DOD timing chain replacement
06-14-2011, 12:48 PM
#1
On The Tree
Thread Starter
iTrader: (2)
Join Date: Apr 2011
Location: MI
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
DOD timing chain replacement Has anyone experienced any timing chain noises coming from the initiation of the DOD system? Noise starts shortly after the car gets into 3rd gear, can be as low as 13mph in TapShift mode. I was told in a previous post that it's considered "normal" operation of the DOD system and is a result of the timing chain. I had originally thought it was lifter tick but after having all 16 lifters and my transmission replaced under warranty I've realized it's probably the chain.
Question, has anyone had this issue? It's annoying like a baseball card in a bike tire annoying, it's very audible with the windows down and I wouldn't be surprised if any pedestrian's in the downtown area where I live think there is a 10-speed with an LS4 strapped to it coming up behind them. Dealership won't do anything about it...
Has anyone changed this timing chain or know the level of difficulty/cost in replacing it? I really don't want to drive around in 2nd gear just to eliminate the noise.
Question, has anyone had this issue? It's annoying like a baseball card in a bike tire annoying, it's very audible with the windows down and I wouldn't be surprised if any pedestrian's in the downtown area where I live think there is a 10-speed with an LS4 strapped to it coming up behind them. Dealership won't do anything about it...
Has anyone changed this timing chain or know the level of difficulty/cost in replacing it? I really don't want to drive around in 2nd gear just to eliminate the noise.
06-14-2011, 02:05 PM
#3
On The Tree
Thread Starter
iTrader: (2)
Join Date: Apr 2011
Location: MI
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
65k. Pontiac replaced all 16 lifters less than 60 days ago, the noise was present before and after. I took it back and questioned the lifter job and they told me it was a timing chain noise and nothing to worry about. Unless they really mucked up the lifter replacement or failed to do it all together I'm doubting it's lifters.
06-14-2011, 02:13 PM
#4
12 Second Club
iTrader: (26)
Join Date: Sep 2004
Location: Liberty, MO
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
Why would your timing chain make noise in 4 cylinder mode as opposed to 8?
As far as my knowledge is nothing should change with the timing chain when going from 8 to 4.
As far as my knowledge is nothing should change with the timing chain when going from 8 to 4.
06-14-2011, 02:47 PM
#5
On The Tree
Thread Starter
iTrader: (2)
Join Date: Apr 2011
Location: MI
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
I really don't know...It only makes noise in what I assume is 4 cylinder mode. In my car DOD will activate in 3rd gear as long as the throttle input stays constant even at the lowest speeds. So say I shift into 3rd there will be about a 2 second delay then I will begin hearing the chain noise, if I downshift into 2nd gear it disappears. I took it to Pontiac and they told me it's the DOD system engaging and it's doing what it should and that the noise is "normal". They used some stethoscope technique to listen to the engine and the transitions.
What are the other possibilities? I mean ALL 16 lifters and the entire transmission have been replaced, the noise was there before and after.
What are the other possibilities? I mean ALL 16 lifters and the entire transmission have been replaced, the noise was there before and after.
06-14-2011, 04:34 PM
#7
On The Tree
Thread Starter
iTrader: (2)
Join Date: Apr 2011
Location: MI
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
Looking at the summary now they ordered 8 lifters with P/N 12639516 and 8 P/N 12576400, in the description they are both listed as "Lifter 0.459", doing a little research now to see if these were the right parts. If anyone knows feel free to chime in.
Trending Topics
06-15-2011, 11:07 AM
#8
12 Second Club
iTrader: (26)
Join Date: Sep 2004
Location: Liberty, MO
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
GM parts direct show part# 12576400 @ $16.07/pack of 8 and part# 12639516 @ $37.41/pack of 4
when I searched for a 5.3 DOD I got the 12639516 as being the correct lifter, I couldn't find what the 12576400 was for, but something tells me if they cost half as much for half as many (so 1/4th the cost) they are not correct.
Again, I'm no expert on the DOD but something doesn't seem right.
when I searched for a 5.3 DOD I got the 12639516 as being the correct lifter, I couldn't find what the 12576400 was for, but something tells me if they cost half as much for half as many (so 1/4th the cost) they are not correct.
Again, I'm no expert on the DOD but something doesn't seem right.
06-15-2011, 10:44 PM
#10
12 Second Club
iTrader: (14)
Join Date: Jun 2007
Location: Renton, WA
Posts: 2,563
Likes: 0
Received 0 Likes
on
0 Posts
It's the DOD solenoids activating. They are very noisy when the oil is cold. Drive around in tapshift mode when the engine is cold and hold 2nd gear at around 30mph. You won't hear a dam thing. Once the trans shifts into 3rd (back in drive) you'll hear that stupid rattle sound again. Engine won't go into DOD mode in 2nd gear.
06-16-2011, 01:19 PM
#11
On The Tree
Thread Starter
iTrader: (2)
Join Date: Apr 2011
Location: MI
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
It's the DOD solenoids activating. They are very noisy when the oil is cold. Drive around in tapshift mode when the engine is cold and hold 2nd gear at around 30mph. You won't hear a dam thing. Once the trans shifts into 3rd (back in drive) you'll hear that stupid rattle sound again. Engine won't go into DOD mode in 2nd gear.
If it were DOD solenoids activating wouldn't it be a transient noise? Based on some of the DOD system stuff I've read the entire cylinder deactivation cycle takes less than 250ms. The way I understand it is that the solenoids shouldn't change states unless they are commanded to by the ECM. Since the noise is constant I'm guessing it's not the solenoids.
I also don't need to be in drive for it to activate, 3rd gear in tapshift mode creates the same scenario as long as I don't get on the throttle. If I do it goes away.
