Engine Sounds

[schovil69]

New engine runs great. That is, it idles and revs as expected. There is this noise, though, that the cause of which eludes me. The sound of this noise is dead on for loose rocker arms. It has a distinct metal on metal click type of sound you would expect from loose rocker arms. It is loudest to me when standing next to the passenger fender with the hood up. Dad believes there is no difference in sound from anywhere in front with the hood up. Standing next to the driver door, on the other hand, with the hood up this sounds appears to be coming from under the vehicle.

I have lent my ear to 1/2" drive breaker bar with the other end placed on each valve cover, the oil pan, the timing cover, the front of the intake manifold, and the distributor cap with the engine running. The noise appears loudest in this manner when the breaker bar is located on the front of the intake manifold.

The loose rocker arm theory is a dead horse been thoroughly beaten. Another potential cause for this sound could be an exhaust leak at the manifold-head or manifold-exhaust pipe interfaces. These have also been checked and rechecked...no leaks found there. My next thought for the potential cause of this noise was the distributor drive gear on the cam so I pulled the distributor and found nothing abnormal there.

My next plan is to 1) Pull a valve cover and the distributor then using a priming tool reverify the oil pump is doing its job by pumping oil to the rockers...and presumably everything else, 2) Remove intake manifold to inspect roller lifters, 3) Remove timing cover to inspect for timing chain interference. I may reverse the order in which these inspections take place for 2 and 3. One potential culprit could be the water pump pressing on the timing chain cover. I was wary of this on assembly and took action to remedy any potential interference at that time but I may have missed something.


Are there any other potential sources for this noise that I'm not currently considering.

[72SB]

While breaker bar, long screwdriver or piece of fuel line have been used as a stethascope...a $4 Harbor Freight one, for me, gives more precision probing around

With that said you pretty much have a plan of attack to find the noise source. Pulling the valve cvers and then starting the motor would be first thing I would do. I assume you have checked valve lash. One lifter just may be dead. Look for any witness mark inside valve cover, especially if you are running roller rockers for potential contact

If you don't find anything during that...pull intake manifold and then lifters and carefully look through lifter bores to cam lobes as someone slowly rotates motor

If this is a rebuilt flat tappet cam motor....I assume you used high zinc content break in oil or additive

You checked cam end play...have cam button??

[schovil69]

Originally Posted by 72SB

While breaker bar, long screwdriver or piece of fuel line have been used as a stethascope...a $4 Harbor Freight one, for me, gives more precision probing around

With that said you pretty much have a plan of attack to find the noise source. Pulling the valve cvers and then starting the motor would be first thing I would do. I assume you have checked valve lash. One lifter just may be dead. Look for any witness mark inside valve cover, especially if you are running roller rockers for potential contact

If you don't find anything during that...pull intake manifold and then lifters and carefully look through lifter bores to cam lobes as someone slowly rotates motor

If this is a rebuilt flat tappet cam motor....I assume you used high zinc content break in oil or additive

You checked cam end play...have cam button??

Thanks for that quick response.

This is a hydraulic roller lifter engine. Even so, high zinc oil was used for the owner's(my Dad) peace of mind. I did not notice anything abnormal when watching the engine run with the valve covers removed. All rocker arms appear to move as expected. I did not look inside the valve covers at that time for any witness marks. I can tell you, though, the noise is present without the valve covers installed.

The cam button is Comp Cams COM202, https://www.summitracing.com/parts/CCA-202.
A 0.031" thrust washer was used. Cloyes 9-201, https://www.summitracing.com/parts/clo-9-201.
Timing chain is Cloyes C3001K, https://www.summitracing.com/parts/clo-c-3001k.

With these parts, camshaft endplay was set at 0.006". I believe min/max is 0.004"/0.010" for camshaft end play.

The rockers are Comp Cams roller tip 1412-16, https://www.summitracing.com/parts/cca-1412-16.
Lifters are Comp Cams CCA-853M-16, https://www.summitracing.com/parts/c...make/chevrolet.

[pontiacvince]

I had the same noise on the passenger side the other day with my new engine. I pulled the valve cover and there were 3 loose rocker arms. I have the poly-locks, but I didn't loosen the set screw, and just took my 5/8" box end and tightened the locknut about 1/8 of a turn. Problem solved....

[72SB]

new motors with new lifters, even ones soaked overnight in oil and then a lash....sometimes one lifter will just never pump up so you need to you need to do another valve lash paying attention to finding zero lash and feeling if there is any resistance when doing preload turn

IMHO given a noise....may be worth to do. If noise remains....then pull intake and look closer.

