I am sure this has been asked a million times, but again like my last thread I have poured though forums looking for an answer and I just don't seem to find what I am looking for.

I am losing coolant. Not at an alarming rate but it is still going away. It is leaking around the degas cap for sure. I don't have some of the signs that a lot of people mention in other threads such as white exhaust smoke, obvious coolant contamination or water in the oil. I have never witnessed a drop of smoke white or black coming from my exhaust except under heavy acceleration under load and that was only black. The coolant is clean and the oil has always looked great every time I change it. I would like to determine if I am losing it from a EGR cooler leak, head gaskets or both. I will run down what info I have.

I pulled the EGR valve a while back and it was sooty and slightly damp. Pointing me in the direction of the EGR cooler leaking. It wasn't super wet but the soot was not dry.

I have tested the pressure in the cooling system two ways. One was the way shown on Bulletproof Diesel's website using a tube in a water bottle. The results I got were a bit deceiving and it didn't seem like I could get the results to repeat. I also set up a pressure gauge in line to the degas bottle. I was getting pressures over 16psi when driving although not extremely high. Maybe 18psi or so, but probably enough to push the coolant out the cap under the right circumstance.

I have no clue what this means if anything but I have also noticed that I lose more coolant during just normal driving than when I am towing my 5th wheel camper. I noticed the coolant leaking a few days before I moved my camper from Chattanooga back to southern Indiana. I had to move it so I pulled it home. The drive took about 6 hours or so and when I got here I had not lost one drop of coolant from the cap. I did check it each time I stopped for any reason on the way. I could be reading this all wrong but I would assume that when the engine is under more load and the turbo is pushing more boost that it would cause more issues if the head gaskets are leaking. Again. I may be completely wrong.

I am just brainstorming right now while I wait on my FICM to be repaired to fix that issue. I am also thinking I have an injector issue but I will wait on the FICM to decide if it is the injector or the FICM that is actually causing that issue.

 

Did you park the truck nose down over night then pull the EGR Valve? do you have the New Degus cap? there are many Places for leaks to appear .
1. EGR Blue hose
2. Heater control arm
3. Heater Core
4. Heater Hose / Hoses , one being lower FICM wraps around the Back of Engine.
5. EGR Cooler
6. Water Pump
just to name a few.

 

I haven't parked that way to check it. And yes the first thing I did was replace the cap. I have not been able to locate a leak anywhere external besides where it comes out of the cap.

 

After you check for moisture in the EGR valve, you might try connecting a Scanguage II or equivalent to check the oil & coolant temps.

Drive it down the freeway (empty on level road) at 65 or so after a complete warm-up.

The difference should be less than 15 degrees F.

If it's NOT, and the oil temp is a LOT higher than 15 deg above the coolant, you could have a plugged oil cooler.

That would cause steam to be produced in the EGR cooler which would raise cooling system pressures to the point where the cap would vent.

This won't end well if the EGR cooler cracks from the heat and starts allowing water into the intake (if it hasn't already)


Good luck!


Rick

 

Where do you maintain your coolant level? It should be maintained at or slightly below the minimum mark molded into the degas bottle.