3400 SFI Engine Noise

Oh, well then I guess my next question is. When this car hits 200k miles, do
you think it will still run? Its my moms car, and she doesnt drive it hard,
I stomp on it now and then, but it gets its oil changed every 3k miles, and
we use a synthetic blend 10w-30. Hopefully GM will cover the problem if
something like this ever happens because of the defect of the engine. I
swear my 4.3L in my S-10 does it every now and then, I can really hear it
when its warm. Its not a knocking either.


"shiden_kai" <violet_lightening_modified.RemoveThis@hotmail.com> wrote in message
news:ttdkd.167739$nl.49059@pd7tw3no...
 > Kiel Uyttenhove wrote:
 >
  >> Hey, I was just wondering. The 3400 SFI V6, is it supposed to make
  >> weird noises while running? Such as lifters and such. I have heard
  >> other 3100's and 3400's make the same noise. I was wondering if this
  >> was normal and what causes them to make these noises.
 >
 > You are probably hearing what is referred to as " piston slap". Fairly
 > normal on these engines, but they can be fixed. We replace pistons
 > on them all the time. I just did one yesterday.....it was way over
 > warranty, but we "good-willed" the repair as it's an obvious defect
 > in these engines. Contrary to what most people believe, GM is
 > fairly good about standing behind their product if it's a "known"
 > problem. When you dis-assemble these engines, there is actual
 > physical damage to the pistons....which is why GM fixes these
 > engines, but doesn't bother with the newer small block v-8 engines.
 >
 > Ian
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise 

Howcome it doesn't bother with the 5.3's. Mine sounds like crap from new.
Brought it back twice they say its normal.
 >> Stay informed about: 3400 SFI Engine Noise 

lol, I know what you mean. My mechanic has a 2001 Silverado with a 5.3, and
his does it too. I heard that GM bought back an undisclosed amount of these
vehicles because of this problem, not sure if its true or not. But
eventually the engine will take a shit because of this problem, atleast
thats my opinion. I love the 5.7 Liter and the 4.3 Liter. Always owned one
or the other or both and they both have the power i need and they are very
dependable.


"Randd01" <randd01.RemoveThis@aol.com> wrote in message
news:20041110185858.06270.00000167@mb-m23.aol.com...
 > Howcome it doesn't bother with the 5.3's. Mine sounds like crap from new.
 > Brought it back twice they say its normal.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise 

Randd01 wrote:

 > Howcome it doesn't bother with the 5.3's. Mine sounds like crap from
 > new. Brought it back twice they say its normal.

Probably because there is no real physical damage being done to
the engine. I started a 1999 new style truck up the other day and
it sounded "horrible". But the noise was gone within a minute or
two of running. 3.1/3.4 engines that are really bad will be noisy at
all tempertures. And there is real and observable physical damage
to the pistons. Since I've never seen a new style small block engine
apart for this type of noise, I cannot comment on what the pistons
look like with this noise. When I finally see one apart....I'll probably
comment on it.

Ian<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise 

"shiden_kai" <violet_lightening_modified.TakeThisOut@hotmail.com> wrote in message
news:c0Bkd.181674$nl.111519@pd7tw3no...
 > Randd01 wrote:
 >
  >> Howcome it doesn't bother with the 5.3's. Mine sounds like crap from
  >> new. Brought it back twice they say its normal.
 >
 > Probably because there is no real physical damage being done to
 > the engine. I started a 1999 new style truck up the other day and
 > it sounded "horrible". But the noise was gone within a minute or
 > two of running. 3.1/3.4 engines that are really bad will be noisy at
 > all tempertures. And there is real and observable physical damage
 > to the pistons. Since I've never seen a new style small block engine
 > apart for this type of noise, I cannot comment on what the pistons
 > look like with this noise. When I finally see one apart....I'll probably
 > comment on it.
 >
 > Ian

Ian is GM fixing the engine because of customer noise complaints or actual
engine failure?
My 98 Montana w/3.4l engine has 106K miles and rebuilt at 30K miles by GM
because of cold start tick. The TSB talked about the noise source being
caused by the connecting rod to wrist pin fit. The fix was new fitted
piston assemblies. The noise never completely went away but was
considerably less after the rebuild. Now at 106K it can be fairly loud for
the first couple minutes after a cold start but goes away. Of interest when
it's started in 50F or less the noise is noticable reduced. I just stopped
worrying about it and change the oil every 4000. Still using 5W-30 and
comsumption is nil between changes.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise 

DonW wrote:

 > Ian is GM fixing the engine because of customer noise complaints or
 > actual engine failure?

I've never seen an actual "failure" because of the piston problem.
In other words, I've never seen an engine blow up, stop running...etc
....due to this problem. They just get very noisy.

 > My 98 Montana w/3.4l engine has 106K miles and rebuilt at 30K miles
 > by GM because of cold start tick. The TSB talked about the noise
 > source being caused by the connecting rod to wrist pin fit. The fix
 > was new fitted piston assemblies.

Yeah, at one time that was either the theory, or maybe it was the
problem, but I've always seen the piston skirts scuffed. This problem
has been around for years of the 60 degree v-6's. When the Pontiac
transport came out, we were replacing the front three pistons in those
engines like crazy. Even today....it's almost always only one bank
of pistons that displays the problem.

You will probably run that engine till it dies or you sell it with no
failure.

Ian<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise 

My Father-in-law has a 3.1 in a Cutlass with 249,000 miles, still runs,
though it does sound kinda rough. Like the pistons are swapping holes or
something.
 >> Stay informed about: 3400 SFI Engine Noise 

Hey Ian, I heard that in the 80's, GM coated some of their pistons with tin,
is this true? In high school I used to drive an 1989 Buick Regal with a 2.8
Liter MPI V6. It had the loudest knock you have ever heard, I ended up
having to rebuild that engine. My mechanic told me GM did that with some
engines. Just curious if GM actually did that, and if so, why would they do
something like that?


"J Grant" <snuffy2220.DeleteThis@webtv.net> wrote in message
news:1681-41941E6D-290@storefull-3314.bay.webtv.net...
 > My Father-in-law has a 3.1 in a Cutlass with 249,000 miles, still runs,
 > though it does sound kinda rough. Like the pistons are swapping holes or
 > something.
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 3400 SFI Engine Noise