murphysf

Considering the RX300 has a sludge engine what is the recommended oil change interval? For standard oil and also synthetic oil?

I've heard of some mechanics not leaving synthetic oil in longer than 3-5k miles in the 1MZFE engine

Also in the case of a vehicle that isn't driven that frequently how many months should the oil be left in the engine and similar for a vehicle that is onlt driven very short distances where the engine oil never gets up to full operating temp?

I ask because I have multiple vehicles that have the 1MZFE.

salimshah

These are the questions that do not have an exact answer.

The question about getting the temp up to normal .. will get a common answer ... You need to drive enough to get the temp up. It is not a question about the oil as such but more about your use.

Do what makes sense to you.

Salim

ukrkoz

We had RX300 for 120 000 miles and never had sludge issue.
I did synthetic oil changes on it around 12 - 15 000 miles, engine was so tight. Didn't burn oil at all.

That's us.

As of cars not driven frequently.. I had several. Usually, ones that were sitting for sale. I still will take them out for a spin once in two weeks. Maybe 4-5 miles. It's not just engine, everything else needs to move to redistribute grease.

LoveMyRX56

Had oil analysis done w oil changed at 8600 miles on oil. Veh has 58,600 miles on it.
TBN was at 2.3 , and other wear indicators were good, so I’m changing every Oct and April, at the 7500-8000 mile range. I’m not going the Toyota /Lexus recommended 10,000 mile range. It’s MY car, they’re not really worried , it’s all about lower maintenance costs/claims.

ashukla12345

I have a 2000 RX300 190K miles. The car has the engine light on due to knock sensor issue so it does not go to the top gear. That causes high RPM at high speeds (around 4500 RPM at 65 MPH), most likely that in turn causes oil to burn. I replace the engine oil every 3000 miles with Kirkland synthetic. I have heard/read that the oil should be changed every 6 months even if the vehicle is not driven.

salimshah

Not intending to hijack the thread, but why are you not addressing the knock sensor issue? There are temporary fixes and permanent fix discussed here in CL. You are daring your wallet by not fixing the problem.

Salim