Hey I am still having problems with adjusting the valves. I have gone through the process about 15 times or more. Both static and with the motor running... The motor seems to quiet down after I adjust the valves on one side. Then by the time I am done with the other side. The car starts ticking again. I think the nuts may be loosening themselves. I put the car back together and took it around the block and then idled it for about 5 min. or so then I heard a loud tapping every 10 seconds or so like one of the rocker nuts had worked loose then 2 min. later the loud tapping was constant and I had to shut the motor off (it was scaring me)


The motor was replaced with a new motor few years back (Maybe like 8 years ago. The machine shop told me the heads were off a 95 4.3L. Could this new motor need a different method to adjust the valves? Do the valves even need to be adjusted on a 95 4.3L? The rocker nuts are not lock nuts of any kind.


Also, The rockers only spit oil when I loosen the nuts and it ticks... Is this normal? Please help. I am running out of things to try.

The rocker nuts are supposed to be self-locking. Get a new set.

The rocker nuts are the same ones that I took off the car... It ran perfect for 60,000 miles with those nuts. I don't see how replacing them will make it any better. I was just putting that in my description to help describe the motor since it was a replacement motor. I am assuming my car does not need locking rocker nuts because the new motor did not come with them. In other words I am asking, since my motor does not have locking rocker nuts... does that mean my motor has self adjusting lifters and the nuts should be tightened all the way down?


are rocker nuts a one time use part? Do they need to be replaced once removed?

IT seems every time I go to check on the rocker nuts they are loose. I just went out and pulled the valve cover on one side of the car and 4 of the 6 valves were loose. I could move the rockers side to side without much resistance.


what do the rocker lock nuts look like? do they have plastic on the inside?

The rocker nuts are the same ones that I took off the car... It ran perfect for 60,000 miles with those nuts. I don't see how replacing them will make it any better. I was just putting that in my description to help describe the motor since it was a replacement motor. I am assuming my car does not need locking rocker nuts because the new motor did not come with them. In other words I am asking, since my motor does not have locking rocker nuts... does that mean my motor has self adjusting lifters and the nuts should be tightened all the way down?


are rocker nuts a one time use part? Do they need to be replaced once removed?

IT seems every time I go to check on the rocker nuts they are loose. I just went out and pulled the valve cover on one side of the car and 4 of the 6 valves were loose. I could move the rockers side to side without much resistance.


what do the rocker lock nuts look like? do they have plastic on the inside?
i always thought they where just poly/nylon lock nuts

The stock nuts are self locking. If the swage on top (the acorn looking part) is worn, they may back off in service. Either your nuts are not locking, the studs are pulling, or the cam lobes are wearing very fast. I'd start with the nuts, but you can check the stud height with a straightedge and/or caliper if you suspect they are pulling.

Most cars go through their factory-set valve adjustment and that is it for the life of the motor. Maybe one more if it has a repair at some point or someone gets ambitious and does a valve adjustment.

Doing "15" valve adjustments plus having it apart a few times could be cause for the nuts wearing out. Since they are the easiest thing to change, I agree on getting a new set and take it from there.

Bob

Ok thanks for the input. I will try to get my hands on a new set of rocker nuts. Thanks... I had to take the valves off to change the heads gaskets.


What do you mean when you refer to the studs pulling?

If I have time I will try to get a pic of the valve nuts... The original nuts do not have the nylon locking ring on them... Hopefullly the new ones will.

Why would you have to remove the valves to replace the head gaskets? Something isn't adding up here ...

The rocker stud (the thing you attach the nut to) is pressed in to the cylinder head. There have been times when the stud will actually pull up, thus 'loosening' the nut. You can either pin the studs, so they remain in place, or you can use screw-in studs (either method requires a machine shop). If you are experiencing stud pull, then you would have to take it back apart anyway.

I doubt the studs are pulling out. I've only seen that on very few small blocks and it was with a lot of street racing abuse, oversized valve springs, etc.

Another reason to like hi-perf big blocks, they all have screw in studs!

Bob

The stock rocker nuts don't have a nylon insert. They are swaged (crimped slightly out of round) at the upper end to prevent them backing off.

http://mysite.verizon.net/strey/files/RockerView.jpg

Hey thanks for the picture.... Those are exactly what my rocker nuts look like. I did not have enough time to get my pic up. Also, thank you for clearing up the "Locking Issue"

Also, I did not take the valves off the heads when I did the head gasket replacement. I just took off the rocker nuts, rockers arms, and pushrods.

I doubt the studs are pulling out. I've only seen that on very few small blocks and it was with a lot of street racing abuse, oversized valve springs, etc. ...

Bob

As an aside, my 1972 Impala (20 years ago) had two studs that pulled up, and this on the 2-bbl L65 engine. Just normally driven, so I've seen it personally. ;)

As an aside, my 1972 Impala (20 years ago) had two studs that pulled up, and this on the 2-bbl L65 engine. Just normally driven, so I've seen it personally. ;)

Or maybe I've never noticed it, I've only seen it during head disassembly. I worked in a machine shop so I was able to drill and tap them for screw in studs.

http://www.automotiveforums.com/vbulletin/C:%5CDocuments%20and%20Settings%5CJess%5CMy%20Docu ments%5CMy%20Pictures%5CCar%20Photos%5C2008_01_30


I still have not gotten the new nuts yet. I am looking into the nuts that lock down with a set screw, but I do not know the stud thread pitch etc.

