Do chemicals repair engines?

[Jassy]

Apart from an engine rebuild (which I cant afford right now), has anyone had any noticeable improvement to piston slap using oil additives?

I am suspicious of a chemical that can fix a mechanical problem.

[CREWZIN]

Most of us are suspicious also. Saying that, there's a few of us that use fuel injector cleaner although some of the adds on TV say that THEIR fuel does it all. I used to believe in a can of STP to quiet down sticky valves but I don't have that problem any more.

Found this in a search:

I've seen tear-downs of slapping engines and saw different things. If the piston slap is caused by carbon build up at the edges of the piston and near the top of the piston stroke then something that cleans that out can help. If it's mechanical contact between engine parts then nothing will help short of a mechanical fix. Piston slap comes from a lot of cases and until they can be separated you are just guessing, which could make solving the problem more difficult. If say GM says it causes no harm you don't know if that answer is coming from an engineer or a bean counter.
But an interim solution is worth the experiment. Try cleaning out the engine and then a different oil.

[rob342]

I am also suspicious of a chemical that can fix a mechanical problem.

unless you're burning too much oil i really wouldn't worry about it.

it runs fine, just sounds like this when cold?

[Busted_PT]

Which engine are you running? We only have the 2.4 here in the states. The good thing is, oil additives won't do any harm in my opinion.

[Gold2006]

Auto and oil manufacturers advise to steer clear of oil additives. They do nothing to fix piston slap and can degrade the oil.

If the issue is carbon build up, use of fuel system cleaners that have been proven to clean combustion chambers may be useful. As would air intake cleaners proven to do the same. As easy as pouring in the gas tank or spraying into air intake. Then use a better oil and fuel to maintain.

[boonie2]

I have a 95 Conversion Van 5.7 L that sat for years before i bought it , the rear main seal was leaking really badly , and used an additive from "bars leak" to soften up the seals.. hasn't leaked a drop in 2 years .. I don't believe that's totally true about the Oil Additives Gold but its your opinion

[quicksilverdon]

Originally Posted by boonie2

I have a 95 Conversion Van 5.7 L that sat for years before i bought it , the rear main seal was leaking really badly , and used an additive from "bars leak" to soften up the seals.. hasn't leaked a drop in 2 years .. I don't believe that's totally true about the Oil Additives Gold but its your opinion

Seals, yes. Piston slap? I'd say depends on the cause of the slap. If the bore is too big for the piston, I can't see an additive fixing that.
I've heard of people who fixed a leaking radiator with a chemical - I haven't had luck except I do feel injector cleaners added to gas can help.

[boonie2]

Piston slap could also be a wrist pin too , if that's the case forget additives

[NitroPT]

anyone remember the J C Whitney engine restore chemical treatment that had the little dark color balls you placed in each cylinder. Claimed restore engine power and reduce smoking wooooow!!

[rob342]

Guys if that's the neon 2.0, it's neither uncommon or dangerous. The video I posted is a car that has been running fine with piston slap for 60k miles. With Hondas peopl would complain they sounded like sewing machines because the rockers tick, but those are designed that way.