Engine knocking lightly - not sure what to do
02-03-2016, 08:36 AM
#1
Engine knocking lightly - not sure what to do
Update 24th Feb:
Oil sump pulled off, bearings have no wear at all on them and the oil pan had no debris at all. Compression numbers were fine. Valve adjustment was carried out 6k miles ago with new chain tensioner, chain, cam sprockets and lost motion springs.
Nasty rattle still present when engine is above 2200 rpm, worse when getting on the move and can be heard in muted form when cruising along on part throttle. I wonder if it has something to do with the clutch or flywheel.
See this video: https://youtu.be/D4tKyMcupcc
The horrible rattle is obvious. I will carry on driving until something blows up but would appreciate any ideas.
Update 10th Feb:
Thanks windhund. I haven't tried taking the coils off when the engine is running yet. I have used a mechanics stethoscope to try and locate the source of the noise. The engine is too loud and I cant hear anything through the ear pieces over the ambient noise.
Since I said the noise has got worse after the oil change, I have been out driving it. The very faint knock like sound can only be heard with a cold engine. Otherwise the only symptom is the nasty rattle at around 2500-3500 rpm especially when using the clutch setting off in 1st or reversing. I believe this is because using the clutch holds the revs a little longer at the rpm point where the rattle occurs.
There is also a harmonic type sound you hear when on light throttle around that rev range when moving.
I'm still tempted to get the sump pulled and the bearings looked at and likely replaced. The other part of me thinks I should carry on driving and accept this is a noise it makes.
Original post:
Hi all, having a few issues and would appreciate any advice.
I've owned my 2002 S2000 since early November and for 5k miles. I believe the knocking has been present through all or almost all of my ownership.
I visited a well regarded Honda specialist yesterday and discovered What I always thought was a loose cat heat shield rattling is actually the engine knocking.
Old videos showing piston slap and not the main problem:
Sitting in the car and displaying the knock (about 5 mins after start): https://youtu.be/33-JHUNGDvo
Fairly long cold start video: https://youtu.be/ROuCwIQdTTQ
The noise is obvious whenever you pull away and use more than 2k revs, though is mainly around the 2-3k rpm range. It sounded like a buzzing sound to me. On the move it is less obvious though this may be due to the road and intake noise covering it up. The engine feels fine when revving up to 9k rpm in 2nd and 3rd, letting off in 4th, which I do several times a week at least since owning it.
Short video with warm engine revving to 3k rpm: https://www.youtube.com/watch?v=a9bBOY33YyY
The oil was dropped and put through a paint strainer and no debris was found. After the oil change it now makes a more obvious light knocking sound when idling with a cold engine, this disappears once warmed up though.
The previous owner had a "health check" carried out on the engine at a rally engine builder. The invoice states a new oil pump, timing chain, TCT, lost motions springs and big end bolts. This was 1k miles before I bought the car. I did consider not buying car due to the owner having just coughed up for the £2k invoice and was now selling up, but bought it anyway. I'm not too sure what significance this factor has on the knock.
My options are:
1) Don't drive it, get the engine stripped and hopefully rebuilt or get a used engine put in.
2) Continue to drive and hope the knock doesn't get worse (whilst constantly worrying). As the knock has been present for a significant amount of time with extended high rpm operation, maybe it will keep going for a while.
3) Sell it. I don't know who would buy it and if they did, it would be a huge loss to me as I will be accurate in my description.
What option would others go for? And does anyone else have experience of a long lasting engine knock?
Sorry for the long post.
Cheers[/size][/size]
Oil sump pulled off, bearings have no wear at all on them and the oil pan had no debris at all. Compression numbers were fine. Valve adjustment was carried out 6k miles ago with new chain tensioner, chain, cam sprockets and lost motion springs.
Nasty rattle still present when engine is above 2200 rpm, worse when getting on the move and can be heard in muted form when cruising along on part throttle. I wonder if it has something to do with the clutch or flywheel.
See this video: https://youtu.be/D4tKyMcupcc
The horrible rattle is obvious. I will carry on driving until something blows up but would appreciate any ideas.
Update 10th Feb:
Thanks windhund. I haven't tried taking the coils off when the engine is running yet. I have used a mechanics stethoscope to try and locate the source of the noise. The engine is too loud and I cant hear anything through the ear pieces over the ambient noise.
