Thermostat shenanigans and running hot after t-stat change

[Dezert4Runner]

My 4Runner has taken a lot longer to reach operating temp than it should, and I figured that my t-stat was toast and stuck open or something. I got a genuine Toyota t-stat & gasket online, and some Zerex Asian formula coolant and got to work on it. I drain the coolant and disassemble the lower hose/ housing covering the t-stat and I find this!!!

On a separate note, my truck is now running hot. It's just a hair over 1/2 way in the temp guage on the dash. The jiggle valve is positioned at 6 o'clock as per this write up.

I've tried burping the system 3 times with the front end jacked up, radiator cap off, and front vents set on high heat and rear heater cranked too. Upper radiator hose gets hot and vents have no lack of heat so I know the radiator isn't clogged. I'm going to burp the system one last time (with the engine revved around 2k rpm's and with the cap on this time since I didn't do this yet) to give it one last shot, and then check the fan clutch strength at operating temp to see if that's the culprit at that point. Any other input?

 

[alumarine]

Looks like someone punched the thermostat out.
Maybe to stop it from overheating.

You could get the Torque App and a Bluetooth OBDII interface and check the actual temperature.

 

[pauldub]

I don't think that "a hair over half on the temp gauge" tells you anything. You need to read the actual temp if you want to know what the temp is.

 

[Dezert4Runner]

I have IOS not android so the toque app won't work for me and I don't have Scan Guage or similar device to have an exact measurement of coolant temp. Last I checked they didn't have anything for iPhones. I have owned a couple 3.4 Toyotas and I know what the temp guage should be at normal operating temp, and this is running hot. I doubt the guage is not reading right. It shows movement when warming up, it just reads higher than normal at idle and normal driving even after my 4th attempt trying to purge the cooling system of air.

I did the fan clutch test using an empty paper towel roll to stop the fan and it only took about 4-5 seconds to stop the fan at idle so is that conducive of a bad fan clutch? Would the fan be strong enough to resist stopping with that test?

Thanks for the feedback, all help is appreciated.

 

[cbr900boy]

Yep the only way to be sure is with the obd 2 reader and torque app for correct readings. After i placed the jiggle valve at the 6 o'clock position the temp never goes past 195 no matter the load and outside temp.

 

[AZPartsGuy]

I have IOS not android so the toque app won't work for me and I don't have Scan Guage or similar device to have an exact measurement of coolant temp.

Roughly $10 more than I spent on my OBDII/Torque app. Might be able to help you out. Or go to Oreilly's after a "spirited" drive and pull the data really really fast? with the IFR tool you can pinpoint hotspots, too.

 

[BrianSD_42]

These 4runners are notoriously hard to properly burp.

 

[StreetCreeper]

I have IOS not android so the toque app won't work for me and I don't have Scan Guage or similar device to have an exact measurement of coolant temp. Last I checked they didn't have anything for iPhones. I have owned a couple 3.4 Toyotas and I know what the temp guage should be at normal operating temp, and this is running hot. I doubt the guage is not reading right. It shows movement when warming up, it just reads higher than normal at idle and normal driving even after my 4th attempt trying to purge the cooling system of air.

I did the fan clutch test using an empty paper towel roll to stop the fan and it only took about 4-5 seconds to stop the fan at idle so is that conducive of a bad fan clutch? Would the fan be strong enough to resist stopping with that test?

Thanks for the feedback, all help is appreciated.

Since I've had my ScanGauge, the highest I've seen is 222* and the stock coolant temp needle never moved. So if your seeing it move above the normal spot, you are indeed running hot in my opinion.

As for the fan clutch test, that's what I've done to test mine last year and I could not stop it. However, I used a rolled up newspaper. The fact that you can stop yours with an empty paper towel roll tells me you may need a new fan clutch.

I'm no expert though, so take everything I say with a grain of salt.

 

[LittleCaesar]

I am curious where the rest of the old t stat is.

Before jumping to conclusions get some hard data via a OBDii scan tool.

How old is the H20 pump, t belt, clutch, cap?

One would think there would be an app for such considering the Iphone is so widely used by all....

 

[Dezert4Runner]

I am curious where the rest of the old t stat is.

Before jumping to conclusions get some hard data via a OBDii scan tool.