While I have used Comp lifters and have them, 850's, in my 383 and even ran ther 875R (short travel) without issues...there are reports they are having quality issues. Morel and Lunati seem to be the go to these days.

Sucks when new motor has these kind of issue. Been there...windage tray on my 383 was not reinstalled using washers to stand it off from the stroker crank....as I had repeatedly advised shop to do vs not installing it. Sounded like hell with rod bolt just scraping windage tray. Other than having to drop pan on a then installed engine, no harm or foul...but just one example of a wtf

[Truckin Fool]

A long shot ,but possibly a bad mechanical fuel pump. If the spring is weak or broken it will clatter. Dan.

[HO455]

Did you check the flexplate for cracks? Assuming it is an automatic.

If it's a manual then check out the throw out bearing and it's fork and linkages.

Also try running the engine with the belts removed to isolate the driven accessories. Then check if the balancer is loose or if the pulley is loose on the balancer before reinstalling the belts.

[CC69Rat]

Originally Posted by Truckin Fool

A long shot ,but possibly a bad mechanical fuel pump. If the spring is weak or broken it will clatter. Dan.

What I was thinking too.

Is the fuel pump new?

[weq92f]

.

I had lifter noise like crazy with comp retro fit roller lifters installed in my BBC. I went through all the same sort of diag steps verifying lash, cam button settings, etc... In the end, the solution was to replace comp lifter set with a Howards set. After that, no more noise. While troubleshooting, I found lots of other guys out there that had the same problem with the comp roller lifters. Not sure whether your particular ones are the noisy ones ( like mine were ), but if so I'm afraid there is no easy/cheap fix.

Have a look at this discussion.

http://67-72chevytrucks.com/vboard/s...hp?t=811356&#7

-klb

[twoskies]

Had an issue with my rebuilt small block, chased it to distributor cap, seemed to help, thought exhaust leak, no change, ended up being worm cam lobes , only bout an hour runtime on new build, got lucky if you can say that, cam wore without chunks, only powder, had engine gone through again, going with a Howards cam this time, cross fingers, firing up hopefully tomorrow,
something else / i could hear my ticking on passenger side through the exhaust without any listening item

bonus on mine is Machine Shop covered most of the work without charging me anything else second time

Hope yours is something simple and cheaper than mine

[schovil69]

Thank you, everyone, for chiming in here to offer potential causes for this noise. I will respond to all here but let me know if I miss something.

The rocker arm adjustment, or valve lash, has been gone through three times. There was the initial setup on the engine stand where I tightened a rocker arm nut until I could not raise and lower the pushrod anymore then turned another half turn. Second round through the process was after install and initial startup where the engine was bumped over until one valve of a cylinder was fully depressed at which time the other valve's rocker arm nut was tightened until the rocker arm could not be moved up and down. Not all but there were some that required adjusting at this time. The third round through the rocker arm adjustment all rocker arm nuts were tightened between 1/4 to 1/2 turn merely to positively eliminate the potential for them to be loose at all. At no time during any of this adjusting was there any notable resistance.

These Comp Cams lifters sat in fresh oil for a couple weeks before I got around to installing them. Not that the excess soak time makes a difference. I'm hopeful it's not the lifters because those babies aren't cheap. I expect Comp Cams will replace one that is not working properly.

The mechanical fuel pump is not a new unit, however, it was new about two months prior to pulling this engine for the rebuild.

The alternator is a new unit and spun freely prior to install. The power steering is all that's left for accessories. I'm going to skip running without belts, though, as these parts are not the likely culprit given the apparent location of the noise.

The flex plate is a new TCI 399604, https://www.summitracing.com/search/...keyword=399604.

I have about an hour to run over there tonight. The plan for tonight is to pull the distributor and run the oil pump with a priming tool/drill to ensure oil is pumping to the top and that it's not the source of this sound.

Beyond that, the intake will be next. What do I look for to see if a hydraulic lifter is not pumping up or operating properly?

[72SB]

Originally Posted by schovil69

What do I look for to see if a hydraulic lifter is not pumping up or operating properly?

first thing, look at all the rocker nuts or polly locks if you are running RR. The exposed threads should be the same on all. One with more exposed thread would suggest that lifter is just not holding

On lash I would start from scratch from this point. Losen all rockers. Let engine sit for about 1/2 hr to allow lifters to come back (one or more may not and that would be the problem if they correspond to the source sound of what cylinder you suspect by location of noise)

Relash each cyl. The The IOEC method is reputed to be the best way but every FSM (factory service manual) states to do the various intake and exhaust valves starting at #1 TDC then rotate engine one revolution to #6 TDC and do those respective I/E valves. What I always do

If while lashing any of the valve, one or more offer no resistance after finding zero lash (BTW you are doing that right by confirming no more up/down movement vs spinning with fingers till drag method) and then 1/2 turn if any of those offer no real resistance than that lifter is weak. Mind you very soon after lash any rocker will become lose shortly after as the oil will bleed out of a rocker, normal. Once motor starts oil pressure brings the lifters back.

