Lukaskli

Hi guys first time posting I've recently had a problem with my 2001 Lexus gs300. It has 160k miles on the clock. So one day I was driving it was a cold morning but not - temperature. I let the car warm up for about 20 mins and started driving. At first it was perfectly fine nothing abnormal, as I went to over take another car on the motorway I've noticed the car has a major loss in power, I drove it another like or so to a place where I can stop safely as soon as I stopped the car started to steam up from underneath the bonnet even though the temperature inside the car showed normal. Now the car starts fine idles alright but will not rev up over 3.5 k and makes a sort of rattling noise from the back left of the engine. I've taken out and cleaned the throttle body and checked the valves all seem fine.

can anyone help in diagnosing the problem ?

Letsride

Is the noise coming from the starter area?

Lukaskli

Hi, yes from that general area.

Letsride

Without hearing the noise I would look at the starter while the engine is running to make surer the housing is not cracked (rare). Also is the noise there at idle or only when you rev the car up? Is it possible for you to take a video of it?

PS.....I have seen 3 gs's in the past with noises in the general area and they all had cracked/broken flex plates!

Lukaskli

Yes I will post a video too. Its only when you rev the engine at idle it sounds normal. What is the flex plate would that have caused the over heating ?

Letsride

The flex plate is what connects the transmission to the engine to conduct the power to the wheels. Its also what the starter spins to start the engine!

lexusfever

Remove your 02 sensors or disconnect your headers from the mid pipe and see if you can rev. If so you have a clogged exhaust. I just had it on my 03 GS300 after replacing complete exhaust car is running great. Before I knew it was clogged exhaust I tested everything and was also getting smoke from down by the transmission thought I had a leak hitting the exhaust. Since the new exhaust no more smoke at all.

burteboy

Did the mil came on. Even if it did not come on check for trouble codes.

QLex300

Hi did you figure out the issue
Thannks

03GS300SJ

Hi guys, I see this is an old post but I am experiencing similar problem with loss of power. The engine ran fine before but just yesterday morning I started the car going to work and when I step on the gas, I see the rpm goes up to 4K or higher but car has little or no power. I can only do maybe 40-50mph MAX. Then the car totally loss of power after that and max speed down to ~10mph. I ended up getting it towed back home. I conected to an OBDII reader and see if there was any code but none whatsoever show up. I am buffled on what is wrong with the car since normally I would see a code at least if something like this happen to get some kind of clue on what is wrong with the car. The car also developed a low tone coming now from the exhaust which sound like I have an aftermarket muffler system but it is completely stock and never have been modified. The only thing was replace was the catalytic converter from the exhaust manifold to the midpipe due to CEL which was replaced over 1 year ago.

Just little more history of the car, it has a recently rebuild head and a valve job due to overheating but this has been fixed 6 months ago and it has been running like new since. It also has the throttle body lever sensor(TBLS) replaced with an aftermarket part about 4 months ago. At first I thought the TBLS failed again but the fact that the RPM can rev up over 4-5K RPM doesnt seems to be the same problem. When I have the TBLS failed there were no power until I step the gas down all the way but I dont have that now since the throttle response is normal and linear. Greatly appreciate any advice and thanks in advance.

P.S. my car is 2003 GS300 3.0L 2JZ with automatic trans. Currently at 133K miles and completely stock for now.

03GS300SJ

Just want to follow up on the issue I have with the GS300. The issues was a clogged up catalytic convertor after the bank2 oxygen sensor. After removing the entire section including the muffler, I have a bunch of ashes in the the second catalytic convertor. Not sure if it was from the catalytic convertor at the exhaust manifold that was replaced previously. After it was cleaned out and put back together; it is running good as new.