Q: Heater blows cold.

asked by on November 16, 2016

After using coolant leaking stopper 3 months ago, heater has blown cold weather. I changed thermostat, Flushed heater core radiator 2 times, and replace the coolant reservoir cap, but the issue never been resolved. The car does not get overheat and heating gage raised to the middle and stays cosistant untill turning off the car and getting cool down. When turning heat on there is hot blow for seconds and eventually dropt to cold one.

My car has 70000 miles.
My car has an automatic transmission.

Heater is not working Inspection $94.99 - $114.99 Get a Quote

Hi there. Leak stopper should only be used in emergency situations as it usually causes more problems than it "fixes". It sounds like the leak stopper may have settled in your heater core and is preventing the proper amount of coolant from passing through to provide heat inside the car. The only way to repair this is usually to replace the heater core and check the hoses for blockages and restrictions as well. There could also be a servo malfunction that has coincidentally surfaced. A visual inspection of the servo operation can usually identify a mechanical fault, but not an electrical fault. If you can gain visual access to the servo, turn the temperature to max cold then max heat and observe the movement. If the servo is moving both directions fully, then it is working and the fault is in the heater core. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several technicians available that can assist you with a car has not heat inspection.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car makes chirping noise on startup
When you hear the noise, it may be a belt noise or a starter noise. The starter's on these engines have a problem with a gear reduction squeal during the engine's start up. To fix the issue the starter would...
Changed battery and the alarm keeps going off and the car won't start now.
The computer had to reset after sitting a few hours and alarm reset. The vehicle thought it was being stolen and did what it was supposed to do. You should have locked all the doors with remote or key and...
Ok so I got into a wreck last week and my head light is smashed and my bumber is pushed against my wheel is it driv
Hi there. I would say that it may be drivable without the bumper functionally. However, depending on your state's vehicle code regulations, it may not be legal to drive without a bumper. I would check your state's laws regarding this...
Fluctuating RPM gauge when going up hills
Hey there. It's hard to tell without further information. Automatic transmissions rely on solenoids and electronic sensors to shift. If these sensors have failed, the symptoms would be similar to yours. Issues with your fuel system will also produce similar...
Car has intermittent acceleration problems - 2001 BMW 325
There are a couple of places to start looking. The proper fuel pressure is required for good performance and a technician can check fuel pressure to see it if is low which will point to a clogged fuel filter or...
Car damaged by garage
I can comment on the need for the ecu, without knowing if they in fact damaged it or not. I can say that it is possible to damage any vehicle electronics when working on or near any power source such...
Vdc light and slip light.
The slip and vdc lights are related to the traction control system on your vehicle. The traction control system works in conjunction with the engine. When the wheels begin to slip, the traction control can temporarily disable the engine to...
1993 chevy z71 4x4 auto trans stuck in limp mode 2 gear only
Hi KC. Thanks for contacting us today. If I understand you correctly, you're having a problem with the vehicle being stuck in second gear - even after replacing the transmission. If this is correct, the issue is electrical as you've...
I have a 08 ford focus, its super cold and it tries to turn over but ultimately won't, the battery is giving me 12.3 volts.
When the weather gets cold, I replace a lot of batteries. If your battery is marginal, it will work just fine until the temperature drops, then it won't have enough reserve to do the trick.Testing it with a voltmeter won't...

Related articles

A Buyer’s Guide to the 2012 Cadillac CTS
The The 2012 Cadillac CTS comes with high tech features and a large amount of standard equipment when compared to its Japanese and European counterparts. The CTS is available in wagon, coupe, and sedan models to fit the needs of...
A Buyer's Guide to the 2012 Cadillac Escalade EXT
The 2012 Cadillac Escalade EXT has a 403-hp, 6.2-liter V8 engine, a fully configurable cargo bed, and a fuel-saving cylinder-deactivation system.
How to Get Cadillac Dealership Certified
Cadillac car dealerships offer automotive technician jobs to mechanics who are certified through one of the many Cadillac training programs.