View Full Version : V6 Guys inside please
Pampered-Z
10-01-2006, 09:11 AM
1998 Camaro. Engine has a tick we can't locate. Doesn't seem to me coming froma rocker or from the pan. Lifter maybe?
Anything common on these engines to check for?
JB
GP99GT
10-01-2006, 11:57 AM
they pretty much all tick....unless its a really loud one coming from only one spot. sometimes injectors can tick, though.
FBODYFirebird
10-01-2006, 12:19 PM
here's a more thorough writeup, most 3800 series have a normal sounding slapping noise during cold startup "yes it's normal" 5W/30 oil will help , because it flows better and quicker when cold...
the fix: replacing the wrist pins and cylinders
* Iron blocks, or aluminum blocks with iron sleeves.
* Aluminum pistons, period.
(The above excludes exotic ceramics, and the old Vega 4-cyl that had a skeeveless aluminum block with silicon embedded in the cylinder walls for toughness.)
* MANY engines have piston slap upon cold start-up; most do not, yet they still have two different metals.
* 'Different alloys' isn't a definitive explanation of GM 3.1/3.4 60* V6 piston slap.
2. The ORIGINAL GM 60* V6 was the carb'd 2.8 (used on late 70's Citations, and '85 Jeep Cherokees).
Then came the 3.1 and 3.4 (plus some goofy specialty engines, and now the new Caddy CTS line of DOHC's)
* The 2.8's never had piston slap.
* The 3.1 is an 8mm stroked version of the 2.8, and the pistons were shortened 4 mm (~3/14") to fit within the cylinders.
* That material was taken off the skirt at the bottom of the piston, and it still projects into the crankshaft a bit at BDC.
* Bottom line: The 3.1 and 3.4 pistons are so short that they 'wobble' a bit until the skirts heat and expand enough to fit snugly.
For *some* V-6's, this wobble causes noise (piston slap).
* * *
It only takes about 15 seconds for the aluminum piston to expand from the heat of combustion, and the engine should ALWAYS be treated gently during this warm-up due to lack of lubrication at the bearings.
all that info was for 60* V6 motors like the 3.1 and 3.4. He is talking about the 3.8 which is a 90* motor....totally different.
edit
It could be the injectors if you know the noise is coming from the top of the motor. if not, you might want to try letting it run and have someone hold a bunch of rags over the tailpipe to see if its exhaust related.
Savage_Messiah
10-01-2006, 08:36 PM
Mine has ticked and made many ysterious noises since I bought it, never looked into it and that was almost 30k miles of use and abuse ago
GP99GT
10-01-2006, 08:45 PM
mine has also ticked since forever, its just a 3800 thing...been driving it for 40k miles(110k to 150k), hasnt made a difference. though i do have a loud tick when i first start it which goes away, not sure what it is.
FBODYFirebird
10-01-2006, 11:08 PM
all that info was for 60* V6 motors like the 3.1 and 3.4. He is talking about the 3.8 which is a 90* motor....totally different.
edit
It could be the injectors if you know the noise is coming from the top of the motor. if not, you might want to try letting it run and have someone hold a bunch of rags over the tailpipe to see if its exhaust related.
not going to work.......
edit
all previous shown includes 3800 series
piston slap is the cause thank you very much!
:scratch:
I dont see how info for a 60* motor applies to a 90* motor. then again, I dont know too much about V6's in the first place.
GP99GT
10-02-2006, 05:36 PM
not going to work.......
edit
all previous shown includes 3800 series
piston slap is the cause thank you very much!
how does the previous include 3800s? 3800 is a 90 degree v6, 2.8/3.1/3.4 is 60 degree. id be willing to bet that its not piston slap
IROCdan330
10-02-2006, 05:59 PM
how does the previous include 3800s? 3800 is a 90 degree v6, 2.8/3.1/3.4 is 60 degree. id be willing to bet that its not piston slap
i agree...i think the piston slap wouldve been there always, not just develop one day. i know GM has the same issue with a lot of their truck engines...they slap when cold because of the piston skirts.
if you have a tick i would suggest getting a long screwdriver, and touching it to different areas of the engine with your ear on the other end...cover your other ear. if the noise isnt normal, when you get close to it, it will make itself very pronounced.
FBODYFirebird
10-02-2006, 11:40 PM
typical signs of v6 GM engines..... hmmm i wonder, if the 60' engines have the same problem maybe they have a SIMILAR if not the same EXACT problems...... or maybe 2+2= 9 take your bets
also doesn't it make sense now that there is slapping since it's colder outside, if your confused please read above ^ or just keep getting mad because you have nothing else to do but debate everything with me
Savage_Messiah
10-03-2006, 12:11 AM
typical signs of v6 GM engines..... hmmm i wonder, if the 60' engines have the same problem maybe they have a SIMILAR if not the same EXACT problems...... or maybe 2+2= 9 take your bets
I'd bet against it, seeing as how the 60 degrees and the 3.8 have absolutely jack **** in common. As in seriously nothing at all in common.
Pampered-Z
10-03-2006, 07:41 AM
He's had the car about a year and this is a new noise. It's louder then piston slap, but not loud like a rod knock could be. Almost sounds like it's behind the time chain cover?
GP99GT
10-03-2006, 08:01 AM
He's had the car about a year and this is a new noise. It's louder then piston slap, but not loud like a rod knock could be. Almost sounds like it's behind the time chain cover?
not sure if the f-bodies have it, but the FWD 3.8s have a plastic-ish timing chain dampener (pushes against the chain to keep noise/vibration down) and eventually it gets worn out. might wanna look into that
typical signs of v6 GM engines..... hmmm i wonder, if the 60' engines have the same problem maybe they have a SIMILAR if not the same EXACT problems...... or maybe 2+2= 9 take your bets
also doesn't it make sense now that there is slapping since it's colder outside, if your confused please read above ^ or just keep getting mad because you have nothing else to do but debate everything with me
I would think that since the 90* motors and the 60* motors use different blocks, cranks, rods and pistons that 60* info would have no real bearing on 90* motors.
He's had the car about a year and this is a new noise. It's louder then piston slap, but not loud like a rod knock could be. Almost sounds like it's behind the time chain cover?
how many miles are on the motor? in all fairness, if it is a high mileage motor, the bore could be tapered enough to allow the pistons to **** slightly and make some noise.
coming from behind the timing cover, I'd maybe just pop the cover off and see if there is anything visibly wrong.
Pampered-Z
10-09-2006, 09:00 AM
Turned out to be a rod bearing. Seems the previous owner didn't bother with little lings like oil changes! Engine was full of sludge. So new crank, bears, oil pump, clutch ( since it had 70K on it and was out ). are now installed.
Tru2Chevy
10-09-2006, 11:56 AM
Heh....that will do it. Sucks that it had to be something major like that, but at least they have a fresh motor to play with now :)
- Justin
GP99GT
10-09-2006, 04:53 PM
wow, i was convinced it was piston slap....:roll:
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