piston slap ?

[chrismanchr]

hi I'm a new member and just bought a very late 944 s2 sept 1991 ,having searched for an s2 for some years

Ive had a 944 before and I am generally into classic cars also owning a mr2 mk1 in excellent condition

when I viewed the car the owner picked me up from the local railway station in the car and drove me back to his house

the car seemed good I checked out the coolant,oil ,oil pressure
the car had extensive history,just 100k miles ,5 previous owners and looked in good general condition
titainium in colour ,decent tyres ,virtually new discs and pads and a clean interior

so I bought it !
on the way home i found that the cars cooling fans didnt work ,the car had monumental transmission backlash
and the dampers seemed to be quite worn out ,well it wasnt the end of the world
but the next morning I started the old girl up and I could hear what sounded like piston slap
now I know these are aluminum engines and I'm wondering how common this is ,and if it is bore/piston wear
what to do about it ?
after taking it round to my mates house he thought it was a really beautiful 944 ,and drove it and said the backlash isnt that bad
but then a steel brake pipe burst and I had totally no brakes ;-(
the car is currently in a garage near my friends home having a new brake pipe fitted and they also noticed a bad fuel line
that broke open when it was prodded so theyre being done as well
I called the previous owner and said come on lets be straight ,and he told me they'd got rid of it because his brother
had borrowed it and overheated the engine as it had run low on coolant and up till the mot had no antifreeze in it

I really like the car coming from a newish very boring bmw and being intrested in classic cars but this possible piston slap worries me deeply

 

[George Elliott]

Chris,

welcome.....nice colour.....

sounds like a nice low owner car that has been neglected in the last few years. The engine sounds goosed to me, its probably not but heat damage in aluminium engines is undesirable.

I'd go either - replace the engine with a S2, replace with a 968 with loom and ECU's, or research this fully - if brave enough - find a 944 turbo engine (M44/52 complete(very)) with loom & ECU / KLR and put your S2 Crank in it to produce a 2.8L turbo.

The metal pipes for fuel & brakes are a common problem.

Its easier to fix an engine issue than a tatty car, and it sounds like you will enjoy the finished job - it will not be boring anyway.

George
944t

 

[chrismanchr]

thanks mate I am willing to throw a few quid at it lol

the car looks very nice

but I know I have alot of work ahead of me

few more questions ,sorry about this lol right the aluminium block ,Ive notcied with abit of searching on the internet that the blocks can be re-bored ,nikasiled ,new
liners even steel liners and infact with just sending the block to the engineering company its not that expensive but ! all these engineering shops that do this that
Ive found have been in the US and here in blighty Ive not found one ,although I sent an email to hartech and they said its not recomended because it runs into
several thousand pounds

anybody that knows alot more than me please speak up lol

I mean as soon as the car is back home i'm gonna compression test it and borescope the bores hopefully this will reveal I'm being a windy bugger
rather than scored or damaged bores

 

[Diver944]

Contact http://www.emcmotorsport.co.uk/

They know the 944 engine well and have experience with liners when needed. They are one of the cheaper 944 specialists but it still won't be cheap.

The cheapest option would probably be to drop in a secondhand engine

Before you layout serious money on this car have you poked and prodded the bodyshell for rust issues. Many a shiny 944 will fail its next MOT with terminal rust. Check the inside of the sills through the vent at the bottom of the B pillar in the door shut

 

[Frenchy]

Good luck and keep us posted, a seconhand lump may be cost effective if that is what is required, you will love it once sorted.

 

[George Elliott]

I am willing to throw a few quid at it lol

good to have another enthusiastic owner aboard......there will be lots of opportunities........[8|]


I think Paul is suggesting the borescope would be put to good use in the sills.....[]


George
944t

 

[zcacogp]

Hello and welcome.

Before we get too excited about new engines and whatnot, can you give us a bit more detail about what you think is piston slap? As in, what exactly is going on and when? I don't doubt that it is making funny noises, but don't jump to the worst conclusion just yet - it may yet be something less severe.

In my experience, you can get all-alloy engines pretty hot without doing damage. (I drove my S2 about 150 brisk miles one cool evening without an operational water pump. Yes it got hot, but suffered no long-term problems.)


Oli.

 

[ChasR]

This is what mine sounded like with piston slap in No.2, It was diagnosed as being seriously overheated for a good period of time (but not quite hot enough to ruin a HG). The inside of the bore was scrap as far as the Nikasil coating went:

http://www.youtube.com/watch?v=HnQwkcIsVAg&feature=plcp

Lazy lifters can sound the same. What does your oil look like and what is in there (if you have that information)?

 

[Eldavo]

Drivetrain backlash makes me think that the clutch is goosed too and is on the "get me home" pins rather than the rubber.

 

[chrismanchr]

ORIGINAL: ChasR

This is what mine sounded like with piston slap in No.2, It was diagnosed as being seriously overheated for a good period of time (but not quite hot enough to ruin a HG). The inside of the bore was scrap as far as the Nikasil coating went:

http://www.youtube.com/watch?v=HnQwkcIsVAg&feature=plcp

Lazy lifters can sound the same. What does your oil look like and what is in there (if you have that information)?

what did you do about it chasR? secondhand engine ?

