Q: Went to flush radiator, car heated up and refused to turn off

asked by on

I replaced the water pump yesterday and went to flush the cooling system today, I filled with flush and water, put cap on and started engine, my car heated up quickly and refused to shut off, I had to hit the stop lever on the engine to turn off... did I mess up somewhere?

My car has 300000 miles.
My car has an automatic transmission.

There is a vacuum pump on the front of the engine near the water pump, The large vacuum line that comes out of it branches off to three or four smaller lines not far from the pump connection. They are made of plastic and become very brittle over time. You probably disturbed one or more of these vacuum connections while you were working at the front of the engine. The shutoff valve is vacuum operated so any leaks will leave you unable to shut off. Also, I recommend you leave the radiator cap off while running the flush. The system is going to "burp" a few times and need topping off. Likewise, leave the cap off during the warmup so you can continue to top the system up. If you have trouble sorting out this shutoff valve, or if you continue to have cooling system problems, Your Mechanic can send a technician to your home to sort out the vacuum leak for you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Went to flush radiator, car heated up and refused to turn off

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

Get a quote

What others are asking

Q: Have front wheel drive no rear wheel drive

Hi there. Raise up the vehicle and put it on jack stands. Start up the engine and put it into gear. Watch to see which tires move. Put the transmission in neutral and put the transfer case in 4WD high....

Q: Car cut off, and will turn over but not fire.

This is a common sign of a lack of fuel supply to the intake manifold. This is usually caused by several things such as faulty fuel injectors, low fuel pressure (regulator) or not enough air supply. I would suggest having...

Q: Rattling noise when shifting

Hello. I suspect that the motor mounts are the cause of this rattle. Motor mounts are designed to dampen engine movement and vibrational rattles. The dealer recommends inspecting the motor mounts at 60,000 miles and every 20,000 miles after that....

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...