Bumbobee

Hey guys,

I had my transmission rebuilt last year. I also recently replaced a bunch of sensors on the car as I was getting a check engine light. Recent work that's been done is as follows:

Transmission rebuild (1 year ago)
Timing belt with water pump (3 weeks)
Variable Valve Timing solenoids (3 weeks)
2 upper Air/Fuel ratio sensors and 1 oxygen sensor (2 weeks)
MAF sensor (1 week)
Knock sensor (will be replaced this week)

When I drive the car sometimes the transmission won't shift into the over drive gear. It stays in 3rd and the RPM"s rev high. If I stop the car, turn the engine off and back on again, the problem goes away and I am able to get into over drive again. During driving I have tried everything, letting off the gas pedal, switching overdrive on and off, but it doesn't help, only a turning the car on/off does the job.

What can this be? Is it something electrical or with the computer? Or is the transmission going again?

Bumbobee

One more thing, do you think replacing the knock sensor will fix this? The CEL light is on and has the P0325 code. I ordered the cheapest sensor off rock auto.

PFB

Can't comment on the overdrive issue, but I can definitely tell you that purchasing after market knock sensors for this car is a big no no.

Most of them don't work properly with our Lexus cars, and will likely either not eliminate your code, or will cause it to return within a short time.

You should also change the knock sensor wiring harness at the same time, as they tend to deteriorate.

In fact many times the problem is the wiring harness and not the knock sensor.

Bumbobee

So the CEL light will be on because of mis reading but the after market sensor will be operating still?

Do you have a part number for the harness or know where it is on rock auto?

Also, how hard are the knock sensors to change? Are they easy to access? There's 2 sensors correct?

Bumbobee

Is this the harness?

http://www.rockauto.com/catalog/x,ca...parttype,13326

PFB

Check out this YouTube Video, Its not very good, but it will at least give you an idea as to where they are and what needs to be done.

In terms, of the wiring harness, YES, it looks like the right one, but you can probably pick up an original one from your Local Lexus Dealer, for not much more (I think). And at least you don't pay shipping to Canada.

Bumbobee

Where's the video?

PFB

Oops sorry, Here is the Link. Its for a 2000, but its the same as yours. If you do a search on You Tube you can find some other relevant Videos as well.


Have a look at this link as well.

http://www.justanswer.com/lexus/2rvq...xus-es300.html

clintbw

Having a bad knock sensor will put your car into limp mode, from my experience. That means your car's computer will decrease your engine's performance (your car may seem really sluggish) and disable overdrive.

mitmaks

Who rebuilt your transmission? I would address issue with that shop. I would think they'd offer some type of warranty.

ES300doc

Any code stored (Check Engine Light On) for the following you listed will disable your overdrive. It's designed that way, to get you into the shop.
Variable Valve Timing solenoids (3 weeks)
2 upper Air/Fuel ratio sensors and 1 oxygen sensor (2 weeks)
MAF sensor (1 week)
Knock sensor (will be replaced this week)

You must find and repair the engine performance issue to resolve this. If you have a knock sensor code active then you will need to get it repaired before you have normal operation of overdrive again.

Knock sensors and Crankshaft and Camshaft sensors all should be replaced with OEM Lexus sensors only. Otherwise you will probably be doing it twice.

Bumbobee

The guy in the youtube video comments says that the P0325 code is most often not the sensor but just the wiring harness?

And holy **** that looks like a lot of work to replace the sensors

Bumbobee

Ok I bought 2 new knock sensors and 2 new wiring things. What else do I need for this job? Intake manifold gasket? Which one? Just the upper or lower or both?

crwys

I'm glad you are asking these questions because I need to do my knock sensors and harness's as well. Did you buy yours online? Can you give me the links for both the sensors and harness's, 1999 lexus es300 here. Thanks.

Bumbobee

Here's what I bought

http://www.rockauto.com/catalog/x,ca...,parttype,5108

BECK/ARNLEY Part # 1580780 More Info **#8961512050, 8961512090, 8961532010} x 2

and

http://www.rockauto.com/catalog/x,ca...parttype,13326

DORMAN Part # 917032 More Info **#8221907010}
Ignition Knock Sensor Harness x 2

Now I understand these aren't original parts and have been advised by forum members they won't work well with the car, but I am taking a gamble, we will see what happens...