Skip the auto shop - Our mechanics make house calls

Q: white smoke after head gasket repair

asked by on

I had a blown head gasket repaired. I am no longer losing coolant. I changed the oil and filter twice to make sure all coolant and oil mixture is out of the engine. However, I still see intermittent white smoke from exhaust. I know this is coolant still burning. Is this normal and how long will it take to get all coolant out of the engine? Is there anything I can do to speed up the removal of remaining coolant from engine?

My car has 121000 miles.
My car has an automatic transmission.

A: When ever an engine blows a head gasket and...

When ever an engine blows a head gasket and leaks coolant into one or more cylinders and pushes the coolant into the exhaust flooding the catalyst and muffler with coolant. After the repairs to the engine are made to fix the leaking head gaskets the engine can then be started. Once started the exhaust heat will now start to burn off the coolant and water that was pushed into the exhaust system. When this fluid is heated it will come out the exhaust as white smoke or steam. It may take a few days to a week to burn off all this fluid out of the exhaust. One of the quickest ways to burn off all the coolant quicker is to hold the throttle at about 2000 rpms when in park for about 10 to 15 minutes. This will get the exhaust to its hottest level and burn off excessive fluids out of the exhaust. Just a note that the coolant that got into the exhaust system may of contaminated the O2 sensors and the substrate of the catalyst. If you start having check engine codes for the O2 sensors or catalyst efficiency then you may need to test and replace the catalyst and O2 sensors to repair the codes.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: heater fan wont work

I recommend you request an electrical diagnostic on the blower motor circuit. It has to be determined if 12 volts is being delivered to the blower motor when the blower motor switch is on, in any or all switch positions....

Q: Car stopped after rough idle

This is a common symptom of a faulty idle air control module. This module regulates the control of air being mixed with fuel at idle. When this is faulty, it will cause an imbalanced amount of air and fuel to...

Q: White smoke coming from exhaust.

White smoke is an indication of coolant burning, especially if you having to add coolant frequently. If the white smoke is coming out the exhaust pipe then it is most likely being consumed in the combustion chamber. A common cause...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.