After reading this post, I decided that I would try out a new ECT sensor on my 1997 4Runner. I have been complaining here of poor drivability and bad gas mileage lately. The symptoms of a faulty ECT sensor seemed to match my complaints pretty closely so I gambled and replaced the old one without testing it. My gamble paid off.

The truck starts quicker/smoother both cold and warm. Shifts are smoother, coast to gas transitions are much more controlled. I've only driven 60 miles but the needle is right at the 3/4 mark on the gas gauge, something I have not seen in years on this truck! Lately, I could only manage just under 40 miles when the needle reached the 3/4 mark.

I am going to test the old sensor by checking the resistance at various temps. But my OME gear comes in tomorrow so the test might get put off while I install and play with my new junk I'll post the testing results when I can. The old sensor did look very dark compared to the new one but it didn't look milky white like the one in the link. I read somewhere that severe overheating can damage the ECT sensor; I think that might be the root cause because I started noticing the symptoms several years ago, around the time I let it overheat multiple times due to a leaky water pump and my noobness.

I also finally got some fresh Toyota Red coolant back in the cooling system which I feel better about than the Prestone green that has been there for the past year.

 

The ECT reports through ODBII. You could have troubleshooted this a while ago, without replacing or taking anything apart.

 

Yep, I am kicking myself for never hooking it up to a computer. I did use a code reader on it once and it reported nothing so I incorrectly assumed there must have been a mechanical problem. Now I know that sensors and such can be out of spec without throwing codes.

I think I will be purchasing a OBDII scanner very soon. Probably a very good investment now that I have decided to keep my truck for a few more years.

Anyone have suggestions for high-quality, relatively inexpensive OBDII readers? I see the PLX Kiwi WiFi w/ iPhone interface on URD's site. That looks something that would work well for me except I don't have an iPhone or iTouch and I think my wife would get aggravated if I started hogging her iPhone. I guess the scan tools that use a laptop for the software might be my best bet.

 

This is the one I have, bought it 2 years ago and works great. It graphs and shows readiness monitor status:
http://www.scantool.net/scan-tools/s...creader-v.html

 

That's a reasonably priced unit and looks like it would do all that I would want. Thanks!

 

What so you look for in the OBOII reader, mine idles at 550-650 range but it doesnt sound like anything is wrong, i do have access to a reader so it cant hurt to check.

 

I can only speculate as to what as to what the readings may have been from my bad sensor. It'd be nice if someone with OBDII experience and wisdom would chime in or provide a link to a basic primer for using one of these scan tools.

Your idle speed doesn't sound out of the ordinary, if you are talking warm idle.

 

You can get an ODBII interface for under $10 shipped from Ebay, or a number of sites that ship directly from China. All you need to make it work is a laptop with USB. It's should be the first tool in any auto mechanic's toolbox, especially now that they costs as much as a McDonalds meal.

 

I assume the software for these interfaces run on Windows... Anyone ever head of one with software for Linux (openSUSE)? I know, I am a nerd .

 

There are some open source packages to use those USB interfaces, they are all standardized. Worst case you can VirtualBox Windows just for that dongle.

 

You got my curious gene going. I found this one:

http://www.obdtester.com/pyobd that looks like it works with the Hong Kong Bluetooth jobs on e-bay.

Plus a few others that don't look ready for primetime.

 

I will definitely play with pyOBD as soon as I get the chance. It looks decent and should work nicely on my laptop. There is no RPM package so I'll have to compile from source but that shouldn't be that big of a deal.

Thanks Durk!

 

If there is one sensor I'd replace every decade, it would be the ECT sensor. I've never had any of my autos throw a code for it, but always have had them warm up faster, smoother idle, and better gas mileage after changing the sensor.


TheDurk, thanks for the link. This looks to be a good addition to using my Scangauge ii.

 

What's the toyota PN for this sensor?

 

ECT sensor: 89422-35010
ECT sensor gasket: 90430-12005
Fuel Pipe washers (4 needed): 90430-12026

 

Thanks for the info!

 

I went ahead and bought a cheap ODBii USB inteface. It cost me about $20. It looks like pyodb willl work just fine even though it doesn't do any graphing or does it have any other fancy features. However, there is another piece of software that runs under WINE that has these features. If pyobd doesn't doesn't do enough I can try/buy something a little more sofisticated.