2019 Volvo VNL 760 D13 - Coolant Loss No Visible Leaks

Question

I'm running a 2019 VNL with the D13 and I'm losing coolant consistently but can't find a drop on the ground. Pressure tested the system to 20psi, and it held for 30 minutes with no visible external leaks. There's no white smoke from the exhaust and no coolant in the oil (dipstick looks clean, no milky residue).

I'm suspecting the EGR cooler or maybe the air compressor? I’ve heard of the compressors pumping coolant into the air tanks but the air dryers seem dry. I'm really hoping it's not a head gasket or a dropped liner. Anyone seen this on the newer D13s?

PeterbiltPete · Answer

Don't rule out the expansion tank cap. They are notorious for failing to hold pressure, allowing coolant to boil off as steam through the overflow tube while you're driving. You won't see a leak because it's only happening at operating temperature and pressure while at highway speeds.

TireGuyTrevor · Answer

✅ Confirmed fix: It was a leaking EGR cooler. On the D13, these can leak internally and the coolant gets vaporized and sent through the intake, so you won't see a puddle. To verify, I pulled the EGR pipe and found white crusty residue (dried coolant) inside. Replaced the EGR cooler and the coolant level has been rock solid for 10k miles.

2019 Volvo VNL 760 D13 - Coolant Loss No Visible Leaks

Suggest a repair