mmccutchin

1993 LS4000 here (165K). . .got the car back 200 miles ago from a major service (incl. tune up, valve adjustment, replacement of t-belt, w-pump, pullies, tensioners, several cams and a crank seal, drive belt, fuel filter, ignition cap/rotors and spark plug wires).

*Imagine being behind the wheel. . .right hand firmly on leather wrapped gear shift (yes, it's an automatic). . .right foot on gas acceleration. . .now engaged in "city" driving. . .0-40 MPH. . .TONS of starts/stops. . .connecting yourself with your car. . .you know, the Lexus Zen thing.

*When I purchased my car 5-6 weeks ago and drove it 300 miles. . .there was this incredible silky smooth, quiet, vibrationless ride to the car while engaged in "city" driving. . .exactly like my 13 year experience with my 1992 ES300 and a friend's 1994 LS400. . .you know. . .the LEXUS DRIVING EXPERIENCE that all of us have come to know and love!

*Now I'm feeling something definitely less smoother. . .especially when the RPM is 800-1,500. . .NOT a stiff or firm feeling which I would have expected from just having done a tune up/valve adjustment (until the car's broken in, etc.). . .more like "noticeable vibrations". . .a louder engine that you can now FEEL and, at times, hear. . .and while your right hand is on the gear shift there is a more noticeable vibration when the car is "in gear". . .yesterday, the shift *** actually shook briefly while driving on a flat, smooth service. . .my car feels like it doesn't have a muffler-like function!

What's going on here? Does this really sound like a "motor mount" problem?

I don't know enough about cars to know where to look for myself. . .and when I took the car back to the independent who did my major service. . .he drove the car then told me there was absolutely nothing wrong with the car. . .that it was either in my head, I was complaining for nothing. . .or that I didn't have a clue how LS400s should feel!

Thank you in advance!

mmccutchin

I find it incredibly AMAZING that 40+ members have viewed this post. . .but have absolutely nothing to comment on. . .so I shall consider myself fortunate. . .the ONLY LS400 owner to have run into this particular problem. . .or at least this week!

Happy Holidays all!

ToyLexmods

If you have a service history on this veh and the engine and trans mounts have not been changed......change them. Or, you could go down and visually inspect the trans mount to see if it has collapsed

Tammy

Have you considered that since the engine ran smooth prior to you having it torn down, perhaps the condiction is a result of a defective part installed. It could be anything. Valve now out of adjustment. A kink in the fuel line. Throttle body problem. Fuel injector bad. Bad wire or ground to any sensor... Anything.
This is a thirteen year old auto with almost 170K. I would start by having it scoped on a "Sun" type machine to determine if it is ignition or fuel.. affecting one, two cylinders or all.. Then go from there. Hopefully it's simple.
If not, who did the work? Are they responsible?
What about the transmission and engine mounts mentioned on your previous post... Are they sound or broken.

mmccutchin

Thanks all: I'll check ASAP. . .earliest I can get into a dealer is 1-2 weeks. . .will report back here what I learned.

mmccutchin

Okay. . .so I bit the bullet and took my car into the dealer. . .two problems. . .when my tires were recently rotated they were out of balance (local dealer rebalanced them. . .this took the vibrational annoyance factor down a couple of notches). . .also. . .as some of you suspected. . .the engine/transmission mounts were inspected and they are worn. . .but not entirely gone. . .service consultant told me I should save my money.

I'm probably a hopeless V6 driver and since my LS400 (and V8) ownership is pushing 3 months now, I'm discovering that a heavier engine will probably produce more noticeable vibrations when things like mounts are wearing down.

After seeing the new LS460, I'd be inclined to save my money, ride this 1993 LS400 into the sunset, and then start again with the new LS in a few years, maybe sooner!

PureDrifter

iTrader: (10)

id say go against the service tech and replace the tranny mount at the least. its a relatively simple and cheap upgrade and u will FEEL the difference.

up675

I have a 1990 LS 400 and I changed my transmission mount today and it did calm the vibration a bit and I will have my mechanic change the two motor mounts tomorrow and hopefully this will change it a bit also but overall the car is running smooth I had the timing belt and tune up done on the car and now my check engine light is on so I have to take it back to my mechanic and have him to figure out what went wron and why the check engine light is on.