Q: I have a coolant leak...recently changed the expansion tank...now I have a leak right in front of the radiator 2008 BMW 750Li

asked by on

There is coolant in the pan right in front of radiator. It looks like a lower hose leak...

My car has 140000 miles.
My car has an automatic transmission.

Hello - there is an air bleed hose that runs across the top of the radiator (under a plastic cover) and into the expansion tank. There is a coolant level sensor, and a coolant transfer hose (expansion tank to the water pump) that could be leaking onto the undertray. Any of these connections can cause leaks where you describe - but, my money is on the air bleed hose - it is terribly easy to cut when replacing the expansion tank. I recommend a coolant leak inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.

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

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!
  1. Home
  2. Questions
  3. I have a coolant leak...recently changed the expansion tank...now I have a leak right in front of the radiator 2008 BMW 750Li

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: My 2007 bmw 750li, makes noise when I'm not pressing in the gas. The car indicated oil level was ok. What could causing the noise

Hi there. It really depends on what type of noise you are hearing that will determine what is causing the noise. If it's a constant ticking noise, it's possible your serpentine belt or the pulleys that drive that belt are...

Q: My 2000 VW Passat 1.8 turbo recently was flushed to try and clear up heater core, but now my coolant is running out quickly

Engine coolant can leak externally through a hose, radiator, water pump, etc. or internally due to a leaking head gasket and sometimes a leaking intake manifold gasket depending on the engine design. External leaks are typically found by simple pressure...

Q: I tried to back up out of a parking but it didn't move.

Hi and thanks for contacting Your Mechanic. It sounds like the transmission low and reverse clutch has failed. This will prevent the vehicle from going into reverse and cause a stumble into drive until the second gear has been engaged....

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...
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...
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.