some problems with my new toy

[Hondafreak333]

Hey guys so I recently got a t4r for a good price but it has some problems. First some background, it is a 93 sr5 automatic with the 3.0 efi v6. The minor problems that dont really concern me are the passenger window won't roll down and there's no light for the stereo or climate controls but thats not really what im asking about for now. The problems that are the major concern that I would like to adress are
1. The check engine light comes on intermittently mostly when the engine isint up to operating temp causing a dramatic loss of power. After its up to temp if I park and shut the engine off and restart it its gone as are the symptoms.
2. Overdrive isint working properly. The overdrive only engages when the temp gauge reaches the halfway mark and once it engages the engine cools down a lot and overdrive disengages. From what ive read this problem is related to engine temp and I belive its directly related to the last problem.
3. Massive fluctuation of engine temp. (Not overheating) something definitely isint right. The truck takes a very long time to warm up and runs pretty cold compared to my moms 95 t4r. The temp gauge usually stays below the temp symbol while on the highway and sometimes drops as low as touching the C on the left side of the gauge leading me to believe the thermostat has been drilled or completely removed to possibly compensate for an overheating issue that the previous owner didn't mention (praying its not a head gasket). There are no leaks of any fluids and everything is at the proper levels. I'll be getting a service Manuel from the library today to hold me over till I download and print the factory manuel from a link I found on this forum. What are everyones thoughts?

 

[fire runner]

First thing first check all fluids make sure they are all full and in good condition second check to see if t stat is even inplace it could have been removed and need some more info on engine light once you get manual find out code defenition and start from there also check to see if fan clutch is staying ingaged
On second note for trans if you or a budy are mecanicaly inclined to solve auto trans prob you can do like many have done and convert the runner into a stick shift i am just about done with mine and i am only 300 bucks into it i had a prob with overdrive on mine then i staryed to loose gears and major slipping so i decided to abort the auto trans let me know if i can be of more help if i dont have the answer i can find it or there are tons of really smart people here that would love to help you out

 

[Hondafreak333]

Ok, so as for the overdrive Issue, the fluids are all at proper levels and the fan clutch is working properly. I'll be getting a new thermostat and coolant to check out that possibility on Wednesday.
As for the check engine light, its throwing a code 52 engine knock sensor which makes sense why it would be losing power when the cel comes on. The pictures in the manuel are very vauge and I am unable to locate the sensor to test it. It is a 3vz-e and any help to direct me to that sensor would be much appreciated, thanks.

 

[Hondafreak333]

Alright, so ive been doing some some testing and thinking about the code 52 ( knock sensor signal). I put a tank of premium in the runner and drove it around to see if maybe I was actually having an preignition knock and the cel came on just the same as before. Sometimes it comes on sometimes it dosent leading me to belive either the sensor is bad or there is a short in the wiring between the sensor. I have a new sensor and pigtail on thr way and am planing on relocating the sensor to the engine lift point as described in threads in this forum. My question is I have a slight valve tapping constantly on the drivers side head and I was wondering if there's any possibility this tapping could throw the code 52? Thoughts?

 

[Hondafreak333]

Update

so today i opened the thermostat housing to fing there was no thermostat installed. i installed a new thermostat with the oem temperature rating, filled the system back up and bled the air out of the system before going on a test drive. it warmed up much quicker and once it got up to temp the gauge stayed dead locked just to the left of the halfway mark and i was on the gas pretty hard to check for overheating. it shifted much smother throughout all the gears and overdrive workes perfectly now. it also dosent stay in a higher gear while coasting downhill. im expecting my knock sensor pigtail to arrive from the factory tomorrow so ill give another update after my knock sensor is relocated.

 

[2ndGen4runner4x4]

Get it out on the highway for 25 - 30 miles at highway speeds and you will find out if there is a head gasket issue.
As you said before, sounds like the previous owner was trying to hide something maybe?
Then again, I had a thermostat hang closed one time and I just removed it to get back on the road and didn't get around to replacing it until the following winter.

 

[Hondafreak333]

Yea I drove it all day today with no issue so hg's are good. Im guessing the po tried to change the thermostat and didn't burp all the air out of the cooling system causing it to over heat and making him run it with no thermostat. The temp gauge didn't move once it was warmed up and a was on the gas pretty hard to make sure there was no hg leak.

 

[nicnmike]

My 1990 v6 5-speed also came without a t-stat. It also had a new radiator. I suspect it kept running hot, so taking out the t-stat was one of the things they did to help cool it. I'm pretty sure that replacing the radiator was the actual solution. The PO also suspect a blown hg. I haven't had any indication that it has one. The only thing that makes me nervous is that the directions for using blue devil (the hg sealer) is to run it without the t-stat.

 

[Hondafreak333]

Yea there was some copper flakes from a raidiator pour in sealer in the coolant I drained out so I flushed everything out real good. Mine also has a new raidiator so im guessing that sealer crap sealed his leak then clogged the raidiator lol. That blue devil stuff is bullcrap! My little brother used it in his honda civic. It dampened the overheating for about a week then the hg blew all the way causing lots of white smoke and a loss of power. When I had dte head off I noticed the blue devil crap had practicaly completely crystalized the entire cooling jacket and the radiator and the heater core despite following the directions to a t. Moral of the story: DONT USE MIRACLE FIXES IN A BOTTLE! THEY ARE A RIP OFF AND WILL MAKE MUCH MORE WORK FOR YOU. Sorry for yelling lol.