Piston Slap - Does anyone know the full story
12 January 2004, 07:47 PM
#1
Scooby Regular
Thread Starter
Join Date: Apr 2000
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
Guys,
I know there are loads of posts about this, and I have looked at most of them. A few questions:
1) Was it only MY97 & MY98's that were affected or did the problem exist in MY99 cars as well?
2) I understand that Subaru made modifications to their engines following the piston slap problems. I have an RB5 WR Sport. It is a 1999 car. Just want to know if the engines fitted to these were modified to eliminate piston slap.
Information on this topic seems to be very subjective, so an answer from anyone with definate knowledge would be much appreciated.
Cheers
I know there are loads of posts about this, and I have looked at most of them. A few questions:
1) Was it only MY97 & MY98's that were affected or did the problem exist in MY99 cars as well?
2) I understand that Subaru made modifications to their engines following the piston slap problems. I have an RB5 WR Sport. It is a 1999 car. Just want to know if the engines fitted to these were modified to eliminate piston slap.
Information on this topic seems to be very subjective, so an answer from anyone with definate knowledge would be much appreciated.
Cheers
12 January 2004, 08:16 PM
#3
Scooby Regular
Thread Starter
Join Date: Apr 2000
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
Huw,
Piston slap occurs when the piston skirt or bores wear slightly allowing it to rock in the bore under power. As the engine heats up the slack is taken up by thermal expansion and the noise cannot be heard anymore.
The problem occured because Subaru fitted pistons with too small crowns/skirts.
Piston slap occurs when the piston skirt or bores wear slightly allowing it to rock in the bore under power. As the engine heats up the slack is taken up by thermal expansion and the noise cannot be heard anymore.
The problem occured because Subaru fitted pistons with too small crowns/skirts.
12 January 2004, 09:45 PM
#4
Scooby Regular
iTrader: (1)
Join Date: Oct 2001
Location: South East
Posts: 1,300
Likes: 0
Received 0 Likes
on
0 Posts
not sure this is 100%, but this is what i've learnt ...
it WAS only the 97/98 design that caused the problem.
it was resolved by a new design piston, which i assume was used in 99 onwards engine.
the fix to 97/98's was to
a) replace piston (usually no 4 (nearest turbo)
b) replace complete short block
the reason it does it is due to the design / materials of the crowns / skitks etc.
it is very evident when cold, and should dissapear when warmed up.
on mine (MY97) its evident when you dab the gas when cold. after driving down the road, for 2 mins, its gone.
saying that, i neva take it above 2500rpm until its fully warm & no boost obviously!
Not sure that it DOESNT occur in other years .
not sure its a real problem, as some cars, like cossies etc are REALLY REALLY bad cold. and some forged rods& pistons sound like that (although I wouldnt be able to dive a car like that!)
hope that helps some.
Steve
[Edited by ScoobyDuck - 1/12/2004 9:47:31 PM]
it WAS only the 97/98 design that caused the problem.
it was resolved by a new design piston, which i assume was used in 99 onwards engine.
the fix to 97/98's was to
a) replace piston (usually no 4 (nearest turbo)
b) replace complete short block
the reason it does it is due to the design / materials of the crowns / skitks etc.
it is very evident when cold, and should dissapear when warmed up.
on mine (MY97) its evident when you dab the gas when cold. after driving down the road, for 2 mins, its gone.
saying that, i neva take it above 2500rpm until its fully warm & no boost obviously!
Not sure that it DOESNT occur in other years .
not sure its a real problem, as some cars, like cossies etc are REALLY REALLY bad cold. and some forged rods& pistons sound like that (although I wouldnt be able to dive a car like that!)
hope that helps some.
Steve
[Edited by ScoobyDuck - 1/12/2004 9:47:31 PM]
13 January 2004, 01:15 AM
#5
Scooby Regular
Join Date: Aug 2003
Location: devon
Posts: 437
Likes: 0
Received 0 Likes
on
0 Posts
i think ull find all scoobs suffer ...well from what ive read anyway..mines a my 96 and slaps like a goodun when cold [sounds like its well knacked]but is ok when warm i think its a drawback with a horizontaly opposed engine[u cant stop gravity]
13 January 2004, 07:31 PM
#7
Scooby Regular
Join Date: Oct 2001
Posts: 1,833
Likes: 0
Received 0 Likes
on
0 Posts
So could my oil consumption be associated with the tapping noise first few minutes at iddle?
I changed belt tensioner and oil in my last service and noise dissapeared for two days, now is back, I don't know if this is due to fresh oil that prevents temporarily slaping sound, due to new tensioner that failed again or something else!
Subaru claims that new age cars don't suffer from such problems,
but the service can't find it as it's present only below 1350-1400 rpms for few minutes, only when car is full cold and more pronounced from the turbo down side of engine.
JIM
I changed belt tensioner and oil in my last service and noise dissapeared for two days, now is back, I don't know if this is due to fresh oil that prevents temporarily slaping sound, due to new tensioner that failed again or something else!
Subaru claims that new age cars don't suffer from such problems,
but the service can't find it as it's present only below 1350-1400 rpms for few minutes, only when car is full cold and more pronounced from the turbo down side of engine.
JIM
Trending Topics
14 January 2004, 01:37 PM
#10
Scooby Regular
Thread Starter
Join Date: Apr 2000
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
Depends what colour it is. If it is white and wispy then it is water vapour which is totally normal. If it has a blue tinge then that means there is oil in there too and this is not so good.
