Hello

I've recently changed my oil. The car was originally filled with Castrol Megnetec by the dealer but i've used Millers 10w60. Since then the car seems to have developed piston slap. It is most noticable when it is started from cold and gently revved. As the engine warms the slap reduces significantly but does not disapear altogether.

Could the oil be the cause of the problem and should I go back to magnetec. I changed to Millers on the advice of a tuner.

Thanks

 

iv'e got an 03 sti ppp,all iv'e ever put in mine is magnatec,i have a bit of piston slap on start up in the winter,none at all in summer but after no more than a minuite its gone!!u might want to have it looked at if the noise does'nt go altogether!!

 

Magnatec is EVIL stuff, its jammed full of detergents and runs thin as ****...

The scoob I just bought has got 10w60 in it and I think its a bit to think, the top ends rattle on a cold start as I dont think the oil is thin enough to pressurise the lifters.. Just got to get round to changing it for 10w40 s/s..

 

piston slap generally happens when from cold,as the engine warms up and tollerances reduce as things expand the noise stops..... if it still is noisy when warm its not piston slap....... there has been cases when oil changes carried out that big ends have gone soon afterwards,get it checked out to be certain.

 

my feeling is that if the oil has the right numbers & letters on the back if the bottle and says it meets or exceeds manufacturers recommendations its fine!!
of course this is my own opinion and i dont want to start all out war when the dreded black stuff is mentioned!!

 

I had problem with piston slap when changed to Magnatec.Then tried Millers, no change.My m8 had an Escort Cossie with same problem when cold.He told me he decided to flush engine with Cheapo oil for a couple of miles but noticed piston slap gone & no adverse effects.He now uses ASDA own oil, changes every 5k & says car never been better.!!! It's all a big con this oil thingy, as long as there is lubricant there aint much difference with specs.

 

how many miles ago did you do the oil change?

not wanting to worry you but if it wasn't long ago are you sure it is only pistonslap?

Simon

 

Was going to say this. When do you get the noise? When warm or when cold? Or all the time? Where are you based?

 

You don't say what model and year! 10/60 is a bit thick for the latest versions. 97/98 cars sometimes showed piston slap problems.
Millers is a good brand, so the oil itself is not a problem but the viscosity could be. Having said that, viscosity usually has little effect on piston slap.
JohnD

 

Everyone

Firstly thanks for your replys. Here is some more info.

I changed the oil a week ago, subsequently from the first time I used the car the noise was present, which does point to the oil. After doing some further testing I've found that after 5 mins , when the engine is warm the noise disappears. I've only done 75 miles in the car since the oil change. The car is a UK classic Y reg (MY00) with PPP.