Ticking under load - any ideas?
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From: Tucker, GA
Ticking under load - any ideas? Chasing down a super annoying tick/clack that I've just noticed. Probably due to having the windows up now that it's cold. Background ERE383, probably 6 months old now, about 5000 miles on it. Runs like a champ. 28-32 psi oil temp hot idle in gear. 60 PSI hot driving. Oil pump body is hitting the pan baffle which makes a bit of a racket, so I have that going for me.
Its not a knock - its a bit deeper than a rocker tick. Only happens at-speed, and under specific circumstances. Correlates to what sounds like one cylinder or valve/rocker/lifter.
I got the car up to temp and went to a parking lot. Got out and opened the hood. Slowly increased the rpm and heard a good bunch of valvetrain noise and the oil pump, but nothing else. Got back in the car, drove it home. Heard the clacking at 2500r's and about 60 mph on a slow accel - sometimes its noisier than others, and the rate of clacking increases with rpm's. Cruising, it is just barely there, sometimes.
Got home and went to a desolate road. On a slow accel, in 1st and 2nd, no noise. It comes in during 3rd. Stopped the car and opened the door so I could hear better. Put the car in drive and power-braked it, slowly increasing the rpm to 2500-2700 - until the front tires started to slide. No clacking or tick. Did this multiple times at varying throttle intensities and rate of increase. No clacking or tick. Got back on the road and could hear it.
Got home to the garage. Opened hood and took out the stethoscope. Increased rpm and poked around. No tick or clack. Checked the entire exhaust system for leaks - nada.
Oil is clear - so sparkles.
I am totally stumped. I have a new Denny's driveshaft coming because the oem shaft, rebuilt, vibrates now @ 65-70 after I had the rear-end re-geared. Wondering if its the u-joints or something? Can the 4L60E tick?
Thanks for your input
Its not a knock - its a bit deeper than a rocker tick. Only happens at-speed, and under specific circumstances. Correlates to what sounds like one cylinder or valve/rocker/lifter.
I got the car up to temp and went to a parking lot. Got out and opened the hood. Slowly increased the rpm and heard a good bunch of valvetrain noise and the oil pump, but nothing else. Got back in the car, drove it home. Heard the clacking at 2500r's and about 60 mph on a slow accel - sometimes its noisier than others, and the rate of clacking increases with rpm's. Cruising, it is just barely there, sometimes.
Got home and went to a desolate road. On a slow accel, in 1st and 2nd, no noise. It comes in during 3rd. Stopped the car and opened the door so I could hear better. Put the car in drive and power-braked it, slowly increasing the rpm to 2500-2700 - until the front tires started to slide. No clacking or tick. Did this multiple times at varying throttle intensities and rate of increase. No clacking or tick. Got back on the road and could hear it.
Got home to the garage. Opened hood and took out the stethoscope. Increased rpm and poked around. No tick or clack. Checked the entire exhaust system for leaks - nada.
Oil is clear - so sparkles.
I am totally stumped. I have a new Denny's driveshaft coming because the oem shaft, rebuilt, vibrates now @ 65-70 after I had the rear-end re-geared. Wondering if its the u-joints or something? Can the 4L60E tick?
Thanks for your input
Last edited by atlantadan; Jan 7, 2018 at 09:30 PM.
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could be one of several reasons...some are:
Spark plug arc...but you should also notice a miss/stumble if that was it
The Oil pump body hitting something in pan...surprised Karl let a motor out if that was going on but if it is fix that as that interference is likely causing PCM to pull timing if it sees that as knock
crack flex plate or lose flex plate or converter bolt
exhaust leak...but you say you checked. I had a pin hole in a header weld where pipes merged that I could not see which caused a lifter tick sound. Chased that noise for some time before finding it
Had a rotor screw bounce around in opti and sounded like a tick/knock but car ran fine
Lose lash on one RR
If you have a mechanical fan...is it just hitting something?
You are way closer to the car than us on the web...so can only ffer what has caused these kinds of sounds.....without hearing it/being there
Spark plug arc...but you should also notice a miss/stumble if that was it
The Oil pump body hitting something in pan...surprised Karl let a motor out if that was going on but if it is fix that as that interference is likely causing PCM to pull timing if it sees that as knock
crack flex plate or lose flex plate or converter bolt
exhaust leak...but you say you checked. I had a pin hole in a header weld where pipes merged that I could not see which caused a lifter tick sound. Chased that noise for some time before finding it
Had a rotor screw bounce around in opti and sounded like a tick/knock but car ran fine
Lose lash on one RR
If you have a mechanical fan...is it just hitting something?
You are way closer to the car than us on the web...so can only ffer what has caused these kinds of sounds.....without hearing it/being there
Possible new motor paranoia syndrome? I've been suffering since 2002. Your comment " it is just barely there, sometimes." is something I understand but have been accepting of my condition. LOL Now I just ignore and change the oil. If I can't easily hear it with a stethoscope I try and forget about it. Try to.
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Checked all the exhaust bolts, per suggestion. All good there.
Yes, it does not make the sound in neutral - only when driving. Slow, even increase in RPM's when hot and in neutral do not make the sound reappear. (It DOES make my speedometer increase to 3 mph - while stationary - which is a new thing...) This morning, it sounded more like a knock than it ever has, so I'm starting to lean towards a rod bearing. Karl wants me to cut open the filter and have a look. I will do so this weekend.
I wish that's what it is. Unfortunately, this is a real noise. Since it is most noticeable during the drive to work, during the commute tomorrow I'll kill individual cylinders with eeHack to see if that eliminates the racket. If so, well... we know what that means....
