Oil Leaks

[traveler68]

My 1998 GS400 just turned 130K miles and was brought in for a routine oil change. Lexus service advisor notified me there was oil leaking from the 'cam seals' and some transmission fluid leaking. No leaks were ever noted on the major 120k service or the minor 125k oil change. Have any of you had similar issues with these leaks with similar mileage and age? I am new to this forum and am the original owner of this vehicle which up until today has never caused me any issues other than brake pads, oil changes, and filters. I welcome any input you all have.

Thanks

[SRK]

It might be an idea to place some newspaper or similar under the car when you park it - even a sheet of plywood - to see if the leak is big enough to make a spot. I have found some shops will claim a leak when what's happening is a slow "wicking" of oil under the seal, enough to attract dirt, but do little else. Sounds like you have been doing routine oil changes and that nearly garantees long seal life.

So you may be able to diagnose it yourself, and then make a decision.

[mshaw]

I agree, to an extent, with SRK, that there are various levels of leakage. In our shop, we label leaks in three levels between ourselves and to customers. The first is seepage, which is what SRK defines above - it may allow enough oil out to make some of the immediate surrounds damp and collect dirt, but no real harm. Then there is leakage, which is oil loss sufficient to create a trail of dampness, but not a trail which stays continually wet. The worst is blown or pouring, which would be oil slinging from a seal encasing a rotating shaft, such as the cam or crank seal, and/or creating a trail which stays continually wet, leaving drops hanging off the engine/frame and/or falling to the ground.

As far as 'suddenly' being there? Yes, it can happen like that. Cam seals are a high pressure point on an engine, and the seal is being subjected to rotational force at its inner lip whenever the engine runs. This means that small tears can develop rather quickly, creating anything from seepage to pouring, dependent upon the severity of the breech. Placing something under the vehicle may not be revealing, even in the case of a pouring seal, as the cam seal will actively leak only when the engine runs, and, when shut off, the trail created can burn off a hot engine fairly quickly.

The last problem with deciding on the severity of the seal leak is that it is completely hidden behind both the timing cover and the camshaft sprocket, even after the cover is removed. This means that a good share of the oil that may be leaking could be trailing down behind the sprocket, tensioner, idler and the covers, not to mention being potentially slung into small droplets all over the inside of the timing cover by the rotation of the sprocket and the moving timing belt. Also keep in mind that oil will degrade and weaken the timing belt, shortening its useful life.

The best advice may be to have an independent shop verify the leak, or just go ahead and get the seals replaced (many shops are fully capable and competent, other than the dealer, to work on your veh - but far more affordable). In the future, I would suggest that you do what we recomm to our customers, which is that when replacing the timing belt, also replace the water pump, cam seals, idler and tensioner. This greatly reduces the possibility of ever needing to open the timing area in between belt changes.