 

[chrismanchr]

ORIGINAL: Eldavo

Drivetrain backlash makes me think that the clutch is goosed too and is on the "get me home" pins rather than the rubber.

it doesnt clunk in, the gear changes are ok ,but that big rubber effort on the flywheel could be the culprit
although it has alot of history and right throughout dif wear is mentioned

 

[edh]

I hope you didn't pay much for it....sounds like an expensive set of problems. I suspect you may have to spend more than it's worth to fix it.

the upside is that once you fix the mechanical problems you should have a nice s2. definitely check for rust before you throw money at it.

the hydraulic tappets (lifters) can be very noisy if the car has been stood for a while. if that was the problem then presumably you'd have heard it when you bought it and drove it home.

where are you based? we can probably point you to a local specialist who can give you an informed opinion.

 

[Diver944]

The injectors are also very noisy compared to modern cars, the constant tick tick ticking at idle with the bonnet raised has worried many a first time owner.

 

[chrismanchr]

Based in south Manchester , the piston slap noise is only present when the car is cold it sounds silky smooth when warmed up , I didnt pay a fortune for it but if I'd noticed these problems I would have wanted to pay less , I'm going to buy a borescope , but a silverline version it looks pretty good and isn't expensive

 

[zcacogp]

ORIGINAL: chrismanchr

... the piston slap noise is only present when the car is cold it sounds silky smooth when warmed up ...

Such is the way of a couple of things which can make similar noises. Hydraulic lifters can be very noisy, particularly worse when cold. And these get noisier in cars which haven't been used for a while ... same goes for injectors, which can make a phenomenal din (although those don't get quieter when the engine gets warm.)

Before you reach for the cheque book, try a good engine flush (Wynn's do one that is recommended for Porsches) and changing the oil. And take it for a good, long, hard drive to get everything warmed up properly. If it is piston slap then doing this will make no difference at all, but if it is lifters then it will make a difference (for the better).

Clutch-wise, how bad is 'bad' when you talk about transmission lash? The drivetrain is long, with a number of components in it, and they always have more lash in than a modern car. I suspect that if it was a goosed clutch which was running on the metal stops then it would be massively noisy and very unpleasant (and changing gear nearly impossible.) Have you jacked it up and had a look in the clutch inspection port? You may see things which tell you what's going on. Or get someone who is a bit more familiar with 944's to have a drive and see what they say.


Oli.

 

[chrismanchr]

ORIGINAL: zcacogp

ORIGINAL: chrismanchr

... the piston slap noise is only present when the car is cold it sounds silky smooth when warmed up ...

Such is the way of a couple of things which can make similar noises. Hydraulic lifters can be very noisy, particularly worse when cold. And these get noisier in cars which haven't been used for a while ... same goes for injectors, which can make a phenomenal din (although those don't get quieter when the engine gets warm.)

Before you reach for the cheque book, try a good engine flush (Wynn's do one that is recommended for Porsches) and changing the oil. And take it for a good, long, hard drive to get everything warmed up properly. If it is piston slap then doing this will make no difference at all, but if it is lifters then it will make a difference (for the better).

Clutch-wise, how bad is 'bad' when you talk about transmission lash? The drivetrain is long, with a number of components in it, and they always have more lash in than a modern car. I suspect that if it was a goosed clutch which was running on the metal stops then it would be massively noisy and very unpleasant (and changing gear nearly impossible.) Have you jacked it up and had a look in the clutch inspection port? You may see things which tell you what's going on. Or get someone who is a bit more familiar with 944's to have a drive and see what they say.


Oli.

yes oli I am thinking worse case lol but I have plenty of mechanical experience with other cars ,I'm going to compression test and borescope next week ,fingers crossed its a different issue ,I will change the oil and maybe engine flush although to be honest I'm not a fan of engine flush ,also going to coolant flush,new thermostat ,air filter ,take the whole induction system
off and clean and inspect it, the piston slap like noise is only heard when the engine is cold ,when warm it sounds really nice and oil pressure is good

The transmission backlash is bad compared to a modern car but compared to one of my mates 924s which is an 's' it is worse but not massively ,in the history for the car (which is very extensive) it says dif/pinion wear from about 50k miles on every report ,I spoke to the previous owner to the one I bought it off and he had the car for quite a while and said it was the same then ,he also asked how the car was looking as he really liked the car when in his possesion and he'd spent a small fortune on it

 

[Frenchy]

Nice colour and a nice plate AFN were a Porsche dealer.

 

[chrismanchr]

ORIGINAL: Frenchy

Nice colour and a nice plate AFN were a Porsche dealer.

yes it was owned by them first

 

[944 man]

AFN (Archie Fraser Nash) were the original Porsche concessionaire and they were eventually bought by Porsche. The AFN dealerships are still operating as OPCs now, owned directly by Porsche Cars GB.

 

[chrismanchr]

the cars history ,low owners ,lowish mileage at just 100k ,and the extensive history is what attracted me to this car ,I think I did pay too much but ive looked at cars double
what I paid for this and theyve been in worse condition ,the AFN link also contributed to my deciesion