Car Knocking on cold
10 January 2005, 10:29 AM
#1
Car Knocking on cold
For the last few weeks when i start my car in the morning's i hear my engine knocking, i thought this was normal as the car is cold. However my brother pointed it out to me this morning..
My engine was rebuilt i think near 20K miles ago, including pston slap by the previous owner..my car only has near 66K on the clock..Never drive on boost till the car is fully warm, always let it cool down before turning it off..Also the oil and filter is changed every 3000 miles.
Any thoughts on what this could be caused by or what this could mean..
Thanks...
My engine was rebuilt i think near 20K miles ago, including pston slap by the previous owner..my car only has near 66K on the clock..Never drive on boost till the car is fully warm, always let it cool down before turning it off..Also the oil and filter is changed every 3000 miles.
Any thoughts on what this could be caused by or what this could mean..
Thanks...
10 January 2005, 11:02 AM
#6
Cheers Andy:
3.14 Piston Slap
It seems a small percentage of the MY98 cars have had problems with Piston Slap after a period of 10,000 to 20,000 miles has been covered. This manifests itself as a knocking noise which is much more pronounced when the engine is cold. This should not be confused with a ticking/tappet type noise which is common on all Impreza engines , but a distinct knocking noise which is most noticed between 1,500 and 2,000 rpm. In the UK, Subaru have been resolving the problems by fitting an a completely new short engine (block, crank, pistons) , and this cures the problem completely. Some cars are apparently much worse than others, with very lightly driven cars being just as susceptible as those driven hard! All Subaru dealers should be aware of this problem, and offer to resolve (free of charge under warranty) if the problem exists. If your dealer denies all knowledge, then go to another dealer who may be more sympathetic to your cause. The work takes between 2 to 3 days to perform, and as well as running it in again, you most get your ownership document(s) updated with the new engine number. If the problem occurs on a normally aspirated engine, then a simple piston replacement can be used, instead of a whole new block.
Am trying to call CheamMotors to find out exactly what was done to the car, by the previous owner..Though i would think if the car went to them for the problem of Piston Slap they would have done the above...
3.14 Piston Slap
It seems a small percentage of the MY98 cars have had problems with Piston Slap after a period of 10,000 to 20,000 miles has been covered. This manifests itself as a knocking noise which is much more pronounced when the engine is cold. This should not be confused with a ticking/tappet type noise which is common on all Impreza engines , but a distinct knocking noise which is most noticed between 1,500 and 2,000 rpm. In the UK, Subaru have been resolving the problems by fitting an a completely new short engine (block, crank, pistons) , and this cures the problem completely. Some cars are apparently much worse than others, with very lightly driven cars being just as susceptible as those driven hard! All Subaru dealers should be aware of this problem, and offer to resolve (free of charge under warranty) if the problem exists. If your dealer denies all knowledge, then go to another dealer who may be more sympathetic to your cause. The work takes between 2 to 3 days to perform, and as well as running it in again, you most get your ownership document(s) updated with the new engine number. If the problem occurs on a normally aspirated engine, then a simple piston replacement can be used, instead of a whole new block.
Am trying to call CheamMotors to find out exactly what was done to the car, by the previous owner..Though i would think if the car went to them for the problem of Piston Slap they would have done the above...
10 January 2005, 11:07 AM
#7
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You'll be surprised how many people just live with it!
I daresay your car is out of warranty now, so I suspect that if you want it done, you will have to dig into your own pocket!
I daresay your car is out of warranty now, so I suspect that if you want it done, you will have to dig into your own pocket!
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10 January 2005, 02:00 PM
#8
Looking at my invoce Dated 9/7/03
Balance of Engine Piston repair
Replaced Clutch - suplied by customer
Flywheel Skimmed
Replaced Spigot Bearing
Resealed oil rear seperator plate
Parts used:
Ball bearings
V Belt
Shim Valve x4
Gaskit and Seal Kit
GSKT - Rocker CVR LH 2
Gasket Rocker cover
Washer Rocker cover
Plug Clyinder Head
Mod piston + Rings
Castrol 10W40 Oil
Coolant
Total bill £998!
This was paid to Cheam Motors towards the end of 2003 and the car had 48K on the clock..
Though also my clutch has been judring for i think for 3000 odd miles ago...
