0 compression problem solved?

[Mephisto]

Maybe....

Well first off, let me come right out and say I'm an idiot.

Sorry for wasting everyone's time asking dumb/speculative questions instead of just tearing into this bitch to see what was wrong.

I'm even more angry at myself now, because my truck has been sitting for 2 years with what I thought was a blown head gasket. Went and bought a new compression tester yesterday, pulled all the plugs, and rechecked all of the cylinders. Turns out I have a solid 150psi in 5 cylinders and 0psi in #1. With all the plugs still out, I reinstalled the #1 plug, pulled the radiator cap, and tried to turn it over for 5sec... nothing... no bubbles... So if that poor man's head gasket test is legit, then maybe the head gasket isn't blown. Today I pull the drivers side valve cover off and find this... :roll::roll::roll::roll::roll::roll:

My guess is because the motor had been sitting for so long before I put it in, that the valves got gunked up and this one was so sticky the push rod just popped out. I pulled the push rod and there's a little shine where it was rubbing on the head, but it's perfectly straight... Now fingers crossed it's not actually a burnt valve.

Reference my earlier "I'm an idiot" statement... should I attempt to reuse the same push rod? Or just go get a new one? Also, what's the torque spec on the rocker? 25ftlb? 50?

If this thing runs like a top after I fix this, for stupidity's sake I may just have to quit these trucks haha.

 

[Slyclone]

Re: 0 compression problem solved?

Good luck with your truck. Hopefully something fruits out of this.

I have to look but I'm pretty sure I have a box of factory pushrods sitting around I pulled from 1993 Typhoon engine. If you need one two or all of them let me know. I haven't had a use for them.

 

[IGottaSy]

Re: 0 compression problem solved?

Look at it this way, your truck has less miles as a result. Good for you. Easy fix.

To set preload...

Loosen nut till you hear clicking
Tighten till clicking stops
Then go another 1/4 turn

At least that's what I do with hydraulic lifters.

 

[wildphil]

Re: 0 compression problem solved?

Never mind. I posted a thought that may not be correct so I deleted it.

 

[Mephisto]

Re: 0 compression problem solved?

Look at it this way, your truck has less miles as a result. Good for you. Easy fix.

To set preload...

Loosen nut till you hear clicking
Tighten till clicking stops
Then go another 1/4 turn

At least that's what I do with hydraulic lifters.

Thanks GottaSy for the heads up! :tup:

I'll dive back into it next weekend when I have more time, and keep my fingers crossed that this was the sole culprit. Although this does have me wondering if the whole motor is all gunked up from sitting for so long. Oil change is definite, but I'm debating if I should throw some Mystery oil in and run it for a while just to see if I can clean any of that out before putting new oil in.

Also, I can't seem to find anything online that links this as a cause for high idle at start up... any of you guys ever heard of high idle from a popped off push rod? Might have a whole other problem to sort out after this.

And by high idle, I mean 2000 to 3000 sometimes even higher... sometimes it corrects itself after a few minutes and goes back down to normal... other times it doesn't. Already replaced the MAF sensor twice just to be sure, and swapped 2-bar and 3-bar MAP sensors with no change. Could it be something else that's getting stuck and after the engine warms up it breaks loose? Some other sensor I'm not thinking of?

 

[Static]

Re: 0 compression problem solved?

High idle could be a vacuum leak. I would also pull the TB and clean out the IAC passages. Possibly carboned up. We dont have a MAF sensor. You need to have a 2 bar with a 2 bar tune.

 

[Z SKI]

Re: 0 compression problem solved?

Dude... All I gotta say is.....:rotf:

 

[Mephisto]

Re: 0 compression problem solved?

High idle could be a vacuum leak. I would also pull the TB and clean out the IAC passages. Possibly carboned up. We dont have a MAF sensor. You need to have a 2 bar with a 2 bar tune.

Hahaha sorry, had MAF sensor on the brain from my DD... meant to put IAC valve.