14 January 2004, 02:42 PM
#11
Scooby Regular
Join Date: Jul 2000
Location: Lancashire
Posts: 2,209
Likes: 0
Received 0 Likes
on
0 Posts
Steve,
If no.4 is nearest the turbo then your engine is in the wrong way around
I believe it was no.3 they changed on my car.
Andrew...
a) replace piston (usually no 4 (nearest turbo)
I believe it was no.3 they changed on my car.
Andrew...
15 January 2004, 11:24 AM
#14
Scooby Regular
Join Date: Mar 2003
Location: Edinburgh
Posts: 154
Likes: 0
Received 0 Likes
on
0 Posts
yep had it annoyed the f*ck out of me when to subaru and they fixed it MY98 proven warrenty so its a used car.slap can happen on any age of impreza it depends on how the engine is run in and luck. but my 98's did have a design fault with the pitons being to small
15 January 2004, 01:55 PM
#17
Scooby Regular
Thread Starter
Join Date: Apr 2000
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm, new ones can have the problem too. It seems to me that the problem was worse with MY97/MY98 but it can affect other years to.
The next question is, 'does the slap stabilize (can it be stabilized) or does it progressively get worse? Any comments?
Mark.
The next question is, 'does the slap stabilize (can it be stabilized) or does it progressively get worse? Any comments?
Mark.
15 January 2004, 04:58 PM
#20
I've had slap on an MY97 JDM since 45,000 miles. Its now done 90,000 miles. The noise at start up is horrendous and is still audible when warm (up to 2,500 rpm) but oil consumption is still what it was back at 24,000 when first bought.
I still give it some welly after 15 mins and it still puts out 260 bhp and pulls very well.
The downside is trying to sell it. No one wants a car that sounds like a tractor and to get rid of it would cost £2000 - hence why it is being despatched back to the HP company.
Nick
I still give it some welly after 15 mins and it still puts out 260 bhp and pulls very well.
The downside is trying to sell it. No one wants a car that sounds like a tractor and to get rid of it would cost £2000 - hence why it is being despatched back to the HP company.
Nick
15 January 2004, 10:50 PM
#23
Scooby Regular
Join Date: Feb 1999
Posts: 1,467
Likes: 0
Received 0 Likes
on
0 Posts
Sure I read in another thread that Scoobysport will sort the usual slap problem (replace no 3 piston) for about £600 for the whole job.
Kevin - STI3, and yes it slaps a bit too...
Kevin - STI3, and yes it slaps a bit too...
16 January 2004, 08:28 AM
#24
Scooby Regular
Thread Starter
Join Date: Apr 2000
Posts: 62
Likes: 0
Received 0 Likes
on
0 Posts
Nick,
What oil are you using? - just out of interest.
Has anyone tried Slick 50 in their engines to help reduce slap or stopping it from getting any worse??
Mark.
What oil are you using? - just out of interest.
Has anyone tried Slick 50 in their engines to help reduce slap or stopping it from getting any worse??
Mark.
16 January 2004, 10:18 AM
#25
Scooby Regular
Join Date: Mar 2003
Location: Edinburgh
Posts: 154
Likes: 0
Received 0 Likes
on
0 Posts
i kicked up a fuss with subaru when they told me they would not fix it. managed to only pay £250 for half the labour charges after loads of ranting from me. car sounds fine now and everything seams ok after about 7 months with it done. its so nice to get rid of that horrid sound it made.
16 January 2004, 05:10 PM
#26
Mark,
I use whatever Subaru put in at service time plus top ups with Mobile 1 motorsport. Top up has never been more than 0.5 litres in 7,500 miles.
Don't think slick 50 will help at all. You need more metal in the bore to take up the slack. Only an overbore plus bigger pistons/rings will help.
Nick
I use whatever Subaru put in at service time plus top ups with Mobile 1 motorsport. Top up has never been more than 0.5 litres in 7,500 miles.
Don't think slick 50 will help at all. You need more metal in the bore to take up the slack. Only an overbore plus bigger pistons/rings will help.
Nick
17 January 2004, 01:00 AM
#27
Scooby Regular
Join Date: Feb 2003
Location: Zed Ess Won Hay Tee
Posts: 21,611
Likes: 0
Received 0 Likes
on
0 Posts
mine is a 97 wrx and it might sound a bit slappy, specialist said it was the lash adjusters, but tbh im not that botherd
its gone when warm so i dont care, the car is tickled about till its wram anyways so there isnt really a problem IMO
my mates uk car with less miles then mine has a simmiler sound from cold (but not as bad)
ill "fix" it if it blows up but im not expecting it to happen, ive heard a lot of cars now with noisey engines
its gone when warm so i dont care, the car is tickled about till its wram anyways so there isnt really a problem IMO
my mates uk car with less miles then mine has a simmiler sound from cold (but not as bad)
ill "fix" it if it blows up but im not expecting it to happen, ive heard a lot of cars now with noisey engines
19 January 2004, 05:21 PM
#28
Scooby Regular
iTrader: (1)
Join Date: Oct 2001
Location: South East
Posts: 1,300
Likes: 0
Received 0 Likes
on
0 Posts
Andrew , woops ! ok , so i cant count !
3 4
1 2
(front of car)
and fires 1,3,4,2 : left left, right right ? hence to boxer note. or something like that! Im getting there.. honest!
Steve
3 4
1 2
(front of car)
and fires 1,3,4,2 : left left, right right ? hence to boxer note. or something like that! Im getting there.. honest!
Steve
Thread
Thread Starter
Forum
Replies
Last Post
fatboy_coach
General Technical
15
18 June 2016 03:48 PM
