Knock/diesel rattle
06-25-2017, 04:20 AM
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Knock/diesel rattle
Hey folks,
What can cause a slight knocking noise in the bottom end of a 22R that isn't rod or crank bearings (as they are new and were measured up by the machinist)?
When the engine warms up there is a medium level noise that sounds almost exactly like a diesel. You know that diesel rattle/knocking. It is not super loud, but loud enough to be heard when idling from a few meters away.
When i get the revs up over 2k RPM i cant hear the noise anymore. It is a pretty slow knock (maybe a few a a second).
Apart from the knock, the engine is a new rebuild and runs real strong, with lots of power, no leaks, clunks or other rattles, runs at good temperature and has great oil pressure...
I read some threads that said that timing can cause a knock? My ignition timing is spot on and the cam timing is set as normal during build.
I cant quite locate the exact source of the noise with the engine running - It sounds like the bell housing area, when i am closest to that area and the front of crank/harmonic balance when i am closer to that... Basically it is somewhere down the bottom of the engine.
Thanks for any tips as to what else can knock down there. It is the only thing wrong with the new rebuild and is driving me mad!
What can cause a slight knocking noise in the bottom end of a 22R that isn't rod or crank bearings (as they are new and were measured up by the machinist)?
When the engine warms up there is a medium level noise that sounds almost exactly like a diesel. You know that diesel rattle/knocking. It is not super loud, but loud enough to be heard when idling from a few meters away.
When i get the revs up over 2k RPM i cant hear the noise anymore. It is a pretty slow knock (maybe a few a a second).
Apart from the knock, the engine is a new rebuild and runs real strong, with lots of power, no leaks, clunks or other rattles, runs at good temperature and has great oil pressure...
I read some threads that said that timing can cause a knock? My ignition timing is spot on and the cam timing is set as normal during build.
I cant quite locate the exact source of the noise with the engine running - It sounds like the bell housing area, when i am closest to that area and the front of crank/harmonic balance when i am closer to that... Basically it is somewhere down the bottom of the engine.
Thanks for any tips as to what else can knock down there. It is the only thing wrong with the new rebuild and is driving me mad!
06-25-2017, 02:17 PM
#2
Use a stethoscope, wooden dowel, or long screw driver. Along both sides of the oil pan at the block and you should be able to isolate the location.
Don't assume it's not a connecting rod bearing just because it's a fresh build, mistakes happen like plugged oil gallies bearing got put in wrong or a cap in the wrong spot
Don't assume it's not a connecting rod bearing just because it's a fresh build, mistakes happen like plugged oil gallies bearing got put in wrong or a cap in the wrong spot
06-25-2017, 04:23 PM
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It speeds up with the revs.
When i am driving it, i can hear it as i accelerate up to 2k RPM during the first couple of gear changes. The noise comes through the transmission tunnel forward of the gear sticks behind that little removable plastic panel.
I am actively trying to assume it's not a connecting rod knock!
I fired it up before work this morning and i think most of the rattle noise, is the valves. Although i have adjusted them twice - they seem to have gotten louder on the last trip out bush.
Can i adjust the valves a bit 'tighter' than 0.008 and 0.012? As they still seem to rattle and sound like a diesel. Once i get them quietened down i will see if the other knock is still there.
I noticed that the splined drive shaft that goes into the transmission when i did the engine swap had a bit of play in it. I could wobble it a couple of mm up and down/side to side. Is that normal?
When i am driving it, i can hear it as i accelerate up to 2k RPM during the first couple of gear changes. The noise comes through the transmission tunnel forward of the gear sticks behind that little removable plastic panel.
I am actively trying to assume it's not a connecting rod knock!
I fired it up before work this morning and i think most of the rattle noise, is the valves. Although i have adjusted them twice - they seem to have gotten louder on the last trip out bush.
Can i adjust the valves a bit 'tighter' than 0.008 and 0.012? As they still seem to rattle and sound like a diesel. Once i get them quietened down i will see if the other knock is still there.
I noticed that the splined drive shaft that goes into the transmission when i did the engine swap had a bit of play in it. I could wobble it a couple of mm up and down/side to side. Is that normal?
Are you able to make a video of the noise?
06-25-2017, 04:53 PM
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I will adjust the valves again. Check the cover is not hitting the rockers. Then put in a new exhaust system.
Then if the noise is still there, i will make a video.
I will adjust to 0.007 and 0.011 - if this is ok?
Then if the noise is still there, i will make a video.
I will adjust to 0.007 and 0.011 - if this is ok?
06-25-2017, 06:42 PM
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More investigation reveals that the crank pulley wobbles like crazy when the engine is running.
I will take a video of it.
I wouldn't think this could be caused by a bad bearing - could it be the source of the ominous rattle?
The keyway looked ok, and the crank pulley bolt was torqued right up as well.
Interestingly the rebuilt engine is new to me (not my old engine) so i have no baseline if the rattle was there before the build (possibly indicating harmonic balancer?).
I will take a video of it.
I wouldn't think this could be caused by a bad bearing - could it be the source of the ominous rattle?
The keyway looked ok, and the crank pulley bolt was torqued right up as well.
Interestingly the rebuilt engine is new to me (not my old engine) so i have no baseline if the rattle was there before the build (possibly indicating harmonic balancer?).
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06-26-2017, 12:00 AM
#8
Bent crank ??
Which should have been spotted by the builder !!
Counter weight just hitting one of the bearing caps
It also might be the pulley hitting the outside of the oil pump .
When turning the engine over by hand with the plugs out do you feel a spot where it gets tight then frees up again??
Which should have been spotted by the builder !!
Counter weight just hitting one of the bearing caps
It also might be the pulley hitting the outside of the oil pump .
When turning the engine over by hand with the plugs out do you feel a spot where it gets tight then frees up again??
06-27-2017, 02:20 AM
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Thanks guys.
So i swapped the harmonic balancer, as the old one was wobbling like crazy. The new one is smooth as. Still the noise remains.
I pulled the plugs one at a time and it made no difference at all to the knock.
I removed the belts at the front, and the noise remained.
I swapped out the exhaust and the noise remained.
I did a good job and tightened up the valves to 0.007 and 0.011 and the top end is almost silent now.
But the other noise remains. I am thinking that perhaps i am being paranoid about the little knock/'tappetey'/click noise. It is just that it is a new build.
Here is a quick vid of the noise as best i can. You might need to turn up your speakers as it is not super loud. It sounds kinda like valves! Perhaps this is just the sound of the engine? Also, i like the sound of my LCE headers with hi flow exhaust!
So i swapped the harmonic balancer, as the old one was wobbling like crazy. The new one is smooth as. Still the noise remains.
I pulled the plugs one at a time and it made no difference at all to the knock.
I removed the belts at the front, and the noise remained.
I swapped out the exhaust and the noise remained.
I did a good job and tightened up the valves to 0.007 and 0.011 and the top end is almost silent now.
But the other noise remains. I am thinking that perhaps i am being paranoid about the little knock/'tappetey'/click noise. It is just that it is a new build.
Here is a quick vid of the noise as best i can. You might need to turn up your speakers as it is not super loud. It sounds kinda like valves! Perhaps this is just the sound of the engine? Also, i like the sound of my LCE headers with hi flow exhaust!
