twaage88

to start off this is for a 22re and it has been running fine till now. It started having a high idle even when warm, and I have noticed that when I remove the radiator cap and the flow stops, the idle then drops to normal idle. When I put the cap back on and it starts flowing again, the idle goes back up. I'm stumped!! thanks

rworegon

Check the thermostat. It may be stuck open not allowing the coolant to get to full operating temp thus causing the idle to stay high.
If the t-stat has been in there for some time, maybe best to just replace it with a new one from Toyota.

twaage88

the thermostat is about two weeks old and the truck seems to be reaching operating temp, before coolant starts to pass. but if I remove cap it drops to normal, put cap back on and slowly jumps back to high idle.does the idle air control get coolant to it?

thefishguy77

iTrader: (1)

What type of thermostat do you have. A Toyota dual temp? A modified parts store one made to perform like a dual temp? Also what temp thermostats did you put in there? Had you parked the truck on a steep incline with the front end up to bleed the air out of the system that way. Air locks cause problems on these motors. Your upper radiator hose is higher than your radiator cap. There for when you fill it and or run it with out the cap on air can still remain stuck in the hose. Just some suggestions. Hope this helps. Let us know what you come up with.

twaage88

thanks for the help guys, I just got done trying to figure out my problem, and turns out I'm leaking coolant from what I hope is a gasket and not a cracked head. its leaking out above the head gasket, looks like where the neck with cold start timing switch and the coolant temp sensor housing connect to the block, I'm assuming there is a gasket there??

thefishguy77

iTrader: (1)

Can you get a picture of the suspected problem area

twaage88

i will try to in the morning when i get a chance, its on the passenger side at the from of the motor, even forward of intake. and about 3 in above the the head gasket, something bolts to head there, i didnt have much time to look today.

twaage88

im almost positive its where the coolant comes through the head right before it hits the sensors and then on to thermostat.

twaage88

after doing some research, it looks like its where the intake manifold connects to head. any ideas on how big of a job this is? time wise?

FGZ

I'm interested to see how this turns out. I've had an intermittent coolant temp sensor (for the dash gauge) since I got the truck a month ago, but now that I have changed the thermostat my gauge has been dead starting about a week after I swapped the t-stat.

I went to the dual stage t-stat because I had some bad temp spiking when outside temps were below freezing. Even with the old t-stat while the temp was spiking the gauge would work most of the time. I did the t-stat and it fixed the spiking instantly, but now the gauge has stopped working altogether. Plus I had an weird high-idle happen while sitting in a parking lot today, so long story short I wonder if I have air trapped somewhere.

I just did a search on burping the cooling system, so I'll try some of those and see if my temp gauge comes back to life. If not, it's time to start looking for a worn wire.

twaage88

i have had this truck about a month as well, i do know there are two different temp sensors, one is ecu related and the other is for your guage, i believe the temp sensor for your guage is located somewhere on the back of the motor by the firewall. i had the usual cold start high idle, but when i came off the interstate and had a high idle i knew something was up. Now to see if the intake gasket is something i can handle myself or if ill be taking to shop. Hope your problem is not as a pain in the arse like mine. ill update when i replace gasket.

FGZ

Mine commonly idles high, and will usually come down when I blip the throttle a little. I just thought it was something sticking. She's now my DD, so I expect some stuff to clear up with regular usage. Then today's high idle was odd: normal, then high for 3 seconds, back, repeat a few times. Not too worried yet.

You're right about the sensors, but the gauge sender is between cyl 2 and 3 near the cold start injector. It's pretty far back there, I've taken the wire off, greased it, put it back, thought things were better but now it's been dead a few days so I'm going to chase air bubbles then start trying to trace that wire. Tapping the cluster doesn't do anything, so I don't think it is a loose connection there, either.

Good luck!

twaage88

Thats odd, my last truck that has an idle surge was a head gasket, hope not the same for you!! air pocket sounds likely, let me know if you have any luck with you fix!!

FGZ

I don't think I have an air pocket because the few times that my gauge has come back to life it's very quick and snappy. It seems like an air pocket would cause fluctuation but at a relatively slow pace, so my issue sounds more like wiring.

twaage88

ahh i see, yeah makes sense, maybe just bad ground?? i got mine tore down to the lower intake manifold, time to put gasket back on tomorrow and hopefully it will fix my problem, taking apart wasnt too bad, couple tricky bolts was my only pain, putting back together might be a different story lol

ToddShaw

You may have an issue with your temp gauge itself. Apparently this is a common problem with Toyotas. Look at what this guy found with his temp gauge.
https://www.yotatech.com/forums/f116...ge-fix-271152/

twaage88

HELP!!! I replaced my blown intake manifold gasket thiinking this was causing my high idle problem, but no luck!! Drove to work today and as soon as i came off the interstate i had a high idle again, truck never overheated, but when i got to work and popped the hood, there was coolant blown everywhere from the radiator cap. any ideas??

ToddShaw

twaage88, Take a look at this video. This could be part of the problem. If you have any gunk in this tube it will cause the engine to have a surging idle. And if you have gunk in this tube then you could have this gunk in the entire cooling system. I had to replace my radiator about 9 years ago because it just would not cool down the coolant anymore. They do wear out. So a radiator replacement might help you.


Hope this helps,
Todd

twaage88

thanks for the help, I did check this when I replaced my intake manifold gasket. my truck does not surge, it has a constant 2500 rpm idle, and its building lots of pressure in the coolant system. I'm starting to think head gasket or cracked head.