napa Autoparts lists 3 different lengths at 5.42"/5.45"/and 5.48", so not sure which one to look for.

Thanks

 

[rockwerks]

So I am planning on replacing my pushrods as I have excessive valve train noise and they appear to be the commonly worn part on the 4.0L OHV. Question I have is could worn out push rods cause the cold start to act as if the valves aren't opening completely in a few cyl. causing it to crank over hesitantly and then idle rough? Or would this symtom be more of a lifter bleeding off after sitting for a long time?

I have searched the forum and could find anyone with this same situation, just noisy pushrods.

Also searched for OEM pushrod length and couldn't find it. Napa Autoparts lists 3 different lengths at 5.42"/5.45"/and 5.48", so not sure which one to look for.

Thanks

So where did you find out about the pushrod problem. Frankly Ive never heard of a pushrod problem, got a link?

 

[Fordtoughranger]

Maybe I should have specified the pushrod to rocker arm ball and socket being worn and becoming galled. From what I see valvetrain noise in a 4.0L OHV engine is most likely due to worn pushrod/rockers and not the hydraulic lifters.

 

[Big Jim M]

You haven't been around long enough! Back in the day before hydrolic lifters all we had were solid lifters.. We had a saying..If you can hear em, they are doing Ok!
Noisey hydrolic lifters don't cause hard starting!
As for the length.. If you can already hear em you most likely could use the longest available.
Back to the hard start. If it just cranks and cranks and then after a while it starts and runs as it should.. That could be the fuel pump leaking back into the tank while not running. The cure: Turn the key to the run position for 10 seconds and then turn it farther to the starter.. If this works leakback is the culpret..
It could be the engine/computer temp sender not telling the computer the engine is cold.. and the engine trying to start with the setup for warm engines.
Could also be other things.. But in winter these come to mind first.
Big JIm

 

[Original_Ranger84]

Yeah I'm not sure about this pushrod knock... they are made of hardened/heat treated steel and are pretty much invincible... could be the rocker arms

 

[rockwerks]

Yeah I'm not sure about this pushrod knock... they are made of hardened/heat treated steel and are pretty much invincible... could be the rocker arms

That was my thought. when I rebuilt my 427 I reused all the pushrods. none of them showed any wear after 200,000+ miles

 

[Big Jim M]

Rock that 427 had adjustable rockers..didn't it? Our rides don't have any adjustment in them except the small amount available by installing the slightly longer pushrods.. These longer pushrods are designed to be used when the ROCKERS are worn! The extra length allows for the wear in the roickers and the rockerballs.
Big JIm

 

[rockwerks]

Rock that 427 had adjustable rockers..didn't it? Our rides don't have any adjustment in them except the small amount available by installing the slightly longer pushrods.. These longer pushrods are designed to be used when the ROCKERS are worn! The extra length allows for the wear in the roickers and the rockerballs.
Big JIm

Why would anyone build a non adjustable rocker? That is moronic at best and designed obsolesce, typical of the new ford..........lets make it so you have to spend tons to keep it on the road

 

[Fordtoughranger]

With the starting issue I was just thinking it should be related to the noisy valvetrain as when it seems to have a little bit of a rough start the noises seem to be that much worse. Then the one time it acted as if the engine was trying to be turned over but it was under compression as if the exhaust valve in one of cylinders may not be opening enough, but after a few seconds it finally got enough to start and then idle rough for a few minutes. Most of the time now it will start okay, but have lots of valvetrain noise, and then putting a load on the engine I can notice it is not running on all cylinders. Then once it gets warmed up everything seems fine other than the noise that comes at about 2second intervals or so.
I may be crazy but I just figured that if the pushrods were worn and rocker arms were worn bad enough and the lifter is having issues pumping up then maybe it wouldn't be able to open its valve the neccessary amount causing the hesitation and miss. My thinking may be wrong though.
I hope to work with it tomorrow and try some different things.