Not sure if this is in the right section but I though it was worth a try....I've got a question regarding my UK '96 Impreza Turbo. When I start it up from cold I get a little 'Piston Slap', the piston seems a little loose in the bore/cylinder and it rattles until the engine warms up. Once the engine is warm the car is fine. I took it to a local Suburu specialist and they said that I shouldn't worry about it too much as it wont do any harm.

My only concern is that I do tend to drive the car quite hard (can't help it) and I don't wont to cause any serious problem internally. The last thing I want is an engine re-build!

Am I being a little too cautious or should I get this problem sorted? If so, what's involved and how much do you think it would cost?

 

Hi.

Got MY97 with it too. No problems mt8. Just let it warm properly before u give it any, 7-8 miles etc. Long as it doesn,t use oil etc should be fine. Never thrash a cold Engine Anyway

 

Good advice above , My MY99 has got it too I was told not to worry also , try a search 0n here as there are hundreds of threads about it , but I seem to remember reading about Scoobies that are pushing 100k with Piston slap with no problems .

Dave

 

Cost wise mate a fortune. With 4 options.

1, Replace offending piston, may only be 1 piston but perhaps 2. main dealer wants £74 per piston plus vat. then labour , gasket set etc. May be only tempory repair thou. Could be back in 15,000 miles

2, Get you block redone . ie rebore etc and new pistons.

3, Get second hand Engine from Subaru specialist ??

4, Speak to someone at scooby clinic. This is the option i will take come summer. Low milage bottom end off them, with your heads etc and ancillaries swopped over from your to the other block

Which ever way you look at it you are looking over the £1000 mark.
unless people on here no different ??

 

Have a MY96. Thought I had PS but not sure. When I had the Gems fitted and on the road mapping, Steve mentioned I had a little bit of slap but nothing to worry about.

It seems Subaru engines get slap regardless. Could it be something to do with the flat four rather than being in line four? Gravity works differently.

Yes mine does get driven hard. Red line is often visited.

 

Brilliant, thanks everyone for replying.

I feel a lot more re-assured now, thanks for the advice

 

We do a 'proper' repair to these to cure piston slap, using genuine Subaru oversize pistons. In our opinion the quick fix [ Subaru genuine - 'just a bit oversize, but it'll fit ok'] piston has a useful life of around 9 / 10,000 miles before the problem returns. OK if you want to ditch the car but not if you want to keep it.

Done properly the slap is cured until very high mileage, but cannot reasonably be done for less than about £1200. It involves engine removal, a COMPLETE strip and clean, rebore to first oversize, new pistons, rings, big end shells, gaskets and seals. no shortcuts and a proper guaranteeable job that we can stand up to should you have any problem during our warranty term.

You need to be sure that it represents value to you before you set off on this road. After all piston slap is annoying [ I hate it ] but ultimately until the engine starts using large amounts of oil it is an annoying noise and nothing more.

David API engines

 

David,

Do you rebore all 4 bores or just the offending ones? Following on from this, do you swap all pistons for new ones??

Lastly, do you fit slightly longer pistons than standard Subaru ones to guarantee that it will not come back. I believe the problem with slap is due to the pistons being a bit short allowing them to rock a bit (worse on 97/98 cars).

Cheers
Mark.

 

Mark, No, the odd piston trick is what is done elsewhere. It is possible of course to re-liner the block back to a standard size and re-use the original pistons - not recommended, but is possible. We always rebore and fit 4.

There is only one piston to use in the later style engine and the length is short but that's it, no chance to change. However built properly [ By Us - LOL ] the pronblem goes away and stays away.

Others try to short cut and it comes back at them.

David API Engines

 

Cheers David,

What is your opinion on Slick 50? The idea of coating metal to metal contact surfaces with PTFE to reduce wear seems like a good way of postponing any onset of piston slap?

I have used it on previous cars with apparently no detrimental effect and in one (no ecu/engine management/fuel injection) I immediately noticed an increase in idle speed - and my only explanation for this was a reduction in friction.

Mark.

[Edited by Spatch - 1/16/2004 4:00:59 PM]

 

Spatch, I use slick 50 and always have in my own cars. Great stuff !! I'm sold on it.

HOWEVER, there are a number of threads on here from before that state absolutely NEVER to use it in a Subaru, posted with facts and figures from the States 'proving' that it is rubbish and is the last thing to put in your engine ever. Not my experience.

So, before l get flattened by the masses: l use it myself in my own cars, we DO NOT put it in customers cars unless they request it and leave you to decide whether you wish to use it yourself.

David API Engines hiding below a big wall LOL

 

David,

I know what you mean, the jury is still well and truly out on the Slick 50 issue. I, like you, have found it to be good (well certainly not bad), and personal experiences count for a great deal of advice from others.

Mark.