Any special methods to do this beside letting it run and having thermostat open?

 

I hear you there. I've seen it on the FSM. I'm just saying that mine was installed at 12 o'clock before I had it, and the Techs at Toyota are saying 12 o'clock.

Is there a possibility that Toyota made changes after the FSM, and now it's supposed to be at 12 o'clock since they are coming like that?

 

Happy Easter everyone!

So with the thermostat (82 degree Celsius tstat) at 12 o'clock I was running 198-212, and the fan would kick on and it would settle at 208.

So I flipped it today to 6 o'clock. And now it sit at 186-188. Every now and then, it bumps up to 190, and then back down 188.

Am I running too cool now? This is mess.

Should the jiggle valve be at the 3 o'clock to hit that magical center of 195 - 203?

Kinda frustrating...

 

You're in great shape temp wise now! FSM gives a normal temp range after warming up of 176 - 203 deg F (80-95 deg C).

My 95.5 generally runs 191-193 deg F.

Pat yourself on the back for a job well done.

 

Thanks for your help!

 

You're most welcome!

Kinda crazy how flipping the t-stat to the 6 o'clock position would lower the temp, but we've seen it documented here numerous times.

 

Well.. Flipped the thermostat and filled the radiator back up and while I was there I replaced the radiator cap since the old one's rubber gasket has cracks in it. (190k miles)

Now I noticed that there's coolant leaking to the bottom. It seems to be coming from where the top plastic cap the runs the length of the radiator meets the metal frame that starts the cooling fins.

This could be a cause of the flipped thermostat right?

It can't possibly be from installing a new (toyota oem) radiator cap?

Seems like things keep coming up. Any ideas?

 

Sounds like you are due for a new radiator.

 

If that's in fact it, I have a few thoughts/questions maybe you could help me out.

It's seem this small leak has developed because of a build up in pressure in the system. Did this just happen because...

1) The thermostat is at 6 o'clock, so the air isn't permeating out the jiggle valve? (vs 12 o'clock)

2) The old radiator can't gasket was shot and always letting out air. So the radiator was always bad, but it was wasn't building up enough pressure to develop a leak.

And now the new cap, with new seal is allowing pressure to build up and the leak has appeared.

3) Some bigger issue?

 

I'm adding to this thread instead of startng a new one about T belts and thermostats. I just had my T belt/ pump/thermostat changed and the owner of the shop and the mechanic both acknowledged that the jiggle valve needs to be at the down position. The owner has the same engine as I have. I think they did an excellent job, based on looking over the work and the repair bill comments. I also had a HD fan clutch put in. However, my truck runs hotter! It was 100 here yesterday, and my truck went up to 203. Last week, with temps around 97, I might have seen 195 on a hill. I have no reason to doubt that the t-stat is in the right position, but I would have thought with the new HD fan clutch I would see slightly cooler, not hotter temps.

 

Humm, sure it was properly burped? And, how are you getting your readings?

 

I have a scangauge hooked up. I tried two different procedures for burping it. There may have been a few air bubbles in there.

 

No scan gauge on my truck...

I just replaced what seemed like the original thermostat, at 190,000 miles. Was installed at 12. And my Haynes manual said to install at 12, so that's what I did.

Then someone pointed out this stuff to me...I went back in and flipped it over to 6 yesterday. It might just be my imagination, but I thought the gauge was right in the center before. It's just below center now, so just maybe slightly cooler than before, if our gauges are capable of that kind of sensitivity, which it kind of sounds like they aren't...

Either way, once I read through this thread, it wouldn't quit bugging me! So I had to do it. Truck went almost 200,000 miles with the thermostat in the 12 position, as far as I know, so I'm sure it would have been fine. But I plan on towing, and of course I want it to be "right".

 

It's is a bit mind boggling what flipping that thermostat to 6 o'clock does.....but the engine will absolutely run 7-8 degrees cooler.