wvuguy

I am thinking of swithing to Mobil1 0W-30 on my 99 RX300 with about 133k miles. When I bought the car I noticed a few drops of oil on the garage floor. They seemed to be coming from between transmission the engine (I am guessing rear main seal). After I did an oil change at walmart (they used pennzoil), the leak disappeared. I have not seen a single drop for a month. I am not sure if the motor has synthetic oil before. Now after reading on this forum I want to switch to mobil 1 synthetic 0W-30 which is easily available locally. Do you guys think its a good idea or should switch to a high milage synthetic oil instead as I am afraid oil might start leaking again?
Thanks.

Lexmex

I'd be interested to know what kind of Pennzoil were they using, was it Pennzoil Platinum 5W30 or just conventional Pennzoil. That Pennzoil Platinum is a very good oil and I'd use that over the Mobil 1 0W30.

wvuguy

They used Pennzoil 5W-30 conventional oil with Fram filter. I wanna change the filter ASAP as I have seen bad reviews about it.

wvuguy

I changed to Penzzoil platinum synthetic 5W30 with Toyota oil filter. Been two days and no leaks so far. I can feel the engine running much smoother. I was expecting that changing the oil filter would be really hard but it was't so bad after all. Before changing the oil, I drove the car for 15 minutes and then drained the oil while it was hot. I let the engine cool down for an hour and then attacked the filter from the top. It took me some time to figure out exatly how to position the filter wrench but once I got the hang of it, it was easy to take out and put the new one in. I will put some picures for the reference shortly. Thanks.

sktn77a

iTrader: (2)

I changed from dino to synthetic in my RX300 a couple of years ago and eventually had cam seal leaks. If I had to so it again, I'd probably pass on the synthetic and just change the dino oil every 5000 miles.

I doubt the car is truly running any smoother, although I recall on several occasions thinking the same of my BMW after getting the oil changed - placebo?

powerslide

Rx-300, 2001, 87,000 miles. I switched from Dino to Mobil 1 syn. 0-30 about 5 oil changes ago. I did it to use a better oil and try to ward off the sludge issue. No problems so far. I even started using it in my 1997 F-150 truck. Also went Full syn. Mobil 1 multi. vehicle trans oil.

wvuguy

You said you eventually had cam seals leak. Could have started even if you had not changed to synthetic? I did feel the engine was much quite after changing oil and filter. May be it is psychological but I did feel the difference.

sktn77a

iTrader: (2)

Yes, it could have. But there are just so many reports of leaking seals after switching to lower viscosity synthetics that I suspect the oil. I could have probably just gone back to dino but couldn't be bothered flushing and refilling!

lexus114

wvuguy, Lexmex will slap me upside the head for saying this (sorry Lex) but I switched from the German Castrol to the Mobil-1 0W-30 and my RX has never run any better! its more powerful to pull the step hills after work(which is why I switched in the first place),quieter,gas millage is better.I cant say enough good about this oil so far.

Lexmex

Actually I won't. I have mentioned that Mobil 1 might be fine for people, but problem is from my own experience and from UOAs I have seen, there's a point it really won't reach compared to other oils that often have a similar price. In addition, some grades of Mobil 1 are better than others, 0W30 being one of them and also the 0W40, but their 5W30 is like a sin to me.

lexus114

Yeah I heard the same thing re;that some mobil-1 is better than others.

wvuguy

I will try mobil 1 0w-30 a try on the next oil change. 5 qt bottle at local walmart is only 28 bucks. I am guessing my oil leak was because the car was parked at the dealer for some time. I havent seen a drop of oil for more than a month after the first oil change.

Lexmex

That's not a bad price, because some of the auto stores around me soak you for like $7 a quart for that Mobil 1.

JohnLX300

iTrader: (2)

The same 5 qt. bottle at my local wal-mart is $22.

jevanof

I just got my 99RX300 and it slowly leaked oil in the rear main seal, I changed the oil to Mobil1 5W30 and it seems to be leaking more. I have read previous post that people say not to use synthetic and they cause the oil leaks and some people have said that they switched from Synthetic to standard and the leak went away. if that is true can I do this? I was told that you never go from Synthetic to Standard.