Author Topic: valve bridges  (Read 2679 times)

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Csechols

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valve bridges
« on: November 26, 2011, 10:07:30 PM »
Has anyone ever had a problem with their rocker arms getting worn out were they ride under the bridges?? Mine have grooves worn into the sides of the rockers causing valvtrain noise I believe.  Its a 95 2.5 133xxx. I have all ready changed the lifters and timing chain with no luck. I didn't notice the grooves until I read somewhere that it could be an issue?

Offline sharpxmen

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Re: valve bridges
« Reply #1 on: November 26, 2011, 10:14:51 PM »
Has anyone ever had a problem with their rocker arms getting worn out were they ride under the bridges?? Mine have grooves worn into the sides of the rockers causing valvtrain noise I believe.  Its a 95 2.5 133xxx. I have all ready changed the lifters and timing chain with no luck. I didn't notice the grooves until I read somewhere that it could be an issue?

measure the preload on the lifters, if you got new lifters and pushrods the only reason they'd be noisy is if the preload is not adequate. the worn bridges and/or rockers can cause the lack of preload. Also, how's your oil pressure?
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
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Csechols

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Re: valve bridges
« Reply #2 on: November 27, 2011, 11:36:58 AM »
How do you check the preload? My oil paid is 35 at idle and. 60 at like 2500 rpm.

Offline sharpxmen

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Re: valve bridges
« Reply #3 on: November 27, 2011, 12:41:02 PM »
How do you check the preload? My oil paid is 35 at idle and. 60 at like 2500 rpm.

oil pressure is good. did you change the pushrods along with the lifters? if not buy 8 of them and replace the old ones.

2 ways you can check the preload
 - bring the cylinder in compression (at ignition stroke tdc with both valves closed), put a dial indicator at the end of the rocker where the pushrod seat is, set dial to zero, release both bolts slowly little at a time and keep going until the dial stops, read the dial indication - that's your preload

 - put a straight edge on the cyl head along the pushrods, bring the cyl in compression just like above, mark the pushrod level with the straight edge (a blade from a cutter works best and rub it against the pushrod), release the rocker bolts and mark again, measure the distance between the 2 marks.

first option is easiest though.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Csechols

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Re: valve bridges
« Reply #4 on: November 28, 2011, 09:55:48 AM »
Thanks. i will have to try and measure it. the old lifters that i replaced were in good condition.. They werent mushroomed at all and came out really easy. i did not replace the pushrods and i know i should have but i allready orders new rockers, bridges and pushrods and they should be here thursday. I hope this fixes it. I know i have good oil flow up to the valves. My compression is damn near perfect at 147psi in all cyl. I Inspected the lower end and everything looked good. kinda worries me that no one has had this issue.. haha One other thing is... i just notice this but i took my intake tube off to look down my throttle body and when i started the jeep without the intake tube on the tapping noise was 100% louder.

Csechols

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Re: valve bridges
« Reply #5 on: December 04, 2011, 01:20:40 PM »
Ok, so i changed the push rods, lifters, and rocker arms with no luck. the noise is still thier. i just spent an hour with a stethoscope and located exactly were the noise is coming from .. i used a rubber fuel line hose as my stethascope and when i put it on the bottom of the oil pan right under were the #2 piston would be i can hear the noise really loud. if i move it in any other direction the noise is still thier but not as loud as the number 2 piston. it must be a rod bearing since the noise is constant on every crankshaft revolution? when i unlpug the #2 injector the noise gets way louder. after the jeep worms up you cant hear it as much but if you stick that stethascope thier , you can hear it loud and clear. were is the oil pump located under that pan?

Offline dwtaylorpdx

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Re: valve bridges
« Reply #6 on: December 04, 2011, 01:52:50 PM »
Several years of the 2.5 and 4.0 had issues with "piston slap" it made a
clacking noise, sometimes on 1 piston sometimes on all of them. It was usually
louder when cold and quieter when warmed up.

Rod or main bearings "usually" are constantly noisy on the ones that failed for me.

Up side is its easy to drop the oil pan and check them....

Dave
94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio

Csechols

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Re: valve bridges
« Reply #7 on: December 04, 2011, 01:58:11 PM »
Yea i want myself to believe its piston slap but i just want to make sure it is... i just used my stethascope again to just double check.. i cant hear that noise on both sides of the engine  block even when i stick it near the # 2 and 3 spark plugs. the noise has not gotten any worse after 10k miles on it... im sure whatever it is if it hasnt broken yet it should be good hahaha.

