Got oil on top of your spark plugs??
 

Hopefully this gets sticky'd. There seems to be some debate over WHERE the oil comes from. I'm here to settle this once and for all, as I am tired of replying over and over again to this simple problem that anyone can repair very easily.

First of all, many DOHC engines have spark plug well seals. This, however, is not the case on the 87-92 7M engine.

Please refer to my custom diagram. When it says (color, shape) that is what I'm talking about. Pretty straight forward.

http://i44.photobucket.com/albums/f2...fe/diagram.jpg

Go buy a 14mm allen head socket from napa. Take the No.3 cyl head cover off and throw it into the garbage. Now divert your attention to my shitty diagram:
If you have oil here (green arrows) then it is possibly coming from 2 places. Everyone says, "It's coming from the valve cover gaskets" (red boxes) which, I too thought when I was new to supras. So I replaced the valve cover gaskets, yet the oil was still "appearing" in the spark plug gallery. Not as much as before, but it was still appearing. No track marks from where it was coming from, just a puddle. It was very frustrating. I then discovered (through no help of any forum, they all said it was valve cover gaskets) that the No. 3 cylinder head cover BOLTS (yellow circles) were leaking. They are 14 mm allen head. You can A. Go to the dealer and get a new No.3 cylinder head cover (its a cover AND a gasket all in one, bad design) or B. bring 1 of your 14mm allen head bolts to an auto parts store and match up an oil drain plug gasket that fits. That's what I did, I used red ones (yellow circles), cuz it matches the red lines on the valve covers.

Hope this helps.

Very well done ^^^.
Also, if you want to keep the old #3 gasket/cover on the motor,(and not pay the $38 for a new one), you can apply a little silicone gasket sealer (or FIPG) at those big threaded plugs.

Note: if enough oil leaks into the spark plug boot area, it will start causing misfires.

so can you help us a little further and tell us what the part number or size of those gaskets are??? I am having that problem myself and I feel it is more then the valve cover gaskets!!!

I don't know what the part number for the no.3 cylinder head gasket is, because I didn't replace mine I threw it in the garbage because that is what it is- garbage.

Since you asked, I went to NAPA and got 4 gaskets Part # 704-1076.

Wow, I thought you guys had enough sack to bring 1 of your 14mm allen head bolts to a parts store and figure it out for yourself, I had to. I guess I have to spoon feed information to you people.

Anything else I can help you with?

i got oil showing up on top of my valve cover

hey IHateHacks
 

hey..i dont have oil on top of my spark plugs buh i have oil ontop of my valve cover and it looks thick too im prolly going to clean it off on tuesday to see if it comes back or not..buh wha could that mean

check your pcv system.......

so i have a black thing going across where all my plugs are, is that the spark plug well seal? or is that just like a cover and the problem is deffinetly the cylinder head cover bolt seals? Thanks.

If you read the first post, I said there are no plug well seals on a 7M. Go look at any other OHC engine and you will see that the spark plug wires go through the valve cover. Those are where plug seals are. Do our plug wires go through the valve covers? No? Then we don't have spark plug well seals. That black thing is your No.3 cylinder head cover AND gasket. Its a one piece combination cover and gasket. See the picture in the first post? See the yellow circles? Those 4, 14mm allen head bolts are what holds the No.3 cylinder head cover in place. They thread into the oil gallery. That is where the oil comes from. Those 4, 14mm allen head bolts are where the oil comes from. Should I repeat it 3 times like they do in commercials? I don't care how you do it, you can RTV your stock No.3 cylinder head cover like some cheapskates do, or you can throw your No.3 cylinder head cover in the garbage and use oversized drain plug gaskets like I did, or you can go get ripped off at the dealer for a new No.3 cylinder head cover.

I guess I should have warned you guys in the first post, you must have some kind of mechanical knowledge to do what I did, because obviously people are still confused as to what I'm talking about, even with pictures. I bet if I showed you in person, you still would not comprehend. I guess thats why Toyota designed the head like this, to confuse people and make them bring their cars to the dealer. Job security.

could oil also be coming from the three 14mm allen bolts that are right next to the spark plugs??

and also is it necessary to have the no3 head cover on or can you run with out it?

thanks for the post, im having this problem and i didn't know what it was till i found this thread.