Did the 03 4.2l 's have the piston slap?

03envoy

Original poster
Member
Dec 25, 2011
537
I have noticed that my 03 envoy seems to have a little "slap" sound almost like a knock but not that loud. It seems to go away of isn't noticeable after driving around town. Should I be concerned if it does have this sound?
 

ScarabEpic22

Member
Nov 20, 2011
728
Are you running synthetic oil? If not, start with that the next oil change and see if it quiets down. My 02 was noticeably quieter when I switched to Amsoil (and stayed quiet when I went to Mobil 1).

And no, only a certain VIN range of 02s fell under that particular GM extended warranty (my 02 was one of them, was hoping Id get a new engine out of if but it keep trucking along as is).
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
ScarabEpic22 said:
And no, only a certain VIN range of 02s fell under that particular GM extended warranty (my 02 was one of them, was hoping Id get a new engine out of if but it keep trucking along as is).


Are you thinking of the cylinder liner slipping down in the 02's?

I believe the cold start knock is fairly common on the 4.2 I6.

I may be miss-remembering.
 

ScarabEpic22

Member
Nov 20, 2011
728
OK then most of GMs engines have piston slap, I should clarify that some 02s were put under an extended warranty from GM in case the liners failed. Some of the precursor to the failure was an increase in piston slap. Most failed outright though, working fine then the liner dropped and seized the engine.

Good catch Wooluf1952, I was thinking the OP was asking about the liners dropping and not just if the I6 has piston slap. Doh!
 

03envoy

Original poster
Member
Dec 25, 2011
537
I am running Mobil 1 synthetic rightnow.... Its just that thought of damage and it scares you, But Even if it does have the slap it shouldnt hurt it. Just very annoying!
 

91RS

Member
Dec 4, 2011
105
If it goes away when warmed up, you've got nothing to worry about. If you are still worried, get your oil analyzed by Blackstone and see if your wear metals are high.
 

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