The thermostat is a 15-30 minute job and it will cost you $10, tops to do it yourself.

 

Yesterday AM I started my Jeep and CEL was still on. Went to my dads before going to mechanic, and when I started the Jeep afterwards, the CEL was off. But engine temp still didn't seem right. I went to local dealership to purchase thermostatm, and they had none in stock. Person at parts desk said an aftermarket one will be just fine. Anyways went to my mechanic swapped the thermostat and jeep has been fine since.

 

CEL came back on today. Same one. Gonna get an OEM thermostat and try this again

 

That CEL might need to be cleared using a code reader to keep the light from coming back.

If you buy an aftermarket thermostat, make sure it's a 195 degree thermostat (obviously the OEM will be the correct temp). Jeeps do NOT like running cold. I have a 195 degree Stant brand aftermarket thermostat in mine and it's perfect. The temp should reach 210 on your temp gauge (give or take a little, and by a little, I mean just a slight deflection, not a hash-mark on either side of 210) within about 7 minutes of starting the engine cold and should stay on 210 even when it's 100 degrees out with the A/C on assuming everything else in your cooling system is functioning properly. During warm-up, mine will very briefly go past 210, but then you can see the temp gauge drop as the thermostat opens, and the temp drops right down to 210 and does not move.

 

this is where mine has been sitting with the new tstat, after being warmed up fully, and driving some. I honestly don't remember where the one sat that was there before it.

I don't think the code just needs to be cleared out, as it has been gone since tstat was replaced.

 

Did you mean to take the pic of ur Odometer like that, or just taking a pic of the temp and it happened to be coincidence?

 

LOL. I took the pic for the ODO. It came in handy to show the temp too haha

 

Is that with the new OEM thermostat in there, or is that with the new aftermarket thermostat?

 

that's with the new aftermarket one. I have a new OEM one on the way.

Thats about where mine runs. Disconnect the battery cable for 10 minutes, then see if the code comes back. You should be alright.

I cleared the code out before and it came back with in 10 miles

 

Thats about where mine runs. Disconnect the battery cable for 10 minutes, then see if the code comes back. You should be alright.

 

If you're still getting the code, the jeep is running too cold. Chances are the guy at the parts shop gave you a 160 or 180 degree stat instead of the 195 degree one. At this point, just wait until the OEM one arrives, put it in and you should see the temp gauge rise to 210. This is where normal is on the jeep. You can still drive it in it's current condition, but you'll get poor(er) fuel economy.

 

thanks for your help. I should have the oem one this week. And it installed the following week, when I have time haha. Yeah I thought it used to sit a little higher. Like just to the left of center and the oil is to the right of center.

 

No problem...and you're correct about the gauge readings, should be a lot closer to "12 o'clock" than it is. Your oil pressure reading in the pic you posted looks exactly like where mine reads. Let us know how it turns out.

 

I thought it was the same code. So didn't check, but checked again this AM and it was P0051. O2 sensor Bank 2, sensor 1. I replaced that one like 3 months ago. I know the thermostat is still an issue as the engine temp isn't going high enough. But now I am trying to figure out why the 02 sensor needs to be replaced again. I cleared it this AM again, and when I started up this afternoon, CEL on, code P0051 again.

 

My guess is that the P0051 might be related to the thermostat....since the jeep is running cold, your jeep will never feel "warmed up." What that means is that it is introducing more fuel into the combustion chambers than is necessary. This could cause a problem with the O2 sensors (would be reading too rich) but I'm not sure why there wouldn't be a code for the bank 1 sensor as well.

My advice is to get the thermostat changed, clear the codes and see if P0051 comes back. We KNOW for sure the stat is causing the P1281, and it could be causing the P0051 too, so try that first.

 

gotcha gotcha. That's what I will do since the tstat is on it's way. So basically since the jeep hasn't "warmed up" persay for the last 2 weeks or so, the 02 sensor finally caught on. I guess this is also why I have noticed my steady 15.9 mpg drop down to 15.8 and then now at 15.7?
thanks again. I will post back when resolved.
do you think the 02 sensor could have gotten damaged in all this? Or that once tstat is replaced all will go back to normal?

 

No problem at all, glad my "experience" can help someone else.

I have no idea if the O2 sensor is being damaged beyond repair....I would think if you replaced it not too long ago it should be OK, but I could be wrong. Anyone feel free to put your 2¢ in.

I previously thought the O2 sensor throwing the P0051 code was AFTER the cat, but it turns out it's before the cat, which makes a LOT more sense. The extra unburned fuel being introduced into the exhaust because of the jeep not reaching operating temperature is being picked up by the upstream O2 sensor (before the cat), but is then cleaned by the catalytic converter enough to keep the O2 sensor after the cat from throwing a code. This is my theory about why you're getting the P0051 code, but I could be WAY off...and if anyone else has ideas, chime in.

 

well had mechanic install OEM Tstat today and that problem is solved. Engine temp is now where it needs to be. On to the 02 sensors. I was mistaken, the code I was throwing was P0031 Bank 1 Sensor 1. That is no longer the case. This AM before I started the jeep I checked the code and its P0051 Bank 2 Sensor 1. Mechanic didn't think the sensor should need to be replaced again. Each time the code was cleared out immediately up start up it came back. Mechanic started testing and came up with no resistance at the resistor. He didn't have enough time today. Said to bring it back he will need atleast half a day to test wires coming out of the ECU. He told me also to just keep driving it and maybe it will straighten itself out on it's own.
Anyone have any insight?

 

How dare u leave us without a conclusion!!? What happened?? Did it got cleared? Or did u sent that jeep to the junk yard where they all ougth to be? Jk....