Hey guys,

I am trying to diagnose a problem with my LS400. The car has a vibration coming from the engine bay only when the rpms are around 1400-1700. So if I am accelerating through any gear it always vibrates at that point. If I am driving about 50mph keeping the rpm at 1500 it is vibrating, if I put the engine into neutral and coast at 50mph, the vibration immediately stops. So my guess is first the crankshaft pulley. I understand this to be the harmonic balancer? Any input would be greatly appreciated here. I am going to take the car into my local shop and have them replace whatever it is that I think would be the issue.

*Edit - See comments below and my post with pictures for the answer to my worries!

 

Could possibly be a motor mount / transmission mount. I say this because you get it when the car is in gear, and it stops when you put it in Neutral. In my experiences a harmonic balancer is going to cause roughly the same level of vibration whether the car is in gear or not.

 

+1 for the transmission mount.

 

+2 for transmission mount

make SURE to get the genuine Toyota part, it is very cheap to buy and very easy to install yourself!

if that doesn't cure all of the vibration, then get the two main motor mounts, and they too must be genuine Toyota (aftermarket are complete garbage) - the two main motor mounts are not so low cost and much more of a pain to install yourself than transmission mount.

I highly doubt there is anything wrong with your harmonic balancer (crankshaft pulley)

 

Wow thanks for the help guys. Glad to see this is a unanimous suggestion Calling my nearest dealership today for that transmission mount! Any good diy threads for this job?

 

the part number is 12371-50060 - don't over-pay - make them give you a nice discount, as an example, Lexus of South Atlanta charges $36

just search on here for tutorials on this job, there are several!

 

late to the party but yes, transmission mount!

 

You guys were spot on! Here's a couple pictures to show that the mount was actually broken. Once I put the new one in, the vibration was gone and everything was right with the world once more lol

 

Congratulations on your quick fix.

I have a question, MrStiles. Didn't you feel that 1 or 2cylinders were misfiring at around 1500rpm when the problem was going on?

When my car had your type of vibration, it was a month after I've changed spark plugs. I initially thought there were mis-firings. But it turned out to be the transmission mount.

 

Excellent! Glad we were able to help!

 

I am most impressed at how you were able to get you car upside-down in order to take that photo!

 

HAHAHA, I was thinking the very same thing when i saw that picture, Cowboy!

 

LOL! how many miles does the car have? i'd like to note the typical mileage the owners start to notice, though of course it all depends on the owner too, plus climate, and driving habits, etc.

 

I have definitely seen these break in less than 100K

 

I found that mine was in this condition at 88K miles / 141K km when the vibration was quite noticeable. Judging from the level of the crack and minor vibrations started months ago, the breakage must have started at 80K or earlier.