# 1968 GTO valve ticking



## rob40999 (May 18, 2018)

Hello Jim and Bear: 

Well, we pulled the valve cover's and my new old mechnic looked at the rocker arms and the push rods. He tighted down the rocker nut to 20 Ft. Pound's. Ticking still very weak. Meaning not as much noise. I wonder if we replaced the rocker arm and push rods will this help. The mechanic did really do a expection of the push rods. He said, this engine was rebuild at some time. He believes the cam is getting worn. He said alot of stuff which I did not know?????
Just wondering if we changed out the rocker's and push rods will this stop the ticking noise????? 
Happy Holiday's boys: Bobby


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## BearGFR (Aug 25, 2008)

rob40999 said:


> Just wondering if we changed out the rocker's and push rods will this stop the ticking noise?????


It's impossible to say for sure, not knowing what else may be going on with your engine. Before you start throwing money at parts, I'd say change the oil, filter, and give it some time to see if it settles down.

Bear


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## rob40999 (May 18, 2018)

*1968 gto valves ticking*

Hello Bear: Great Idea. We did change the oil wt. Went from a 10w30 to a 20w50 new filter. My mechanic is very one step at a time. Do the simple things first. I mention the new rockers and pushrods, because it is cheaper than doing a rebuild. I like trying the simple things first, but I don't know all the simple things. He mention something about "blow down". Got know idea what that is. The ticking sound went down. We had 3 rocker's loose. We tightened them down to the 20 ft lbs. He mentioned that the engine was rebuild some time ago. I must appoligize that I don't remember a lot what he said. I think I saw a new rocker kit for $176.00 on ebay???????? Does that sound right????? 
Another mechanic I know said, to put a quart of Miracle oil in the engine?????? I have not done that.... When the engine get's over 1,000 rpm's you don't hear the tapping of the lifter's. He said, if they where bad you would hear them louder at the high rpm's? I'm ready for the rebuild some time down the road???
The car has the matching number's so I'll just keep the engine stock. You guy's have been great. Keep giving me Idea's. The engine isn't ready to blow up yet. New old mechanic #4 seems to know his stuff. You should see his Drag car. WOW... Merry Christmas, Bob


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## PontiacJim (Dec 29, 2012)

Since the engine was believed to have been rebuilt in the past, it is possible that the pushrod length was needing to be adjusted and they could have thrown in the ones that were originally in the engine and may be a little short. So when you torque the rocker arms nuts to 20Ft pounds, they stop on the bottle neck rocker arm stud as they should, and will not drop down any further so the rockers will not take up any play if there is any.

My next suggestion if you wanted to try this, is to make your rocker arms "adjustable." Simple enough to do this and if you have found a good mechanic, he will know what to do.

Your heads should have screw-in rocker arm studs. Replace them with Big Block 7/16" ARP Rocker Arm studs. Here is a set from Summit Racing: https://www.summitracing.com/parts/arp-135-7101/overview/

My 1968 Service Manual says to tighten the screw-in rocker studs to 50 Ft pounds.

You will _NOT_ use the factory rocker arm nuts as they are too small in diameter (3/8" for the factory studs) and they will not tighten down because there is no shoulder (bottle neck) like the factory stud.

You will need a set of these Polylocks: https://www.summitracing.com/parts/cca-4606-16/overview/

Your mechanic should then adjust each lifter/rocker arm to "zero lash." Best to do with engine warm and running. May get a little messy, but this is the best way to adjust. Adjust 1 side at a time.

Put the polylock on all the rocker arms and tighten down so there is little to no play between the rocker arm and pushrod so the engine will run as normal. I would lightly snug down the allen screw, but not too tight, as the mechanic will have to adjust the polylocks once the engine is running.

With engine warm and running, back off of the polylock until rocker arm starts "clicking," then stop. Then begin to slowly tighten the polylock down until "clicking" stops. Wait about 20 seconds for the lifter to bleed down/normalize. If it begins to click again, tighten a little more until it stops. Repeat if necessary until the "clicking" completely stops.

