Need a motor, what to do

[MENTION=99565]kolelt[/MENTION]

You can't effectively measure gas mileage by doing a visual look over on the gas gauge. For one thing the guages get less accurate with old age. Just search gas gauge to read more.

The only real way to know you mileage is to fill it up till you hear one click, reset the ODO. Drive until the needle is on the bottom of last notch, basically below E, then go refill it and write down the gallons and miles.

Repeat this about 3 times and you should have a good idea of your mpg.

Also not that when making the calculation you can add about 6.4% to your miles driven to adjust for the 33s.

I'm getting about 15.5 MPG city/hwy (adjusted for 33s) which means that after 16 gallons I've driven about 246 miles but the ODO will only say about 230 miles. This is totally normal.
 
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FOLKS I AM NOT A WOMEN! I MAY SOUND LIKE A WOMAN, BUT I AM NOT A WOMAN. I AM A 36YR OLD MALE.....See what you did Brian :(

Ok, but that doesn't matter to the question at hand.

If you are asking if you can perform a valve job, I can guarantee that you (or anyone else asking that question) do not yet possess the knowledge, skill, experience, and tools to properly do the job.

My advice would be to take it to someone that is qualified to do the work. It will save you a lot of headache in the long run.
 
If you are asking if you can perform a valve job, I can guarantee that you (or anyone else asking that question) do not yet possess the knowledge, skill, experience, and tools to properly do the job.


Thats what I was thinking as well. I've never done one besides in HS auto class 15 years ago and that was on a lawnmower.

My cousin did some valve work on his Honda that was having some problems. I didn't think he knew much about cars but he bought a fix-it manual (or so I was told) and started working on it. He got it all put back together and drove down the street - made it about 4 blocks before it basically exploded itself. It turns out he didn't use any precision instruments to make the measurements.

A few months later they tried again to fix the car and this time they just did an engine swap -- without touching the valves etc.
 
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I don't think that frequently reminding the OP of the EPA fuel mileage ratings is very productive. Those "ratings" are all relative. The OP knows his 4Runner better than anyone else. So if he consistently got higher MPGs, and now they're lower, something changed.

Before we start talking valve jobs, and other ridiculous remedies, start with the simple stuff. Personally, I'd start with cleaning the Mass Airflow Sensor, and replacing the oxygen sensors. Oxygen sensors need to be replaced in higher mileage vehicles.
 
Just for a frame of reference….

I have a 2002 t4r sr5 2wd that I bought brand new. It just turned 208,000 miles.

-I have changed the oil religiously every 5k miles.
-I've replaced the spark plugs numerous times with OEM ones.
-Same with the air filter…(many times actually).
-I have replaced the timing belt and water pump twice.
-Both rear axle seals have been replaced, including rear diff fluid.
-I just changed both bank 1 and bank 2 O2 sensors..(kept throwing CEL saying bad catalytic converter but was really just the sensors).

-Had transmission fluid flush once completely and then a drain and refill again about 50k ago.

-Replaced the entire drive shaft. U-joints seemed to be sloppy so just replaced the entire thing.

-Had both valve cover gaskets replaced.
-Replaced PCV while we were there

I'm sure there's a few other small items I've missed but you get the picture…

I consistently get 18 mpg (city ~17, hwy70mph ~19)….

I'm just now starting to see my rear main seal and oil cooler gasket starting to leak…getting a little oil being blown under the car while driving and can see small drops of oil on the bell housing….

I guess my point is valve cover gaskets will probably leak on this motor given some mileage on it regardless. So will the rear main seal as well as the rear axle seals. This motor/truck just does that…

I think you should start a list of all the things you replace as you go along to understand what's good and what's not….
 
Do a compression test and compare the results to the factory specs, if any (or all cylinders) are out of spec then take it to a shop and have them do a leak down test on the engine.
A leak down test is where you bring each cylinder up to TDC (top dead center where both the intake & exhaust valves are closed or right when combustion is occurring) you screw an air line into the spark plug hole and inject air press into the cylinder @ a set psi on the main gauge (usually 100psi) and then you read the pressure that the cylinder is able to maintain (always less than the main pressure) the pressure difference is the sum of the leakage past the piston rings into the crankcase, past the valves into the intake manifold or into the exhaust manifold.

If the compression test is OK, then the internal mechanical parts are OK and your fuel mileage issue is being caused by other factors than a "bad" engine.

You might spend $2k+ on a newer engine & still have the fuel mileage problem.

Frosty
TRD Track Support Engineer 1995 - 1998
 
You can buy a compression tester for ~$50.00 (add it to your toolbox!)
All you have to do is pull all of your spark plugs, disconnect your ECM or unplug the leads to your fuel injectors. You then install the compression checker into a cylinder, crank over the engine until the needle on the gauge stops moving and the record the max pressure. Continue the same process for the remaining cylinders.

If you have an air compressor, you can buy a leak down tester for less than $100.

Frosty
TRD Track Support Engineer 1995-1998
 
Should I replace my O2 or Air to Fuel sensors if I don't have a code or am I wasting my money?

Yes. O2 or Air/Fuel sensors (whichever one you have) can get "lazy" without tripping the check engine light.

After my '97 got totaled and I just bought my '99, I noticed I was my new-to-me rig was getting poor mileage compared to my previous one. I changed the front O2 sensor and cleaned my MAF, and mileage returned to normal.

I'm not saying your O2 sensor is 100% the problem, however on a high mileage vehicle, they should be replaced if you're still on the original one.
 
I rebuilt the power steering pump today. Only thing I did wrong was didn't flush with the front wheels off the ground. Hoping the whining noise will go away the more I drive it.
 

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