Skip the auto shop - Our mechanics make house calls

Q: Overheating and leaking during driving

asked by on

My car has been overheating lately. It doesn't happen while it idles, but during the first 4-6 miles that is has been running. There is also some leaking that I saw under the car after driving it. There are no leaks while the vehicle is idling though. What could be the underlying issue? Thanks.

A: BMW had a TSB (technical service bulletin) ...

BMW had a TSB (technical service bulletin) out for a casting flaw where a leak could develop on the lower right side of the cylinder head. Good news though, that was on the M52TU engines and you have an M54 engine, so you are not affected by that bulletin; it’s a good thing because the fix is a new cylinder head.

Common leak areas are under the thermostat housing, and the bottom of the coolant reservoir. Look for a white residue in these areas to see if a leak has developed. If no leak is present in one of these two areas, a cooling system pressure test may need to be performed to locate the leak.

Please note: never open or service the engine cooling system while the system is hot or pressurized or serious injury may occur.

You may want to enlist the help of a mechanic, such as one from YourMechanic, who has the expertise and training to inspect your overheating issue, then locate and repair the cooling system leak, if that is the cause of your issue.

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

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: Transmission issue, car limps and very slow in drive

Hello. If this light is coming on, then the computer is detecting a transmission issue. I always start by checking the fluid. If it is low then this will occur. If the fluid level is fine then the condition needs...

Q: The Check Engine Light is on

Hi there. There are a lot of things that can cause the Check Engine Light to be illuminated. A flashing check engine light is a sign of serious trouble. If the light is not flashing, then I would use a...

Q: Car misfire

They do not need to be replaced and be in the same shape but it sometimes is recommended to replace all of the coils at the same time since they seem to start failing one after the other in a...

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 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...