Bleeding cooling system

[yuthanasia]

So I'm entertaining the possibility that I may have installed my thermostat with the jiggle valve upside down. It's a single unit in a plastic housing and can only go on 1 way, but the car gets hot under hard acceleration only and I'm out of ideas as to what the cause could be. Water pump is fine no leaks, I changed the thermostat because the car was getting hot and it would cool back to normal with the heater on. Upper radiator hose was hot, lower one was just real warm so an indication that coolant wasn't circulating. It still gets hot under hard acceleration, but cruising on highway it's fine. So how can I get any possibly trapped air out without doing this bastard of a job all over

 

[vavavroom]

Maybe there's air trapped in the heater core. One of the the heater core hose barbs may may have a bleeder hole that can be exposed.

 

[michaelluscher]

If you didn't do this procedure, there's probably still air trapped



You can get these funnels on Amazon now for about $20 or so

 

[ripcord]

What kind of car? Hot upper hose, cold lower hose and overheating at speed is usually a coolant flow issue. Have you visually checked to see whether or not the bottom hose is collapsing if you rev the engine? Is it possible that the radiator is partially clogged? Also, have you visually inspected to see if the radiator is clean (externally) and the fins are not packed with crud? A lot of times it's hard to tell with the AC condenser in the way.

 

[yuthanasia]

What kind of car? Hot upper hose, cold lower hose and overheating at speed is usually a coolant flow issue. Have you visually checked to see whether or not the bottom hose is collapsing if you rev the engine? Is it possible that the radiator is partially clogged? Also, have you visually inspected to see if the radiator is clean (externally) and the fins are not packed with crud? A lot of times it's hard to tell with the AC condenser in the way.

2014 IS350, both hoses are hot with the new thermostat but it still gets about 2/3 on the gauge if I floor it like getting onto the freeway, turning the heater on brings it back to normal and it's fine on the freeway. Maybe there's just air trapped in it somewhere. Seems like it would have stayed hot though. I'm going to take the radiator cap off tomorrow and run it with the heater on for a few minutes and see if the coolant drops, I'm hoping that's all it is.

 

[madeej11]

So I'm entertaining the possibility that I may have installed my thermostat with the jiggle valve upside down. It's a single unit in a plastic housing and can only go on 1 way, but the car gets hot under hard acceleration only and I'm out of ideas as to what the cause could be. Water pump is fine no leaks, I changed the thermostat because the car was getting hot and it would cool back to normal with the heater on. Upper radiator hose was hot, lower one was just real warm so an indication that coolant wasn't circulating. It still gets hot under hard acceleration, but cruising on highway it's fine. So how can I get any possibly trapped air out without doing this bastard of a job all over

Maybe try parking on an incline with engine running and rad cap off. Let it get up to temp (thermostat open) with heater on full fan and full hot. Have protection for hands and arms and squeeze upper and lower hoses 4-5 times each which should rid the system of air. It could be a little messy but it worked for me. Parking on incline is key. Good luck.

 

[yuthanasia]

Maybe try parking on an incline with engine running and rad cap off. Let it get up to temp (thermostat open) with heater on full fan and full hot. Have protection for hands and arms and squeeze upper and lower hoses 4-5 times each which should rid the system of air. It could be a little messy but it worked for me. Parking on incline is key. Good luck.

Rhino ramps should work? I'm going to try that, I watched some YouTube videos with the funnel and turning the heater on and running it for about 20 minutes... I'm hoping it's just air. I did pull off about 3 hoses changing it out and a lot of coolant came out so I'm thinking when I hooked them all back up air got trapped in the system. Honestly I just filled the radiator to the top when I was done and called it good.

 

[foot3ch]

Use a coolant vacuum purge and refill tool kit. You can either go to a shop that has this kit or buy this kit. It does require a strong compressor. I used this when spill free funnel cannot fix my cooling issue. My car wasn't over heating but no pressure on upper radiator hose.

 

[Astro14]

Doesn’t sound like a thermostat issue. If the thermostat were stuck, it would run hot all the time.

