Symptoms of too loose/tight rocker arm?

[Clark6]

I already know what the symptoms (FOR ME) would be for too loose of a rocker arm. mine started clacking loudly (one #3 exhaust arm) after I got on it on the highway, as soon as I let off the pedal, clak, Clak, CLAK!! all the way for about a mile on my way home. I took the covers off adj. the exhaust rocker, it was loose- I just snugged it on the pedistal mount rocker and locked it down.{I have no feeler gauge, Ive done this last year and was fine} The bee hive springs looked good ..... Put every thing back together and drove it for about 2 days rode smooth.

Now Im getting the horrible buck at 45, 55 mph. I get on it, it goes away. I try to start cruising it bucks again.?? cranks up and idles fine, no backfiring while driving at all. Just the surge or bucking is the best way to describe it.

Thought it was the plug wires, changed them to new ones, unplugged the tcc solenoid; same thing,.. changed the ignition module to a new ac delco, spark plugs doesn't look wet or too bad. Changed the coil pack too with various ones that I have.. All it does is just change the rpms at which it starts bucking again.

Is it possible that when I adj. them the lifters had bled down and later then somehow I have the push rod a SMIDGE too tight keeping it opened too long or something? That was the last thing I done but it shouldn't have rode as good as it did for 2 days if it was that, I was thinking. I thought it was bad gas but I filled up at a Chevron station where I always do. but thats what it acts like bad gas or a bad spark plug wire. No engine codes are showing up.

I haven't taken that cover off but would that be a symptom of a loose or I meant too tight a push rod adjustment? Thanks guys in advance.

And sorry for my typing illiteracy.

 

[Amelio]

sounds like you may have answered your own question.........yes you could have adjusted your rocker with a lifter that bled down....then when it pumped back up you are having an issue.I have not had that on my GN cause I got stock valve train but I did have that issue on my buddies tired 350 in his vette. I was constantly adjusting and basically the motor was old and tired.....I out a new oil pump cam and lifters and have not touched it since.

How many miles on your engine? Flat tappet...solid...roller?

 

[Clark6]

Thanks Amelio, Im hoping thats what it is, I hate for it to be a wiring issue that I can't find.
The only thing that gets me like I said it drove great for 2 days. If it had bled or pumped back up I assumed it would have done it a few miles down the road.

Miles on the engine?,,,, hmm I don't know roughly about 4000.. Ive changed the oil at least 2/3 times . I change mine when the oil is black around (2000) with alky.

valve trane is Scorpion rockers with a Comp 212 roller cam. (In sig).

I'll get to removing valve covers tomorrow when I get off work. Im gonna just back off just a hair, enough to feel the push rod spin around.... even though thats what i did last time.


My original question though, what would be the symptoms of a rocker adjusted too tight? Or if anyone else has had this problem, would that be an indicator? Ive had it too loose and it either clacked real loud, or when the engine was running it seemed as if I had a BIGGG Cam in it and loped big time. With a little spit sound coming out of the exhaust. Never had a symptom of one being too tight... Until now if thats what it is, Thanks I was just wanting to know before I had to go by some more gaskets, didn't want to dig in again unless it was a last straw.

 

[Amelio]

sorry....to your original question yes it will spit and sputter cause your hanging the valve open when it should be shut either way an exhaust or intake its gonna cause popping sound and sputtering. I have had popping sound come back through the carb when an intake valve is too tight...compression coming back up....I have not had that issue with an injected car or a turbo car at the least could be some serious issues there. and on the opposite too loose it just clacks and will cause performance loss cause now your not opening the valve enough.

best just to start over and check all of them so you know where you are and if the problem is still there then you know where not to dig. If it is still there and you think you have a wiring issue 9 times outta 10 its a ground. Check both positive and negative batt cables since they both run right by the Down pipe. then start with checking all your grounds. You will save a lot of time starting there.Trust me I recently went through every wire in my harness running down gremlins.

Best of luck.

 

[TurboTnZ06]

Check the TPS voltage slowly through the pedal travel, maybe there is a dead spot? Edit - sig says u have a scanmaster, so should be easy to check

 

[Clark6]

better than that, I have powerlogger and a new tps. Recorded runs rompin around on the back roads when it does it tps was checked first. Thanks for the repsonse though. Even swapped computers. Logs not showing anything unusual.