Once the clicking stops, turn the polylock 1/4 turn more and lock it down with the allen screw - holding the polylock with a box wrench and tighten the allen screw. Don't over tighten the allen screw, but it has to be tight enough so the polylock won't back off. Your valves are now set for "zero lash."

Do this for each rocker arm. If the rocker arm/pushrod/lifter has any play in it, this should remove it AND your valve ticking should also go away.

You should not have any clearance issues between the valve cover and top of the polylock. If for some reason you do, you can buy thicker valve cover gaskets or double them up. Polylocks can be short or long in length depending on engine/rocker stud type and application. These should be the shorter ones and work on your engine.

And, if you should have to rebuild the engine somewhere down the line, these can still be used on the new build as well, so not a loss if you invest in the studs & polylocks.

This procedure should be no problem if your mechanic knows what he is doing. :thumbsup:

Also, *you posted in the wrong section.* We are not the 2004-2006 GTO guys.


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## rob40999 (May 18, 2018)

*1968 gto valves ticking*

Hello Jim: Again you came through. Sounds like a simple thing to do. This will be the first thing to do for the ticking. GREAT.... 

You are the best Jim, wishing all the GTO crew a Merry Christmas...
Tks, Bobby 

When done I'll post a after lifter job done, and what happened to the engine....
This will be good for all the GTO owner's with ticking lifter's....
BYE


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## Honeyharbour62 (Jul 15, 2018)

I've had this problem and what fixed it for me was putting in proper Pontiac lifters. The builder who first rebuilt my engine used chevy lifters and the oil holes are not in proper location for Pontiac motors, as a result they can bleed down and give you valve train clatter.


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## GoatBawb (Dec 18, 2016)

I had the same problem with a '69 400. I kept torquing the nuts down, but it gradually came back every time. I even tried the Chevy-style lock nuts with the set screw in the side of them, to no avail. At some point, I noticed the valves would float at 4,000+ RPM, so I went ahead and did a re-build. The culprit: 3 lobes on the cam looked like a broom stick.


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## 1966tempest (Jul 14, 2015)

rob40999 said:


> Hello Jim and Bear:
> 
> Well, we pulled the valve cover's and my new old mechnic looked at the rocker arms and the push rods. He tighted down the rocker nut to 20 Ft. Pound's. Ticking still very weak. Meaning not as much noise. I wonder if we replaced the rocker arm and push rods will this help. The mechanic did really do a expection of the push rods. He said, this engine was rebuild at some time. He believes the cam is getting worn. He said alot of stuff which I did not know?????
> Just wondering if we changed out the rocker's and push rods will this stop the ticking noise?????
> Happy Holiday's boys: Bobby


I have the same issue, its 67 GTO engine, replaced the cam lifters comp cams roller tip rockers with poly locks.. still slight ticking.. wondering if its a noisy valve, its coming from the same area. when I get a chance I will check for a broken valve spring as well..


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## PontiacJim (Dec 29, 2012)

1966tempest said:


> I have the same issue, its 67 GTO engine, replaced the cam lifters comp cams roller tip rockers with poly locks.. still slight ticking.. wondering if its a noisy valve, its coming from the same area. when I get a chance I will check for a broken valve spring as well..


Keep in mind that there are many complaints of the Comp Cams XE line of cams/lifters seem to have a ticking noise due to the fast ramp closing of the valve. If you do a search, you will see this mentioned on almost every car forum where the XE cam has been used. I had the XE274 in my previous 400CI build and didn't seem to hear anything excessive. I used matching springs from Comp as well, so you may want to make sure you have new springs and not older springs which might not have the correct seat and open pressures. 

