2010 emission, (low mount egr cooler, twin turbo) keeps pressurizing the cooling system blowing coolant out the cap. WILL hold pressure with no external leaks over night, WILL NOT hold a vacuum. Run engine up to temp and have a fairly constant flow of air out of surge tank (hose into water filled container) used exhaust gas detection fluid, DID NOT CHANGE COLOR, twice. does not smell of exhaust either. On recommendation changed egr cooler anyway. same condition after cooler replacement. Swapped in another compressor to rule out a bad head gasket or cracked head there. Same conditions present. with out the detection fluid showing the presence of exhaust gases what am I missing? Recap: no coolant in last oil sample detection fluid not changing color new egr cooler known good compressor pressurizing condition still present other than a head gasket what am I over looking??
Granted it was a Cat C7...I never would have believed the fix if I didn't see it with my own eyes...the water pump was the culprit. It was sucking in air but not leaking out. Bizarre.
I was thinking that over the weekend. the bubbles take longer to appear with the belt off but are still present. waiting for some new detection fluid to arrive as mine was 9ish years old. just want to take that out of the equation too..
These engines are known for the dropped liner condition ( which ends up being a head gasket failure) the block frets and when you rebuild you recut and add shims to bring liner back upto deck height
OEM trained in wiring and all engine platforms for over 20 years
We did a DT466 2 years ago with same problem , head gasket let go, we had to shim the liners to get them within spec. As soon as you started it would pumped antifreeze out. I think we ended up building something to hold liners down and measure with dial indicator.
I have seen a couple of times where head gaskets would only leak while under load. The block check fluid wouldn't change color at idle or even at higher RPM's, but would overheat under load.
Well after 30-40 miles of foot to the floor full load driving, it has not pushed any coolant out. Put it on a route tonight and we will see what happens.
2012 MFDT pressurizing cooling system
Posted - 04/05/2019 : 2:03:12 PM
