tdolinar

I recently purchased a one owner 98 GS300 with 154,000 miles. I took it to a lexus specialist and they gave me a list of repairs an costs:

valve cover gaskets leaking- $362
6 spark plugs and wires- $257
Timing belt/water pump/ tensioners/cam and crank seals- $875
Transmission Mount sagging-$174
Trans. service- $69
Differential Service- $55

I took it to another mechanic for a second opinion and they only found an issue with the valve cover gaskets needing replacing.

I've never owned a lexus, only toyota, and I've seen a lot of people saying that the timing belt job should include the valve cover gasket job, that the transmission mount could need replacing given this type of mileage, etc. I guess I'm just looking for some experienced feedback and I'd like to know if the first estimate is reasonable or not.

The car occasionally vibrates at idle through the steering wheel and I can see the hood vibrating; is that an engine mount issue?

Thanks for any all feedback, much appreciated!

MrHimbert

Toyota=Lexus.

There has been quite a few people that have only replaced the transmission mounts, and had even worse vibration, id do the engine mounts at the same time if you are going to do that. Does your cars RPMS change or does the needle bounce at idle? My gs300 was doing that, and it was just a dirty MAF sensor. But my mounts need to be changed as well. I would find out the history of maintenance and judge what you need to do from there. Personally when i get a car, all fluids are changed immediately so I have a fresh timeline on maintenance. Does it have the original water pump?

tdolinar

Thanks for the reply. The RPM's don't change and the needle doesn't bounce. According the car fax, it was dealer serviced regularly. I have no idea if the water pump is original. I was going to do all of the fluids for sure.

tdolinar

Important to note, the lexus guys said the spark plug wires were original and it's recommended to replace them. Does that sound like it's necessary, or just new spark plugs?

MrHimbert

Well thats good that the needle doesn't bounce. But I think cleaning the MAF sensor, and probably the throttle body would help as well. Those are things that should be done every few oil changes in my opinion. Its very simple to do yourself, and I'm sure there are plenty of youtube videos to help you. Of course check the intake filter and see what its condition is in as well. Im **** and would probably check the spark plugs to see their condition as well. They are kind of a ***** to get to the rear ones, but a ****ed up gap can hurt an engine after a while. As far as that transmission goes, be careful about flushing it. These trannys are almost worse off with a flush any synthetic fluid. I personally wish i didn't even do a fluid change to synthetic. My car now jolts into gear and it is very annoying. Users on here will tell you, don't change it if it feels fine right now! The lovely lexus is a touchy B****

Sounds like you have a good idea for what you need to do along with a few personal pointers to help you get ahead of any future problems.

Behemoth7

Any idea when the timing belt was done? They are recommended to be done every 90k, if yours was replaced on time, you have some time before that needs to be done. Spark plugs, wires, and valve cover gasket are pretty easy jobs that you could probably do yourself. As far as the mounts go, if they are original, just get them replaced. Better safe than sorry. And lastly, yeah I would definitely get all of your fluids done, as Mrhimbert said. But DO NOT FLUSH THE TRANSMISSION. As a matter a fact, unless the transmission is exibiting problems, you should only drain and fill.

Hope that helps!

MrHimbert

Nailed it!

raytseng

If you're going to the trouble to change the spark plugs, you might as well change the wires. The wires are only about $30. The majority of your cost in this service is the labor.

While you're in the sparkplug service, you should get the Throttlebody cleaned too, since that'll be off for the spark plugs.

But, whether you need to change the plugs in the first place depends on if you can find out when they were last changed.

ttaylor993

If you join LexusDrivers.com you can access the service records of the vehicle. This would be all services performed by Lexus dealers and any services reported by previous owners. Here is a link to the site.

https://secure.drivers.lexus.com/lexusdrivers/home

This may give you information about what services have been done. Sometimes there is a sticker on the upper timing belt cover when the timing belt has been changed. Although it is an easy fix when the timing belt is off, unfortunately the water pump is not always changed at that time. Same goes for the seals. There is no way to tell if they need replacing unless they are leaking.

If you are mechanically inclined, I'd give a shot at replacing these myself if I were you. I did. I am no mechanic but it is not that hard. Here is a video on how to change the timing belt and water pump if you want to try.


If you search this site you will find a series of videos by Jeff Tsai on how to replace the timing belt, water pump and cam seals. There is also a thread with a series of photos on replacing the valve cover gaskets.

Anyway, I hope this helps.