v6 oil leaks

[dirty4v]

got a '94 v6 with some oil leaks. i steam cleaned it from the bottom today, gonna see if i can figure out where they are coming from. what are some of the more common things to leak of these engines?

[DHC6twinotter]

Mine had leaks from the valve covers and the distributer o-ring. I think my rear main seal has a small leak now.

Other leaking areas could also be the front and rear cam seals, the rear main seal, front main seal, etc.

:thumbup:

[Osiris]

rear main seal, oil pan gasket, rear main seal, valve cover gaskets, rear main seal, front crank seal, rear main seal.

Just to name a few of possibilities. :)

[dirty4v]

thanks for the replies. it is coming from the top i believe and leaking down. i know the valve covers are leaking just a little, but don't look too bad. it's bad enough that oil is dripping on the ground a couple drops a night. didn't know anything about rear cam seals, i'll have to check that out. appears to be from top rear of engine. as far as rear main, i'll have to see after i get the top leaks gone. i really really hope the oil pan isn't leaking, cuz that looks like a crap job to do!

[dirty4v]

it's the valve covers leaking. this an easy job? looks like the intake has to come off to do the right side

[DHC6twinotter]

It's not too bad. The upper intake plenum does have to come off to do this. Unbolting the plenum itself isn't hard, but keeping track of all the vacuume hoses can be a pain. Nice thing about the '94 V6 engines, is that you don't have to worry about the coolant bypass running under the intake. Makes it easier than my motor in some ways. :D

I would replace the PCV valve while you're at it. It's easy, especially if the intake is removed. Also, make sure you get some sealant to dable on the corners of the hump at the rear of each head.

[dirty4v]

i was told to do the pcv valve if the intake comes off. now what about this adding sealant to the hump of each head, is there an area the gaskets don't cover?

[DHC6twinotter]

There are 4 places on each head that Toyota recommends adding a small dab of sealant. When you take the valve covers off, you will see a bearing cap hump at the front and rear of each head. At the corner where these humps meet the flat surface of the head, you will want to add a bit of sealant. The little bit of sealant is just extra precaution and once the sealant is placed in the corner, the gasket goes over it. So you have double protection in each of these corners.

A not so great diagram showing this:

http://i13.photobucket.com/albums/a256/DH6twinotter/misc/valvecovergasketpicture.jpg

[DHC6twinotter]

Oh, and just a tip here. Since you have to remove the valve cover, I suggest replacing the PCV valve once the cover is off the head. Sometimes the grommet around the PCV valve gets hardened and falls appart as you pull it out. Removing it while the valve cover is off the head eliminates the risk of broken bits of grommet falling into the head. :thumbup:

[dirty4v]

what type of sealant would you recomend, rtv or some type of silicone?

[DHC6twinotter]

I recomend the FIPG sealant sold at Toyota. Seal packing part number is listed two posts back. It's good stuff, and you can use it on all kinds of things. :thumbup:

[Obi..]

*Put a little bead of sealant on the areas of the cover/cam seal gasket where the seal becomes a corner rather than a gradual arc.

Also, IMHO wait to put on your plenum until the covers/etc have fully cured, then go back and throwing a dab of FIPG on your finger, hit the outside of those corner spots again. Reinstall your plenum etc and be done with it...or..

..If you really want to Geek-Out get yourself some Flourescent Dye to add to your oil, then drive about 500 miles, park it so the front is up a little (like a slanted driveway) and wait 4 hours while things cool down and any spot you've missed on the covers will start to let a little drip start. Break out a blue/black light and look for the drips.

[Obi..]

Oh, and just a tip here. Since you have to remove the valve cover, I suggest replacing the PCV valve once the cover is off the head. Sometimes the grommet around the PCV valve gets hardened and falls appart as you pull it out. Removing it while the valve cover is off the head eliminates the risk of broken bits of grommet falling into the head. :thumbup:


* :wrenchin: *
Also as long as you're in there take a look at your rear sensor bank at the rear right of the center of the block and the heat shield mat. The sensors with the blue (Temp?-I forget what this one is right now) and green (vacuum) plastic should be a dark blue and a medium-dark green, not light in color. They're relatively cheap to replace versus the possibility of breakage and issues later b/c you skipped them. The heat shield mat keeps the dash components and your feet cool. :) Also the u-shaped PITA-Hose.(Preventative maintenance.)

http://i164.photobucket.com/albums/u3/bamzippow/T100/IMG_3095.jpg

[slosurfer]

Also check to see if your oil cooler is leaking. (if yours has an oil cooler)

[Obi..]

Also check to see if your oil cooler is leaking. (if yours has an oil cooler)


Left side of your block, just behind the filter. Round thing w/ the hose coming off. :thumbup:
http://www.next-trade.co.jp/asknetwork/2008/03/04/imgs/3.jpg


IMHO, use an old leather belt to remove it if the seals are going bad, last guy I saw do one kinked one tube and broke the other off.

[slosurfer]

Yep, some have them, some don't. :)

It wasnt' too hard to fix when i did mine.

[dirty4v]

ahh, oil cooler, that's what that thing is. yeah, i got one. it's was wet, but not sure if it's leaking or just runoff from the valve covers. gonna fix the valve covers first, steam clean it, then see what other leaks appear. thanks for all the help!

[DHC6twinotter]

Also the u-shaped PITA-Hose.(Preventative maintenance.)

http://i164.photobucket.com/albums/u3/bamzippow/T100/IMG_3095.jpg


I HATE that hose. Major pain to fix while the plenum is still on, especially if the clamps are broke. :chair: