Hi guys, I have a 2006 TL with 58000 miles on it. It developed a rough idle not so bad when its in park but you definitely feel it, it gets worse when I put it in drive with my foot on the break like at a red light. It is the same whether the car is cold or warmed up. So i was wondering if someone can point me in the right direction on where to start on what to check.

Thanks Anthony

 

No one?

 

Most likely a bad motor mount or three if the TL isn't throwing codes. G/L.

 

Search motor mount or misfire. I don't know if it's possible to have a misfire that doesn't throw a code or blinking SES light.

 

that's right. if you're feeling it inside the cabin, noticeably, then more than likely all your motor mounts are done for. if one went out, you wouldn't be able to feel it. that one mount puts more stress on the rear one, and forces that one to go, and lastly, the front one. goes side mount, rear mount, then the front.

good luck! parts aren't too expensive, the install's a little annoying...especially if you want to do it right (to this day, i still don't understand how the vac lines goes back on).

 

Is the 'rough idle' similar to a dead cylinder (misfire) or is it the shudder (small drop in rpm) like I describe here:

https://acurazine.com/forums/showthr...alling+problem

My shudder was not the same as a completely dead cylinder...it was a defect in the coil pack that showed up under load.

 

It seems like the same situation, I have not checked my motor mounts. What would be the best way to check them.
I dont think I would have the power the car has if it was missing, but again not sure. I need to check my plugs as well. I am just trying to get as much info as possible and start with the basics so I can check it all out in one shot and hopefully pinpoint the problem.

 

take a glance at the ones you can see....and with the car running and the hood open....rev it a little and see if the motor rocks when doing it

 

I checked the plugs they look good. As far as the motor mounts I did not see anything major under a quick inspection but I think they might be on there way out. I'm going to try a more detailed inspection of them. I think they are the problem. I also get a vibration on the highway.

 

Put the e-brake on, open the hood and watch the engine as someone puts it in drive (with the e-brake and normal brakes on) and gives it gas. Then do the same thing in reverse, powerbraking it to see how much the engine moves.

If your vibration gets better inside the car in reverse, it's the mounts.

Check the vacuum line going to the engine mount. If it's broken or disconnected, the mount will firm up and it will idle rough.

 

I didn't know about the vacuum line does it go to all the motor mounts?

 

The front and rear mount have a vac line on the underside (between the bottom of the motor mount and the subframe). This is meant to stiffen the mounts at startup to avoid excess movement/vibration.

The best way to check would be jacking the car up and feeling underneath each mount to make sure they are still attached. Then follow the lines up to where they connect to the intake manifold. Look for cracks or any other damage that may be causing a leak.