rockysdad

I got a 1993 ES 300 with about 230k miles on it and so far its still running pretty good with one exception. It has a slow oil drip that lands on the exhaust pipe and starts smoking as it burns. It seems to be dripping on the front part (between the exhaust header and radiator) sort of near the oil filter. It's not the oil filter gasket but somewhere around that area. My question is there anything there that can leak oil? I can't see what between the exhaust manifold and exhaust pipe on the eingine block. But, I can see that the burnt oil on the exhasut pipe. Any ideas of that is around that area? I'm guessing I have to remove the exhaust header to get to it. How difficult is that?

TIA...

BDSL

It might be your valve cover gasket.

LeX2K

Most common leaks on these cars is valve cover gaskets, distributor O-ring, and the oil filter adapter O-ring. If the adapter O-ring is bad, it does drip right onto the exhaust. Another but less common leak is rear main seal, and of course the front crank and camshaft seals can also leak but that won't cause oil getting onto the exhaust system.

To replace the oil filter adapter seal, you have to remove the exhaust header, which can be a fairly easy job or a difficult one depending on how badly the nuts and bolts are rusted.

EEngineer

i'm pretty sure this is the problem. I had the same problem and replaced the o-ring.
The exhaust header's joint to the y-pipe is the real *****. without a hoist it's hard to undo those.
and if you don't tighten them down to like 50+ lbs of torque, they will leak and make a loud tractor noise from the header.

here are some pics for reference

LeX2K

I got lucky when I did mine, everything came apart quite easily. But someone replaced the Y-pipe on my car before I bought it, so the nuts/bolts were still in good condition. Always use anti-seize on exhaust parts, it makes it so much easier next time around. BTW, my bad adapter seal made it look exactly like a rear main seal leak, the oil would pool and drip right in the center of the bell housing.

For gaskets, use ones that look like these, Bosal makes good ones, Ishino is Toyota OE. Don't use gaskets that are all aluminum, they don't seal well and over time they will fuse themselves to the exhaust, often making it impossible to remove without damaging for example the headers.

rockysdad

I think this is it since I already changed my valve cover gaskets (even the one on the back side). When you mention "hoist" does this mean just getting to those bolts from the bottom or do I need to remove the motor mounts and lift the engine up?

This doesn't sound like fun. Maybe I'll just take it in and let the professionals do it. Have to replace my timing belt again so I'll just let them go at it. That's why we pay them the big bucks...

Thanks for the replies!

EEngineer

^no no, you don't need to touch the motor mounts.

It's just that the bolts connecting the header and the ypipe is pointed towards the ground. without lifting the car up, it's hard to undo those bolts since they are pretty tight. it's even harder to tighten them back together because of the angle.

It's one of those things that if you bring it to the mechanic, you are paying 99% for the labour, since the O-ring is barely a few dollars.

I mean, if you are good at wrenching, go for it! If I get this problem again, I'd do it myself again.

donbryce

Whoa! I replaced the exact same O-ring, between the oil filter bracket (pictured) and the block. All I needed to remove was the front exhaust 'Y' pipe connections, both of them, to allow the pipe to be dropped down a bit for access. I think I also pulled off the rubber pipe hanger off at the front to allow it to drop enough. NO NEED to remove the manifold! Just jackstand the front end up high as you can to work.
First off, thoroughly clean and dry the area all round the mounting point, then observe if the oil is coming from there. If it's the O-ring, you'll see oil in under a minute.
Lastly, as mine started leaking in the spring, and I didn't want to deal with it, plus I needed a week for the dealer to get the O-ring in, I fabricated a small aluminum drip-shield to deflect the oil from the pipe, and attached it to one of the exhaust mount bolts (exact one I can't recall). It's still on there.

rockysdad

Okay, you guys talked me into doing it myself. Sounds like this gasket is a dealer item only. I wonder if a Toyota gasket is the same. Could be cheaper if it doesn't say Lexus...

BTW, is it three or four bolts that holds the bracket? Looks like four...

LeX2K

Toyota part is the same, 4 nuts IIRC.

EEngineer

dude, the exhaust manifold is simply 7~8 nuts...it's quick!
why bother putting the car on jackstand and having to unhook the y-pipe from the hanger?

donbryce

I've had several nasty experiences with manifold bolts/nuts stripping or breaking from years of rust and heat. There's only 4 studs/nuts on the 'Y' pipe, and almost all cars as old as mine and the OP's have had these changed at least once, as opposed to manifolds, which are more likely never been off. Plus, the front pipe has to come off the manifold anyway, so you've already done 1/2 the job. Anyway, to each his own....

donbryce

If you mean the oil seal, yes, it's the same. I got mine from the Toyota dealer. Just ask for part no 90301-68005 O-ring. The exhaust gaskets are too. If you're careful, and they are in good shape, they can be reused, with a bit of high-temp sealant.

vintagelex

Sorry to revive such an old thread but my oil filter bracket is also leaking, and I was wondering why exactly you have to take off the Y pipe to replace the oil seal. Maybe it's because I have an aftermarket Y-pipe, but I can get my wrench on all three of the oil filter bracket bolts without a problem. Is getting to these bolts the reason why you guys loosened the y-pipe, or is it because even when I get those bolts off I won't be able to get the bracket out of there?

I'll post up some pics tomorrow of how much clearence there is.