87 7m-ge air in cooling sys? - Toyota Nation Forum : Toyota Car and Truck Forums

RUSS MYERS · 01-13-2009, 03:03 PM

WHEN ENGINE IS WARMING UP OR AT OP TEMP, THERE IS A GURGLING SOUND UNDER THE DASH. I SUSPECT THERE IS AIR IN THE COOLING SYSTEM. IS THERE GOOD PROCEDURE TO BLEED THE AIR OUT OF THE COOLING SYS? ONLY 1 THREAD THAT TALKS ABOUT ELEVATING THE FRT END BUT NOTHING ELSE FOR DETAILS.

ALSO, AT COLD START UP, THE DASH TEMP GAUGE WARMS UP NICELY AND HEAT BLOWS OUT VENTS, BUT THE MECH TEMP GAUGE SITS ON THE BOTTOM 100 DEGREES FOR AT LEAST 10 MINUTES WHILE DRIVING. THEN THE DASH GAUGE STARTS TO CREEP UP TO ALMOST TO THE REDLINE THEN THE MECH GAUGE SHOOTS UP TO 200 WHILE THE DASH GAUGE SIMULTANEOUSLY DROPS THEN THEY BOTH LEVEL OUT AT 180 DEGREES. HERE IS A PICTURE OF THE THERMO AND CONNECTIONS:

AS YOU CAN SEE THE MECH GAUGE IS DOWNSTREAM OF THE TERMO AND DASH GAUGE IS UPSTREAM.

THANKS

RUSS MYERS · 01-13-2009, 03:13 PM

OH,
FORGOT TO MENTION THIS CAPPED OFF HOSE. IT SPRUNG A LEAK A YEAR AGO SO I CUT IT AND CAPPED IT OFF. NOW I CAN'T REMEMBER IF IT WAS CONNECTED TO SOMETHING. CAN'T FIND ANYTHING IN HAYNES ON HEATER HOSE ROUTING.

***bgrieger*** · 01-13-2009, 07:51 PM

Lift the front end as far as you can, start it with the rad cap off and top up fluid as required until it belches out the air. Play with the heater as well on and off to try to purge the heater core. Keep it up for a while until no more air appears.

It is possible that the temp sensor is seeing the air pockets, but you want to keep an eye on your fluid level. If it overflows or you have to keep adding, you may have a more significant problem on your hands.

Tire Shredder · 01-16-2009, 10:01 PM

after burping and there is air still in the system, there's a good chance you have a BHG.

do a pressure test on the cooling system and make sure it's still air tight. In my experience, it's not very hard to get the air out. and unfortunately 7Ms are prone to headgaskets going...

RUSS MYERS · 01-18-2009, 09:53 AM

Raised front of car ~ 20 degrees elevation, Started engine, coolant very slowly dribbled out of radiator cap opening for 10 minutes, heater on full, finally fluid dropped slightly and kept topping it off. Reved engine to 2K a couple of times and some bubbles emerged but not a lot. Kept radiator full. Mech temp gauge would only go to 160 and then bottom out to 100 degrees.

Drove car next day to get bread and milk and same crazy up and down between the 2 gauges again as described above 1st time, except it took longer to react about 15 min.

Oh, also, we had 22 degree temps outside and I do have a 180 degree thermo installed. This has been happening since last summer so I put in the 180 because the mech gauge would go to 210 on the highway on hot 90 days.

Your recommendation on a good pressure test gauge I can buy?