4.0L V6 Valve Cover Gasket Replacement
 

My 2004 4Runner has 116,000 miles on it. I changed the oil and spark plugs and found that the spark plug on the driver side closest to the driver side firewall had some oil on top of the plug--not on the bottom. There was a smudge of oil on the outside of the coil tube and a small amount of oil at the base of the spark plug hole. A quick search of this Forum (and Youtube) suggested that it is a common issue with our V6 engines and a new valve cover gasket corrects the issue. Ran to Toyota and picked up valve cover gaskets for both sides. May as well replace both since I don't plan on taking the top of the engine apart again if I can help it. $21.10 per gasket.

Since so many of you have helped me find solutions to issues with our 4Runners (...like the dreaded seized calipers and replacement), here's some pictures of what it takes to replace the valve cover gaskets. Its not necessarily a hard job to do, but it does take time undoing those frustrating connectors and unscrewing hard to see bolts holding tubes of wires, etc. I took my time and triple checked my work. This job took me about 4 hours total to take the engine apart, replace the gaskets, and put it back together. This also includes removing and thoroughly cleaning the throttle body.

When I pulled the valve covers off, the gasket stayed behind. Simply peel the old one off and press the new one into the groove on the bottom of the valve cover--it should stay put as you place the valve cover back on the engine.

It was nice to see inside the engine. I have used Mobil 1 (5W-30) for the last 56,000 of 116,000 miles. I have only used Toyota oil filters. Looks clean to me! :hungry:

Started up after putting it back together and it idled high for a while. I test drove it and the throttle was very responsive and it ran real smooth. It idled normal when I got home and after I started it up again.

***See photo; you will need an 8mm hex bit socket to remove part of the air intake on top of the engine.***

Cool.

I've got a V8 but it's still cool to see inside someone else's engine.

I've seen several pics of V6 plugs and they always tend to be darker on that driver's side rear plug. Even on my V8 that plug seemed to be darkest on the threaded area. Interesting.

Glad it went well!

Thanks for the pics!

Thanks for the write-up and the pics; this is on my to-do list for this winter.

Looks like a good time. Could you see where the original gasket was failing?

Not really and that surprised me. So far the only difference I could tell was that the original gasket was stiff and the new gasket was soft. I didn't see anything too obvious.

How are your Valve covers so clean mine are gray and dull looking

Thanks! Well, I guess its from using an engine cleaner about once per year.

So now that its been a while, is number 6 plug still leaking, or did the new gaskets solve the problem?

I know I'm digging up an old thread but what kind of cleaner did you use to get the gunk off the cover?

Thread is from 10 years ago, I don't think the OP is still around. I'd try simple green, that stuff is very good. I'm jealous of his clean valve covers, mine are all pitted (rust belt).

EDIT: Brake cleaner is a favorite of my mechanic friend to clean just about anything.

Hi guys! Just joined. I was wondering if anyone knew the torque spec on the valve cover bolts? -same type as shown in this old thread. Thank you.

BUMP for more views.
Anyone know the torque on those valve cover bolts? -Please?

torque spec - Tacoma World Forums

12-15 lb/ft

Valve Cover Torque
 

WHOA! Hold it! You will break those valve cover bolts. I'm trying to send you the FSM page but that 137 Kb limit is way too small. "Bolt B" are the 3 bolts in the middle. You are supposed to put "seal packing" on the timing cover joint also. I assume that is an RTV or gasket maker.

Torque: For bolt A
10 N*m (102 kgf*cm, 7 ft.*lbf)
For bolt B
9.0 N*m (92 kgf*cm, 80 in.*lbf)
For nut
9.0 N*m (92 kgf*cm, 80 in.*lbf)