Offline grumpygy

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Re: valve bridges
« Reply #8 on: December 04, 2011, 03:50:19 PM »
Piston Slap will drive you nuts.  Have a 2000 Gmc Sierra 1500.  When 1st starting it on a cold Morning it is bad, but let it Idle till its gone and it does not come back as long as its warm,  Started about a year after I bought it, So Have had that noise since 2007 and its still running strong.  But that noise drives me nuts.
94 YJ, Cool Air intake, 19lb Inj, 4.0 Throttlebody with spacer,  31/10.50/15's

Csechols

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Re: valve bridges
« Reply #9 on: December 04, 2011, 04:40:15 PM »
Yea its really annoying. Is the oil pump on a 2.5 located kinda by the #2 piston under the oil pan? and its ran off the distributor correct? im almost wondering if its my oil pump since when i first go the jeep i had about 40 at idle and 75 at like 2500. now its down to 30 at idle and 45 or 50 at 2500. Would oil pumps make this type of noise though?

Offline sharpxmen

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Re: valve bridges
« Reply #10 on: December 04, 2011, 06:15:03 PM »
could be a broken piston skirt, same issue was described in another thread and that turned out to be the problem - dropping the oil pan will tell. Oil pump won't make that noise
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

SDWE61988

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Re: valve bridges
« Reply #11 on: December 08, 2011, 10:34:19 AM »
could be a broken piston skirt, same issue was described in another thread and that turned out to be the problem - dropping the oil pan will tell. Oil pump won't make that noise

Sounds like Sharpxmen is talking about my jeep.  The symtoms of the noise near the #2 piston is exactly what I found after rulling out the valve train.  I hope I can  pull the head this weekend if I get time and pull out the pistons.  Hopefully the wife and others will give money for xmas so I can buy some new pistons :smile:

Offline dwtaylorpdx

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Re: valve bridges
« Reply #12 on: December 08, 2011, 03:15:08 PM »
I would not bother to just replace the pistons, If I found a broken skirt it would be rebuild time.

You can check the pistons just by dropping the pan.
Usually if its a broken piston it obvious. You either find bits in the pan, or you can see the cracks from below.
(Occasionally not but that's where I'd start.) While your at it make sure you have a new front main seal and
oil pan gasket set they are not really re-usable and they are not too expensive.

Beyond that a standard NAPA rebuild kit has pretty good parts, you'll need most of them just to swap the pistons...
To do the pistons right your like 80% of the way to just rebuilding the engine...

Just my 2 cents,, probably overpriced!

Dave

 

94 YJ - 2.5 Hesco Cam B&B Ported - AX5 Trans w/Centerforce Dual Friction Clutch - 4" Rough Country Lift W/Skyjacker Shocks - D44 Rear/ARB - D30/ARB - ARB Compressor - Warn M8000 in Custom Bumper - Reunell Rear Bumper - Metalcloak 6" Body Armor Kit - Tuffy Console - 265x85-16 Tires - 2M Radio

Offline sharpxmen

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Re: valve bridges
« Reply #13 on: December 08, 2011, 03:27:49 PM »
I would not bother to just replace the pistons, If I found a broken skirt it would be rebuild time.

You can check the pistons just by dropping the pan.
Usually if its a broken piston it obvious. You either find bits in the pan, or you can see the cracks from below.
(Occasionally not but that's where I'd start.) While your at it make sure you have a new front main seal and
oil pan gasket set they are not really re-usable and they are not too expensive.

Beyond that a standard NAPA rebuild kit has pretty good parts, you'll need most of them just to swap the pistons...
To do the pistons right your like 80% of the way to just rebuilding the engine...

Just my 2 cents,, probably overpriced!

Dave

 



full  engine rebuild is a whole other story so i'll have to disagree - you add crank, cylinders and cyl head rebuild and will add up to a lot more than just $150 for a good set of pistons and rings (add another $30 or $40 for the gaskets - oil pan, cyl head and valve cover is all you need). really, we're talking about 5 times more in the end (will get to $1k if not more with all the parts and machining costs) - not saying it's a bad idea but major cost difference between the 2.
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Csechols

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Re: valve bridges
« Reply #14 on: December 08, 2011, 04:29:43 PM »
Finally took my oil pan off. The noise I heard was most noticeable near the number 2 cylinder. With the oil pan on. All connecting rods could be moved from front to back - in line with the crank. None of them had play up and down. I'm not sure if Mine have too much side to side play? I mean they move from one side of the crankshaft to the other side. All the pistons looked good. No cracks or broken skirts. I'm not sure were to go from here. The oil pump and distributer are in that area were the noise was coming from. One other thing is I kinda twist the connecting rod and see the piston move sideways a little bit. Every cylinder does this. I'm not sure what to do next. Here's a video
 <a href=http://s1128.photobucket.com/albums/m494/csechols38/?action=view&current=VID_20111208_144859.mp4 target=_blank><img src=http://static.photobucket.com/player.swf?file=http://vid1128.photobucket.com/albums/m494/csechols38/VID_20111208_144859.mp4 border=0 alt=>[/url]