While I mentioned earlier my Comps in another motor are fine (not what you have) but Comp has had several lifter thread issues with Howards, Lunati, Crowler, Morrel being ones with good reports.

[HO455]

Originally Posted by schovil69

Thank you, everyone, for chiming in here to offer potential causes for this noise. I will respond to all here but let me know if I miss something.

The rocker arm adjustment, or valve lash, has been gone through three times. There was the initial setup on the engine stand where I tightened a rocker arm nut until I could not raise and lower the pushrod anymore then turned another half turn. Second round through the process was after install and initial startup where the engine was bumped over until one valve of a cylinder was fully depressed at which time the other valve's rocker arm nut was tightened until the rocker arm could not be moved up and down. Not all but there were some that required adjusting at this time. The third round through the rocker arm adjustment all rocker arm nuts were tightened between 1/4 to 1/2 turn merely to positively eliminate the potential for them to be loose at all. At no time during any of this adjusting was there any notable resistance.

These Comp Cams lifters sat in fresh oil for a couple weeks before I got around to installing them. Not that the excess soak time makes a difference. I'm hopeful it's not the lifters because those babies aren't cheap. I expect Comp Cams will replace one that is not working properly.

The mechanical fuel pump is not a new unit, however, it was new about two months prior to pulling this engine for the rebuild.

The alternator is a new unit and spun freely prior to install. The power steering is all that's left for accessories. I'm going to skip running without belts, though, as these parts are not the likely culprit given the apparent location of the noise.

The flex plate is a new TCI 399604, https://www.summitracing.com/search/...keyword=399604.

I have about an hour to run over there tonight. The plan for tonight is to pull the distributor and run the oil pump with a priming tool/drill to ensure oil is pumping to the top and that it's not the source of this sound.

Beyond that, the intake will be next. What do I look for to see if a hydraulic lifter is not pumping up or operating properly?

Doing the "run without belts" test will ease or confirm your concerns about the water pump. Without belts the water pump won't be pumping.

Run the engine with the valve covers removed. (Messy! Don't Rev the engine! Google how to use a junk valve cover to cut down on the mess.) Use your listening tool and put it on each rocker stud. You maybe able to locate a specific valve problem or at least which bank. You also will get a good visual on the oil flow to the rockers.

Ten years ago my brand new SFI flexplate failed within 300 miles on my 401. It was cracking around the outside just inside the gear ring. It made me think I had lost a lifter.

Not trying to be too gloomy but, a cracked piston can also make a similar noise. Let's not go into how I know this.

These days I don’t trust new parts to be good parts. Unfortunately it's a sad fact we have to live with.

[LS short box]

May not help but back in the day when I was a Chev line tech when we were playing with valve lash we had a cheap stock valve cover with a slot cut into it so you could adjust the valves without getting oil all over the place.

[schovil69]

Originally Posted by weq92f

.

Have a look at this discussion.

http://67-72chevytrucks.com/vboard/s....php?t=811356

-klb

Thanks for the link. I will not be returning to the Comp Cams roller lifters after reading the several testaments to their failure out of the box.

I will shoot a short video today and capture the noise.

I hadn't considered the water pump as being the source of the noise. I may have to run without belts after all.

With the roller tip rockers I'm using and rocker arm fulcrum/nut, not poly locks, a socket does not fit around the nut when the rocker is in the valve closed position. Due to this, I will not be attempting to adjust rockers with the engine running.

I will visually inspect the flex plate for cracks.

[schovil69]

I had less than two hours to look into things tonight. I pulled the valve covers and distributor then ran the oil pump with a priming tool and drill. It barely got oil to the top and out some push rods before the drill got hot. So, in went the distributor and we started the truck. Oil came out of all the push rods on the driver side and all except for two on the passenger side. One rocker on number 2 and one rocker on number 6 did not have oil coming out of the push rod. The oil pump is a new Melling M55, shouldn't have any issue in regard to oiling with this pump.

Could messed up lifters be the cause for this oiling observation?

On another note, I figure the oiling issue may fare better with some RPM so I grabbed on old Sears induction timing light and set the timing at 8 degrees with no vacuum advance and the tach at 800ish RPM's. Perhaps a brief drive will help get things in order. That is, if the root cause isn't from faulty lifters.

[geezer#99]

You know you’re 8 initial might be closer to 2 initial or lower.
That’s because your mechanical timing in the distributor typically starts to kick in close to 750 rpm.

