cheerio3

Hey, I have a 99 RX 300 with 112K and have noticed a burnt smell from the vents while driving on occasion. I looked underneath car and noticed a collection of burnt, sludgy oil on the chassi that I was able to scrape off with my finger and noticed oil collected on the serpentine belt. Where is a logical source for that oil to be leaking and is it something that I could try to fix? Any thoughts or suggestions would be great!

Phil

thomas1

First is it engine oil or Power steering oil...I would wash that area down with simple green, rinse, and then see were it is leaking...could be power steering pump, or it could be crankshaft seal, or maybe overspill from removing the oil filter over the years....

hypervish

First off, clean all of the oil off. This way, you can see where the oil is originating from.
The leak could be on one side of the car, but you may only see the oil on the opposite side.. LOL, that happened to me. My rear valve cover was leaking slightly on the driver side, and the oil made it's way over to the power steering pump (passenger side), and I thought it was the power steering pump leaking. I was about to order a power steering pump, boy am I glad I didn't! LOL It helps to thoroughly look under the hood and from under the RX to see where the oil is coming from. I had to get the RX on a lift at my uncle's shop, to see that the leak was from the rear valve cover.

cheerio3

I'm fairly certain it's engine oil as I have needed to add about a quart over the last 1200 miles. I would assume it originates from near the timing belt and drips down to the serpentine belt if that is possible (I am far from an expert on the anatomy of the car). Is there a likely suspect seal that is near that area?

C-Stone

One can purchase a small bottle of UV dye at Napa for $5 or so. Add it to the oil. Run or drive the car for a while, then use a backlight (or you can purchase UV glasses) in a dark garage to see where the oil leak is originating from. This will help you nail it down. Sometimes, leaks can start from one location and drip/drain to another... so this technique can help. Good luck.

cheerio3

I used full synthetic the past few oil changes 5w-30, and was wondering if going to a higher viscosity might stop the leak, like a 10w-30. I know that synthetic is thin and often leaks where conventional wouldn't. If that seems like its worth a try, I can do it prior to taking it to a repair shop.

hypervish

Synthetic is not thin, it just flows better than Conventional.
I suggest taking it to a repair shop, and finding out where the leak is coming from.

Stemmer

For what it's worth, I have always used conventional in my RX300. I asked a knowledgeable mechanic I use who does a lot of Lexus/Toyota work about switching to synthetic and he advised against it as his experience was the vehicles often leaked. You might want to drain out the synthetic and use a high mileage conventional oil and see if it solves the problem.

Iluvlexus

I use PNZ Ultra 5w30 full synthetic in my 141k mile 2001 RX300. Purrs like a kitten, uses an ounce or two between 5k oil changes, and doesn't leak a drop. Doubt it is the synthetic oil or the viscosity. Likely a mechanical reason for the leak.

hypervish

X2. If you want to read up on synthetic oils, and debunk the myths. Check out http://www.bobistheoilguy.com/

Jpdelaunay

did you ever figure out where the leak was from. Mine is doing the exact same thing..

Drcoffee

If the power steering pump is oil coated, its likely the camshaft seals. If its hitting the exhaust then likely the rear valve cover gaskets. There's no substitute for crawling underneath and actually putting eyes on the problem.

lexina

Your oil leak could be from the top two cam seals. Mine is leaked from front top cam seal; what a pain that the cam pulley and shield has to be all removed to get to it, with a cam holding tool too.