 

[TurboBuRick]

Sounds like the converter.

 

[Clark6]

Kinda thought of that too. But as stated thats exactly what it feels like. The converter is not that old. However i did take the lock up solenoid loose, still did it, and also it did it in 2nd gear and now since I changed the coil/ignition module it just changed the rpm in which it bucks/surge/chuggle etc. With one ign & coil set up it started doing it worse as I was pulling out of the yard and when the car was warmed up. Put the other back on It does it as soon as i drive out of the yard then quits as I get up to speed say 25mph. does it, then i get on the gas a little more it quits, let out the gas right before lock up it does it... either way I'll find out tomorrow Im gonna see if the exhaust push rod on # 3 valve is harder to rotate with the finger than the rest of them, that way I think I will know. I should have slight resistance on all of them. Not too tight. I'll report back with findings when im done with that.

 

[Clark6]

NAHH. Thats not it. rockers looked fine. I still backed off one or two on the exhaust rocker #3 & 5.

Put everything back sorta the same thing.
So im thinking it's electrical now.

Heres what I did. I put the old coil pack/ module back on.
Disconnected the tcc sol. from the trans once again.
Noticed the tps reading would hear it very slightly jerk or miss as I backed out the yard the tps between .54-94. Is when it starts out the yard, However Past that it was a little better.
With the tcc disconnected the bucking/jerking is FAR less pronounced. No bucking but you can still hear it miss slightly, but no surging; I guess 4th gear and lock up just ampiflies it. But disconnected its a little better, instead of feeling it now I just hear it.

I did notice that my tps wires, I would wiggle them outside and the car stumbled as though you would tap a bad maf.
So I took the original tps back on and took off the O'reillys same thing so it may be an issue there.
On driving back home here is what I noticed and where I left off.

It slightly surges or miss every time between the tps values .54-1.12. Once past that its pretty much under slight load and car eases on as it should.

get to fourth gear around 1700-2000 rpms with the tcc disconnected, I can still hear the vrooommmm/mmmm vruuummmm/mmmm back and forth till Im past the 2000 rpm mark.

flip the scanmaster back to see what the tps is during this its between 1.00-1.38. hence around lock up which makes it seems like its worse around this parameter once lock up is engaged.

So that look like thats where I am as of now.

So what do you think, tps wire, one. cam sensor next? took the cap off, it looks fine also.

I'll trace my tps and fix that first but that's been that way around since summer time I think. (As long as I left it alone and set it right it was fine.)

On all power log scans and looking at the tps while driving, It Never dropped or spiked up or down it just held the number and increased as it should when I eased on the throttle it's just that in these spots is where I hear the miss which feels and sound like bad plug wires. So im not to sure right now , it could be a hundred of things... This is why I really wished it was the rocker arm that way I know I could fix it. But this here could be a night mare, we'll see.

 

[TurboBuRick]

Huh......... thats a pisser.

Is the cam sensor stock?

Balancer bolt is tight?

 

[Clark6]

No the cam sensor was new with the engine build. Balancer bolt don't know. I put another crank sensor on about 2 months ago it was fine then. Its been a year since I had to put that Harmonic balancer back on because I had a water pump gasket leak. I used a small impact wrench, I suppose I'll go back one evening and double check. Thanks Rick.

 

[hiboom]

miss

with the car at idle wiggle the connectors on your fuel injection harness etc. you may be surprised i had a similar problem ended up being both the ignition module connector and the injector harness under the coil added extra ground from module to firewall.if your idle changes when you wiggle them I'll bet that's your culprit.

 

[TurboDave]

I had a similar problem to this several years ago. Surging and strangeness mostly while highway cruising at light throttle settings. Bugged me for years. Never saw anything on scanmaster. Didn't see until I had (back then) Direct scan running one day.

TPS dropouts

Something to check.

 

[Clark6]

with the car at idle wiggle the connectors on your fuel injection harness etc. you may be surprised i had a similar problem ended up being both the ignition module connector and the injector harness under the coil added extra ground from module to firewall.if your idle changes when you wiggle them I'll bet that's your culprit.

