nowright

Greetings All. I just discovered this forum since I blew the head gasket on my 93 4Runner. After a couple of days of researching I’ve started tearing it down. After breaking two extensions and smashing my finger removing the down pipe, I’m down to the heads.

My question - how do I remove the back of the timing cover? Do the cam sprockets have to come off? How is that done?

Also note the piece of broken metal in the head. It came from the shield under the oil fill.

Thanks for the help. I’m sure to need more going forward as I’m currently feeling like I’ve bitten off a little too much.

ChickenLover

Welcome, and relax. The membership here can walk you through this entire process....(everything from torque specs, valve sizes, valve adjustments, P&P, torque sequences, modified lobe angles, blown HG membership dues, etc..)

Yes, the cam sprockets have to come off. You will need to buy a pulley remover from harbor freight or something similar - to hold the pulley in place while you crank on the nut.

Wow. That is quite the 'milkshake' you've got pooled up in your heads.

If you are not familiar with a 'pulley remover' I've pictured one below (for your viewing pleasure).

Manson

It makes me nervous when I see the milkshake oil due to seeing a few 3.0 engines that the block will crack internally where coolant and oil can swap. Be certain that you have a blown head gasket when you get the heads off.

nowright

Thanks for the help ChickenLover. I had locked the right sprocket with a prybar, but chickened out (no pun intended) as the torque was getting up there and I was afraid I could break that tooth. (I've already broken the fan shroud and EGR pipe. Plus my finger - see below.)

I drove about 10 miles after the head gasket let go, so it pumped a good bit of water in the oil. At least I assume that's what happened. You should have seen the smoke cloud I left behind! It never got hot during that time, but my girlfriend got it hot a year ago, so that may be a cause of the failure. It had the factory HG replacement in 98. I'll be sure to check the gasket Manson.

Here's a pic of the broken flap from the valve cover:


And here are the casulties so far:

Weasy2k

the cams have a hex formation on one end that will enable you to put a cresent wrench around it....use the wrench to hodl it in place and get a impact gun to loosen the bolt

Generaly i loosen the bolts before removing the timing belt.

I too am in the middle a 93 Runner HG change...just got the heads back from the shop and getting the cams back from grinder thursday....

I had a fun time getting the exhaust manifolds off...jesus! A pain!

leebee

http://personal.utulsa.edu/~nathan-b...68cylinder.pdf

this might help you out, im sure there will be more people willing to offer suggestions and tips from personal experiences.

good luck and keep us posted.

lee

suprathepeg

Yea those cam sprokets are a bitch, good luck.

nowright

Well, I got the sprockets off with the pulley tool from Harbor Freight (~$12). I didn't see the post about the adjustable wrench until after I had bought it, but that looks like it would have worked too.

Thanks for the link leebee. That will come in very handy when I try to get this thing back together. I got the Chilton manual from the Library, but it has proved practically worthless.

I'm afraid I started this job a little wide-eyed, and am realizing I'm in a little over my head. The last time I did something like this on a V was a '68 Ford Galaxie with a 390. A good deal less complicated. I'm down to the right side cross pipe nuts before the heads can come off. I'm going to have to let my finger heal up some before I can tackle them though. It's just too tender now, and I need the left hand to get in there.

My next question is how much disassembly of the heads should I endeavor before taking them to the machine shop?

Thanks for all the help.

DSMstar

Hey good luck man I just had to do this, but when I got the engine all back together, I had to pull it all back apart because a rod was also bent... (not from the HG, but caused by what caused the HG to blow... water)

suprathepeg

Take the heads complete, less the cams of course.

Elvota

I just got done with my first 3.0 teardown. Pretty nerve racking, but a good learning experience. The scariest part is turning the key for the first time when you get it back together.

I might suggest taking the entire heads plus cams to the machine shop. Have them adjust the valves for you. It is a bit tricky with the shims required for adjustment. You might want to think about having your intake cleaned at the same time. Only costs a little more.

snap-on

I made up a bar out of some angle with some bolts in it that span'd from the left cam wheel to the right. thus "locking" the 2 together. This allowed me to remove (and install) the cam sproket bolts.

Note there has been talk of people in the past useing locktight on them which if thats the case your basicly screwed as there have been reports of them just NOT comming off period. (but not likely your case, just an FYI)

after your cam pulley's are off you WILL have to remove the cam to take the heads off.

dmatter

You guys are Goooood!!!!!!!!!!!

nowright

Thanks for all the help. Heads removed. I'll drop them at the machine shop tomorrow.


And here's the culprit:


Number 6, no suprise there. Here's the rust that has already set in.


The other bank still shows the cross hatching, so I guess that's a good thing. The truck has 140K on it.


Any advice on how to clean up the cylinder wall? I tried scraping off the block and it just rained metal fragments into the oil return passage.