Topic: 3.0 head gaskets

[ccolby3]

Picked up my new project, an 88 4 runner. The wife went with me to pick it up and really like it. It supposedly has a blown head gaskets. Here's my question, is it better to pull the engine or do the head gaskets while the engine is still in the truck.? Thanks, Carl.

[THK Matt]

I'd pull that thing.

[81_yota]

you will hate that motor get rid of it drop in 3.4

[ccolby3 [OP]]

I plan on fixing the 3.0, getting it to run and then pass smog. Then I can decide from there, I have a hot rod 3.8 buick sitting in the garage that used to be in my 82 toy. 

[81_yota]

3.4 bolts right in and plenty of power im not tellin ya what to do but that 3.0 is junk has power of 4 cyl and fuel econ of a v8

[THK Matt]

3.4 bolts right in and plenty of power im not tellin ya what to do but that 3.0 is junk has power of 4 cyl and fuel econ of a v8

a good running 3.0 will knock a 2.4L on its ass. not with style or anything... but the 2.4 is powerless and sucks balls. the 3.0 if kept in running order and the HGs fixed... and some headers.... will be a nice engine. engine swaps are not cheap

[yota4x4sc]

i got the 3.0.. i yanked the motor out and found another..but if ur gonna do the HGs just do them in the truck..drain the oil and make sure the aint all rusted out from sitting

[Snowtoy]

If you know for sure that it is a bad HG, it would be easier to do an in-truck service, than to pull the engine.  If comp is low/zero in a cylinder it could also be from a burnt exhaust valve, the main issue that the 3.0 suffers from.

There is a lot of stuff to keep track of on the 3.0, so take plenty of pics during the tear down for reference during the rebuild, and try to keep bolts orientated to the part and hole they go to, different lengths were used on the same components.

You will need to replace the knock sensor wire, it breaks as soon as it is disturbed, and usually triggers the engine light(smog failure) within about 30 days of the rebuild.  Toyota is also recommends replacing the knock sensor given its location, I did, but it is your call.  You will also have to buy new torque-to-yield head bolts or regular head bolts, reusing them is the number one reason for reoccurring head gasket failure, other  than warped head.  I came across a Toyota service bulletin dated 1998 stating that they were re-usable, but in '04 when I rebuilt mine, the Service department at my local dealer told me they weren't re-usable, as well as my buddies who own their own service shops.  New TTY bolts run about $8/each through the dealer, however you can get non TTY head bolts from EngineBuilder.com $39/set, as well as other items needed for the rebuild.

Here is a link to a '93 Toyota FSM, if you don't have it already.

[ccolby3 [OP]]

Thanks for the FSM manual link, that will be helpfull.

[Jagdverband44]

Why do 3.0s drop exhaust valves on a regular basis? Good luck with your HG project, and be sure to take lots of pictures. Make sure that you blow out the holes for the head bolts with compressed air so you don't crack the block but you probably know that. The thought of running a 3.0 gives me nightmares   .  I know it makes more power but not enough to outweigh its shortcomings.

[yota4x4sc]

they drop exhaust valves cuz of ur stock manafolds run the exhaust gas from the front 2 cyc towards the rear and there all connected so that gets the rear valves way hotter and burns them out over time..headers solve this

[ccolby3 [OP]]

Finally got a day to mess with my 4runner. Found the hg was blown on the #1 cylinder. The compression was way down, 130 to 140 psi average on the other cylinders, only 40 psi on the #1. When I did a leak down, the over flow started blowing water out.
Now I have my work cut out for me. I plan on doing both head gaskets, with new bolts.

[Sparkplug]

I believe the exh valves burn, do to them being adjusted by shims, and the shims wear out, causing a tight valve, causing them to burn, the crap exhaust doesnt help matters,

Ive done a 3slow hg, not too bad. Thins to look out for. The knock sensor wire, replace it while you int he first time, like everyone says. The water tube is a pain in the ass between the heads, either get a gasket, or silicone the out of it so it has no chance of leaking. We pulled the whole upper intake off with pretty much the whole harness attchaded, and just laid it on the pas fender. If you run into any probs doing it, you can pm me, its alls till fresh in my mind,

[Mavericks]

I have a 3.0 in my DD and the water tube that runs between the heads is leaking. I thought it was the water pump and replaced that and then found the leak. I assume you have to take the intake manifold off and the timing belt and cover too? I apologize for the thread jacking.

[Sparkplug]

Yes, lower intake must come off, and even then, o man, its a pain in the ass to get out of there. I ended up pullin heads off with it still between them. I could not for the life of me figure how to squeeze it out between them.

[Mavericks]

I have been looking into how to do it and it looks like a ton of work. Thanks for the info I need to do it, but know its going to suck!

[Sparkplug]

Number 1 thing about diggin into an engine, DONT PSYCH YOURSELF OUT. Its just bolts, it only goes together right ONE WAY. Its not that bad, we took bunch of pics, and ended up not needing them.