How old is the H20 pump, t belt, clutch, cap?

One would think there would be an app for such considering the Iphone is so widely used by all....

I was told the timing belt was changed before the previous owner purchased it, which was only about 3 months before I bought it from the last owner. I don't know what parts were used and I don't have receipts, so who knows.

I'll have to consider ordering and OBDII Bluetooth scanner or Scan Guage II.

The weird thing is, temp doesn't pass that mark mid-guage, whether driving/ AC cranked/ parked & idling, etc. It's just higher than my '96 was at operating temp and my '01 Tacoma with the same motor. The only difference between all of the vehicles is the first two were auto, and this one is a 5 speed so no trans cooler integrated in the radiator.

 

[Arnezie]

http://www.amazon.com/ieGeek-Wirele...&qid=1464483444&sr=8-5&keywords=wifi+ios+obd2
You need a WiFi scanner and the app is engine link on the app store.

 

[Dezert4Runner]

Amazon.com: ieGeek WiFi Wireless OBD-II Mini ELM327 OBD2 Auto Car Diagnostic Scanner Tool Adapter Reader Scan Code Tester for iPhone 6S 5 iPad4 iPod mini IOS PC Windows, Android Device: Electronics
You need a WiFi scanner and the app is engine link on the app store.

Thanks for the link, that's an economical solution!

 

[LittleCaesar]

Without receipts it is all guesswork, as you can see with the old thermostat. Remember, there is a reason or reasons someone is selling the car or truck they likely won't disclose to the new buyer...

Let us know what temps you are getting once you have them.....

 

[Dezert4Runner]

Mystery solved

I got a hold of a diagnostic corded obd2 reader. Temps show 186-188 even with the a/c going and hardly any variation outside of that. I guess my guage just reads a bit higher than I'm used to when I drove my '96 auto. I haven't driven more than a few miles, but I did manage to hit the freeway and plenty of idle at stop lights city street driving. I guess I was successful at completely burping the system after all. You guys were spot on with getting actual temps and not going by the dash. Live and learn!

I liked having live data with the obd2 tool. I think I'll pick up the Bluetooth obd2 reader Arnezie linked so I can monitor more efficiently now that Summer's apon us.

Thanks for all the help!

 

[BrianSD_42]

Damn dude. Scanguage would have paid for itself in the saved stress and effort.

You may want to investigate the sending unit as a possible culprit. Mine started to bad and the guage would jump all over the place.

Temperature gauge/coolant temp sending unit - YotaTech Forums

 

[4Running Daily]

Nice! Ya definitely get yourself a Scanguage, they're a life saver. Mine is a manual as well and mine stays constant at 184 all the time. So I think you're good to go!

 

[alumarine]

Who would have guessed the gauge might have been off compared to the other truck(s)...

 

[Drcoffee]

I have a Apple iphone 4 and use Engine Link and an OBD2 wifi thing from ebay for $30. Works great. Without receipts it never happened. Might be a good idea to change the TB and water pump.

 

[DK327]

Temps show 186-188 even with the a/c going and hardly any variation outside of that

Awesome temps! Mine's currently @ 12pm w/ 202-207, really need to redo @ 6pm...

 

[Dezert4Runner]

Damn dude. Scanguage would have paid for itself in the saved stress and effort.

You may want to investigate the sending unit as a possible culprit. Mine started to bad and the guage would jump all over the place.

Temperature gauge/coolant temp sending unit - YotaTech Forums

Yeah, I saw in your link that there are 2 sensors: 1 for the ECU called ECT, and 1 going to the dash guage. The obd2 reader I used said ECT 186*F, so it was reading the ECT sensor. It makes me think that there could definitely be an issue with the dash guage sensor. Thanks for that info Brian.

Who would have guessed the gauge might have been off compared to the other truck(s)...

Lesson learned, doh!

I have a Apple iphone 4 and use Engine Link and an OBD2 wifi thing from ebay for $30. Works great. Without receipts it never happened. Might be a good idea to change the TB and water pump.

I was in the mindset of "no receipts or it didn't happen" before I handed cash over for this truck. I checked everything I could that you would normally look for like rear axle seals, frame rust, did the car fax, etc and just based my decision to buy off of what I could verify. I just haven't but the bullet on the TB/ water pump/ plus anything else that goes along with it.