Related: Common Radiator and Cooling-System Problems
First, make sure it’s coolant that’s leaking, not another fluid. (Coolant is often referred to as antifreeze, but technically coolant is a 50/50 mix of antifreeze and water.) You can easily check the coolant level in your see-through overflow tank. If it’s empty or low, the next step should be to check the coolant level in the radiator, but that should be done only when the engine is cool. Having too little coolant in the car’s cooling system can cause engine overheating and/or make your cabin heater blow cold air.
Once you know you’re losing coolant, the radiator is a good place to start. Some radiator leaks will be easy to spot — such as a puddle underneath the radiator — but others not so much. It’s best to check the radiator from every angle, not just from above, and pay particular attention to seams and the bottom. Rust inside the radiator or holes from road debris also can cause coolant leaks. Your vehicle may have an aluminum radiator that technically can’t rust, but aluminum can corrode or develop pinhole leaks too.
Antifreeze comes in different colors — green, yellow and pinkish-red, for example — feels like slimy water and usually has a sweet smell. If you can’t see coolant dripping or seeping, look for rust, tracks or discoloration on the radiator. Those are telltale signs of where it has leaked.
If the radiator appears to be OK, the cooling system offers several possibilities for leaks, including the hoses from the radiator to the engine, the radiator cap, water pump, engine block, thermostat, reservoir tank, heater core (a small radiator that circulates hot coolant into the dashboard for passenger-compartment heating) and others. A blown gasket between the cylinder head and engine block is another possibility, allowing coolant inside the combustion chambers — a problem that must be addressed immediately by a mechanic. (Thick white smoke coming from the tailpipe is actually steam, a telltale symptom.)
If you can’t find a leak, have it checked by a mechanic. Coolant has a way of escaping only under pressure when the car is running — possibly in the form of steam, which may not leave a trace. If the culprit continues to evade detection, you might consider a radiator stop-leak additive, available at auto parts stores, which seals small leaks — but it’s always better to find and repair the problem’s source, especially in the case of faulty head gaskets, which can lead your power supply to overheat and cause catastrophic engine Media Editorial department is your source for automotive news and reviews. In line with Media long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of Media advertising, sales and sponsored content departments.Share Contributor Rick Popely has covered the auto industry for decades and hosts a weekly online radio show on Media Email Rick
Coolant Expansion Tank Reservoir BMW K 177 177 17 17 17 BMW
LOSTAR Coolant Reservoir Expansion Tank with Sensor Fits BMW 177i 177i 177i 177i 177i X17 17717375179368
JSD 17 Coolant Expansion Overflow Tank Reservoir for 17
Coolant Low Check the Expansion tank XBimmers BMW X17 Forum
What's this B17 17Addicts BMW 17Series forum
BMW EXPANSION TANK REPLACEMENT
Leaking coolant reservoir tank BMW 17Series E17 E17 Forum
Coolant Expansion Tank BMW E17 17i17i E17X 17i17i17i17i E817 Z17
Low coolant 17Post BMW 17Series Forum
How To Replace Coolant Expansion Tank on BMW E17 E17 E17 E17 See Description for bleeding procedure
17 Coolant Reservoir Overflow Expansion Tank wSensor Cap for BMW E17 E17 E17 E17
Coolant Reservoir Expansion Recovery Tank with Sensor for BMW 117d 117i 117i 117i 117Li ActiveHybrid 117 17
Coolant Expansion Tank Overflow Reservoir for BMW E17 X17 X17
BMW 17 Coolant Reservoir Overflow Expansion Tank Cap Lvl Sensor Set
For BMW E17 X17 E17 X17 Radiator Coolant Reservoir Overflow Expansion Tank Genuine eBay
For BMW 17i 17i 17i Z17 Coolant Reservoir Overflow Expansion Tank BRAND NEW eBay
BMW X17 Coolant Expansion Tank Replacement E173 17 17