I have a 91' 4Runner with the 3.0 V6 (3VZE) I am tearing it down to inspect the heads and hopefuly replace the head gaskets if not scrap the motor. I am using a Haynes manual and it tells me to remove the rear main timing cover but it never told me to remove the timing sprockets. Is there any way that is even possible?
Also, Do I have to remove the CAM's if I am pulling the heads off? The book says to do it but it seems like it might not be necessary.... Any Help would be greatly apriciated.

 

Here you should use this. its the full service manual from toyota. Has detailed steps for everything including taking your heads off. http://personal.utulsa.edu/~nathan-buchanan/93fsm/

 

Thanks for the link... I still dont see why the cam's need to come out though. I guess I will see as I get deeper into the motor.

 

Yeah, when you find that some of the head bolts are under the cam you'll see indeed.

Here's a tool you can make to help you get those sprockets off:
https://www.yotatech.com/51094700-post10.html

You'll also need leverage on that bolt - like a pipe extension over a 1/2" breaker bar and a six point socket. I personally don't like using impact tools on internal engine parts.

You'll want new cam seals, of course. And you absolutely should adjust the valves once the heads & cams are back on. My exhaust valve clearances tend to tighten up over time, and if yours do too, they could stop closing fully, leading of course to burnt valves.

Don't forget to replace the knock sensor pigtail while you're in there. It dries and cracks and can short, causing the computer to have a canary until you fix it.

If you were able to get the block resurfaced, along with the heads, you could use mls gaskets and have much less likelihood of them going again.

 

There are a TON off good threads on this subject; here are a few:

https://www.yotatech.com/forums/f116...-ghost-108156/

https://www.yotatech.com/forums/f116...perate-123651/

https://www.yotatech.com/forums/f116...et-job-104934/

https://www.yotatech.com/forums/f116...w-going-88538/

https://www.yotatech.com/forums/f116...thread-120824/

 

I did the head gasket job without taking the cam's out of the heads. You just have to rotate the cam out of the way sometimes. Also, replace as many of the coolant bypass hoses that you can while everything is easy to get to. I think I replaced 8 while I had it torn down.

 

The cam has a 27mm (1 1/16") flat in the middle. Once you remove the valve covers, you can put said wrench on the flats to keep the cam from turning, and remove the cam sprocket bolt that way. You cannot let the 27mm wrench turn until it hits the head (the aluminum head is too soft). I cut a slot in a scrap 2x4, and used that the brace the head of the wrench against the fender. It worked very well.

 

I wish I would have thought of that before I did mine.

The cams have to come out, one way or another. I cut the timing cover in half and removed them seperately. I never even had to remove the timing sprockets. The machine shop took them off to put the new cam seals on.

 

I ran across some good general tips on gaskets here: http://www.robbos.com.au/myweb/Tech_Gaskets.htm

 

great link thanks

 

if i take my head gasket off my 4 runner its a 3.0 v6 91 model its on gas once i take the heads off will i need to get them machiened

 

before you put the head gaskets on I would buy some copper sealer at your local parts store I did not use it and listened to the factory manual and had to go back to square one since exhaust gas was getting into the cooling system and causing my truck to overheat. learn from my mistake and spend the five dollars for copper spray paint or permatex head gasket sealer and apply it to the block and the gasket.

 

Hey still007,

how ow exactly did you apply the copper sealer? I'm putting my heads back on and can't find anything about where to apply, how much to apply...

thanks

 

The previous poster is wrong about the sealer. It may have covered up a problem, or defect in his block, or heads, or in his prep methods, but using copper-coat, or any other dope on the head gaskets is not the right thing to do on any iron block/aluminum head composite engine.

First, buy genuine Toyota gaskets, make the head and block faces tweekishly clean, degrease the surfaces with acetone, and install the gaskets clean and dry.

Use of the sealants is not a guarantee of failure, but it is likely that whenever the next failure occurs, it will be sooner because of the use of sealants, than it otherwise might be.

 

Alright thanks millball! She's going in clean and dry right now!

 

Previous poster has what's known as a cracked head. The copper sealant is a finger in the dike, so to speak.

 

I'm am also about to pull apart a 3.0 and do the head gaskets. IV done A LOT OF READING. I must ask....MLS OR graphite costed gaskets? Copper gasket spray or no? I won't know how warped things are until I get it apart , but can I get away with not decking surfaces? I thank you all for input and apologize for the gasket questions that have been asked before.

 

Best chance with old surfaces is Factory or Ishino Stone graphite type with no sealer.

Everything depends on how pitted the block deck is.

Facing the heads is relatively cheap.

 

Ok. Besides the dealer where is a good place to purchase these? I looked on eBay and have found a lot of junk. I want to do this in a timely manner but I also don't want to be cheep. A good kit with head bolts? Where should I look?

 

There are some Toyota dealerships that sell a lot of their parts online with much better pricing, especially on their older parts. I have had good luck taking prices I find online, especially on OEM parts, to my local dealership and getting them to match the prices. I have also had good luck just telling the local dealer that their price is too high and that I would pay, say, $50 for some switch that costs $125. You wouldn't believe the wiggle room they have in their prices.

Absolutely buy a Toyota HG set though and above all, get the head surfaced and checked.