Oil Leak Through Head Gasket...help

[ksully_1]

Hello All,

I have a 1999 ES300 with approx 140k. The car is immaculate inside and out and I have babied the engine since I bought it with 99K on it. Have always run Mobil 1 and Bosch filters. It is my wife's daily driver but she only puts about 3k miles a year on it. During a routine oil change I noticed the front (I believe the RH) exhaust manifold wet with oil. At first I thought it was the valve cover gasket but after washing the engine down and taking her for a test ride it appears the oil is coming out of the head gasket right in the middle of the head. There has been no coolant loss or any type of smoke coming from the exhaust. In fact everything seems to be working perfect other that the leak. I have never seen an oil leak out of a head gasket. I have been researching a couple of different manuals for replacing the head gasket and it is obviously a lot of work. I have a few questions I hope you can help answer. 1. Has anyone else ever come accross this? If so how did you resolve the problem. 2. Do you think changing to a high mileage non-synth oil and putting in an additive would help/cure the probem without a tear down? 3. Can you access the head bolts without actually removing the cams and the gears from the top of the heads. 4.if so, do you thing re-torquing the bolts might help? 5. if I tackle the gasket replacement process would you do both heads? 6. would you pull the whole engine and replace rear seal along with gaining good access to rear head.

Whew...I know that was a lot but I wanted to throw it out for your opinions. Thanks in advance for your time and effort in answering.

Have a great Holiday.

Kevin

[lexis lexus]

Kevin,

Firstly, I can't quite understand how you concluded oil is coming from the head gasket. The exhaust manifold attaches to the head above the gasket line, and so oil leaking there would not likely end up on the manifold. The valve cover gasket seems more likely. Maybe a pix of the oil leakage would help clear this up.

Having just been in, out and back in again on my '94 1mzfe, I can comment on your questions:

- Do you think changing to a high mileage non-synth oil and putting in an additive would help/cure the probem without a tear down?

----I believe synth is a bit thinner, especially when hot, more likely to leak through opportunities to do so, plus "dino" oil tends to get thicker during the 3k to 4k miles it runs before you change it. Not sure about the additives, but might help as a low cost attempt to fix your leak.

-Can you access the head bolts without actually removing the cams and the gears from the top of the heads?

--- No.

-if so, do you thing re-torquing the bolts might help?

--- might, but after you've gone to all the trouble, (10.5hrs labor according to the book) why not replace the gaskets, etc.

-if I tackle the gasket replacement process would you do both heads?

--- Interesting question. Half the labor in a head gasket replacement job is due to having to take off the intake side (air intake, throttle body, plenum, intake manifold, water inlet) and of the remaining 50%, I'd say the rear head removal is twice as labor intensive as the front, given it's positioning and difficulties w/ exhaust manifold. It would save you some time and hassle to just do the front head gasket, but again, after going that far in.... If you decided to do just the front head gasket, you should think about replacing spark plugs on both sides, and might also want to replace the timing belt, as you'll have to take it off of the front cam pulley at a minimum. Btw, I bought a full head gasket set from Erista (ebay), for $55, you prolly can't get even one head gasket for that price from lexus/toyota or autoparts stores, and quality seems pretty good. The kit comes w/ all the gaskets you need for the intake side, as well as valve cover and spark plug hole gaskets.

-would you pull the whole engine and replace rear seal along with gaining good access to rear head.

---You don't need to pull the engine to get to the rear head, althou if you had the time, extra money and equipment to do so, the head removal part would be easier. In place though, rear (left) head removal is just more difficult than the front. I unbolted the distal end of the the rear exhaust manifold from the exhaust pipe, underneath, and then removed the head and exhaust manifold together. I think it might be possible to unbolt the exh manifold from the rear head before removal, but you'd either need some fancy wrenches to get up and under, or have to take a lot of stuff off from underneath (frame member?, rack and pinion?) as well as have the car fairly high up in order to do so. Rear head removal is also made tricky as some models have an egr pipe coming off of the exh manifold and attaching to a cooling plate on the block below the head (removal by brail method..)

I hope this helps.

LL

[ksully_1]

Thanks lexis lexus for the reply. The oil is actually migrating to the bottom bolts of the exhaust manifold and very slowly dripping down onto the exhaust pipe as it bends under the engine. I can see the edges of the head gasket and they are very wet with oil. I will try to get a picture of it today. I already replaced the timing belt, pulleys, cam seals and water pump about 20k miles ago. Considering myself a part time mechanic (having a repair facility in the family but not in the same state I live)I felt very comfortable with the timing belt stuff but the cams and all the gears and alignment scare the heck out of me. I do have an Alldata account and have the paperback books but all the same. Thanks for all your answers. Not all what I wanted to hear but it helps in making a decision on what to do.

[st.louis.lexus300]

Thanks lexis lexus for the reply. The oil is actually migrating to the bottom bolts of the exhaust manifold and very slowly dripping down onto the exhaust pipe as it bends under the engine. I can see the edges of the head gasket and they are very wet with oil. I will try to get a picture of it today. I already replaced the timing belt, pulleys, cam seals and water pump about 20k miles ago. Considering myself a part time mechanic (having a repair facility in the family but not in the same state I live)I felt very comfortable with the timing belt stuff but the cams and all the gears and alignment scare the heck out of me. I do have an Alldata account and have the paperback books but all the same. Thanks for all your answers. Not all what I wanted to hear but it helps in making a decision on what to do.

Have you changed the pcv valve, retorqe valve covers?

[tom tom]

I got a 00 gs300 just replaced val.cover gaskets and plugs then I seen rh side oil leaking on exhust manifold where it bolts to head any answers.