Since I said the noise has got worse after the oil change, I have been out driving it. The very faint knock like sound can only be heard with a cold engine. Otherwise the only symptom is the nasty rattle at around 2500-3500 rpm especially when using the clutch setting off in 1st or reversing. I believe this is because using the clutch holds the revs a little longer at the rpm point where the rattle occurs.
There is also a harmonic type sound you hear when on light throttle around that rev range when moving.
I'm still tempted to get the sump pulled and the bearings looked at and likely replaced. The other part of me thinks I should carry on driving and accept this is a noise it makes.
Original post:
Hi all, having a few issues and would appreciate any advice.
I've owned my 2002 S2000 since early November and for 5k miles. I believe the knocking has been present through all or almost all of my ownership.
I visited a well regarded Honda specialist yesterday and discovered What I always thought was a loose cat heat shield rattling is actually the engine knocking.
Old videos showing piston slap and not the main problem:
Sitting in the car and displaying the knock (about 5 mins after start): https://youtu.be/33-JHUNGDvo
Fairly long cold start video: https://youtu.be/ROuCwIQdTTQ
The noise is obvious whenever you pull away and use more than 2k revs, though is mainly around the 2-3k rpm range. It sounded like a buzzing sound to me. On the move it is less obvious though this may be due to the road and intake noise covering it up. The engine feels fine when revving up to 9k rpm in 2nd and 3rd, letting off in 4th, which I do several times a week at least since owning it.
Short video with warm engine revving to 3k rpm: https://www.youtube.com/watch?v=a9bBOY33YyY
The oil was dropped and put through a paint strainer and no debris was found. After the oil change it now makes a more obvious light knocking sound when idling with a cold engine, this disappears once warmed up though.
The previous owner had a "health check" carried out on the engine at a rally engine builder. The invoice states a new oil pump, timing chain, TCT, lost motions springs and big end bolts. This was 1k miles before I bought the car. I did consider not buying car due to the owner having just coughed up for the £2k invoice and was now selling up, but bought it anyway. I'm not too sure what significance this factor has on the knock.
My options are:
1) Don't drive it, get the engine stripped and hopefully rebuilt or get a used engine put in.
2) Continue to drive and hope the knock doesn't get worse (whilst constantly worrying). As the knock has been present for a significant amount of time with extended high rpm operation, maybe it will keep going for a while.
3) Sell it. I don't know who would buy it and if they did, it would be a huge loss to me as I will be accurate in my description.
What option would others go for? And does anyone else have experience of a long lasting engine knock?
Sorry for the long post.
Cheers[/size][/size]
02-03-2016, 11:20 AM
#2
It could be slightly loose valve lash.
02-03-2016, 12:16 PM
#3
Need to pinpoint where its coming from, top end or bottom end, that will effect your course of action as far as investing in the repair or not. Sounds like the previous owner was chasing this sound before you and after dropping cash into it with still no resolve, unloaded his problem on to you. A good mechanic should be able to properly diagnose what's making the sound before you go digging into the engine. Don't take it back to the guys that worked on it previously if you decided to dig into it. I cant hear your video wile at work, but based on what I've heard so far, my guess is you have compromised rod bearings. If so, you may be able to replace these without pulling the crank and get lucky. I would limit your driving on this car to prevent spinning a rod bearing if that's indeed what it is. If you do, you will create a lot more work and expense for yourself.
02-03-2016, 12:36 PM
#4
When the car was up on the ramps, the garage reckoned it was the bottom end, but just a very faint knock.
If I really think about it, the noise it makes was less present when I got the car. The noise primarily being the sound it makes when setting off in 1st and manipulating the clutch. If you pull away with about 2k rpm it doesn't sound too bad.
I'll give the engine builder a call tomorrow and ask the reason why the work was carried out. It looks like a lot of it was to do with the timing chain. guides and sprockets though.
As the car hadn't had an oil change since this timing chain work and there was no swarf in the oil when it just got changed, would any swarf just get stuck in the oil filter / bottom of the sump?
I'll cycle to work tomorrow. Need to use the car on Friday though. I'll try not to VTEC it then, even though it feels healthier doing that
If I really think about it, the noise it makes was less present when I got the car. The noise primarily being the sound it makes when setting off in 1st and manipulating the clutch. If you pull away with about 2k rpm it doesn't sound too bad.
