How did the oil get here?

Fuel · 01-03-2006, 10:00 PM

I have just taken off all my air intake, exhaust, turbo, and wiring harness (to get to my BHG) and I found a TON of oil all around my spark plugs (enough to cover the spark plugs). I was wondering if this indicates that i have a cracked head or is it just the BHG or some other kind of problem. I also took off my cam shaft covers and found that the oil had turned brown. The cam covers were extremely lose (two fingers on my screw driver took all the screws out) and I was thinking that it was just condensation. Any help would be greatly appreciated; i just bought my 87 supra turbo from an auction a few weeks ago, so it had been sitting for about 2 months before I bought it.

SKILMATIC · 01-03-2006, 10:26 PM

Quote:

Originally Posted by Fuel

I have just taken off all my air intake, exhaust, turbo, and wiring harness (to get to my BHG) and i found oil all around my spark plugs. I was wondering if this indicates that i have a cracked head or is it just the BHG or some other kind of problem. I also took off my cam shaft covers and found that the oil had turned brown. The cam covers were extremely lose (two fingers on my screw driver took all the screws out) and I was thinking that it was just condensation. Any help would be greatly appreciated; i just bought my 87 supra turbo from an auction a few weeks ago so it has been sitting for about 2-3 months.

Wait, you took off the valve cover with 2 fingers, or the head caps for the cams? If it was the head caps they should have been on there so tight you would need a breaker bar. The valve cover is fairly easy to take off with little torque. There could be a few reasons why your spark plugs have oil fouling.

First reason could be that the spark plug could be cause of poor starting or misfiring.
Second it could be oil leaking due to a piston ring.
Third it could be cause of cylinder or valve guide wear.

TONY! · 01-03-2006, 10:53 PM

Quote:

Originally Posted by Fuel

I have just taken off all my air intake, exhaust, turbo, and wiring harness (to get to my BHG) and I found a TON of oil all around my spark plugs (enough to cover the spark plugs). I was wondering if this indicates that i have a cracked head or is it just the BHG or some other kind of problem. I also took off my cam shaft covers and found that the oil had turned brown. The cam covers were extremely lose (two fingers on my screw driver took all the screws out) and I was thinking that it was just condensation. Any help would be greatly appreciated; i just bought my 87 supra turbo from an auction a few weeks ago, so it had been sitting for about 2 months before I bought it.

You had an oil leak from your valve covers that leaked into the spark plug valley area.

When you reassemble those valve covers, use some sealant along with the valve cover gaskets

Edit to add below.

Valve cover gasket leaking is VERY common. Most likely that is your deal.
Don't stress it. You should take your head to a machine shop to check for the head being straight. The max warpage on the head is .0039"

It is also common to have a darker color oil residue on your head.
Seen that on both of my 7M heads.

TONY! · 01-03-2006, 11:19 PM

Quote:

Originally Posted by SKILMATIC

Wait, you took off the valve cover with 2 fingers, or the head caps for the cams? If it was the head caps they should have been on there so tight you would need a breaker bar. The valve cover is fairly easy to take off with little torque...

I'm pretty sure he means the valve covers (he calls them camshaft covers--which is what they are called sometimes).

The cam caps aka cam cap bearings are only torqued down to 14 lbs. It does not take that much effort at all to get them to come out at all.

Now the head bolts would be called just that, head bolts--unless someone once changed them over for studs.
You may need a breaker bar for that. But the thread starter has not mentioned that.

Quote:

...
First reason could be that the spark plug could be cause of poor starting or misfiring...

Poor starting or misfiring would not put a puddle of oil in the spark plug holes.

Quote:

...Second it could be oil leaking due to a piston ring...

If rings had a very poor sealing with cylinders, there would be loss of power due to bad compression, loss of oil due to oil consumptions, and the oil sealing/or lack of would go from the lower part of the pistons to the cylinders and be burned. The oil will not go up the spark plug threads to form a puddle of oil.

Quote:

...Third it could be cause of cylinder or valve guide wear.

Cylinder wear would be just like worn rings and give off the same signs.
Worn valve guides is not that common on 7M heads.
If it is the vavle stem seals you mean, the oil would go from the head and into the cylinders to be burned off.
With poor valve stem seals, you would have oil come out of the tail pipes upon start up.

SKILMATIC · 01-04-2006, 01:53 AM

Quote:

I'm pretty sure he means the valve covers (he calls them camshaft covers--which is what they are called sometimes).

