Hi there,

I have a 1992 ES300 that was owned by my Mother in law, she gave it to my husband and I a year ago when she bought a new car. It's in excellent shape, she kept it up at the dealer. I just got the service record for the life of the car and she had all the required maintenance every year, no expense spared.

But, last summer the radiator blew and unfortunately she drove it about 2 kilometers before stopping. The rad was replaced but the knock sensor is malfunctioning causing the engine warning light to go off after the car has been running a few minutes and it stays on.

We took it in and the mechanic said we still have one knock sensor and since there is no engine trouble (touch wood) and to replace it only if we have too. Has anyone ever had anything like this happen?

Also, I'm looking into buy a OBD1 scanner for the lexus, does anyone have a brand to recommend?

Thanks for your help

 

If you have a code for a bad knock sensor, the engine will go into fail safe mode and retard the timming to max value. Which means that you will have poor accleration, and your gas mileage will suffer. But technically the engine will not be harmed.

I have never heard of a OBDI scanner, there is a diagnostic connector under the hood. You short two pins together, and the check engine light flashes the code.

I would recomend purchasing a Hayes, or Chilton manual for the car, and repair the knock sensor as soon as pratical.

 

^ 100% agreed.

You have 2 options for the knock sensor:
1: Replce the bad one
2: Wire the good one into the bad one, so both will be running off of the 1 good one.

1 will be more expensive, but better. 2 will be dirt cheap.

 

The Knock sensor's job is to retard the timing whenever it detects engine knocking. With that said, I don't think you would lose fuel economy, or maybe even gain by a notch or may stay the same. (George is knowledgeable also)

You can read the codes by opening the hood and there is a rectangle black cover that says "Diagnostic", flip it open. Get a paper clip and open it out to a "U" shape and short out "TE1" and "E1". After that, you would count the flashes the engine light gives out. And you can post on here, the flashes you counted and someone will be glad to help you.

 

Thanks very much. I've been scouring the internet for a Haynes manual for a 92 but can't find one, I can only find 1997 and on. Argh!

 

http://www.turboninjas.com/camry/

Bottom, '93 ES Factory Service Manual.

 

Thank you so much

Just one more question. If the one knock sensor that causes the engine light to go off has gone kaput, how do we know if the second knock sensor is picking up engine ping?

I guess you can't

 

If it was bad, the CEL would have both Sensor 1 and 2 codes.

Ironically......my CEL is on for the knock sensors now. Price I pay for having a Supercharger....eehhh

 

Either sensor can trip the CEL. Once a knock sensor sets a fault, the ECU goes into a fail safe mode and retards the timing to max retard. So at that point it really does not matter what the second sensor picks up.

You should detect a noticeable decrease in acceleration, and I feel that you will notice a decrease in mileage, (because you will probably be pressing on the accelerator more to compensate for the lack of acceleration), I could be wrong on that.

Either way, there should be no danger of harming the engine.
I do like the idea of jumping the two sensors together. These are the first cars that I have worked on that have two sensors. I do not see the point, one sensor should be enough to detect pinging.