Rx300 Mk2 Suspension

GlynnB · November 8, 2004

Has anyone noticed a horrendous thump from the front suspension when negotiating speed bumps (humps?) at any thing more than a crawl.

Had it happen twice now in car parks when I wasn't expecting the bump. I don't know if it's the suspension bottoming (but I would have thought the stops should stop the noise?), a rubber joint compressing fully or something else but it doesn't sound nice on a new car.

Amee · November 10, 2004

When this first happened to me I thought my tyres were under inflated, it is some-what annoying as you say. It is as if the rims are whacking off the speed bump at a speed of only 10mph...Not good.

Shahed · September 18, 2007

When this first happened to me I thought my tyres were under inflated, it is some-what annoying as you say. It is as if the rims are whacking off the speed bump at a speed of only 10mph...Not good.

I have the same problem on my 2005 Rx300. As you describe, ionly when over something like 10mph, as it comes down a spped-hump, I feel a knocking sound/thump! Really annoying me. Probnelm is, I just noticed this after fitting LPG conversion with tank where spare wheel used to be underneath the car. Any ideas???

Bobby McLeish · September 19, 2007

When this first happened to me I thought my tyres were under inflated, it is some-what annoying as you say. It is as if the rims are whacking off the speed bump at a speed of only 10mph...Not good.

I have the same problem on my 2005 Rx300. As you describe, ionly when over something like 10mph, as it comes down a spped-hump, I feel a knocking sound/thump! Really annoying me. Probnelm is, I just noticed this after fitting LPG conversion with tank where spare wheel used to be underneath the car. Any ideas???

Just a quick question on the LPG conversion ! Did this affect your Lexus warranty ? I have extended warranty on my 2003 Mark 2 and my Lexus dealer said that if I fitted LPG, the warranty would become invalid.

Duncan Roberts · September 19, 2007

Has anyone noticed a horrendous thump from the front suspension when negotiating speed bumps (humps?) at any thing more than a crawl.
Had it happen twice now in car parks when I wasn't expecting the bump. I don't know if it's the suspension bottoming (but I would have thought the stops should stop the noise?), a rubber joint compressing fully or something else but it doesn't sound nice on a new car.

Presumably this is the coil sprung version NOT the air suspension of the SEL?

Shahed · September 19, 2007

When this first happened to me I thought my tyres were under inflated, it is some-what annoying as you say. It is as if the rims are whacking off the speed bump at a speed of only 10mph...Not good.

I have the same problem on my 2005 Rx300. As you describe, ionly when over something like 10mph, as it comes down a spped-hump, I feel a knocking sound/thump! Really annoying me. Probnelm is, I just noticed this after fitting LPG conversion with tank where spare wheel used to be underneath the car. Any ideas???

Just a quick question on the LPG conversion ! Did this affect your Lexus warranty ? I have extended warranty on my 2003 Mark 2 and my Lexus dealer said that if I fitted LPG, the warranty would become invalid.

Although I have a Rx300 2005 car, my warranty has already expired due to current mileage of 67,000, and I did not opt for extended warranty, don't really believe in them as most warranties tend to have a cap of £1000.00 per claim!

In terms fo the LPG conversion, I would sugest you do lots of research before you decide to convert. I found out that it was not simply an option of Yes or No, there are many different systems on the market and everyone you speak to will swear theirs is better than the others for x, y and z reasons??? All I can say is that I did lots of research and was convinced to go for the Prins System. However, after speaking to the installer, I took his recommendations to go for his bespoke system which has a Voltran ECU and Brand New Vogas Injectors on SGI. I a 60L tank beneath the car where the spare wheel used to be. Trust me, this cars drives like a Rocket on this system, infact you cannot tell the difference when it switches between the two fuels, and it seems it drives smoother and faster on LPG. I would definitely recommend it if you want to save pounds on your fuel bill!