Q: Brown Sludge in Radiator Reservoir and Very little coolant

asked by on

brown sludge in radiator reservoir. I have a 2002 passat 1.8t. Nothing is mixed in with the oil. My father flushed the coolant system, first thing this morning and I drove my other car to work. We let the car run for a few minutes and the radiator reservoir was clear. I came back after work ( approx 8 hours: don't know if it matters), started the car and the check coolant light came on immediately. Checked the reservoir and there is was again. Coolant overflowed everywhere the first time the brown sludge happened and got on a lot of stuff, so I couldn't tell if the white smoke was coming from my tailpipe or if it was burning off because things were hot. No sign of oil leakage either. I did refill coolant the first time the coolant came on but I did not take in consideration the type of coolant and mixed coolants. Also my dad drained the radiator and poured water in the reservoir to flush. I figured you would have to let the water run through the system to completely get all the sludge

My car has 169000 miles.
My car has an automatic transmission.

Brown sludge could be a consequence of mixing incompatible coolants as well as not draining the coolant frequently enough. At this point, you just want to be sure that as much of the contaminants as possible have been removed and re-introduce the correct coolant for your vehicle. If the coolant level was low and you are having to periodically top off the system, that means there is a leak and, if so, that should be repaired. If you suspect a leak, to get the required repair estimated, please request an engine cooling system leak diagnostic and the responding certified mechanic will get this resolved for you. If you want the system thoroughly cleaned and the correct antifreeze added, just request a cooling system flush. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
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. Brown Sludge in Radiator Reservoir and Very little coolant

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: I have a 2002 passat 2.8. I had the fuel pump replaced this morning and refueled and the car wouldn't start. Waited 2 hours and it

If you just replaced the fuel pump and still have stalling or no start issues then replace the fuel pump relay in left side of dash in aux relay box.

Q: 2014 volkswagen jetta ac and heater stopped working

This may be related to a faulty blower motor or blower motor relay. Occasionally, the blower motor itself will wear out or become faulty working intermittently as the brush contacts inside the motor wear out. The blower motor relay supplies...

Q: My engine management light is on all the time and so are my engine fans.

Hello. The engine fan coming on and the temperature gauge spontaneous movement is more than likely caused by the same issue. It is possibly a wiring issue with your coolant temperature sensors. A technician will have to check the wiring...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
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...