Engine/Transmission (1994 - 1998) truck down, help!

[mfunderburgh]

I am having problems with my truck. Friday night the truck started sounding like it had a miss. Ten minutes later the truck just started blowing white smoke and lost power. Check timing and all was ok. Took off vavle covers and #3 intake push rod is not on rocker. It was just kind of off to the side and yet it was still on the tappet. So i pull rod and make sure its ok. No signs of being bent or even any scratches. So i reinstall and set all the valves accordingly. Take it for a test drive and all is well. I continued to drive it around the farm all day and everything seemed a ok.

When i got about 40 miles into my 45 mile drive back to school

the truck started acting funny again. My boost gauge was would bounce when i got over 20psi. Then all of a sudden it started stumbling just like friday night and smoking white again. I managed to get the truck to school but she is sitting for now.

Anyone have any idea on what would cause a push rod to move off the rocker. I haven't checked it yet, because its dark, but i am sure its going to be the same thing i just fixed. Thanks, Matt

 

[JohnE]

bent valve stem?

valve spring compressed?

valve spring seat?



Which valves springs and how much rpm do you run?

 

[Missouri Mule]

mfunderburgh,

Looking thru trouble quides in old service books they did not mention rod just being a little cock-eyed. Seems noise is required but I'll gve you some ideas from the books that sounded like your problem.

The miss and bouncing guage should of been caused by the rod being loose. (not opening the valve all the way).

White smoke?

Rod not centered on rocker arm. Rocker arm bolts not torqued to specs. Burnt valve? Out of round (journal) lobe on shaft?

Connection rod bolts not torqued? Valve springs?



I would check torque on pedestal boltsfor no. 3 cylinder

Compression test would be good idea.



I will try and look at a few other service manuals (chilton's mostly) see what I can find.

 

[mfunderburgh]

Thanks for the replies guys. I will have to check torqs out in the morning but i have a feeling its going to more the just the rocker bolts out of torq. I am running some eep high performance 60lb springs and the titanium keepers and stuff. The head was worked over by them a few thousand miles ago when i built the motor. As far as rpms go i have seen 4920 on my tac playback once. I hope there is nothing wrong with one of these cam lobes as this cam is not a cheap one. All i know is i got to find a daily driver as these pulling trucks are just too much work to keep running on the street everyday. Matt

 

[mfunderburgh]

Well i had a fun afternoon. Took valve cover apart and pushrod was off the rocker. Tried to push the rod onto the tappet and there was no tappet. I proceded to pull the cam and found that the lobe for the #3 intake was tore up pretty bad. Now i got to figure out what in the hell caused this problem. Could a tappet just go to hell and cause all this wear on a cam? I will be headed to eep tomorrow to see what the possibilites are and to get a new cam. Matt

 

[JGheen]

Originally posted by mfunderburgh

Well i had a fun afternoon. Took valve cover apart and pushrod was off the rocker. Tried to push the rod onto the tappet and there was no tappet. I proceded to pull the cam and found that the lobe for the #3 intake was tore up pretty bad. Now i got to figure out what in the hell caused this problem. Could a tappet just go to hell and cause all this wear on a cam? I will be headed to eep tomorrow to see what the possibilites are and to get a new cam. Matt

How long has the cam been in the engine?? Maybe not proper break-in period?? I have seen many gasser cams flatten lobes due to the operator not allowing proper break-in time. Maybe oil stravation somehow, check all oil passages?? Sounds fishy, but I am sure EEP will be able to diagnose the issue being they built the thing. What else is done to the engine?? I would imagine a lot since you said you wrapped it out to 4900 revs!:--)

 

[mfunderburgh]

Cam was put in when engine was built about 3000-4000 miles ago. Trucks got the billet pulling cam flycut marine pistons and so on. I dont think that the break in period is the problem. I'm sure the non street pulling trucks dont see a lot of break in time from time of something like a cam gets put in until the next pull. I'll let you guys know what i find out tomorrow. Matt

 

[baby.driver]

Sounds like a bad cam to me.

 

[mfunderburgh]

Took cam to eep today. Their going to send the cam out and have it machined down on each lobe to match what their going to have to take off of the #3 intake lobe. I will still have the same lift as before, i will just have to screw down the rockers a little further. They said they did have one other truck break a tappet a couple months ago. I'm going to remove all the tappets and replace them with new ones. Matt

 

[baby.driver]

That's a mickey mouse way to do it.

A new cam is in order.

Sorry to be blunt.

 

[dseabaugh]

I have pulled out valve lifters and found the bottom (cam) side pitted where the metal was chrystalized when hardened and came apart. I would also wonder if the valve is gaulding up in the valve guide and staying open ? Weak valve spring? Broken /cracked valve spring? if it is going to toss the lifter then it is bound to tear something up, just the nature of machines.

 

[mfunderburgh]

Not trying to be a smart a$$, just seeing if this is just your thoughts or if i need to be worried, but honestly what are your experiences with regrinding billet cams? Faster wear or what? I dont see eep trying to screw me because i'm at there shop every week and they know i'm not going away. I don't think they would micky mouse my motor knowing that i'm not stopping at 4900rpms. Matt

 

[mfunderburgh]

I have pulled out valve lifters and found the bottom (cam) side pitted where the metal was chrystalized when hardened and came apart. I would also wonder if the valve is gaulding up in the valve guide and staying open ? Weak valve spring? Broken /cracked valve spring? if it is going to toss the lifter then it is bound to tear something up, just the nature of machines.

I have thought about pulling the head to have it checked out. I just dont want this to happen all over again. Maybe i'll just yank the motor again for fun to check everything out. Matt

 

[dseabaugh]

If you ar ecranking out that kind of rpms , then it is very likely that the thing is floating out. You may need stronger valve springs to keep it from happening again. You might want to see if any pistons and valves have had a happy reunion. You may have a bent stem on this valve.