Cyclic vibration when stationary

[mattw1992]

Hello All,

Have been doing a lot lately to try and settle this down and have had little results

I have a cyclic vibration when the car is in park or drive, stationary and driving, mostly felt when throttle is light, around 1500rpm. It is a cyclic vibration almost every half second or second, it is rpm affected in speed and is felt through the steering wheel, floor and seat.

So far i have,

Cleaned MAF, TPS, IAC, Throttle Body, Plenum Chamber.
Replaced plugs & leads.

The car does vibrate on idle, the rpm is 750-780, so in normal range but it is noticeable vibrating (plastic shaking noise etc)

Engine and Trans mounts are fine, harmonic balancer seems fine. Coils seem fine. Where to now?

 

[someguy360]

Mine had the same problem.

Replaced the flexplate and torque converter and that fixed it.

(not sure which one exactly it was so I did both together.)

 

[dirty hands]

this vibration problem is starting to show up on -more VTs autos in this forum this month

think the count is five

..I have got the vibration

some of us are trying different things..ruled out the obvious checks ..still looking for a solution-- as it comes and goes away

most often happening in drive or reverse when stationary with brake on - is where we have timed the event

I dont really want to pull an auto out ..who does - but torque converter and plate is something serious to consider

 

[mattw1992]

this vibration problem is starting to show up on -more VTs autos in this forum this month

think the count is five

..I have got it

some of us are trying different things..ruled out the obvious checks ..still looking for a solution-- as it comes and goes away

most often happening in drive or reverse when stationary with brake on - is where we have timed the event

I dont really want to pull an auto out ..who does - but torque converter and plate is something serious to consider

I'm not sure if it is the same as all of you, in fact i would suggest perhaps looking at other things, i had my transmission & torque converter replaced about a month ago.... issue was there before during and after my transmission issues.

 

[hotrod]

what about your EGR valve .

 

[Immortality]

Hello All,

Have been doing a lot lately to try and settle this down and have had little results

I have a cyclic vibration when the car is in park or drive, stationary and driving, mostly felt when throttle is light, around 1500rpm. It is a cyclic vibration almost every half second or second, it is rpm affected in speed and is felt through the steering wheel, floor and seat.

So far i have,

Cleaned MAF, TPS, IAC, Throttle Body, Plenum Chamber.
Replaced plugs & leads.

The car does vibrate on idle, the rpm is 750-780, so in normal range but it is noticeable vibrating (plastic shaking noise etc)

Engine and Trans mounts are fine, harmonic balancer seems fine. Coils seem fine. Where to now?

I wouldn't completely discount the harmonic balancer as a source of these issues although been very consistent I would possibly suspect a loose timing chain/failed timing chain tensioner. Does the engine seem to have a bit of a rattle around the front/timing case at all?

this vibration problem is starting to show up on -more VTs autos in this forum this month

think the count is five

..I have got it

some of us are trying different things..ruled out the obvious checks ..still looking for a solution-- as it comes and goes away

most often happening in drive or reverse when stationary with brake on - is where we have timed the event

I dont really want to pull an auto out ..who does - but torque converter and plate is something serious to consider

Yes, it does seem to be a bit of deja vu going on here doesn't it.

I'm not sure if it is the same as all of you, in fact i would suggest perhaps looking at other things, i had my transmission & torque converter replaced about a month ago.... issue was there before during and after my transmission issues.

I'd be looking at the harmonic balancer but it may also have a timing chain problem. One of the weak points of the V6 engine is the single row timing chain & tensioner. Eventually the tensioner wears out and you have a very slack timing chain which may cause these types of issues as well.

 

[SavVYute]

Could be the cold weather affecting the rubber mounts throughout the car (engine, transmission, exhaust) if it has only begun in the last couple of months. Just a thought.

 

[dirty hands]

we need a think tank on this one

..
I am going to do a compression test - when I replace the plugs this week
egr valve is working on mine
stetascope on the timing chain cover