I had a similar problem to this several years ago. Surging and strangeness mostly while highway cruising at light throttle settings. Bugged me for years. Never saw anything on scanmaster. Didn't see until I had (back then) Direct scan running one day.

TPS dropouts

Something to check.

FINALLY may be on to something here.

Well I ohmed the tps wire's back to the computer the gray ref. wire was funky readings. kept messing with it and the blue wire on the tps connector till I got good readings on all 3; plugged back into the O'reillys version sorta just let it sit and idle. Wiggled the inj. harness wires and coilpack/module connector as {{hi boom}} said. ran ok.
I just let it idle and I could still hear a slight miss. Just wasn't idling as smooth as I remember it.

So once again... I put the new AC delco ign. mod. swapped with another coil pack (i have 3 old,not new) and didn't label the ones I have. I know one is only bad around 55mph because once I changed that coil pack only with another one It drove smooth as silk, b4 all this NEW stuff happened.

Any way I put another coil on with the new a/c module, I put a spare injector harness I had on right before the coil pack install reflected on what hi boom said.
Reset the computer and cranked the car, It idled SMOOTHLY this time but didn't want to speak to soon until I drove it. I let it warmed up.

and immediately slight stumble then quit.

I got on the road and noticed:

the tps now stumbles between the starting point of .74--.96.

Once past this the car runs as it should.

Stopped drove to the zone to order a part and still between these two spots is where it stumbles and around 1500rpm. Drives smoothly once past that. So don't know if its the coil pack itself or the tps, I don't think its the sensor I actually think it --MAY-- be the tps connector itself, so I ordered one and going to leave all the changing alone to be like it is.

Once I splice that and if it still does it, I'll swap for an exhange on the tps. My original tps was definately bad.

Don't know why its not showing a tps drop out though the #s are holding with the position of the pedal unless im just getting a minUte voltage drop and its too fast for the scanmaster to pick it up.
So I'll eliminate these three once my connector comes in:

1)tps connector
2)tps
3)coil pack.

In that order
and will post back findings. Thanks fellas.

 

[Clark6]

I tried to unplug the cam sensor and it runs sorta rough, just by idling. I leave it in park give it some gas rpms goes up still get the rev limiter sound though not that loud its a mild quiet miss or studder like sound. I didn't even drive it out the yard. I just plugged it back up and it idled a whole lot better. I did the same with the maf sensor, unplugged it: rough stumble. Connected it back much better.

I don't have to drive it to make it stumble; just leave it in park set the scanmaster on tps. Soon as it gets to .74-.85 you can hear the stumble, slight bumble or (chuggle/miss/cutout/ sound) through the exhaust. afr at idle is 13.4-14.8.

Ohmed tps wires to the ecm good, got a new tps, good, tapped maf & translator wiggled all wires again, good.

I borrowed a temperature lazer gun from work and decided to check the temperature at each exhaust header here is what I found:
#1 cy.-582* #2 cyl.-574* #3 cyl.-625* #4 cly.-580* #5 cyl-646*
#6-cyl-483*

anymore suggestions?

I don't know if #6 is because its so far back or what, the distance is a little different so i got up under the car the best I could there is still about 100* difference between that one and the other cylinders.

while running
I pulled ea. injector I get the rpm drop
I pulled ea. plug wire all drop even #6, #3 dropped slightly but not like the rest. If I pull the plug off the coil and hold it close I then get the rpm drop like the rest. soo I dunno.

Compression check: #1 & 2 cyl 160psi. #3 & 4 150psi. #5 150 #6 160.

 

[OneQuikSix]

Have you checked for vacuum leaks? Maybe something affecting your fuel pressure causing a stumble. If the symptoms are evident even while car is in park, I'm inclined to eliminate the usual load-induced problems like a bad ignition module, etc... I'd eliminate any possibility of TPS related problems, then check all grounds, MAF sensor and oxygen sensor. Good luck!

 

[pajo]

If it was me I would take my ignition module and coil pack to somebody with a spark tester and verify that they are ok .Next thing I would do is remove valve covers and run or turn engine to see if you have a wiped lobe ..just my two cents .

