Piston Slap

Vincent,

I had the same problem with mine OBSW 2002 at around 30K km (20K miles). After leaving my car overnight in their shop (Vancouver, BC, Canada) they took it for a test ride, heard the engine knock (or piston slap as they call it) and decided to replace short block. It was covered by the warranty.

It was fine for about 15K km, and now I'm hearing it again. So, I've decided to try an engine block heater and see how it works since they said there is nothing else they can do now.

Noise is much less noticeable (after heating the engine for about 2 to 3 hours before I go anywhere). It's still there, I can't hide it, but it is better then before.

Voja

V>

Voja, can you tell me which dealer you went to in Vancouver. Im going to take my 02 OBS in for the same problem soon, and would like to know which dealer is good enough to replace short block.

Thanks.

Spud (Abbotsford, BC)

Not sure if that info is relevant to the newer engine, but someone solved that problem on the 1997 2.5 DOHC by fitting Impreza Sport pistons:

florian

I also have the dreaded slap on my 02 outback I have 36 k miles . The slap srarted around 6 k miles . I have tried to have SOA take care of it ,but they say as long as the noise goes away when the engine reachs normal operating temp they do nothing about it . I had my oil analyzed on my last oil change and the reading came back normal with minimal wear . So I just learn to live with it ,and take it easy untill the engine warms up .

Mike k

It was Don Docksteader Subaru while they were in Coquitlam, BC. They closed it in March this year.

You can go now to Don Docksteader on Cambie, Vancouver. Their web site is

Spudster wrote:

My 02 OBW exhibited the same symptoms. Remedy? Timing chain tensioner, not shortblock.

Hope this helps,

'98 OBW, 2.5l, 118k. Definite slap in the morning when it's cold out (around freezing). I think the car has been doing it since about '75-80k, maybe the second winter I owned it (bought it with 65k).

Same here.

I think even when it's not making any noise it's best not to accelerate very hard when the engine is cold...I always wait until it's up to temperature. I want to get a oil temp gauge at some point.

Are you sure this isn't the valve lifters? Many cars suffer lifter noise on cold startup.

And how the heck did you determine that it is the #4 cylinder?

I just had the timing belt tensioner changed due because of the cold starting noise it was making . In my case it sounded very different then my piston slap issue. Piston slap sounds like a sombody is hitting the block with a hammer. My tensioner noise was a very deep hollow knocking sound almost like the blowoff valve makes on a cold diesel engine makes when you step on the pedal. I could also feel the belt hitting the timing belt cover on the front of the engine ..

mike k

Vincent,

Ron Donahue

Not the lifters because noise is not heard at idle. The knock, it is fairly deep, is heard only under load; acceleration dependent and gets worse when going up hills etc. Almost sounds like a bad rod bearing except bearings get worse as revs increase.

#4 cylinder determination, unplug the spark plug and the noise goes away when that cylinder is no longer under load.

The slap is also most prominently heard in the car and difficult to hear outside the vehicle, unlike noisy lifters. Don't know why.

Vincent

Just came from my service shop. I've complained again re. engine knock on cold morning starts.

Here is the official wording on their working sheet: (it was on 12/23/2003)

Tested on A.M. for line C-AT this time heard timing belt tensioner noise with customer. Cause: ADW-34 B241-201 Re& Re outer timing covers to replace Noisy timing belt tensioner.

They've replaced it under warranty and this morning (12/24/2003) when I started my car engine it was quiet. So far I'm happy :-)

At least I know what the cause is and it can be fixed even if I have to pay for it in the future.

Merry Christmas, Voja

Voja Ilic wrote:

Voja,

Merry Christmas to you.

Please clarify the events here. They replaced the short block and the knock persisted?? or returned?? and now they fixed the tensioner, which made the knock go away. Can you describe the noise?

Could you have been blessed with two problems??

V> Just came from my service shop. I've complained again re. engine knock on

never mind Voja read your other post. I also have trouble with Rt front bearing and burnng smell at idle. I did see the wet axle; the dealer said it was spill from when they changed the diff oil aout 5K earlier. I didn't believe them. I will recomplain.

Thanks for your posts

Vincent

PS.I don't think I have the clunk on reverse!

BTW my gas mileage is about 24 mpg on highway. What do you get?? I would like for it to be higher. I have tire pressures at 42psi and I do feather the gas pedal. I think the piston slap might be setting off the knock sensor.

Merry christmas,

I was also blessed with both noises on my 02 outback . I was finally able to have the tensioner noise taken care of . It took me three times leaving it at the dealers overnite but they were finally able to here it . Now all I hear for the 1st 5-10 mins of my car running is the knock knock of piston slap.

mike k

What the hell is piston slap?