Having the 3.0 rebuilt and was wondering what is suggested to replace while ill have everything fairly accessible. I have read its ideal to replace the heater bypass hose, knock sensor and pigtail, flywheel and clutch kit. I think I am going to take a gamble and buy the ebay headers and wrap them. Anything else you guys can think of? Thank you in advance!

 

Be sure they use Toyota OEM head gaskets, at minimum. I'd avoid Chinese everything to be honest and only use Aisin/JDM parts for the rebuild.

 

x2 on Genuine OEM Toyota parts!

While everything is apart, I would replace or consider replacing:

• All radiator hoses, heater hoses, and miscellaneous coolant hoses
• Vacuum hoses
• Drive belts
• Fuel filter
• Air filter
• PCV valve
• Thermostat

In what condition are the engine mounts?

In what condition is the battery and main power and ground cables?

In what condition is the air intake boot? Any cracks?

Is the throttle cable still in good shape?

If it has not been done in a while, replacing the distributor cap and rotor is a good idea.

Typically the Genuine Toyota spark plug wires last for a very long time but it does not hurt to inspect them. If some cheaper wires are on your truck, you may want to inspect them and consider replacing them. If they check out good, then it is fine to leave them.

Check the cooling fan for cracks.

If you have time, I think it would be worthwhile to test the various sensors that give input to the Engine Control Unit to make sure they are still working properly and are within specifications.
Off the top of my head:

• Throttle Position Sensor
• Air Flow Meter
• Engine Coolant Temperature Sensor
• Oxygen Sensor
• Cold Start Injector Timer
• Distributor Pickup

If you have time, flushing the heater core out would be easier to do without the engine in. Just something to consider.

There are probably a few things I missed or some 3VZ-E specific things I have not dealt with.

 

I just finished rebuilding my 3.0 and I replaced a lot of things mostly due to wear and age. How many miles on your engine? Are you having the work done or doing it yourself? I would replaced the oil pump, water pump, all the idler bearings the timing belt runs on, have the radiator cleaned and flushed out, a starter, injectors, fuel pump, main battery cables if they show signs of corrosion. Depending on the wear you might want to consider new cams and shims. Plus what the others mentioned above.

 

Wow! Very solid information guys, I really appreciate the effort. This 4Runner is new to me. It has 292k miles and isn't the prettiest truck out there. The paint is faded and clear coat is peeling. This is just a trail truck to go hunting, camping, etc so while Im not concerned about making it showroom again I do want it to be reliable.

I am having a shop rebuild the engine as its only an extra $400 to have them put it together. The machine shop here is very reputable (40 years in business, family owned) and all the local dealerships use them for their machine work and rebuilds. They use proline pistons, clevite bearings and felpro gaskets. The owner showed me all the receipts from doing rebuilds with the exact same parts for the Toyota dealers here so that puts my mind at ease. I am having them slap OEM head gaskets on just for extra peace of mind. Timing components and water pump are OEM as well. Ill be putting in a LUK clutch kit and flywheel. No rust or corrosion as I live in Phoenix and we are fortunate enough to not have to deal with that. As for the ebay headers, that's my thinking of cheap insurance to ensure the head gaskets don't cook. Filters and hoses will be replaced as well.

Im planning on swapping out injectors. What do you guys think about the grey bosch flamethrowers that are on ebay? Ive seen threads here that Flamethrower was selling grey Densos but I cant find them. They are only available in Bosch now and some reviews are bad because they threw too much fuel, etc. Most of the reviews are great so Im unsure. I want to kill two birds with one stone by replacing high mileage injectors while im there and upgrading to a more efficient fuel injector.

 

I don't have any personal experience with the "Flamethrower" injectors but personally, I would look at sending yours out to get cleaned and rebuilt or buy already rebuilt injectors. I think most of the gains people saw was more from the fact the new injectors were clean and new compared to their old injectors, but I don't know.

The OEM stock injectors work just fine and the computer system was designed with the original injectors in mind.

That is just my thought. Again, no personal experience with them so I cannot form a strong opinion on them.

 

I can see people ranting and raving about the upgraded 4 hole injectors being so good because the stockers were worn out. I have to agree stock oem is always best. One thing I am finding out while searching for these different parts is that there are a lot of fakes/clones out their and its difficult to weed those out. Frustrating at best really.

 

Be careful buying the supposedly new Denso injectors. They will have Denso on them, and the right part number. The Denso symbol on them is wrong. I reckon that's how the fakers stay out of hot water by not using the correct symbol.

I don't know what's all available for the 3.0 because I don't have that engine. I am using a new set of Hyundai 4 hole on a 22RE that have been working great for 20 months now.

 

I would avoid Chinese headers. There's a reason they are cheap and not something you want to deal with down the road leaking and cracked.
My experience is use OEM or top brand name products. I had a head gasket fail at 10,000 miles, some offshore budget POS and it sucked!