posted earlier about the much discussed piston slap and wondered whether putting in any oil additives would help quieten it when cold? (only does it when cold)
any additives you would recomend?

 

Just use a decent oil and change it regularly. Which additive were you thinking of? I tried ZX1 and Slick 50 in a Cossie years ago with Mobil 1. Didn't stop the piston slap. If it goes after a few minutes don't worry about it.

 

If oil additives were any good, surely they would be in the oil already. Or am I just being daft?

 

Very true. The only way to cure piston slap is to fit over-sized pistons.....or just ignore it.

 

mate uses slick 50 in all of his cars inc his scooby... it wont cure slap but will reduce wear as its just teflon !

 

well thats what i wanted to check, that basically you can use them. i know it wont cure any piston slap from cold but if it helps protect my engine then why not?!

 

I'd do a search on Slick 50. It may have done something decades ago - before non hydrocracked ester based fully synthetic oils came along.

 

Modern oils have all the necessary additives.

 

I'd have said yes in the past. Now...a resounding NO.

I tend to buy high mileage motors and whenever I've used oil additives to cure a problem or as a preventative measure, I've always had worse engine trouble afterwards. On my Scoob after some kind of high mileage additive it bust a crank oil seal then started getting rattly, in the end I needed a rebuild.

 

Do a search, there have been a number of threads about this kind of thing.

I think you will find the recommendations of engine builders will be not to use engine oil additives such as slick 50 because the particles will block your oil filter and do more harm than good.

Like someone already said, if it just slaps a bit from cold then it's fine, and all you need to use is a good quality proper synthetic oil and change it regularly.

 

Or offset gudgeon pins.

 

Very much don't do it. You don't know if the stuff is fully compatable with the components of your oil. Oil is blended particularly to do a wide range of functions, not just lubricate. If you adjust one of it's qualities do you know what the knock on effect will be?

If the oil needed teflon or tomato juice or whatever in it, it would have been blended as such with the correct amount when it was produced.

Dave

 

so addtitves are a "no,no" then!