Called Cheam, i was only able to talk to some woman in the service department who by the sounds of it did not even know what a Piston was, and refused to put me through to someone who knows little more..
She said she will talk to the guys who wrk on cars, and check if he remembers anything! I thought they would have it all on file!!!
Balance of Engine Piston repair
Replaced Clutch - suplied by customer
Flywheel Skimmed
Replaced Spigot Bearing
Resealed oil rear seperator plate
Parts used:
Ball bearings
V Belt
Shim Valve x4
Gaskit and Seal Kit
GSKT - Rocker CVR LH 2
Gasket Rocker cover
Washer Rocker cover
Plug Clyinder Head
Mod piston + Rings
Castrol 10W40 Oil
Coolant
Total bill £998!
This was paid to Cheam Motors towards the end of 2003 and the car had 48K on the clock..
Though also my clutch has been judring for i think for 3000 odd miles ago...
Called Cheam, i was only able to talk to some woman in the service department who by the sounds of it did not even know what a Piston was, and refused to put me through to someone who knows little more..
She said she will talk to the guys who wrk on cars, and check if he remembers anything!
I thought they would have it all on file!!!
10 January 2005, 03:13 PM
#9
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Had the same problem with mine, the noise does my head in when its cold as anybody nearby thinks you are driving a diesel or if not in sight, a tractor!
Mine is being worked upon as we speak.
Good luck with subaru!
Mine is being worked upon as we speak.
Good luck with subaru!
10 January 2005, 04:24 PM
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My MY98 did that for a while Sam, then the bottom end went altogether. 
It just sounded like a diesel for the first few seconds on start-up then cleared (i presume) once the oil had had a chance to circulate and lubricate the bearings. After a week or so it went altogether (very loud 'solid' knocking) whilst doing about 50mph in fifth lol...
Mine was the same, always warmed up and down and fully serviced etc but at 96,500 miles. I was also 3 weeks out of my extended warranty.
I'd get it checked out asap.
It just sounded like a diesel for the first few seconds on start-up then cleared (i presume) once the oil had had a chance to circulate and lubricate the bearings. After a week or so it went altogether (very loud 'solid' knocking) whilst doing about 50mph in fifth lol...
Mine was the same, always warmed up and down and fully serviced etc but at 96,500 miles. I was also 3 weeks out of my extended warranty.
I'd get it checked out asap.
10 January 2005, 04:26 PM
#11
Cheers Carl...feel allot better now... 
Im up in Mancherster soon, someone did recomend a place, cant remeber there name though..
Will the garage not need to start it from cold to figure out if it is that actuall problem of not..?
Im up in Mancherster soon, someone did recomend a place, cant remeber there name though..
Will the garage not need to start it from cold to figure out if it is that actuall problem of not..?
10 January 2005, 05:12 PM
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Hi,
Mine has been doing this for about 3 years now, worse when its a cold winter morning, load the engine slightly for pulling away ect and you can hear it slap, I think it gets a bit worse every year but when warmed up goes away. Covered 86000 miles, My98. Have been told not to worry about it unless it gets really noisy.
George
Mine has been doing this for about 3 years now, worse when its a cold winter morning, load the engine slightly for pulling away ect and you can hear it slap, I think it gets a bit worse every year but when warmed up goes away. Covered 86000 miles, My98. Have been told not to worry about it unless it gets really noisy.
George
10 January 2005, 07:20 PM
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Originally Posted by Carl Davey
My MY98 did that for a while Sam, then the bottom end went altogether.
It just sounded like a diesel for the first few seconds on start-up then cleared (i presume) once the oil had had a chance to circulate and lubricate the bearings. After a week or so it went altogether (very loud 'solid' knocking) whilst doing about 50mph in fifth lol...
Mine was the same, always warmed up and down and fully serviced etc but at 96,500 miles. I was also 3 weeks out of my extended warranty.
I'd get it checked out asap.
It just sounded like a diesel for the first few seconds on start-up then cleared (i presume) once the oil had had a chance to circulate and lubricate the bearings. After a week or so it went altogether (very loud 'solid' knocking) whilst doing about 50mph in fifth lol...
Mine was the same, always warmed up and down and fully serviced etc but at 96,500 miles. I was also 3 weeks out of my extended warranty.
