Oil in spark plug valley

[SupraTrbo89]

I went to change my spark plugs today and there was a decent amount of oil is the spark plug valley. I am going to clean up the oil prior to removing the plugs but was wondering what I can do to prevent this. I read a bunch of threads on this and felt like half of what I read was not correct. I do not believe the valve cover gaskets are the issue.

1. Does the 7M Cylinder Head Center Cover/Gasket actually seal oil from leaking from anywhere? People stated that they replaced this and didn't have the oil leak anymore. I thought this part served as a place for the wires to rest and to help block dirt from getting down there.

2. Someone said that the 4 hex bolts were actually what was leaking and they used FIPG on the threads and put them back in and it didn't leak. Using FIPG on the threads doesn't seem like a good idea. Another person went to Nappa and got rubber stoppers and used them in place of the hex bolts. This also does not seem like a good idea.

The car runs fine but wanted to prevent this while I have things apart. Any info is appreciated.

 

[George_Bonilla]

The center cover is actually a gasket that goes under the 4 hex bolts. It's does have a double purpose, as a holder for the spark plug wires but it is not necessary. Remove the 4 hex bolts and then remove the center gasket cover and put oil drain gaskets in its place (forgot the size, sorry. I'll look it up later today). I know people who have bought new center cover gaskets from Toyota and they still fail.

 

[George_Bonilla]

Reference

 

[SupraTrbo89]

Not familiar with oil drain gaskets but if you have the size I will get them. Thanks for the help.

 

[George_Bonilla]

Read post #1 and #4.

Mine was overflowing with oil, put in the oil drain gaskets from napa and it never leaked again.

http://www.toyota-supra.info/forums/mkiii-faq/7527-got-oil-on-top-of-your-spark-plugs.html

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[MK3pizzadriver]

I just used Threadlocker blue on the threads of the plugs to seal them (making sure to clean all traces of oil off the threads first).

Whatever Toyota used to coat the cover was all brittle and cracking on mine, didn't look good. Was able to get it all off easy enough.. Looks pretty good now since the metal underneath is anodized dark gray. Once you get that thing clean/smooth, you could probably use oil drain plug gaskets instead of thread sealant, like one underneath and one on top. All else fails, use some FIPG on the gaskets. Might have to adjust your spark plug wires after that, as they will then be sitting slightly higher (shove the wire further into the plug)

 

[SupraTrbo89]

Read post #1 and #4.

Mine was overflowing with oil, put in the oil drain gaskets from napa and it never leaked again.

http://www.toyota-supra.info/forums/mkiii-faq/7527-got-oil-on-top-of-your-spark-plugs.html

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Thanks....ill run to napa and get 4 of the gaskets you noted

 

[George_Bonilla]

Trust me, you won't regret it.

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[gsxr141]

if the leak continues, change the valve cover gaskets too. I struggled with a bad leak on mine for weeks, only to find out the front intake cam cap was loose and spilling oil everywhere.
don't rule anything out. lol

 

[SupraTrbo89]

Thanks, yea I changed out the valve cover gaskets and cam shaft seals a few years ago (~5k miles) when i replaced the valve seals with the head still on the car. I did remember the fipg on the front corners of the valve covers.

Most of the oil in the valley is at cyl. #s 1,2,5,6.

 

[SupraTrbo89]

Trust me, you won't regret it.

Sent from my SM-G935T using Tapatalk[/QUOTE

Got the gaskets you recommended from Napa and put them in tonight. I think they should solve the problem. Just curious what the other 3 plugs down in the valley are for?

I also did a compression test for the fun of it bc I had borrowed a tester from AutoZone a month ago when I got the spark plugs. All cylinders were between 125 and 130 which is on the low end but the engine was cold.

 

[George_Bonilla]

Trust me, you won't regret it.

Sent from my SM-G935T using Tapatalk[/QUOTE

Got the gaskets you recommended from Napa and put them in tonight. I think they should solve the problem. Just curious what the other 3 plugs down in the valley are for?

I also did a compression test for the fun of it bc I had borrowed a tester from AutoZone a month ago when I got the spark plugs. All cylinders were between 125 and 130 which is on the low end but the engine was cold.

Glad to hear it, you shouldn't have that issue again.

The 3 plugs at the bottom of the valley hold coolant. Don't need to touch those.

I would double check when the motor is warm to verify your findings.

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[SupraTrbo89]

I did a compression test a few years ago (~10k miles) and it was 150 across the board. I would find it very hard to believe the rings went bad on all 6 cylinders on stock boost.

Also, I ditches the autolites and went with ngk coppers. The ngk is a longer plug. I was running ngk iridiums.

 

[Nick M]

Whatever Toyota used to coat the cover was all brittle and cracking on mine, didn't look good. Was able to get it all off easy enough..]

It has been a long time since I worked for a Toyota franchise, but back then all the factory FIPG was gray, not black. It seems to me it had some FIPG in addition to cylinder head gasket number 3. Because I saw it also when I changed mine.

The gasket all keeps debris out of the valley where it is tough to clean up. It is your car. And as you should have read, others deleted it and went with a drain plug gasket without having a problem with the plug wires seating.

 

[MK3pizzadriver]

Yes I did read that Nick. Was just trying to give the OP other options in case he wanted to keep the cover like I did. I like how the cover acts as a mount for the plug wires, helping to keep them from moving around. Also for aesthetics and keeping the car original. I had no problems with the plug wires seating because I just used Threadlocker blue to seal the plugs, no drain plug gaskets.

 

[SupraTrbo89]

Nick, I believe I also noticed some fipg on the threads while changing over to the new drain plug gasket's. Ngk coppers are in with new Ngk blue wires. The plugs were gapped to .030. Took it for a very brief ride and it seemed to run well. I did notice though the idle seemed slightly rougher. Previously I had magnecors and ngk iridiums.

 

[Nick M]

I have the Napa 25mm gasket and have cylinder head cover number 3 above it. It sits tight even without being held by those big plugs that spew oil.

 

[IchibanEye]

So quick recap. -Torque in Nm -add gaskets underneath cover #3 where bolts go through.

I just now noticed oil sitting in where my sparkplug#1 is seated and the gallery. I assume the others are in the same shape. All this was noticed while finding dead center and after replacing cam seals, all front engine seals, water pump, pulleys, new radiator/electric fans and belts.

I was a bit bummed as it is getting cold out my way. At least it is not a long hard fix. I want to go the best route here, correctly, no corners cut when I fix this. Should I just order the new oem rubber gaskets too while I'm at it since I'll have all of the covers off?

It has been awhile but I swear one of the aftermarket sites we all use here supplied a better bolt/fastener kit for the 3 covers. I forget who though.

Thanks old timers and pros. Have a happy thanksgiving.

 

[SupraTrbo89]

Use these and not the Phillips head bolts. This site also has valve cover gaskets.

https://www.driftmotion.com/1JZ-2JZ-7M-Valve-Cover-Bolt-p/dm670.htm

 

[IchibanEye]

Use these and not the Phillips head bolts. This site also has valve cover gaskets.

https://www.driftmotion.com/1JZ-2JZ-7M-Valve-Cover-Bolt-p/dm670.htm

Thanks for the link and added information.