Water Pump?

[gnonne]

Has heat issues again on our 2012 Sedan, 1.8L engine. Changed t-stat, broke housing in the process, but I had another one in the garage...

Here is the problem: We still have almost no heat. I have a boiling-funnel and have tried to purge any trapped air out of the heater core (and elsewhere.) I get good heat when the funnel is attached, but as soon as I remove the funnel, basically no heat.

I know it is possible that the water pump impeller is bad (they are plastic) which would make it hard to get water pumped up to the top of the system, aka the heater core. Driving in Manual mode and keeping rpms high helps a little, but not much. Sometimes you hear the air and water gurgling in the heater core at high rpm.

Like I said, I know this is possible, but is it likely? It has never overheated.

Anyone else do a water pump on a 1.8L at 89k miles? How hard is it?

 

[92dakota]

not hard, runs off serpentine belt front of motor lower front passenger side , that said its not more a nylon based plastic.. haha but besides that, easier form the top, remove the motor mount for ease.. use a jack with block of wood to support motor..

I have to ask, have you checked the hoses going into and out of the heatercore when its at operating temp, are they are hot or not?

 

[gnonne]

The hoses are hot, but only with the funnel full of coolant above them. When you remove the funnel, they don't stay very hot. Hoses are not blocked - had one of them off last night to do t-stat housing. Pretty sure I reconnected correctly, but I can double check.

I'm going to try another funnel purge and loosen the top connector to the heater core and see if I get air or coolant out.

 

[gnonne]

Hoses are connected correctly per GM parts diagram. Will attempt to bleed air from top connector before the real cold gets to West MI...

 

[92dakota]

yea we got - 35C here .. sometimes i hate canada weather LOL but it is what it is, but if car isn't overheating and its happy otherwise i wouldnt expect it to be the water pump, but i have seen strange things with air being trapped it odd places.

doing everything from parking with front facing uphill, to adding a inline bleeder/fill port on hoses, to actually having to replace the heater core on a *ford*

the air might not be in the core itself, could be before it on incoming line

regardless i know this vehicle has a specific procedure for filling/topping off coolant 1.8/1.4T same procedure.

 

[gnonne]

Yes, I tried lifting the front of the car and doing the funnel... No improvement.

I'm thinking it is the water pump impeller - there were some odd bits of black plastic inside the engine outlet area when I had the t-stat housing off.

We decided to take it to a local shop Monday morning- I'm just tired of fooling with it. I really don't like paying a lot for repairs, but it might be a simple thing, you never know. We have had it for a bit over 7 years with very little repair cost so far.

 

[skurtov]

Yes, I tried lifting the front of the car and doing the funnel... No improvement.

I'm thinking it is the water pump impeller - there were some odd bits of black plastic inside the engine outlet area when I had the t-stat housing off.

We decided to take it to a local shop Monday morning- I'm just tired of fooling with it. I really don't like paying a lot for repairs, but it might be a simple thing, you never know. We have had it for a bit over 7 years with very little repair cost so far.

The 1.8s have issues with water pump failures. There's a updated full metal water pump that's in circulation now. Bite the bullet, replace the pump. It's not that bad of a diy

 

[gnonne]

I took it to a local Midas shop that I have worked with before this morning. There was about a foot of snow and I had zero wait time... Sort of a cold drive over, but just enough defrost to keep the windshield clear.

They tested the pump, found no issues. They diagnosed a large air pocket trapped in the heater core area and did a flush and fill on the coolant, which has a very odd air bleeding procedure. To bleed it, they lifted the front of the car (on the back end of hoist) as far as they could get it without scraping the rear bumper on the ground, then did the funnel trick. It still took 40 minutes to get all the air bled out. They also loosened the top clamp near the firewall where the heater hose connects to the heater core.

$90 later, the thing will roast hot dogs on the dash. Also, the heater core rattle that I could never get rid of after replacing the o-rings is gone.

Just one problem they put the clamp back on the hose, not on the fitting. It was leaking coolant there slowly on the way home. I carefully moved the clamp into position and refilled the reservoir (I have plenty of Dexcool around from working on three Sonics all the time.)

I called them to let them know what I found and they asked me to bring it back. They did a quick pressure test to make sure everything was OK. No issues since and its 5 degrees here today.

Moral of the story... These cooling systems are very hard to bleed.

I believe all of this started back in August when my daughter had the car for a month. Somehow it melted the o-rings out of the firewall heater hose connectors, leaked coolant there, but never overheated. I replaced those o-rings, but we always had air/water sounds in the heater core. When the weather got fairly cold, we lost the heat. Fooled with the control knob fixes, which did nothing. Concluded it must be a t-stat stuck open, so I got one online and replaced it, along with the housing that cracked in the process, which let more air into the system. At this point, we could get heat when we had a full funnel attached to the reservoir, but as soon as you removed the funnel, it lost the heat.

Then it got below 0 F and I gave up on fixing it myself.

Should be OK, they gave me a 12 month warranty on the work and I've had minor come-backs before. But, they probably only charged me half of what I would have paid at the dealer, and they didn't try to sell me parts it didn't need.

 

[92dakota]

yea the procedures on this car are ridiculous for filling, topping up checking and refilling. never though i would need a PHD just to add coolant lol

 

[skurtov]

Bleeding should be extremely easy. At operating temperature, when thermostat is open. Have the coolant reservoir open and turn heat onto full blast. Allow time for air to propogate and exit. The reservoir tank is the highest point in the system

 

[gnonne]

I agree that it would be easy if the reservoir was the highest point, but the top heater core connector is clearly higher.

 

[Sonicator]

Anyone who needs to change their water pump, should first go to a GM dealership. They changed mine last summer on my 2012 for free. There is a warranty on them until early next year. I guess these pumps seem to be problematic. I'm in Canada. Hopefully you get the same warranty in the US.