On Pontiacs you have to know what the installed height is so you can adjust the seat pressure. An engine build shop can test all the springs to ensure they meet the needed spring pressures for a given cam or cam swap. Factory Pontiac cam springs will most likely be to weak and not meet the required closed/open pressures needed for the higher lift & aggressive ramps of an XE cam - or any other cam having a higher lift than the factory .406" lift. I read that the stock springs are good to around .460", but with use/age, no doubt they become weaker. So I would at a minimum have them tested to make sure they will work with any replacement cam.


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## rob40999 (May 18, 2018)

Hello 67 GTO, Jim and Bear: We are going to replace the pushrods, rockers,studs and put on some poly nuts. This week... Just going to do the whole thing, and see what happens. I got nothing else to do... This is going to be fun. I'll me number 2 mechanic.LOL LOL I'm curious to see what affect it will have on the engine. If it still is making noise a re-build will be in the furture. Hope it's just the pushrods are getting shorter which makes the rockers I believe loose???????? Curious minds would like to know???????? 

You all have a great Christmas, and I'll get back to you all.
Bobby  HO HO HO


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## 1966tempest (Jul 14, 2015)

PontiacJim said:


> Keep in mind that there are many complaints of the Comp Cams XE line of cams/lifters seem to have a ticking noise due to the fast ramp closing of the valve. If you do a search, you will see this mentioned on almost every car forum where the XE cam has been used. I had the XE274 in my previous 400CI build and didn't seem to hear anything excessive. I used matching springs from Comp as well, so you may want to make sure you have new springs and not older springs which might not have the correct seat and open pressures.
> 
> On Pontiacs you have to know what the installed height is so you can adjust the seat pressure. An engine build shop can test all the springs to ensure they meet the needed spring pressures for a given cam or cam swap. Factory Pontiac cam springs will most likely be to weak and not meet the required closed/open pressures needed for the higher lift & aggressive ramps of an XE cam - or any other cam having a higher lift than the factory .406" lift. I read that the stock springs are good to around .460", but with use/age, no doubt they become weaker. So I would at a minimum have them tested to make sure they will work with any replacement cam.


I heard many horror stories, most seem to be that they go flat on break in, I have used 4 XE cams on pontiac, chevy and dodge, never an issue with the break in..( how many XE Cams have they used, one failed oops no good, bashing starts.. it's installer error) and thats with springs that were already installed.. it is wise to change springs, most times these are overlooked.. but on the 400 it ticked on the rear cylinder on the passenger side.. the push rods were soaked in fuel, blown dry and repeated.. the tick was exactly the same, and in the exact location as if no changes were made.. so the problem be in the spring, perhaps valve seat.. I am not sure.. but I can tell you in the dodge and chevy with the XE Cam they were quiet, i think a high lift cam may have the tick mentioned. like I said you can only hear the tick come from one side and at the rear only. it could even be a loose manifold.. its a real nice running engine, I have no idea how many miles are on it, it will eventually be addressed and I will post the results back on here..

thanks Jim for your input,, always good to hear from others..


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## RMTZ67 (Mar 12, 2011)

*Lifter noise*



rob40999 said:


> Hello Jim and Bear:
> 
> Well, we pulled the valve cover's and my new old mechnic looked at the rocker arms and the push rods. He tighted down the rocker nut to 20 Ft. Pound's. Ticking still very weak. Meaning not as much noise. I wonder if we replaced the rocker arm and push rods will this help. The mechanic did really do a expection of the push rods. He said, this engine was rebuild at some time. He believes the cam is getting worn. He said alot of stuff which I did not know?????
> Just wondering if we changed out the rocker's and push rods will this stop the ticking noise?????
> Happy Holiday's boys: Bobby


 I had ticking noise coming from one side. Found the culprit by using a rubber hose and listening thru the valve cover. Tried torquing to no avail. So I installed a new lifter, torqued again and it went away for 5? years of weekend cruising. I could tell the lifter was worn so I figured the cam was too. I probably could have tried it one more time and maybe get a couple more year of mild cruising. But I decided to put in a cam, lifters,etc. Then my story grew. See my post "Cracked my 400 open this is what I found".