Yes, it does not make the sound in neutral - only when driving. Slow, even increase in RPM's when hot and in neutral do not make the sound reappear. (It DOES make my speedometer increase to 3 mph - while stationary - which is a new thing...) This morning, it sounded more like a knock than it ever has, so I'm starting to lean towards a rod bearing. Karl wants me to cut open the filter and have a look. I will do so this weekend.
Possible new motor paranoia syndrome? I've been suffering since 2002. Your comment " it is just barely there, sometimes." is something I understand but have been accepting of my condition. LOL Now I just ignore and change the oil. If I can't easily hear it with a stethoscope I try and forget about it. Try to.
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if you hear what sounds like a rod knock (down low in motor)....typically you will see sparkle in the oil and OR filter. I would do as karl suggests in cutting open the filter.
Simple to pull filter and check....if all is good you are just out a qt of oil
If a ringland crapped or something like that...one of those bore video scopes from HF or something like that. Look through plug hole and rotate motor to see cyl wall. Yeah kinda a PIA but way easier than pulling motor and breaking it down
Simple to pull filter and check....if all is good you are just out a qt of oil
If a ringland crapped or something like that...one of those bore video scopes from HF or something like that. Look through plug hole and rotate motor to see cyl wall. Yeah kinda a PIA but way easier than pulling motor and breaking it down
KW
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From: Tucker, GA
Only under load, and only at speed. Keeping it in 1st and slowly driving off - no noise. Shift into 2nd and slowly increase speed - no noise. 3rd, slowly increase speed up to 60 - and it might happen. OD is where it usually hits. If there's a slight hill, giving it just enough gas to slightly increase the speed and it'll happen each time.
If it is an exhaust tick, I've never heard one like it before. I'll see if I can get it on-camera before I pull the filter and cut it open this weekend.
Thanks for your suggestions, folks. You've given me some different avenues to run into
If it is an exhaust tick, I've never heard one like it before. I'll see if I can get it on-camera before I pull the filter and cut it open this weekend.
Thanks for your suggestions, folks. You've given me some different avenues to run into
I think it's something in your drivetrain, but would like to see/hear video if it's loud enough to pick up on a mic.
Depends. If it's severe enough, yes. A rod knock that is not may present itself as prominently while the engine is under load.
Depends. If it's severe enough, yes. A rod knock that is not may present itself as prominently while the engine is under load.
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Update: Ran a compression test. Everything was ok in that regard. Completely went over the exhaust system with a fine-toothed comb and there are no leaks anywhere. Karl said that this specific oil pump can groan a bit, and others have said online that the body is just a smidge larger than a stock pump and that the body can slightly touch the pan amplifying the sound.
Went through the valves to triple check the lash and found something odd.
I have two lifters that when I was setting lash, had zero resistance when tightening the locknut. As-in, find zero lash, and when tightening the locknut 3/4 turn, you could almost do it with your fingers. One of the two could even be pushed down a bit - easily - when lash was properly set. By 'a bit', I mean like 1/8-1/16 of an inch or so. The other 14 had decent resistance when tightening the 3/4 turn - like you could feel the oil getting pushed out of the lifter as it was being tightened. Compression on that cylinder was normal.
The lifters are LT1 Morel lifters.
What do you think?
Went through the valves to triple check the lash and found something odd.
I have two lifters that when I was setting lash, had zero resistance when tightening the locknut. As-in, find zero lash, and when tightening the locknut 3/4 turn, you could almost do it with your fingers. One of the two could even be pushed down a bit - easily - when lash was properly set. By 'a bit', I mean like 1/8-1/16 of an inch or so. The other 14 had decent resistance when tightening the 3/4 turn - like you could feel the oil getting pushed out of the lifter as it was being tightened. Compression on that cylinder was normal.
The lifters are LT1 Morel lifters.
What do you think?
Last edited by atlantadan; Jan 12, 2018 at 09:47 AM.
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are the alan head locking inserts the same height in the poly lock than the other 14 for the 2 valves you feel no resistance on when applying "pre-load"?
If so those 2 lifters could be suspect
you should be able to find zero lash just by tightening the poly nut with your fingers. then when you apply 3/4 turn "pre load" you should feel resistance from the lifter. After lash the lifter will bleed off some
If so those 2 lifters could be suspect
you should be able to find zero lash just by tightening the poly nut with your fingers. then when you apply 3/4 turn "pre load" you should feel resistance from the lifter. After lash the lifter will bleed off some
The adjusting nut thing could be perfectly normal. I've ran into the same thing. It could be the bore on that lifter has a little more clearance than the rest and drains out quicker, or could be the lifter itself. Take the valve covers off, start the car and keep an eye on the rocker where that lifter is and see if it oils down like the rest. I know it's taboo to talk about Comp R's because of all the fuss, but when I ran them they would immediately lose pressure when the engine was shut off.
I know you said that you checked the exhaust, but I'm just going to say I also suspect an exhaust leak. I had a very similar problem with my truck, an intermittent knocking sound that would only arise on the freeway, last a few minutes, and quiet down. It sounded a lot like a rod knock, almost like a clacking rocker, and it ended up being an exhaust leak where two of the rear most exhaust bolts had snapped off. After repairing it, the sound went away entirely.
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Update: A day after re-setting lash (and I am 100% sure it is correct...) I am hearing more ticking from the valvetrain than before. Hot idle, slow increase in revs and the tick seems to come in and go out at different times. This is a sharp tick, so it's definitely rocker or lifter tap. I did zero lash + 3/4 turn. Ticking appears to be coming from the lifters/valves that were suspect.