I have a 2017 VNL with D13 that has a small coolant leaking by the crossbar behind the oil filters. It runs normal with guages working correctly. However, It takes about a gallon of coolant every 4 to 500 miles. Occasionaly, there is a faint white smoke coming from the right side of the hood area as well. Problem is the leak is only visible after it has been driven. Once it is parked and the leaking has stopped, pressurizing the reservoir does not produce any more leaks. Any idea where it could be leaking from?
Follow the trail of coolant. It leaves a residue, so should be easy. Better pull the EGR cooler inspection plate and make sure that’s not leaking, too. It’s very common on a D13. That’s a leak you can’t ever see/find, but, the truck is using coolant.
I'm betting EGR too but I'd also check around the coolant filter. It's a known leak location (from the on/off valve) and is right above the oil filters. Have you touched that valve lately? They usually fail after being in one position for too long and the you move it and the O-ring gives out.
...so how much coolant should I lose a day if the egr cooler is bad? It was taking about a gallon every 4 to 500 miles but yesterday it took two gallons in a span of about 150 miles. I also notice more of it gets lost under load going uphill. The underside of the truck is wet from coolant splashing/spraying as it moves. Is there like a return hose or high pressure hose down there that could be cracked?
1) not much. 2) find that leak before it gets expensive. If you see it under the engine. Then that leak is not in the egr and should be easy to find. Albeit do to weather you may not want to look for it.
