knocks while shifting what do i do?

[christians87]

My car has really bad knock at the 1 2 shift and 3 4 shift. What can I do to eleminate it? Poly motor mounts or something mabie? Any advice is greatly appreciated!!

 

[DailyDrifter]

Poly mounts for the engine and trans. Do you have a torque strap on it now?

 

[christians87]

Shes got stock mounts all way around as far as I know. And no torque strap. I hurd they can cause the engine to twist over and possibly damage the motor mounts or cause knock or something bad like that I cant exactly remmember so I opted not to get one.

 

[turbojd]

First you have to verify if it's false knock or not, does it (the knock)fade away after the shift point? How many degrees of knock are you seeing? How much timing retard?

 

[christians87]

Yes after each shift it goes away. Ive seen as much as 12* of knock retard according to the sm . Usually its anywhere from 7 to 11 degrees

 

[DailyDrifter]

Your DP might be hitting the control arm.

 

[bison]

Does it occur at under 15psi? Id first eliminate the possibility if not enough octane

 

[christians87]

If it was not enough octane wouldnt it do it the whole time its at wot insted of shift points? I may be wrong but thats just what im guessing. If the dp is hitting would the poly mounts prevent the engine from torqueing over that much during shifts?

 

[DailyDrifter]

If it was not enough octane wouldnt it do it the whole time its at wot insted of shift points? I may be wrong but thats just what im guessing. If the dp is hitting would the poly mounts prevent the engine from torqueing over that much during shifts?

Yes if your mounts are shot they can rock back and forth. I am assuming the knocking is comming from something hitting the engine under the hood. But if its real knock theres definatly something else going on there.

 

[christians87]

Does anyone know of a way to visually look at the motor mounts to determind wether there bad or not?

 

[DailyDrifter]

Best thing to do is SET the E BRAKE. Have someone you trust put the car in drive and step on the brakes. Then give it gas a couple of times, with your foot still on the brake. The engine will torque and you can see if it has excessive play.

 

[Audie1]

Might even check you belt tensioner, I've seen them get really weak and cause much knock.

 

[christians87]

Ill try torqueing the motor over and see if it moves too much this weekend. its supposed to warm up alittle. What should the engine be hitting? Last night I looked around the dp area and I didnt see any signs of the dp hitting any thing. The car has the factory dp so it clears every thing pretty well from what I could see. I dont think its the belt tensioner, I never hear the belt slipping and the belt is in good shape.

 

[turbojd]

As was said, I would now check out the engine mounts for excessive wear and go from there.

 

[rodman99999]

The shift points are where one will normally see the most REAL knock(not enough fuel or octane/too much advance). If something were hitting, it would show up elsewhere during hard acceleration also, especially during a hard launch. A bad belt tensioner is generally noisy all the time. Bad motor mounts will show their a$$ while you're power-braking.

 

[christians87]

It was a broken drivers side motor mount. thanks for all the help guys.