 

[Clark6]

Update!!

Well after doing several tests a little bit at a time. maybe a day here and a day there not really in a hurry; I finally fixed it somehow.

I've done leakdown, compression, parts change outs, new tps wiring and sensor.
And going through the chart on the buick cd rom. (which I think everyone needs). After the compression and leakdowns showed great. I came back here and carefully considered post #10 (thanks Rick). I unplugged the cam sensor and my car would run horribly. Plug it back up its fine. I knew it was a problem that I had to come back to but didn't think that was it.

I thought VERY, VERY hard and say when did all of this start? hmmmm.

One day I was getting on the pedal :biggrin: the car pulled extremely hard as I had been inching up on my boost and tune. This day the car just cut out in the middle of the run then came back in again... I said wow, battery cable? misfire? I looked at the log and showed the AFR had spiked pretty hi then back down. My alky was on and full tank, so I looked at the gas tank had about 1/3rd; you know that gauge ain't dead accurate....

So I said I was gonna change the coil pack first to see if that would fix the misfire. Done that the next day and parked the car... Then thought at work hey I better put some gas in, I also had that same cut out on a low tank. But Im driving the car and it rode fine I just didn't get on it until I had put some more gas in.... drove fine for a day or two and then decided to go fill up.

Filled up and got on it a couple times that's when the rocker arm on #3 worked loose. Fixed that drove it for 2 days hence I'm thinking everything is fine when the bucking started... Im assuming its that darn coil pack/ igni module. Maybe the one I put on was bad, bought a new one coil/mod. same thing hence all the symptoms above in original post..

(Think now this is a Full tank of gas trouble shooting all of this)After a month or 2 of this going by (tank getting low) I said MAYBE, JUST MAYBE there was some bad gas, OR there was a mInUte chance that I put the wrong octane in?:redface: Not sure, but maybe... I've tried absolutely everything else.

So this particular day I said Im draining the $$$$$ the gas. Went to Amoco and got 3 gallons of 93. Put it in after draining as much as I could.
Let the car idle for about 15min. eased on the gas in park, (didn't drive it anywhere) still got the stumble. I closed shop covered car, and went in the house. And said bump it, If I had a match.....

Cooled down and went to work and thought about post #10 again and said this time Im going to drive it with the cam sensor unplugged to see if it goes away. This time I unplugged it the Car did not shut off like before, I said AHA!! It always stumbled or shut of before.
So I drove it no problems... plugged it back up.. no problems for a while after driving around town for about 10 miles it shut off in the middle of the road, plugged the sensor back up and drove it home. Still stumbled slightly but felt like it was clearing up.

I pulled the sensor and resat the sensor, (I had it 0* top dead center) always have. But this time I sat it 24*After----top dead center. I didn't notice a difference but it cranked and ran fine no hickups, burps or nothing also put an old cam sensor cap on I had as a spare I'll swap back later on next month maybe...

So I'm still not sure whether it was the gas(put the remaining in my truck) or cam sensor but glad its finally fixed.

So even though long and frustrating, I learned how to do a compression test, find top dead center with a whistle in the plug hole, changed new tps wires, checked all pin out ecm wires and ign. mod. wires, I can adj. roller rockers now in no time, So I guess I did get something out of all this, I have a healthy engine and now know what to check and what not to check.
So until next time fellas thanks for all your help and I was just updating on what I found to maybe help someone else...... remember the last thing you done on somethings can help out a lot..... Im getting better at this Buick thing.:tongue:

 

[mikestertwo]

My money is on the cam sensor. Setting it at 0* is not good.

 

[Clark6]

My money is on the cam sensor. Setting it at 0* is not good.

Like I say it's possible. However it's been sat at 0* ever since march when I fixed a water pump leak. And it cranked and ran fine. I never unplugged it to see if it would stay running until I had this problem last month and found that issue. So I don't know but sure it needed fixing.

I could never remember what ATDC meant, I did't know if it was At Top Dead Center or After Top Dead Center. I was concentrating on getting the leak fixed and figured, well if it doesn't crank I know I have to fix the cam sensor setting.
This was before I knew better now.:smile: