wjenkins88

I live on a remote island in the Atlantic Ocean and the closest Lexus dealership is over 200+ miles away by ferry ride, needless to say my resources are limited here!

I have had an oil leak for quite some time now. My alternator went out a few months ago because of the oil leak, I was able to change that out myself but didn't due any further diagnostic on the oil leak at the time (stupid I know.)

I have tried Lucas Stop Leak, nothing seems to slow it down in the slightest bit! I am keeping my fingers crossed it's not the dreaded timing chain cover leak or else I am screwed!

The car runs fine with no issues other than the oil leak. The timing cover is on the opposite side of the engine from the alternator and what I have heard from different SA's at Lexus via phone, it happens for that to be the culprit but in rare cases. It's not as common for the timing cover to start leaking on the IS than the other models.

The only thing I was told by the local mechanic is that it looks like the leak is originating behind the alternator. Makes sense because as stated that went out on me not to long ago!

Where should I start if I am told leak originating behind the alternator? Replacing the valve cover gaskets and is it possible the timing chain cover even though located on the opposite side of the engine if it was leaking could cause the alternator to go out?

Any help would be greatly appreciated!

It's a 2006 IS350 with 165K on it!

Gville350

iTrader: (10)

First I'd start by finding the source of the leak. I'd "hose" down the oily areas with brake cleaner, avoiding directly spraying onto the alternator or any electrical connections or sensors. Then you can go directly to running the car and visually watch for where the oil leaks OR pour in some oil-specific UV dye that you can see under black light and more easily see where the oil is leaking out.

Just throwing out two places I can think of where it might leak onto the ALT :

1) driver's side valve cover
2) unfortunately the timing cover

wjenkins88

Isn't the timing cover located on the passenger side of the engine? I don't see how it's possible that much oil can make it's way to the alternator. It's a pretty bad leak as well!

Wouldn't the timing cover seep slowly? When I park the car after about ten minutes there is half dollar coin size amount of oil on the ground.

No burning oil smell and I have ran my hands across the serpentine belt and it is dry as a bone!

Would the valve cover gasket leak that much oil in such little time? Same question but in regards to the timing cover?

Really just going to have to start changing parts and do process of elimination just not sure where to start, if it's the timing cover I am in BIG trouble!

Gville350

iTrader: (10)

No, the timing cover covers the entire front of the motor :

https://www.tlsautorecycling.com/pro.../171512_01.jpg

Normally, yes it would be a slow leak.

If the leak is that bad, after cleaning off the oil residue, you should be able to spot from where the leak is coming from. Smaller, slow leaks are usually the hardest to locate.

wjenkins88

After hours of diagnostic found out where the leak is coming from. It is leaking from the o rings at the cam timing oil control valve!

It's about $7.50 per o ring through Lexus, I bought them for $2.50 each after getting an OEM part number through Lexus and although only $10.00 in parts, labor is about 4 hours to replace.

Could of been much worse!

Gville350

iTrader: (10)

^That was some luck right there!

ruikito

what was the part number?

flowrider

iTrader: (9)

^^^^See this thread:

https://www.clublexus.com/forums/is-...ml#post9424300

Lou