2big4arunner

So I upgraded my 1992 4runner to a 2003 4runner and a 1988 Supra turbo. I think I got a good deal in general since the 1992 was pretty much stock with good tires.

The new truck drives great all summer and I even towed a 1995 camaro for my friend and the v6 didn't have an issue at all. I plan on switching the 4 speed auto to a 5 speed and depending on what I Find for what price i Find it I might trade out the whole motor since my new truck has 300 000 kms/ 187 500 miles.

During the summer I was getting 9.5 L/100km (24.75 mpg/us). I tested the 4x4 engagement and everything disengaged fine. Recently since the temperature dropped below freezing I have been noticing a rapid decline in my MPG. So severe I have TRIPLE checked my 4x4 system to make sure its fully disengaged. I have dropped to 14.8 L/100km (15.89 mpg/us).

The only thing I noticed that happens since the temperature drop around here is the engine cools off VERY fast. Half an hour and i loose my whole temp guage. I assume (yes... makes an ass of u and me) that my thermostat is stuck slightly open and that explains both the fuel mileage and the temp drop.

I will be doing a full drivetrain check again this weekend on my birthday (yahoo time to me) but I am looking for anything else or even a way to check the said items before I spend 100 bucks on a 1 piece thermostat/housing

2big4arunner

bump

2big4arunner

BUMP

2big4arunner

Well since no once else chimed in on it. It was two things that caused my 4runner to drop in mileage so suddenly. One caused the other like always.

#1 - The damn hundred dollar thermostat. I did get a chance to look at a cheap one that is on rockauto but its not the thermostat housing that they sell at toyota so I went with factory and it worked out great. I should have taken pics of the change but if you cant figure this one out then you really really really really...... really shouldn't be near your engine.

#2 - E3 spark plugs fouled out due to constant rich engine. I thought about going back to stock units but the E3's did work really well originally. I have given them one more chance but if I had to choose I would probably go back to Toyota plugs or NGK platinums as replacements.

donomite49

is that the 4.0 engine or the 3.4?

and dual electrode plugs? like the 5vz.

thats some good mpg #s.

2big4arunner

Its a 4.0 1gr-fe v6 with the 4 speed auto. I will be putting the 5 speed in to get a little better mpg. I forgot to explain that the thermostat was stuck open a little which caused the truck to always be in choke mode to keep the engine warm. The choke mode fouled out the plugs due to the short distances I have been driving lately. I also recently put in a can of sea-foam into the gas tank just to keep the system clean.

The spark plugs I have used are diamond fire tech... let me just link the website for it.
http://www.e3sparkplugs.com/

They really do work but I find that the reputation is pretty low right now. They are still new technology and for the everyday truck that drives more then 2 miles it is an option.

I will be putting on a new set of Duratrac's (245/75r16) and see if the mileage changes but so far this motor tire combo seems to work great in this hilly area.