I have a lexus 300rx and the check engine light keeps coming on and now its staying on for good

i would use castrol or mobil I put castrol 5w/30 in all my vehicles

it will cost hours to find leak, all int panel need to come off, if you can do this, get some light talcum power get behing the panels and puff this around the panels, this will show the track left by the water and hence track were its coming from, the interior condestaion is just the effect of leaks

vsc shuts down any time check engine light comes on. repair engine light problem, reset computer monitoring system and vsc light will go off. must scan computer to pull codes for check engine light and go from there.

90000 is a suffficiently long time for a timing belt. I'd listen to the dealership.

The easiest way is to carefully connect jumpleads and start the car or remove the battery and charge it,as the car is probably an automatic i would`nt tow it even fora short distance.

You say it doesn't start. Does it turn over good, but won't fire? Does it click and not turn over? If it turns over good but won't actually start, you would need to check fuel pressure output from pump, check spark coming from distributor to plugs and the control module could be bad if there's no spark, as well as the coils. If it doesn't turn over, but clicks when you turn the key, you could have a bad starter.

there is nothing to do here but have the dealer run a scanner test to see what trouble codes were set with the lights coming on, until then there is no way to tell what the problem might be as there are over 200 possibilities.

disconnect negeative (-) battery cable for 20 seconds....reconnect and start car. Check engine light should now be off. I