Dear friends

To give you a quick background, I have owned sever cars in the past like a Mercedes W140 S600, Toyota Cressida, 1991 LS00, Lexus IS etc. I am capable of doing general small repairs etc on my own and am generally technically minded.

I just purchased a 1998 LS400 last month with 97,000 miles on the clock. I am based in the UK and the weather is generally cool/cold over here.

Here are my problems, hope someone can be kind enough to help diagnose my issues-

1. I hear a lot of road noise in the car from the front right of the car. The noise is similar to tyre noise when driving any car on a worn old road. I had to change the front two tyres anyway after I purchased the car since they were old. The new tyres have made no difference. My friend a mechanic has checked out the front bearings and he says that they are fine with minimal play. The road noise starts from 10mph onwards all the way to highway speeds and increases with speed. Me shifting the car left or right at speed makes no difference to the increase/decrease in sound. Brakes are good and not sticking or anything like that. My 1991 LS400 had no road noise and was much quieter in this regard. One more thing, the noise increases and becomes much apparent on new/smooth roads. The mechanic friend cannot hear anything unusual but I am sure something is not right given my experience with these cars.

2. After driving the car for 10-15 minutes from cold, I get a creaking sound from the rear left suspension. I greased the sway bar bushings but this noise still occurs. The noise disappears after after the car has not been driven for day/two and reoccurs 10-15 minutes after the car has been driven. Do the LS400s suffer from bad struts? Given the car has only done 97,000 miles surely the strut should be ok? Or does anyone have any other hints?


Hope someone can help so that I can get the car in order.


Thanks

 

Has the car ever had the suspension modified in any way? Creaking could be almost anything, what kind of greasing did you do? Spraying a good rubber lubricant would be a good place to start. Also the noise could be from the shock struts, pivot points etc.

 

I have lubed the rear linkage bush using silicone grease. I have not touched anything else. Suspension is 100% factory standard

 

I've not fooled with rear suspension yet on these cars. But if the bushings are similar to say the very bottom bushing on the front shock struts there is no way to lube it.
If its a rubber squeak some rubber lube will help. If the bushings are similar to the ones on the front upper control arms you could get a fine thin tube around the boots and inject grease into the joint, same with the sway bar links since they are all metal spherical joints. Most all rubber bushings if you can call them that have no moving parts other than the rubber that is deforming, and that is why when you tighten something like that lower shock strut through bolt the weight has to be on it to position it in the normal running position so the rubber isn't in constant distortion when the suspension is compressed. When the spring pressure is relieved when jacking up the front end then the rubber bushing is in the distorted condition. So what kinda bushing is it your lubricating?