I'll give the engine builder a call tomorrow and ask the reason why the work was carried out. It looks like a lot of it was to do with the timing chain. guides and sprockets though.
As the car hadn't had an oil change since this timing chain work and there was no swarf in the oil when it just got changed, would any swarf just get stuck in the oil filter / bottom of the sump?
I'll cycle to work tomorrow. Need to use the car on Friday though. I'll try not to VTEC it then, even though it feels healthier doing that
02-03-2016, 12:48 PM
#5
Bottom end usually means rod bearings, as mentioned. It sounds like if that's what it is, its not severe yet to be blowing chunks, but I would expect higher contamination levels in your oil from the bearings such as (copper?) so having an oil analysis done may confirm/point you in that direction, or somewhere else. we have a company here in the states called Blackstone which does an extensive oil analyzing and summery of what they see for $25. Usually takes about 4-6 weeks for turn around though.
02-03-2016, 02:08 PM
#6
Why do you think it might be the main bearings rather than the rod bearings?
Its looking more likely that I'm going to need to get the engine taking out and stripped. This is my understanding of how it works:
1) Get engine out and take the sump off
2) Assess lower main bearing damage and replace.
3) Look at the crank and see if its mirror finish has been lost.
4) Assess upper main bearing damage and replace.
5) Determine if cylinders are scored.
5) Assess rod bearing damage and replace.
Can rod bearings be checked without taking the head off the engine? And is it usual practice to replace the bearings if there is no visible issue with them?
Thanks for the help.
Its looking more likely that I'm going to need to get the engine taking out and stripped. This is my understanding of how it works:
1) Get engine out and take the sump off
2) Assess lower main bearing damage and replace.
3) Look at the crank and see if its mirror finish has been lost.
4) Assess upper main bearing damage and replace.
5) Determine if cylinders are scored.
5) Assess rod bearing damage and replace.
Can rod bearings be checked without taking the head off the engine? And is it usual practice to replace the bearings if there is no visible issue with them?
Thanks for the help.
02-03-2016, 02:31 PM
#7
I listened to the video, it seems like normal noise, but it could be the potato quality masking it. Is a tick or a knock?
To check rod bearings you drop the oil pan, lock the crank, remove the rod end cap, apply plastigauge to the crank journal and torque the rod end cap to spec(18 ft lbs + 90 degrees). Then remove the cap and compare the mark to the plastigauge legend.
To check rod bearings you drop the oil pan, lock the crank, remove the rod end cap, apply plastigauge to the crank journal and torque the rod end cap to spec(18 ft lbs + 90 degrees). Then remove the cap and compare the mark to the plastigauge legend.
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02-03-2016, 02:38 PM
#8
Why do you think it might be the main bearings rather than the rod bearings?
Its looking more likely that I'm going to need to get the engine taking out and stripped. This is my understanding of how it works:
1) Get engine out and take the sump off
2) Assess lower main bearing damage and replace.
3) Look at the crank and see if its mirror finish has been lost.
4) Assess upper main bearing damage and replace.
5) Determine if cylinders are scored.
5) Assess rod bearing damage and replace.
Can rod bearings be checked without taking the head off the engine? And is it usual practice to replace the bearings if there is no visible issue with them?
Thanks for the help.
Its looking more likely that I'm going to need to get the engine taking out and stripped. This is my understanding of how it works:
1) Get engine out and take the sump off
2) Assess lower main bearing damage and replace.
3) Look at the crank and see if its mirror finish has been lost.
4) Assess upper main bearing damage and replace.
5) Determine if cylinders are scored.
5) Assess rod bearing damage and replace.
Can rod bearings be checked without taking the head off the engine? And is it usual practice to replace the bearings if there is no visible issue with them?
Thanks for the help.
The video audio quality isn't very good. And I would have liked to heard it at idle for a wile for one thing. is it coming from the head area or down lower near the pan?
02-03-2016, 05:04 PM
#9
Did you check the accessory belt and associated pulley/bearings & alternator?
02-03-2016, 06:38 PM
#10
Ive had the main serpentine belt tentioner wear out on me before. I kept hearing these intermittent click/clacking sounds and finally isolated it to that and replaced with another used one i had laying around, sure enough that was it. Thing developed some slop in it and would make noise with engine rpm differential. If its something engine related, its usually not sporatic but constant, not always but usually. Accessory related stuff usually starts out more intermittent.