Concerned about loss of coolant

Twice in the last 20,000 miles I have noticed my coolant was down about a quart. At the same time there was a whiteish sludge build up inside the oil filler cap and neck. I vaguely remember an engine many years ago with a similar looking sludge on the dip stick, that had developed a head gasket leak. Has anyone heard of an internal coolant leak in the 1GRfe engine showing this condition?

 

When are you checking the fluid level? When the engine is cold or hot?

 

Your coolant is probably slowly leaking from the water pump weep hole. Check for a trail of pink, chalky dried coolant on the underside of the water pump and down the front of the engine. It's relatively common and is a small enough leak to hide from you (gradual coolant loss but nothing obvious like spots on the driveway).

The white stuff under your oil cap is from short trips with the truck in cooler temps and the engine not reaching a hot enough temp to burn off condensate. It collects under the cap.

I wouldn't worry about a head gasket problem, at least not yet.

 

As Natetroknot said, the sludge in the cap could be from short trips.

However, earlier tacomas 05 and 06 I believe, had a head gasket issue. A TSB was issued for an updated head gasket.