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## rob40999 (May 18, 2018)

Hello All: Got a funny story to tell. So all you mechanic out there can get a good laugh.... LOL LOL

So My new old mechanic puts a long screw driver that looks like it was in WW one to the valve cover to listen to the lifter's. Say's you got a few tapping on each side. I said, yes that's what we use to do when I was 18 years old to these car's, and all we did was tighten down the nut, and it went away. Now that I'm 67 years old, and a much wiser man I thought of using a Dr. Stethscope to listen to the valve cover's. So I go on EBay and buy a Dr. Stethscope for $10.00. I get it and put it over the valve cover, and boy you can hear alot. It was really sensitive. So I put on the valve cover a towel. Now I put the Stethscope over the towel on the valve cover to listen to the lifter's. Much better operation. Yes, I could hear 3 lifter's making a taping noise like you are tapping a glass table with a knife. I would say it really worked well. Now understand we have no tapping at 1000 rpm's. This is something I'm doing just to see what effect it will have on the engine. Cost was only $300.00 for all the part's except the Spring's. (Summit Racing) Like PonticJim said, if I must do a re-build we can use these part's again. Also I'm going to be helping the old mechanic do this job. We are doing this job this coming week. It should be only around a slow 2 hour job. I have alot of mechnical experence being in the Coast Guard working on Helecoptor's for 24 year's. (Aviation Electrician) Also flying as the flight mech, Hoist operator, EMT and seen a lot of stuff you all have never seen. Worked with the DEA in the Bahama's chancing drug boats, and shooting them up when there would not stop. This stuff has never been on the News. I surley would not like CNN waiting for me when we came back from such a mission with a camera in my face. Top secret. Just a little information who I am. So Boy's it's going to be a new experence for me, and my 1968 GTO. I had one of these in High School. You ready for this. Bought a used one, one year old 68 GTO for only $1,800.00. LOL LOL LOL Wish I could post picture's, but I have no Idea how to do this. Car is mint. I have been driving it like an old man when I first got it, but now I'm back to 18 year's old, and every Red Light is a race. Got the His and Her's shifter. Rock and Roll. LOL LOL LOL I'll post when the job is done. 

You all out there have been great to me. You all seem to have a special interest in everyone's problem. GOOD JOB. 

Merry Christmas, Bobby, Safety Harbor, Fl. HO HO HO


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## PontiacJim (Dec 29, 2012)

Neat story. My grandfather was in the Coast Guard during WWII. He had the rank of Captain and served as crew member on one of the ships that used to take supplies to England out of New Jersey on those large convoy crossings.

Just a thought. I assume you have some miles on the engine. Keep in mind that if you have not already done this, the timing chain/gears should be changed out by around 60,000 miles. The cam gear has the nylon coated teeth and they do fatigue and break off and the chains can also get loose over time. So a good idea to change out the timing gears/chain if you have not already done so in the life of the engine. :thumbsup:

PS. They do make a mechanics stethoscope. Harbor Freight and most auto parts stores carry these or can order them. Harbor Freight - $4.00 Click on the link here: https://www.harborfreight.com/mechanics-stethoscope-63691.html


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## rob40999 (May 18, 2018)

Hello PonitaJim: God Bless your Grandfather for a job well done in the Coast Guard. 

You asked Jim about the timing Chain. I did replace the timing cover with a new high flow water pump, and the timing chain was very tight, and looked brand new. No play at all in the chain. It surely didn't look like it had 98,000 miles on it which the car has on it now??????? 

So I got to get to work this Thursday changing out the rocker's, pushrod, and studs, and nuts with poly nuts. I'm sure you must be curious to see how this project comes out. We believe the springs are ok. Will there be tapping or will there be no tapping????

Curious Minds want to know. LOL LOL
Have a good week, Bob HO HO HO


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