The cam caps aka cam cap bearings are only torqued down to 14 lbs. It does not take that much effort at all to get them to come out at all.

Yes I know this but for me cause I am a lightweight it takes me a breaker bar to do so.

Quote:

Poor starting or misfiring would not put a puddle of oil in the spark plug holes.

Well the thread starter didnt specify the spark plug holes he just said

Quote:

and I found a TON of oil all around my spark plugs (enough to cover the spark plugs

This could mean where the diode is or where you torque them in which if thats the case then yes a loosevalve cover is what it would be.

Quote:

If rings had a very poor sealing with cylinders, there would be loss of power due to bad compression, loss of oil due to oil consumptions, and the oil sealing/or lack of would go from the lower part of the pistons to the cylinders and be burned. The oil will not go up the spark plug threads to form a puddle of oil.

Yes I know this as well.

Quote:

Cylinder wear would be just like worn rings and give off the same signs.
Worn valve guides is not that common on 7M heads.
If it is the vavle stem seals you mean, the oil would go from the head and into the cylinders to be burned off.
With poor valve stem seals, you would have oil come out of the tail pipes upon start up.

Again he just got the car. I am assuming he has never owned one before therefore he wouldnt know if it was missing power or compression or not. IN any means I do agree with you.

All of which you said I am in total agreement with.

suprra_girl · 01-04-2006, 09:03 AM

Hi Fuel and welcome to the forum

more than likely the oil has come from your loose valve/cam covers... just go with what tony said and silicone up the covers when you go to put them back on

Fuel · 01-04-2006, 04:42 PM

Thanks for the advice.

lethalwithasupra · 01-11-2006, 07:39 AM

new tappit cover gaskets come with the head gasket set you've prolly bought by now. mine did this, damn things cracked they were that brittle. check that on yours. and don't spill any oil when you fill it up, it collects in the spark plug valley

Bullz_EyE · 01-11-2006, 09:10 AM

Ha, you think those gaskets are brittle? You should see some of my original hoses, they are hard enough to be used as a weapon.

01-03-2006, 10:00 PM	#1
Fuel Stock Join Date: Jan 2006 Location: Gresham,Oregon Posts: 22	How did the oil get here? I have just taken off all my air intake, exhaust, turbo, and wiring harness (to get to my BHG) and I found a TON of oil all around my spark plugs (enough to cover the spark plugs). I was wondering if this indicates that i have a cracked head or is it just the BHG or some other kind of problem. I also took off my cam shaft covers and found that the oil had turned brown. The cam covers were extremely lose (two fingers on my screw driver took all the screws out) and I was thinking that it was just condensation. Any help would be greatly appreciated; i just bought my 87 supra turbo from an auction a few weeks ago, so it had been sitting for about 2 months before I bought it. Last edited by Fuel; 01-03-2006 at 10:38 PM.

01-04-2006, 09:03 AM	#6
suprra_girl 7M POWAH! ;) Join Date: Jun 2004 Location: New Zealand Posts: 2,312	Hi Fuel and welcome to the forum more than likely the oil has come from your loose valve/cam covers... just go with what tony said and silicone up the covers when you go to put them back on __________________ Please use the forum to ask your questions as they will get replied to much faster than pming me Pics of my build. "Good girls are just bad girls that don't get caught" Do a diagnostic first!

01-11-2006, 07:39 AM	#8
lethalwithasupra 3" Exhaust Join Date: Sep 2005 Location: south cantebury Posts: 112	20c new tappit cover gaskets come with the head gasket set you've prolly bought by now. mine did this, damn things cracked they were that brittle. check that on yours. and don't spill any oil when you fill it up, it collects in the spark plug valley __________________ So I bought this old Honda bike, an NSR250. Bit of a street racer, I guess. I'm told they're fast. Delivering it home with a friend driving the Supra for the first time. I drop gears and make a scream from the twin pipes flowing down this pony's flanks and it takes off like it's tail's on fire. I look back when the Honda gets to its tap-out and the Supra's only two lengths behind. No one I've let ride my bike has told me its slow, they've all loved the thing. That car is a good thing indeed.

01-04-2006, 04:42 PM	#7
Fuel Stock Join Date: Jan 2006 Location: Gresham,Oregon Posts: 22	Thanks for the advice.

01-11-2006, 09:10 AM	#9
Bullz_EyE 3" Exhaust Join Date: Oct 2005 Location: San Diego, CA Posts: 238	Ha, you think those gaskets are brittle? You should see some of my original hoses, they are hard enough to be used as a weapon.