I have an ATR chip with 2 bar (still trying to track down a stock chip), and I popped the 3 bar in there and piggy backed the ATR onto my ultimate chip, just to see if the problem was with my 2bar sensor. But no change. The TB looks clean, but I'll pull it anyway just to rule that out.

Dude... All I gotta say is.....:rotf:

hahahaha right??? You gotta figure this thing sat for so long, then I finally get it running and a month later it stops working, and we all thought it's the head gasket... the thought of having to tear the whole truck down again was a kick in the balls and had me ready to drive this thing off a cliff! Especially since I was already in financial hell with my house. It's gonna be even more of a kick in the balls if this is all that's wrong... but on the bright side I budgeted money to get this fixed, so maybe now I can use that for some coilovers. But! Let's wait and see if this is indeed the problem.

 

[DaveP]

Re: 0 compression problem solved?

Is that an Exhaust or Intake rocker that came off? (Regardless of which, remove the rocker and inspect the 'guides' on the rocker tip that keep it centered on the valve stem. Or just replace the rocker with one from a FLAPS to be sure.)
I can't think of an explanation for why the rocker came off if the push rod isn't bent. The nut appears to be in the same position as its neighbors. It didn't loosen on its own.
Are you in SoCal? Have I met you?

 

[Don W.]

Re: 0 compression problem solved?

Dave, Agreed but, looking at the picture it's hard to tell but it looks like the stud might have pulled enough to cause this which would, among other things, indicate a stuck valve. Prolly should lay a straight edge across all the studs to be sure. Since it's by itself between two exhaust valves and the angle of the photo I'm sayin' it's #1.

 

[Mephisto]

Re: 0 compression problem solved?

Is that an Exhaust or Intake rocker that came off? (Regardless of which, remove the rocker and inspect the 'guides' on the rocker tip that keep it centered on the valve stem. Or just replace the rocker with one from a FLAPS to be sure.)
I can't think of an explanation for why the rocker came off if the push rod isn't bent. The nut appears to be in the same position as its neighbors. It didn't loosen on its own.
Are you in SoCal? Have I met you?

Hey Dave, it's an intake rocker. I haven't popped the rocker off yet to take a look at it. You are correct though, the nut is tightened up the same as the others yet there's plenty of room between the push rod and the rocker. I'll see what it looks like at TDC, but even then there shouldn't be THAT much room. Maybe the lifter is just stuck and not actually broken (wishful thinking)?

Yeah I'm in SoCal... We may have met before, it's been at least 10 years since I've been to a meet though. We may have met at Flames in Northridge, or maybe Bob's Big Boy in Burbank, or The Loft in Torrance? Those are the ones I remember with the biggest turn outs.

 

[Timbo]

Re: 0 compression problem solved?

Could a lifter collapse enough to allow that to happen?

 

[Don W.]

Re: 0 compression problem solved?

I suppose. He could put the rocker back where it belongs and see if he can move the pushrod with the rocker. Search "collapsed lifter" on the web to see what I mean. I would still check that stud though.

 

[DaveP]

Re: 0 compression problem solved?

Ok, I didn't think of a pulled stud. Don got it. That would cause the rocker to come off. And now knowing that it IS an Intake, I know what caused it. Detonation. Every time. MattW had the same deal on his V8 4-door. Detonation and pulled Intake rocker studs.

You can pound the stud back in, but it will probably work out again. They make screw-ins that can be installed with the head still on the engine. I would just do the one stud, get it running again, and go from there.

I never went to any of those places back in the day. Most of the gatherings I've attended have been more recent SoBay deals.

 

[Don W.]

Re: 0 compression problem solved?

I know what caused it. Detonation. Every time. MattW had the same deal on his V8 4-door. Detonation and pulled Intake rocker studs.

Interesting correlation. I never would have thought of that. Don't know exactly how that happens but I'll take it.

 

[DaveP]

Re: 0 compression problem solved?

Interesting correlation. I never would have thought of that. Don't know exactly how that happens but I'll take it.

I read this a zillion years ago, probably in one of the "Hot to Hot Rod Your Big Block Chevy" books first published in the early 70's. "A tulip'd Intake Valve, or other destruction on an Intake is always a symptom of Detonation".

