Engine knock
02-02-2016, 12:07 PM
#1
Engine knock
Nasty but not loud rattle (its not a knock) from the cylinder head at around 2200 rpm and above. Valves adjusted with a minor improvement then back to this.
https://youtu.be/YVRDqrHCh3s?t=116
Not sure what else in the cylinder head it could be. May have to look into getting it rebuilt, not sure where to start there.
Update 25th 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.
Hi all,
I've owned my S2000 since early November and have covered around 5k miles since then.
I visited TGM today. What I always thought was a loose cat heatshield turns out to be a slight engine knock.
Old videos showing what is probably piston slap and what is not the 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. Once you're moving it can't really be heard, though this may be due to the road and intake noise covering it up! The engine seems happy to rev up up to 9000 rpm in 2nd and 3rd, letting off in 4th, which I have done so several times a week since owning the car.
Tom advised of the problem and suggested changing the oil, checking for swarf and continuing driving, monitoring the car to see if the noise gets any worse.
I'm not too sure if it was there when I got the car, but I definitely first noticed it sometime in mid November. I tend to drive the car fairly hard at least 3 or 4 days a week and the sound doesn't seem to have gotten any worse.
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.
I imagine a new engine will be on the cards eventually. The fact that I have driven it for so many miles and pushed the engine through the rev range often with this noise present does make me wonder how long it will last.
I suppose the knocking will eventually get louder, be present at across the RPM range and will soon blow a hole in the engine?
Does anyone else have experience of a long lasting engine knock?
https://youtu.be/YVRDqrHCh3s?t=116
Not sure what else in the cylinder head it could be. May have to look into getting it rebuilt, not sure where to start there.
Update 25th 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.
Hi all,
I've owned my S2000 since early November and have covered around 5k miles since then.
I visited TGM today. What I always thought was a loose cat heatshield turns out to be a slight engine knock.
Old videos showing what is probably piston slap and what is not the 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. Once you're moving it can't really be heard, though this may be due to the road and intake noise covering it up! The engine seems happy to rev up up to 9000 rpm in 2nd and 3rd, letting off in 4th, which I have done so several times a week since owning the car.
Tom advised of the problem and suggested changing the oil, checking for swarf and continuing driving, monitoring the car to see if the noise gets any worse.
I'm not too sure if it was there when I got the car, but I definitely first noticed it sometime in mid November. I tend to drive the car fairly hard at least 3 or 4 days a week and the sound doesn't seem to have gotten any worse.
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.
I imagine a new engine will be on the cards eventually. The fact that I have driven it for so many miles and pushed the engine through the rev range often with this noise present does make me wonder how long it will last.
I suppose the knocking will eventually get louder, be present at across the RPM range and will soon blow a hole in the engine?
Does anyone else have experience of a long lasting engine knock?
02-02-2016, 12:22 PM
#2
Here's a quick video with a warm engine. I will do a cold start video tomorrow.
https://www.youtube.com/watch?v=a9bBOY33YyY
https://www.youtube.com/watch?v=a9bBOY33YyY
02-02-2016, 12:43 PM
#3
New Big end bolts would worry me 
02-03-2016, 06:09 AM
#4
The oil was dropped and put through a paint strainer and no debris was found.
After the oil change the the engine is now making a slightly more obvious very light knocking sound when the engine is cold, this dissapears once warmed up though. Still not brilliant news.
For now I will continue to drive, and hope the noise does not get any worse. As it hasn't gotten worse for quite a while and with extended high rpm operation, I hope this means the engine will continue to live.
The other option that I am less keen on is having the engine taken out and stripped. From what I have read, you might as well get a second hand engine instead of even opening up the existing engine. If I do notice a clear increase in knock and other symptoms, I will have the car transported to TGM for either analysis of the engine or have a used engine put in.
After the oil change the the engine is now making a slightly more obvious very light knocking sound when the engine is cold, this dissapears once warmed up though. Still not brilliant news.
For now I will continue to drive, and hope the noise does not get any worse. As it hasn't gotten worse for quite a while and with extended high rpm operation, I hope this means the engine will continue to live.