Your system is not getting rid of heat as well as it should. You add heat with hard acceleration and it can’t get rid of it fast enough. Poor coolant flow. Partially blocked radiator. Bad water pump. All possibilities. Warm lower hose and hot upper hose suggest poor flow or blocked radiator (which would cause poor flow). I’m not sure that purging the air (if any) will make a difference and correct the poor flow.

A water pump that doesn’t leak may be bad if the impeller has corroded. So, not leaking is not the same as good.

How often has the cooling system been maintained by changing the coolant? Is the radiator original?

 

[Trav]

If you didn't do this procedure, there's probably still air trapped



You can get these funnels on Amazon now for about $20 or so

These are not a bad thing and does help at preventing a mess but will not help much with an air bound system. Vacuum filling is the easiest remedy for that issue.

 

[Astro14]

I bought a cooling system vacuum fill system for my Mercedes. It was the only way to properly fill the intercooler system.

Since acquiring it, I realize just how great a tool it is. I’ve done the cooling systems on my Volvos, which used to take a couple of heat/cool cycles to purge the air, with the tool. Now it’s one and done. No air bubbles. No worries.

 

[Sam_Julier]

I had this happen last summer after a coolant exchange. Taking it on the highway with the heater valve full open solved the issue. A vacuum system would be easier and more comfortable on a July day.

 

[Warstud]

What brand of T-Stat did you buy ?

 

[yuthanasia]

What brand of T-Stat did you buy ?

Duralast from autozone.

So I just put it on ramps when I got home from work, when I woke up I popped the radiator cap (it's full), put a funnel in and started the car up with the heater on full heat lowest fan setting. Radiator fans came in after about 5 minutes, coolant in funnel steaming hot. Lower radiator hose cold and top one hot! I squeezed the lower hose and it would move the coolant in the funnel so I know coolant has to be able to pass through the thermostat. How the hell can I drive 80 miles to work and 80 miles back without the engine exploding due to lack of circulation? Temp was a hair below the middle on the gauge driving home... So blocked radiator, or water pump is dead? Again, I don't know how I could drive any distance with zero circulation. I ran the car 15 minutes and the lower hose was still cold...

I'm tempted to pull the upper and lower hoses and flush through the top with a garden hose and see if it's blocked

 

[Warstud]

Is this overheating issue different now that the T-Stat was replaced ? Also is the coolant reservoir to the fill line when hot/cold ?

 

[yuthanasia]

Is this overheating issue different now that the T-Stat was replaced ? Also is the coolant reservoir to the fill line when hot/cold ?

It was worse before, which is why I figured it was the t-stat and replaced it. I drove to work yesterday in stop and go traffic on the freeway, 80 miles no issues until I got gas. When I was flooring it to get into the freeway (tiny onramp) the temp gauge went up pretty high, about 3/4, then back to normal after I turned the heater on. What the heck else could it be? It just seems if it was something serious there's no way I'd be able to go that far and back. Water pump can't be dead, new t-stat, has to be radiator?

 

[ripcord]

You have just enough cooling capacity to keep up with gentle cruising. If the thermostat was stuck shut, it would overheat right away. There is something that is limiting the flow of coolant, most likely. If you feel it's the thermostat, try removing it and see if it still overheats.

 

[yuthanasia]

It'sjust enough cooling capacity to keep up with gentle cruising. If the thermostat was stuck shut, it would overheat right away. There is something that is limiting the flow of coolant, most likely. If you feel it's the thermostat, try removing it and see if it still overheats.

It's built into a housing, I don't think it comes off. I just ran water through the top and it came out the bottom as fast as I could pour, no debris or anything just clear water.

 

[Warstud]

Is the coolant reservoir to the fill line when hot/cold ?
Was the coolant ever replaced ? If not....flush it and replace it with the correct fluid.
Purchase a Spill Free Coolant Funnel.

 

[JohnnyG]

OK OK, this is gonna sound dumb, but I've personally saw it happen with my own two eyes!
The lower radiator hose is under suction. When you floor it, it is being sucked SHUT!
There is usually a wire wrap spring inside that hose that can disintegrate over time leaving the inside of the hose unsupported. To verify, just have someone rev your engine while you look at that lower hose, I'll bet you see it collapse.