They are either 3/8-24 or 7/16 I think. My car has screw in rocker studs so I should not have to worry about the studs pulling.

I was going to post a pic, but I couldn't.

Stock studs are 3/8-24. Some aftermarket screwed studs (and big block studs) are 7/16-20. Top lock rocker nuts are fine, but unnecessary on an engine with stock 85# valve springs and a stock-ish cam profile. A new set of Dorman nuts from your local auto parts supply house should suit you just fine.

Hey guys my valve nut problems continue. I finally got a set of rocker nuts... 3/8-24 self locking nuts.


However, the nuts were too large.:banghead: My rocker studs are only 5/16-24 (found out after they were measured. The machine shop I talked to said that they do not make 5/16-24 locking rocker nuts....


I was told that 5/16 nuts need to be tightened down to 23ft-lbs. The machine shop said the 5/16 rocker studs were not used with adjustiable lifters. I am still worried about the whole sit. Should I tighten the nuts down and hand crank the motor to make sure the pistons do not hit the valves? Then try to start the car so see if it will start/run?:runaround:


Thanks Kevin At this point I do not really know what to do.

Something is funny with your parts combo somewhere. I would physically measure the studs with a caliper or micrometer. 3/8 will measure around .370 to .372, 5/16 will measure around .308 to .310, so you can verify what size studs you have there.

Once you have that solved, go to a good auto parts house and ask for a set of nuts and see what they hand you. I've never heard of a 5/16-24 thread on a Chevy valve train, but I could be wrong, again!

Bob

I'm with Bob. Even the later 60º V-6 engines used M10 studs and bolts, not M8 (roughly the same as 5-16"). Is this an Olds engine? Is the distributor in the front or rear? Check the 8th character of the VIN to be sure.

I had the studs (my studs are threaded) measured at the parts store where I picked up the rocker nuts.. They even pulled out a replacement 3/8 stud to verify the rocker nuts were 3/8 fine thread.

So in any case I know my rocker studs are not 3/8-24. They are smaller. I will try to remember to get the actual measurement when i go back to the auto parts store tonight after work.

My distributor is in the rear. I know for a fact the car is a 88 caprice. My grandparents bought the car new. The confusion is coming from the fact that my grandparents replaced the motor at around 60K with a replacment motor. I do not know when this happened. I think is was in the late 90's.

so I figure my options are:
1. tighten the nuts down and hand crank the motor to check to make sure the motor cranks without hitting the valves. Maybe check compression after doing this??

2. Replace the rocker studs with 3/8 studs and use the new nuts and try to adjust the valves with the new hardware.


Any suggestions. Thank you guys for helping me figure this out.

I've lost track of what you have there. Is it a V6 or V8? Are these the heads that you started out with? I recall you saying that your original rocker stud nuts were either worn out or had no locking feature on them?

For all the aggravation you've gone through (and you're not done yet) you could have dropped a crate motor in and would have had 5000 miles on it by now. But not for nothin' you learned a few things along the way and should be commended for asking for help and not giving up on it.

I don't get involved with the innards of my daily driving cars. If one has a major motor problem, I'm very comfy with "out with the old and in with the new". I save the time consuming work for race car or hotrod motors only, I expect to be fartin' around with those and yank them out once in a while.

Bob

Just to recap, The motor was replaced with a new one awhile back, so the motor itself is not original, I assumed that it was the same as the original motor. It is a 4.3L V-6

I am trying to salvage the motor as it only has about 65k (mostly highway miles) on it.
These are the original heads that I started out with. The original rocker nuts were not locking (or at least I could not tell that they were). The new nuts had an evident crimp.

I really wish that I would have paid closer attention when I was taking the rocker assembilies apart. I had no Idea That I had to adjust the valves durring reassembly... I found out while reading a manual 1 month later when I started putting the motor back together.

So I don't even know that the valves need to be adjusted with my set up. If only I could remember how tight the rocker nuts were when I took them off.

Thanks for the encouragement. I am still pretty young and learning.

Ahh. NOW we're getting somewhere. All 1995 and later 262 V-6 engines used non-adjustable ("net lash") rockers. SOME 1992-95 engines had adjustable rockers, and some didn't depending upon the assembly point.

Therefore, if your replacement engine is a 1992 or later, it MAY have non-adjustable rockers with 5/16-24 rocker studs, and if it's 1995-later it WILL have non-adjustable rockers with 5/16" studs.

I caught the part about the replacement engine before, but didn't realize it was a newer variety and not a remanufactured 1988 version.

You might be able to learn more about some of the differences HERE (http://www.babcox.com/editorial/ar/ar40047.htm)

Thank you very much for helping me out... I still have not been able to get back in to work on the car, but I should be able to get back to it soon.

Does any one know where I can locate the casting number... So I can find out for sure when the motor was built.

Thanks

Thank you very much for helping me out... I still have not been able to get back in to work on the car, but I should be able to get back to it soon.

Does any one know where I can locate the casting number... So I can find out for sure when the motor was built.

Thanks