Mechanics

LEXUS RX 300 TRANSMISSION PROBLEM

2001 Lexus RX 300 • 168,000 miles

I had the Transmission rebuild a couple years ago and afterward started getting an "INTERMITTENT" grinding noise at low speeds both when starting up and also slowing down. I have taken the vehicle back to the Transmission Shop several times and they say they are unable to duplicate the problem and the transmission inspection shows everything is ok. I had the water pump replaced a couple months ago and he also replaced some gaskets and a "VACUUM SWITCHING VALVE". When I picked up the car the mechanic advised me the "CHECK ENGINE LIGHT and VSC LIGHT" were on. He said his diagnostic showed it needed the "OXYGEN SENSOR - BANK 1 SENSOR 1--HEATER CIRCUIT". The warning lights were not on when I brought the car in and I told him so. He denied doing anything that would have caused the lights to come on. I have not made the repair as I am having a dispute with the mechanic however I have noticced the grinding noise is no longer there but after driving a couple miles and warming up" the transmission is sluggish when shifting gears ". This leads me to believe the grinding noise involves the "VEHICLE SKID CONTROL" system. Any suggestions will be greatly appreciated? I have not gone and will not go to the Lexus Dealer and that is a whole other story.
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LexusOwnr
February 9, 2013.




Water pump has no connection to the o2 sensor heater circuit failure. He has no liability on that. The code would have come up even if you did not have the pump replaced.

The grinding may have been the vsc but clearing a code does nothing for the issue as it remains and will come back till it is identified, diaged and repaired.

Check the fluid in the trans. When was the last time you changed the trans oil/filter?

Roy

It just seems like a strange coincidence that the warning lights came on after I dropped the vehicle off for repairs and was not on at all before. While I understand it is not related to the replacement of the water pump, he performed other repairs and could have possibly done something to cause the problem.

The transmission shop dropped the pan and inspected the transmission 2 months ago and advised that everything appeard to be ok.

The problem with the gringing noise is that it is intermittent and sometimes occurs several times a day and sometimes will not occur for several days. Unfortunately, it has not occured the several times I have taken it back to the shop in the past two years. It has not reoccured since the above warning light came on. The reason I believe it is related to the VSC is in the Lexus manual it says when the Engine Warning Light comes on it disables the VSC.
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Tiny
LexusOwnr
Feb 9, 2013.
Other repairs? Thats new information. What were those repairs?

The trans can have issues anytime. 2 months ago it was ok but today there may be a malfunction.

When there is an abs or check engine, the system will de fault until the problem is resolved. That is correct

Roy

In your e-mail response my original message was quite garbled for some reason, I'm sure it was hard for you to follow. Do you need me to resend it?

The other repairs were the "Vacuum Switching Valve", "Upper Manifold Gasket", "Timing Belt", "PCV Valve" and "Valve Cover Gasket". I'm not as concerned with the replacment of the Oxygen Sensor as I am with the changes in the transmission after the repairs.

The interment "grinding" at low speeds has stopped but the transmission now shifts "suggishly" (for lack of a better phrase) after the repairs (this is after the engine warms up), but I suspect the grinding will start again when the Oxygen Sensor is corrected as the auto manual states that the VSC is disabled when the engine warning light comes on..

Tiny
LexusOwnr
Feb 9, 2013.
Yep, did not get it all

vsv valve is for the egr valve, and the rest is stright forward. Should not effect the trans atall. Even the connections are on the other side of the car and it is all electronic.

The back of the motor by the rear valve cover is where the connector is for the o2 sensor. It may not be connected or totally deated. That may be a factor with the repair

Roy

Here is the original message that I think was garbled in the original message.

'I had the transmission rebuilt in my 2001 Lexus RX 300 a couple years ago and afterwards started getting an "intermittent" grinding noise at low speeds when starting up, slowing down or sometimes when just going slow like through a parking lot. I have taken the vehicle back to the transmission show several times and they have been unable to duplicate the problem. They have removed the transmission pan and inspected the transmission twice, most recently about a month ago, and said everything looks fine and it test drove fine. I had the water pump replace a couple months ago and he also replaced the "VACUUM SWITCHING VALVE", "UPPER MANIFOLD GASKET", "PCV VALVE", "TIMING BELT" AND "VALVE COVER GASKET". When I picked up the vehicle the mechanic advised me the "Check Engine Light" and "VSC" warning lights were on. He said his diagnostic showed it to be the "OXYGEN SENSOR, BANK 1 - SENSOR 1 - HEAT CIRCUIT". The warning lights were not on when I brought the vehicle in and told him so. He denied doing anyting that would cause the warning lights to come on. I have not had the repair performd as I am in a dispute with the mechanic as I feel he possibly may have not replaced something properly or knocked something loose. The grinding noise is no longet there but the transmissioni is sluggish when shifting through the gears (after the engine warms up) and it shifted "crisply" before then. This leads me to believe the "Grinding" noise involves the "VEHICLE SKID CONTROL SYSTEM" rather than the transmission. I am going to get the Oxygen sensor replaced and I suspect the grinding noise may start again after the "VSC" is reactivated. Do you have any thoughts on this relating to the "VSC" system and what to do about it? I have seen this same problem in other "LEXUS FORUMS" but no one seems to have resolved the problem or at least they didn't follow-up if they did get it corrected.
Thank you for your patience with this legnthy communication!

Tiny
LexusOwnr
Feb 9, 2013.

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