SureTrack Real Fix: Where’s the Coolant Going?

Real Fixes from the SureTrackĀ® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is currently available free with the purchase of a current Snap-onĀ® diagnostic software version.

If your vehicle is losing coolant and it’s not dripping on the ground, it’s probably going into the engine somewhere. Follow this Real Fix to see how this rough running Audi A4 with a coolant leak was diagnosed.

2004 Audi A4 Avant Quattro 3.0L

P0300, P0303, P0306, Filled Engine Cooling System, Replaced Engine Cylinder Head Gaskets

The customer states the engine coolant recovery reservoir had to be filled twice within one week. The customer also states the engine runs rough.

Examined the engine cooling system and found the engine coolant recovery reservoir was empty. Filled the engine cooling system, used an engine cooling system pressure tester, applied 15 PSI pressure to the engine cooling system to check for engine coolant leakage. With pressure applied found no apparent external engine coolant leaks however the pressure on the engine cooling system lost some pressure. Due to the misfire codes removed the spark plugs, applied 15 PSI pressure to the engine cooling system for an extended period of time and found the pressure dropped considerably. Cranked the engine and found signs of engine coolant in cylinders 3 and 6 indicating cylinder head gasket leakage. Drained the engine coolant, removed the engine cylinder heads and found the cylinder head gaskets were damaged. The results of these tests verified the cylinder head gaskets were faulty.

Replaced the engine cylinder head gaskets, filled the engine cooling system, cleared codes, performed a road test and verified the vehicle operated properly.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.