ErickUa5

So I was having an issue with a pulsation vibration at idle on my 2000 TL for a while, no matter what I did to try and resolve it just didnt work replaced all you name it engine mounts spark plugs timing belt etc. even when I did the Type S swap since the last engine blew thought it was gone nope.

After a bunch of research found out that the transmission creates a drag on the engine while its spinning so at low RPM it would throw the engine out of balance but not enough to see the effect on the tach.
Since the engine mounts turn soft at idle the drag causes the engine shake slightly and may look like a small misfire when in fact its not misfiring.

I started checking the engine mounts with a vacuum pump to make sure they can hold vacuum and both did (they were new anyways) Tested each one with and without vacuum till the vibration went away and it was the front one, its been 8 months now and the vibration is almost non existent. All you have to do is unplug the vacuum hose for the front mount and close off the hose so you wont create a vacuum leak.

I know its the tranny for sure causing this Ive seen a lot of Honda odysseys having the same issue and no misfire reported. Just thought I put this out there tried to explain it the best way I can, I will post a video of this later on to demonstrate it.

Chevelle66

I have that pulsation, and while it's still there, it's less noticeable after installing my CAI. Makes no sense, since everything was checked out previously (it was driving me nuts considering it's a "luxury" car).

james357

iTrader: (2)

does this include a slight vibration at idle & none at anything above idle??

ErickUa5

Same here and let me add that it was the same after the tranny was rebuilt. Try it and post back with results.

ErickUa5

That's right only at idle, I also tried neutralizing the engine mounts and somewhat lessened the vibration but the pulsing was still there.

RONE

Good info. Thank you for sharing. I've noticed the slight surging, which is worse when the engine is cold. Now that I know why it does it, I think it will annoy me less.

ErickUa5

Your welcome Rone Most definitely in cold weather I used to see the steering wheel vibrate along with the pulsing, Last time I saw that was in a older 4 cylinder Hyundai a friend of mine had . Try it out and post back it wont hurt anything just make sure to plug the vacuum line.

BetterBob

I'm sure this is a dumb question to most of you, but I'm totally new to this car.

Why on the earth would an engine mount need to be hooked up to the vac system? I've asked a couple fairly knowledgeable people, and they had no idea... and also stared at me like i was a moron.

Maybe I just read something the wrong way.

ErickUa5

If you search you'll find alot of info about them, To my knowledge all they do is dampen vibrations at idle and firm up when your on the throttle, They also have a hydraulic fluid inside that can leak as they age. But the fix that I came up with is a band aid to lessen the movement of the engine and trans on the mounts. This is only if your TL is running fine you have tried everything like Egr cleaning, No misfire, coils etc.

BetterBob

Thank's for clearing it up for me.

This seems like a much better use of the old ford Lincoln Continental/Towncar suspension system. (although it was pneumatic, not hydraulic)

Skirmich

^ Yah the Hydro Mounts are pretty neat when they work.. You can notice the difference if you have SOLID mounts.

Solid mounts can only reduce vibration within the rubber piece.

Hydro mounts have a rubber piece with a lower section filled with oil
when you come to a stop the suction pressure from the Intake is lower which makes the mounts more soft thus reducing more vibration than a solid mount. When you start to roll and the engine revs, the mount gets stiffer which makes for a firmer shifts and better acceleration off the hole.

Bad things happen when the mounts loose their oil.. Basically without oil there is an AIR gap between the rubber piece and the mount so while the rubber piece is still OKAY the mount can move freely in this "gap" so engine moves more than desired = Toasted Mount even with the rubber piece intact

Stupid luxury cars..

3.2TLc

Manufacturers engineer all this good stuff into the car to enhance the ride quality while it's new. But....the real motive is for these extra goodies to go south about the time the warranty is up. That will get the consumer back into the dealership looking for a new car instead of dumping big bucks into servicing repairs on the old car.

ErickUa5

Have you seen the prices on the 1st gen 3.0CL engine mounts, just the rear mount from the dealer is almost $400 that's ridiculous lol.

3.2TLc

Yeah, anybody that pays dealer prices for most stuff is getting ripped. But, if ya gotta have them installed at the stealership....then you are really gonna get slammed. Buy aftermarket and tell them to stick their parts !

ErickUa5

Here it is guys today I finally had the chance to show a clip of it.

3.2TLc

[QUOTE=ErickUa5;14774429]Here it is guys today I finally had the chance to show a clip of it.


Hmmm, cool vid !!!

Stupid vac assisted hydraulic mounts. Might as well consider the solid ones when replacing. Save the vac for inside the motor.

Nicks2001tl

That keeps the car more quiet at idle. How is the ride?

Keep in mind that the TL`s are luxury cars and the vacuum assisted mounts are what make the car drive more smoothly.

3.2TLc

After 10 years and 100k ......the soft, gentle smoothness and quiet serenity of our luxury sedans seems to normally just fade away gradually each year since new.

Nicks2001tl

Well put. I didn`t know you were a poet/mechanic. I bought a rear motor mount without the vacuum line. The one in is fine now but if it fails might also do the front without the vacuum line.

ErickUa5

Guys the mounts are doing there job the problem is the torque converter is dragging about every second on and off at idle, when the mounts soften up the shaking is more visible and felt in the cabin since it shakes excessively beyond what the mount can dampen.

victus1

What you are describing is a problem with the torque converter clutch, right? Probably what happens as it wears out.

ErickUa5

Thats correct basically the tranny is self-destructing, Im in the process of rebuilding one and possibly post it soon with updated parts. Heres one of the valves that would resolve the converter issue. http://www.sonnax.com/parts/2757

ErickUa5

Honestly it feels the same way no difference. The engine actually moves less when revved without vacuum on the front mount.