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+--- Thread: loosing coolant (/showthread.php?tid=1072)
loosing coolant - milkman4282015 - 10-29-2016
I am running 4 09 ISX engines, 3 in prostars and one in a KW. The KW has been loosing one gallon of coolant every day no matter how far it goes just one gallon! no leaks anywhere just one gallon. Has been pressure tested, warm, hot,cold and no drop in pressure! Anybody ever seen this or have any idea?
RE: loosing coolant - Hammerhead - 10-29-2016
If it's losing coolant, it HAS to be losing pressure.
First, take oil samples, engine & tranny! Overnight them with specific instructions that you are looking for coolant contamination.
Then pressurize the cooling system, and leave it sit overnight. It will lose pressure then. If it's external you'll find it. If it internal, you'll know engine or transmission.
Sometimes the difficult leaks take a day or two to find, but find it or it will leave you where you don't wanna be.
RE: loosing coolant - Hedley - 10-29-2016
If your KW's coolant temperature has ever exceeded 235° then the first thing to go is your EGR cooler, this will drive you nuts trying to figure where the coolant is going, remove your Venturi pipe and check for moisture on the carbon buildup on the Venturi walls.
RE: loosing coolant - Rawze - 10-29-2016
A gallon a day is a lot.
* Replace the radiator cap/pressure relief cap with new one(s)!.
* Pressurize it up to 20-psi and let it sit overnight with the pipe off the back side of the EGR cooler open. Also take loose (at both ends) the pipe the doser injector is attached to and see if it is not oozing out of the Doser injector, and/or the turbo. See if anything is wet the next morning. Also look for leaks on the ground the next morning.
* Check your APU for leaks.
* check tranny for coolant intrusion,.. a gallon a day would make it fill up and have too high oil level.
* Remove the crank case filter housing and look for greenish/slimy residue in the underside of the cover.
* Check the air tanks for excess moisture.
* Crank it up with the Doser pipe still loose and see if the Doser injector is getting wet/damp while it idles.
* when you crank it, it should not have a first-rollover hesitation in the engine. .. If it does,.. It is getting into a cylinder and trying to hydra-lock it.
* Put a pressure test kit on it with an extension hose so you can see the pressure and take it for a spin under heavy torque load. -- See if the coolant system is rapidly building pressure only under load.
RE: loosing coolant - milkman4282015 - 11-14-2016
Thanks guys for all the info! I checked everything that yall sugested except testing under load. I fololowed that truck one day across I88 and it seemed to blow alot of blueish white smoke for quite a long time and i asked driver if it did this alot. Oh ya it does it quite a bit, like its going through a regen. after that i talked to a few more knowlegable mechs and they sugested to change egr cooler so thats my project for this week. keeping my fingers crossed this is it!!
RE: loosing coolant - milkman4282015 - 11-14-2016
By the way I just bought another 09 prostar with a ISX!
RE: loosing coolant - Hammerhead - 11-14-2016
(11-14-2016 )milkman4282015 Wrote: Thanks guys for all the info! I checked everything that yall sugested except testing under load. I fololowed that truck one day across I88 and it seemed to blow alot of blueish white smoke for quite a long time and i asked driver if it did this alot. Oh ya it does it quite a bit, like its going through a regen. after that i talked to a few more knowlegable mechs and they sugested to change egr cooler so thats my project for this week. keeping my fingers crossed this is it!!
Rather than crossing you fingers;
-Pressurize the cooling system (rad)
-remove the two 10mm bolts at the back of the EGR cooler
-use a light and a mirror to look into the back of the cooler for evidence of coolant leak
-if Yes change EGR cooler
-if No, remove exhaust pipe behind the doser and check for coolant
-if Yes, change doser NOT EGR cooler!
-if No, you haven't found the source yet
If you can't make the EGR cooler or doser leak while the rad is pressurized they are not likely your problem. If it appears to be "burning" the coolant and these are not the source of the coolant, you may have;
-head gasket issue
-cracked head
-injector cup leaking coolant into combustion chamber
-injector O-ring leaking coolant into combustion chamber
-liner starting to drop allowing coolant into combustion chamber
I agree that the EGR is the most likely culprit, but it is by no means the only possibility. Changing parts until a problem is solved is the biggest reason we fix our own trucks, too many of us have paid these "technitions" too much money to do exactly that instead of actually diagnosing the problem properly in the first place. I followed that logic for far too long, and Cummins never did find my problem...until AFTER the warranty has expired! Then "Oh, look at that. A manufacturing defect made the head leak coolant into the intake side of the head behind the ECM cooling plate." If they would have (or me) pressurized the cooling system for a longer time period and actually properly eliminated components with good inspections, they should have found it. As soon as the cooling plate was removed, the staining was obvious.
Rawze's instructions in post 4 are more in depth than this.