Getting A New Thermostat

[FloridaRX]

I just bought a 99 RX300. A few error codes came up and I'm having the thermostat changed. Should I have the coolant drained and refilled or flushed?

[lenore]

Have you shared the error codes....sometimes the coolent sensor error comes up and it is not the problem...As for the thermostat make sure it has the bleed valve in it, only a couple of aftermarket ones do. As for a flush, no, just drain and fill but use Toyota Red or Toyota pink fluid. they are expensive, but you will be good to go for 5 years or 150k miles....

[FloridaRX]

I have P1135, P0300, and P330 error codes. I'm getting the o2 and knock sensor replaced, and spark plugs. I was reading somewhere about part of the problem maybe the thermostat. Since I have no service records, I'm kinda guessing. Until I can save up some more and take it to Lexus to finish diagnosing it. However, overall the truck drives excellent. I'm just getting crappy gas mileage! Thanks for your insight!

[lenore]

The P0300 is a missfire code....Maybe one of the coil packs is starting to go bad. The original plugs are good generally for 125k miles....The 1135 should be addressed....I wouldnt replace thermostat with those codes that you have...My 99RX300 had the original thermostat when I sold it and it had 188k miles...

[FloridaRX]

Thanks again! I'll talk to the dealership and hope that they can figure it out. They will replace the 02 sensors for me. I'm sure it needs a tune up as well!

[jaswood]

Crappy mileage and misfires would generally mean low fuel pressure....fuel filter or pump, or maybe clogged injectors. Tell the (St,d) to read the message, not kill the messenger (the knock sensor).

[FloridaRX]

Thanks Jaswood...it's hard trying to do this myself to make sure I don't get screwed over!