The other option that I am less keen on is having the engine taken out and stripped. From what I have read, you might as well get a second hand engine instead of even opening up the existing engine. If I do notice a clear increase in knock and other symptoms, I will have the car transported to TGM for either analysis of the engine or have a used engine put in.
02-03-2016, 08:39 AM
#5
I've heard of (rare cases) where the bolts have come loose and being stretched.
I'd be somewhat worried about damage to rods, shells, end caps via knocking.
Without assembling with those blue mic'ing plastc things, you'd never be sure clearances were right.
I'd be somewhat worried about damage to rods, shells, end caps via knocking.
Without assembling with those blue mic'ing plastc things, you'd never be sure clearances were right.
02-03-2016, 10:13 AM
#6
Could try getting touch with the engine builder,and ask for some pointers regarding the knock present and if new shells were used,did they check end float ect and overall findings inc crank condition ect
As you have the invoice with contact details.
That's if you have not already
As you have the invoice with contact details.
That's if you have not already
02-03-2016, 11:35 AM
#7
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You sure it isn't piston slap?only reason I ask is because you said the noise is there from cold,but disappeares once upto temp?
If it's pistonslap it's probably nothing to worry about,I've heard newly built engines with forged Pistons knocking away until there upto temp.
If it's pistonslap it's probably nothing to worry about,I've heard newly built engines with forged Pistons knocking away until there upto temp.
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02-03-2016, 12:27 PM
#8
I don't think so.
The engine is pretty noisy at warm idle but you can kind of hear a faint knocking sound if you listen closely.
The main issue when its up to temperature is the pretty nasty grinding/buzzing/knocking sound it makes whenever its around the 2-3k rpm mark. Typically pulling away in 1st, shifting up into 2nd at about 10-12 mph it is much less but you can still here a kind of knocking sound. The sound is definitely at its worst when feathering clutch as you start moving. It does make wonder if it has something to do with the clutch engagement or clutch fork.
Once you put your foot down the engine feels strong.
I'm worried if I keep driving it I'll be causing further damage.
I'll give the engine builder a call tomorrow and ask what the reason for the work was, why there might now be a knock and if he did a valve adjustment. The invoice doesn't have anything to do with bearings on it but it only shows parts, so I don't know if any machine work was carried out. Just that the head must have come off due to the big end bolts.
The engine is pretty noisy at warm idle but you can kind of hear a faint knocking sound if you listen closely.
The main issue when its up to temperature is the pretty nasty grinding/buzzing/knocking sound it makes whenever its around the 2-3k rpm mark. Typically pulling away in 1st, shifting up into 2nd at about 10-12 mph it is much less but you can still here a kind of knocking sound. The sound is definitely at its worst when feathering clutch as you start moving. It does make wonder if it has something to do with the clutch engagement or clutch fork.
Once you put your foot down the engine feels strong.
I'm worried if I keep driving it I'll be causing further damage.
I'll give the engine builder a call tomorrow and ask what the reason for the work was, why there might now be a knock and if he did a valve adjustment. The invoice doesn't have anything to do with bearings on it but it only shows parts, so I don't know if any machine work was carried out. Just that the head must have come off due to the big end bolts.
02-03-2016, 01:35 PM
#9
Big end bolts can be changed by dropping the sump and no need for the head to be removed, engine or gearbox.
Mains would be a different story ..
just had a listen, that does not sound like big ends in the video
But as TGM have said that from a listen,must be only be slight one
Many miles on the engine ?
Mains would be a different story ..
just had a listen, that does not sound like big ends in the video
But as TGM have said that from a listen,must be only be slight one
Many miles on the engine ?
02-04-2016, 04:49 AM
#10
Engine has 105k miles.
I did a cold start this morning to get some better footage.
The knocking is now obvious at idle. I'll upload the video later on.
I can't believe it's gone from working well with a bit of a rattle to an audible knock when stationary as the revs drop down from a blip. Its gone from a stable condition to crap straight after the oil got changed.
I did a cold start this morning to get some better footage.
The knocking is now obvious at idle. I'll upload the video later on.
I can't believe it's gone from working well with a bit of a rattle to an audible knock when stationary as the revs drop down from a blip. Its gone from a stable condition to crap straight after the oil got changed.