I'd get it checked out asap.
piston slap noise : although it sounds a bit bad, like a big end, is not due to lack of oil. its due to the piston not fitting the bore correcty when its cold. this is usually due to the piston skirt design that was changed on the phase1.5 (97/98) cars. it was rectified on the later cars, and wasnt an issue on the earlier ones either (usually - but can obviously happen on ANY car!)
The noise you describe sounds exactly like a big end failure due to bad oil feed , or simply a damaged bearing, which ultimatly completely failed because it was driven
once piston slap starts, its made the bore more oval than its ment to be, and it can make it worse. but usually its harmless unless it progresses (and you dont take care of it when cold-be gentil etc)
a change of piston should be ok if the bore wasnt too badly ovaled. which is why subaru generally changed the entier block.
i'd call them back and ask to speak to the servicing manager.
Steve
10 January 2005, 07:29 PM
#16
Steve,
I am waiting for a call back from them...though i think when i spoke to them originally they said they only changed the Pistons! Though if this is Piston Slap shorley it would still be covered under the warranty of the work they carried out towards the end of 2003?
Sam
I am waiting for a call back from them...though i think when i spoke to them originally they said they only changed the Pistons! Though if this is Piston Slap shorley it would still be covered under the warranty of the work they carried out towards the end of 2003?
Sam
10 January 2005, 07:34 PM
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Looking at your invoice it looks like only the Pistons were changed.
As for the warranty on the work they carried out, we are well over a year on from that point, and if you car is out of warranty now i would think that you would have a struggle getting anywhere with that one, especially as your car is modified now.
Ian
As for the warranty on the work they carried out, we are well over a year on from that point, and if you car is out of warranty now i would think that you would have a struggle getting anywhere with that one, especially as your car is modified now.
Ian
10 January 2005, 07:35 PM
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Hey Steve. I think wires are being crossed here... When i refered to my car making a similar noise as Sam describes i was doing just that, not referring to piston-slap specifically. Indeed, Sam's car has yet to be positively diagnosed, all we have is the presumption it must be PS because it's a MY98.
I did actually say it was the big-end which went on mine, but thanks for reminding me. Perhaps i should clarify, mine never had piston slap.
I think wires are being crossed here... When i refered to my car making a similar noise as Sam describes i was doing just that, not referring to piston-slap specifically. Indeed, Sam's car has yet to be positively diagnosed, all we have is the presumption it must be PS because it's a MY98. I did actually say it was the big-end which went on mine, but thanks for reminding me. Perhaps i should clarify, mine never had piston slap.
10 January 2005, 07:45 PM
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Carl - ok was just trying to make things clear that a big end 'can' sound like piston slap & visa versa .. although you can usually tell if you know what you are listening for
sorry for reminding you
Sam - i susspect u will be out of luck
but try anyway. if its come back this quickly and it was just a piston that was changed (as invoiced) then it should have been of modified design and shouldnt have come back , but what can you do ? ask them!!
i would say that if its come back this quick, then their repair wasnt that wonderful!
Steve
was just trying to make things clear that a big end 'can' sound like piston slap & visa versa .. although you can usually tell if you know what you are listening for sorry for reminding you
Sam - i susspect u will be out of luck
but try anyway. if its come back this quickly and it was just a piston that was changed (as invoiced) then it should have been of modified design and shouldnt have come back , but what can you do ? ask them!!i would say that if its come back this quick, then their repair wasnt that wonderful!
Steve
11 January 2005, 09:08 AM
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Originally Posted by SamUK
Looking at my invoce Dated 9/7/03
Balance of Engine Piston repair
Replaced Clutch - suplied by customer
Flywheel Skimmed
Replaced Spigot Bearing
Resealed oil rear seperator plate
Parts used:
Ball bearings
V Belt
Shim Valve x4
Gaskit and Seal Kit
GSKT - Rocker CVR LH 2
Gasket Rocker cover
Washer Rocker cover
Plug Clyinder Head
Mod piston + Rings
Castrol 10W40 Oil
Coolant
Total bill £998!
This was paid to Cheam Motors towards the end of 2003 and the car had 48K on the clock..
Though also my clutch has been judring for i think for 3000 odd miles ago...
Called Cheam, i was only able to talk to some woman in the service department who by the sounds of it did not even know what a Piston was, and refused to put me through to someone who knows little more..
She said she will talk to the guys who wrk on cars, and check if he remembers anything! I thought they would have it all on file!!!
