Reducing Piston Slap Noise with Oil Choice

[Oldswagon]

A friend of mine just bought a 2000 Buick Century with a 3.1 L V6. He got the car for a steal, and it's actually in decent shape save for the typical cold start piston slap (this car has one of the worst cases I have ever heard). It does get much quieter after it warms up for a minute or two though. The car has about 150K miles on it curently.

Is there any type of oil that helps reduce the piston slap noise? He's not looking for this car to run forever, even if it dies after 1 year he'd still come out ahead with the money he paid for it. Just looking to reduce the noise if at all posssible. Also keep in mind the car needs to start during a Canadian winter, so thicker grades are probably not an option.

Here's a story for a laugh. My friend is not a mechanical person at all. He talked to a few co-workers about the noise. A co-worker advised he had a similar problem with one of his former cars and he reduce the noice with by adding VARNISH to the oil! My friend almost considered doing that until I told him otherwise.

Why do people who have no knowledge about cars give out advice on cars??

 

[mcrn]

how do you add varnish to oil?

 

[mechtech2]

Piston slap is attenuated with thicker oil.
If that is truly what the problem is, it's your only oil option for help.

 

[Oldswagon]

He meant varnish you use to finish wood, not the kind we find in engines.

http://en.wikipedia.org/wiki/Varnish

I thought I have read on hear in the past, that certain brands of oil helped reduce piston slap? Maybe I remembered wrong, to be honest I have never paid that close attention, because I have never owned a car with piston slap.

 

[sangyup81]

get some xxW-40 or xxW-50 in that!

 

[pcfxer]

Originally Posted By: sangyup81
get some xxW-40 or xxW-50 in that!


+1

 

[lipadj46]

In the winters I would try syntec 0w30 (German Castrol) first or if you want to try an HDEO try a 5w-40 oil like Rotella, mobil 1 TDT, Syntec etc...

If you want to use a Dino oil just use a thicker HM oil.

 

[lexus114]

GC or Mobil-1 0W-40 would be very good as well.

 

[addyguy]

Yeah, go thick. If you have 5W-30/10W-30 in it, try adding some STP.

 

[mcrn]

Originally Posted By: Oldswagon
He meant varnish you use to finish wood, not the kind we find in engines.

http://en.wikipedia.org/wiki/Varnish

I thought I have read on hear in the past, that certain brands of oil helped reduce piston slap? Maybe I remembered wrong, to be honest I have never paid that close attention, because I have never owned a car with piston slap.




Oh wow I never would have thought that is what he meant! Thats funny!

 

[IndyIan]

Chinadian Tire has some Formula 1 synthetic 5W50 on sale this week if he wants to try the most extreme example. I run rotella T 5W40 in my tracker for the winter too and it starts well in -30C...

 

[demarpaint]

Originally Posted By: Oldswagon
He meant varnish you use to finish wood, not the kind we find in engines.

http://en.wikipedia.org/wiki/Varnish

I thought I have read on hear in the past, that certain brands of oil helped reduce piston slap? Maybe I remembered wrong, to be honest I have never paid that close attention, because I have never owned a car with piston slap.



Tell your buddy to tell his friend that after doing a little reading up on varnish that he suggests next time to try Spar-Varnish. Or a Marine Spar-Varnish for even longer lasting results. LOL

 

[SteveSRT8]

we have a fleet of GMC trucks and all older than 07 have the 'slap'.

Some of them have 400k miles! The 'slap' is nothing more than an annoyance. The engines still run forever.

 

[lui]

the 3.1L engine's require the updated re-designed pistons. no oil will cure a deformed piston skirt.

good luck.

 

[Gary Allan]

Just tell him to run a good fuel injection cleaner through it before doing anything else. CCDI and piston slap are just about identical in all perceivable ways. Noisy at cold start and always retreating to nothing as the engine warms. That's just to eliminate that as the cause. No sense in using heavier oil when you may not need it ..if it would in fact reduce the annoyance.

 

[tig1]

Originally Posted By: lui
the 3.1L engine's require the updated re-designed pistons. no oil will cure a deformed piston skirt.

good luck.


+1. Jasper engines does that very thing in their overhauls. They go with redesigned pistons. Stops the noise.

 

[Gunatics_Adler]

Very true, GM has had a lot of trouble with engines having piston slap in them. Some are quiet when warm, some are always a little noisy, and some sound almost like a noisy diesel. With hypereutectic pistons that dont swell much as plan cast or forged pistons they warm, piston design and fit matters much more. Well GM decided to be lazy about a few things and cut corners. Usually these engines will still run a long time, but the pistons and cylinder walls of the ones I tore down for overhauls or head gaskets (cylinder walls) showed which ones were slapping and were not.

When my father and I rebuilt the wifes 3100 5 out of 6 pistons were scored. It was a relatively noisy 3100 both warm and cold. We put new pistons in it and its been slap free.

 

[mechanicx]

I don't think any oil is going to get rid of the piston slap. I'd say thinner oil like 0W30 and 5W30 would be better when cold. If the noise goes away quickly after warm up then I don't think it would be worth worrying about. If the pistons slap even while hot then you probably have a lot of clearance that never gets taken up and will have higher wear.

 

[Oldswagon]

I am not looking to "get rid" of the piston slap, or have the engine rebuilt in this beater Buick. All I was looking for was if there was any oil that people have succesfuly use to reduce the noise from the piston slap.

I may suggest he try one of the cheap (ie Motomaster) synthetic 5W50's or a high mileage oil to see if that helps. If it doesn't no big deal.

Like I said, this car is a beater, so he's not going to invest any serious cash into it, and he's not really all that concerned on how it operates. But it would be nice to quiet it down a bit if possible with the oil.

 

[jeepman]

Dump some 10w30 Maxlife in there and forget about it. Maxlife will quiet it down as much as anything, and is a very good oil.