Knock when cold

[rdezs]

.... And I'm sure there's a joke in here somewhere about short skirts? LOL

 

[j91z28d1]

the e38 ecm actually has tables and settings to try and address piston slap. I'm not going to pretend to know what it does, but they are there and labeled something about piston slap.

my guess that's slow why they switched to a injector closing time strategy from opening time on the Gen 3 ecm's.

 

[Marky Dissod]

Have 02 Yukon that has piston slap since new. Tried to get warranted when new, no go.

Too bad GM were building the rest of the engine so well that apparently the piston slap wasn't enough to wear those engines out sooner.

I have tried different weights of oil, and the one that works best (least noise and quickest slap stop) is 5W30 semi synthetic.

Brand of oil, or specific flavor of brand of oil, makes no difference? ANY GroupIII 5W30?

No matter what motor oil I've tried, 1st min of every winter cold start outside, lil bit of piston slap.
0W30 or 5W30 Valvoline, preferably Restore & Protect, with a Purolator PBL 25288 or Mobil1 206.
If I drive like my right foot is broken for the 1st min, only I can detect the piston slap.

 

[Blackcar]

Too bad GM were building the rest of the engine so well that apparently the piston slap wasn't enough to wear those engines out sooner.Brand of oil, or specific flavor of brand of oil, makes no difference? ANY GroupIII 5W30?

No matter what motor oil I've tried, 1st min of every winter cold start outside, lil bit of piston slap.
0W30 or 5W30 Valvoline, preferably Restore & Protect, with a Purolator PBL 25288 or Mobil1 206.
If I drive like my right foot is broken for the 1st min, only I can detect the piston slap.

I use Pennzoil but the semi synthetic is hard to find so probably will go to full synthetic.
I have enough semi for about four more oil changes. I also use AC oil filters my 02 has 65000 miles on it now.

 

[Denalibro76]

L9H is free of any and all Engine Half@$$ hardware or software bullschidt.

Cap'n Obvious says:
Engine'll likely last longer and age more gracefully if you don't move out of park for a min after starting it,
and drive as gently as reasonably possible for the next five or six min.

Cap'n Obvious might not know that, if you choose the right motor oil and oil filter,
it might actually help minimize piston slap over and above driving gently til it warms up.

Yeah I always let idle for 10 minutes or so before I drive in the winter here. What’s the “right” oil and filter?

 

[Marky Dissod]

What’s the “right” oil and filter?

Without objective tests that measure things we care about, and without the data being published so we can compare them, we're gonna keep getting stuff like
"I've been ignoring data for decades about how the brand I trust has been getting worse", or
"I don't differentiate between the different motor oil formulations my favorite brand makes", or
"I ignore any test results that indicate that the OE factory fill's performance has been exceeded by another motor oil", or
"I fail to consider why the factory fill in Europe (or even Mexico) is different from the factory fill in the US" ...

Which is why I think that the motor oil industry is an oligopolistic cartel
(like cable tv companies that bundle the channels so that you have to buy more bundles to get the channels you want).

All that said - even though changing motor oil / ATF / coolant / etc MORE often than the manual says is just as important -
(if you change oil every 5000 or more miles, and you have oil consumption, have you bothered trying changing it before the oil consumption occurs?)
I've been using 'vette-spec 0W30 or 5W30 Group IV synthetic in every GM engine I've ever owned,
and Mobil1 or Purolator PBL oil filters, for nearly 30 years, because I used to drive like a cabbie on meth, and figured I needed extra protection.

 

[EddieC]

Just a spin off, you should hear the piston slap on old Brit bikes I've owned. It's near to a ringing sound.
And it's the least of the noises they make.
It takes some getting used to but then something to look forward to.

 

[donjetman]

What’s the “right” oil and filter?

 

[Fless]

Which is why I think that the motor oil industry is an oligopolistic cartel
(like cable tv companies that bundle the channels so that you have to buy more bundles to get the channels you want).

This is a common misconception. The video distributors are tied to the programmers' contracts, many of which require their multiple program streams to be carried on the lower tiers (more subscriber viewing = more income from subs and from ads, etc.). Either put it on the lower tier or don't carry it - gotcha! This is why 'a la carte' programming availability is so scarce; the programmers don't allow that unless they're streaming (and have you seen and priced the streaming packages lately?).

Take a look, for another example, at ESPN on any channel lineup. The contract will probably read that ESPN and ESPN2 are carried, but they MUST be on adjacent channels.