I validated this statement on the inaugural run of the 11:1 327 in my ski boat back in 1977. I destroyed all 4 center valves in one big "POP" with flame and shit coming out of the stack. Pretty cool stuff, but A: I couldn't afford to fix it again but had to, B: I wasn't sure what had happened, C: It was a long way back to the trailer with it barely running. Turns out jetting for a 1/4 mile set-up is WAAAAY too lean for full throttle marine applications. It got too hot in there, detonated, and bashed in the valves. The engine had been in my Chevelle prior to going in the boat. I didn't know better about tuning at the time.

I posit that the detonation against all that Intake valve area deflects the stem upwards against the rocker which has a mechanical advantage to lever the stud upwards. The hydraulic lifter doesn't deflect. As the stud moves up, the clearance increases, but the lifter takes it up. Eventually the lifter is fully extended, and off it comes. The head of the Intake valves is fairly thin. I can see where it could deflect then spring back, causing the stud to push.

That's my guess.
I

 

[Don W.]

Re: 0 compression problem solved?

Sounds good to me.... Thanks, Dave. In my limited experience with stuck valve they stuck open not closed anyway.

 

[Mephisto]

Re: 0 compression problem solved?

Ok, I didn't think of a pulled stud. Don got it. That would cause the rocker to come off. And now knowing that it IS an Intake, I know what caused it. Detonation. Every time. MattW had the same deal on his V8 4-door. Detonation and pulled Intake rocker studs.

You can pound the stud back in, but it will probably work out again. They make screw-ins that can be installed with the head still on the engine. I would just do the one stud, get it running again, and go from there.

I never went to any of those places back in the day. Most of the gatherings I've attended have been more recent SoBay deals.

I'll check the stud height with a straight edge tonight and see if that's what happened. What I'm curious about though is if I add a threaded stud, how exactly do i thread the head to take the new stud without getting shavings down into the head? Unless they make rocker studs that are kinda like some wall mounting studs where the stud is splined and you insert it, and as you tighten it the bottom buckles and cinches on the backside?

Ahhh ok, so then we probably haven't met before. Just figured since you'd been around since 2000 we may have crossed paths at one point or another. A lot of the old school SoCal guys have all sold off their trucks. Doug, Brian, George, Adam, Steve. There's only a few of us still hanging on haha. I wonder if Dean still has his? I'm sure Scott still has his white challenge Sy, that's a Charlton Heston "from my cold dead hands!" truck haha.

 

[DaveP]

Re: 0 compression problem solved?

The stud I'm thinking of doesn't have the "hex" on the bottom like factory-equipped screw-in studs. The factory stud requires that the boss be machined flat for the hex to bottom on. The "fix-it" stud I'm suggesting has threads on the bottom, and after the hole is tapped, it is screwed in with red loc-tite. Don't worry about chips falling into the hole, it's just water down there and they won't hurt anything. DO try to prevent chips from going down other holes into the valley, and clean up everything in the head. Any stray chips may find their way into the pan, then through the oil pump. Not all oil is filtered, the chips can make their way to the bearings, or into a lifter and cause problems.

I talk to Scott from time to time. He still has the Challenge truck. And a Royal, and two SoGt's. I saw Brian and Cliff about a year ago, and Brian still has his Ty, but I don't think it runs. Same with Cliff. I haven't seen Dean in 20 years. He popped on here a few months ago; still has his truck, but it doesn't run either. There's a trend with these things if you keep them long enough. They end up broken and forgotten.

 

[Don W.]

Re: 0 compression problem solved?

Quick search found these:

http://www.speedwaymotors.com/Screw-In-Rocker-Studs-3-8-Inch,838.html

I didn't research how to install them. When you drill just be sure to thoroughly plug the drain backs at each end of the head then you can clean things up and finish with an air gun which should pretty much get everything.

Not cheap but this:

https://www.goodson.com/Rocker-Arm-Stud-Conversion-Kit/