Balance of Engine Piston repair
Replaced Clutch - suplied by customer
Flywheel Skimmed
Replaced Spigot Bearing
Resealed oil rear seperator plate
Parts used:
Ball bearings
V Belt
Shim Valve x4
Gaskit and Seal Kit
GSKT - Rocker CVR LH 2
Gasket Rocker cover
Washer Rocker cover
Plug Clyinder Head
Mod piston + Rings
Castrol 10W40 Oil
Coolant
Total bill £998!
This was paid to Cheam Motors towards the end of 2003 and the car had 48K on the clock..
Though also my clutch has been judring for i think for 3000 odd miles ago...
Called Cheam, i was only able to talk to some woman in the service department who by the sounds of it did not even know what a Piston was, and refused to put me through to someone who knows little more..
She said she will talk to the guys who wrk on cars, and check if he remembers anything!
I thought they would have it all on file!!! )Bear in mind they have just had a major refit, so they were still sorting out the office last week.
21 January 2005, 12:54 PM
#21
Had a chat with Colin
Piston 2 & 4 were changed due to the slap... in July 03
Out of warranty now so will have to pay to have my care looked at!
Colin recken's if the knocking is occuring it maybe from Piston 1 & 3 as they are still the original pistons.
Though it would have made sense to change all the pistons rather then putting 2 modified pistons that resolve the issue and leaving 2 of the older type in...
1998 cars suffered from Piston slap, and they swaped the existing pistons for modified Pistons to resolve the problem..
Piston 2 & 4 were changed due to the slap... in July 03
Out of warranty now so will have to pay to have my care looked at!
Colin recken's if the knocking is occuring it maybe from Piston 1 & 3 as they are still the original pistons.
Though it would have made sense to change all the pistons rather then putting 2 modified pistons that resolve the issue and leaving 2 of the older type in...
1998 cars suffered from Piston slap, and they swaped the existing pistons for modified Pistons to resolve the problem..
21 January 2005, 01:02 PM
#22
the oficial change was to replace the short motor on Turbo MY98's sufering piston slap. For NA MY98's they fitted an oversize ceramic coated piston. Sounds to me like they didnt follow the oficial fix procedure on your Turbo model.
21 January 2005, 01:09 PM
#23
Sam,
From listening to your engine with the det cans, it's definitely piston slap, but it goes after about 30 seconds to a minute, and it's not actually that bad. If all the subaru dealer did was to replace some pistons, they could have done almost anything. The pistons should be matched to the bore (or the other way around if building motor from scratch) and unless they did this, you could have wrong clearances still.
I dare say that the piston noise is the reason for some of your knock events in the low 20s on the commander when engine is a little cold.
Paul
From listening to your engine with the det cans, it's definitely piston slap, but it goes after about 30 seconds to a minute, and it's not actually that bad. If all the subaru dealer did was to replace some pistons, they could have done almost anything. The pistons should be matched to the bore (or the other way around if building motor from scratch) and unless they did this, you could have wrong clearances still.
I dare say that the piston noise is the reason for some of your knock events in the low 20s on the commander when engine is a little cold.
Paul
Last edited by Pavlo; 21 January 2005 at 01:14 PM.
21 January 2005, 01:20 PM
#24
What suprised me was they only changed 2 Pistons and not all 4!
Collin was walking to the Senior technician at the time of my call, and he said all that was needed to be done was the piston changed for a modified one...
Paul on the knocking side...i have never again reved above 3000rpm when cold..On warm knockin is averaging near 7 - 9. I may see a 12 once in a blue moon...Though it did hit 20 twice in the last week...on that front i think we are ok...
Collin was walking to the Senior technician at the time of my call, and he said all that was needed to be done was the piston changed for a modified one...
Paul on the knocking side...i have never again reved above 3000rpm when cold..On warm knockin is averaging near 7 - 9. I may see a 12 once in a blue moon...Though it did hit 20 twice in the last week...on that front i think we are ok...
21 January 2005, 04:50 PM
#25
My bro-in-laws Catalunya (MY97) had piston slap on one piston.... dealer changed entire short engine. I'm with John and this and thought that was the official fix. Maybe speak to IM and see, if so maybe you could get something sorted as the dealer didn't follow the guidelines? But if it's only what Paul describes i won't be worried.
Tony.
Tony.
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