[Grumpy old man]

https://www.summitracing.com/parts/cca-853-16/reviews

Are these the lifters your using ?

trying to diagnos engine noise on a forum without even a video is like trying to describe the color white .

[72SB]

Originally Posted by Grumpy old man

https://www.summitracing.com/parts/cca-853-16/reviews

Are these the lifters your using ?

his link says these, same part # but followed by "M" and a little cheaper than ones you link

https://www.summitracing.com/parts/c...make/chevrolet

IDK what the difference is between the two but the ones you link have bad reviews....echoing OP's issues

[KQQL IT]

My experience with comp retro fit roller lifters. They're to heavy for any revs.

[schovil69]

Originally Posted by Grumpy old man

https://www.summitracing.com/parts/cca-853-16/reviews

Are these the lifters your using ?

trying to diagnos engine noise on a forum without even a video is like trying to describe the color white .

Originally Posted by 72SB

his link says these, same part # but followed by "M" and a little cheaper than ones you link

https://www.summitracing.com/parts/c...make/chevrolet

IDK what the difference is between the two but the ones you link have bad reviews....echoing OP's issues

The lifters in the engine right now are the 853M's. What I'm seeing across the internet, though, is to steer completely clear of Comp Cams roller lifters. Not sure what to do with them, pricey little paper weights.

In looking at Howard's roller lifters, the 91160's have a larger diameter roller than the 91164N. The 91164N appears to be the only one in stock anywhere, though. This engine is not meant for anything other than an old man driving around town when he needs a pickup so the 91164N's should work just fine. The engine will most likely never see 5K RPM's.

Does anyone have experience with the Howard's 91164N roller lifters?

Also, to reiterate my previous question...Can these messed up Comp Cams lifters be the cause for oil not getting to the rocker arms through the push rods?

[72SB]

Originally Posted by schovil69

Also, to reiterate my previous question...Can these messed up Comp Cams lifters be the cause for oil not getting to the rocker arms through the push rods?

yes, if they are not functioning as they should in terms of full travel....let alone because of a manufacturing defect

with that said poor engine block cleaning (read EVERY oil galley is NOT pristine clean) unfortunately is an issue with some lifters, thus PR & rockers, not getting oil in rebuilds. low oil pressure would be an indicator of this

the more likely suspect in your case is the Comp lifters which appear to have a chronic negative review on exactly what you are experiencing

I have not heard of anything bad for Howard lifters.

[schovil69]

Originally Posted by 72SB

yes, if they are not functioning as they should in terms of full travel....let alone because of a manufacturing defect

with that said poor engine block cleaning (read EVERY oil galley is NOT pristine clean) unfortunately is an issue with some lifters, thus PR & rockers, not getting oil in rebuilds. low oil pressure would be an indicator of this

the more likely suspect in your case is the Comp lifters which appear to have a chronic negative review on exactly what you are experiencing

I have not heard of anything bad for Howard lifters.

My main concerns are the lack of oiling and the potential for a roller to not be functioning properly that could ruin the cam. I'm amazed the such a reputable name as Comp Cams has allowed this poor quality to exist for so many years. I read reviews at Summit that are eight years old. A guy would think, "Oh, they would have fixed it by now," but nope...the problems still exist. Stay away from Comp Cams roller lifters, for sure.

Given the abundance of information available out there in addition to the experience of all my fine Chevy trucking brethren right here, I have put in an order for the Howard's roller lifters, 91164N, and will look forward to performing this work followed by a happy walk away from this project as others are piling up. These are not the large roller versions, 91160, but the street version that have a smaller roller, 91164N.

[72SB]

Good choice. Needless to say a fair amount of work to do the swap. Might want to carefully look at the rollers of the Comps when yo take them out for any signs of wear/heat and if so look down the lifter bore of that lifter to see how cam lobe is. Ideally no harm but if so better to find out now you need to swap cams

[schovil69]

Originally Posted by 72SB

Good choice. Needless to say a fair amount of work to do the swap. Might want to carefully look at the rollers of the Comps when yo take them out for any signs of wear/heat and if so look down the lifter bore of that lifter to see how cam lobe is. Ideally no harm but if so better to find out now you need to swap cams

Yeah, I was being facetious about looking forward to the work. I have an '05 Equinox halfway through its head gasket job waiting to be finished and a '56 Belair with just the rear end/suspension complete that needs to be road ready by May 2023. The sooner I can put this thing to bed the better. There is concern for the cam due to roller malfunction, will be looking things over quite closely.

Does anyone have a solution for getting rid of the faulty lifters? Do vendors take them back? Does Comp Cams take them?