2006 CRD Limited Loosing Coolant... Pass Cold Engine Test.

thomasnelson

New Member
Joined
Dec 25, 2016
Messages
6
Reaction score
1
Location
Spring, TX
Hi All.

I need help figuring this out...I know this has been covered many time before... but none of the previous solutions fit here...

Situation. Every few days, not all, I get a LoCOOL message on the instrument cluster and have to top off the reservoir. The distance driven can vary from 10 miles to 400 miles. I preformed a Cold Engine Test. After 5 minutes there is absolutely no pressure in the reservoir. And after the thermostat opens at full operating temp there is still no pressure in the reservoir. But driving about 10 miles pressure starts to build yet no coolant loss at this time.

For some reason the system loses coolant after being driven yet there is no signs of a leak on the ground and the engine start normally... no indication the coolant is entering the cylinders and burning off.

I was thinking I might have a crack in the reservoir but I soaped the whole thing down looking for leaks.. found none.

I am the original owner, Had the EGR deleted in 2019, Running GDE EcoTune Full torque.
 

turblediesel

memberable
Joined
May 31, 2015
Messages
2,677
Reaction score
400
Location
Isolation Alaska
It must be going somewhere. Water pump weeping? There are a lot of little elbow hoses in there. The elbow on the engine oil cooler gets a lot of heat. Maybe the "LOW COOL" level switch is hanging up.

Other options are cracked head or bad head gasket.
 

thomasnelson

New Member
Joined
Dec 25, 2016
Messages
6
Reaction score
1
Location
Spring, TX
I've checked the reservoir for exhaust gases with a chemical tester... Negative. That should rule out a bad head gasket correct?? Are there any other signs that would indicate a cracked head??

I'll recheck all the hoses again and report back.
 

thomasnelson

New Member
Joined
Dec 25, 2016
Messages
6
Reaction score
1
Location
Spring, TX
No coolant in the oil pan... nothing but fresh oil.

It seems to lose the coolant after I turn off the engine. I've check the levels before I take off and when I get to my destination and there is no change. After the Jeep sits for a while, when I recheck, the level has dropped. Still no coolant on the ground.
 

Michael Wolfe

New Member
Joined
Feb 14, 2021
Messages
15
Reaction score
2
So somewhere it's consuming coolant, then when the system cools, and the remaining coolant contracts, it draws from the reservoir as designed.
If there are no physical leaks, (radiator, water pump weeping, heater core, viscous heater, not leaking at any plugs where the EGR components fell off, and all connecting hoses) then it must be passing into the engine oil, or maybe the transmission (if your transmission oil cooler is part of the radiator), otherwise it's going out the tailpipe. I assume you don't smell coolant anywhere.
Unless it's a very small amount, oil would turn milky. a small amount may boil off since the oil gets hotter than 212 in various parts of the engine.
unless the head is cracked somewhere that lets the coolant enter the intake or exhaust side of the valves, I would think your coolant would be pressurized.
Have you actually ran a pressure test of your cooling system? I mean pressurize the system to the rated cap pressure while the vehicle is off with a cap adapter? If you can't find a physical leak, then either way, the head is most likely going to have to come off.
 

Billwill

Full Access Member
Joined
Nov 26, 2009
Messages
1,906
Reaction score
411
Location
White River, South Africa
Have you checked the "Low Coolant Sensor" connected to the bottom of the plastic reservoir?

This is fitted in somewhat loosely with a thin rubber O ring.

My sensor got slightly dislodged and slowly leaked water out years ago.

I fitted a new O ring and to be on the safe side sealed the whole lot with Permatex sealer.

In my case I could see the slight leak though.;)
 

thomasnelson

New Member
Joined
Dec 25, 2016
Messages
6
Reaction score
1
Location
Spring, TX
So somewhere it's consuming coolant, then when the system cools, and the remaining coolant contracts, it draws from the reservoir as designed.
If there are no physical leaks, (radiator, water pump weeping, heater core, viscous heater, not leaking at any plugs where the EGR components fell off, and all connecting hoses) then it must be passing into the engine oil, or maybe the transmission (if your transmission oil cooler is part of the radiator), otherwise it's going out the tailpipe. I assume you don't smell coolant anywhere.
Unless it's a very small amount, oil would turn milky. a small amount may boil off since the oil gets hotter than 212 in various parts of the engine.
unless the head is cracked somewhere that lets the coolant enter the intake or exhaust side of the valves, I would think your coolant would be pressurized.
Have you actually ran a pressure test of your cooling system? I mean pressurize the system to the rated cap pressure while the vehicle is off with a cap adapter? If you can't find a physical leak, then either way, the head is most likely going to have to come off.

No signs of leaks on the ground.
No Coolant in the oil. Not Milky
Exhaust doesn't smell like coolant is passing through the engine.
Chemical coolant test doesn't indicate exhaust gases.
Reservoir not pressured after several minutes when starting from Cold. Does slowly pressurize after reaching full operating temp and thermostat opens.
Don't have the means to pressurize the system with the engine off.
Don't really want to "pop the top" unless justified. I don't have the fund for a mechanic to go on a fishing expedition.
 

thomasnelson

New Member
Joined
Dec 25, 2016
Messages
6
Reaction score
1
Location
Spring, TX
Have you checked the "Low Coolant Sensor" connected to the bottom of the plastic reservoir?

This is fitted in somewhat loosely with a thin rubber O ring.

My sensor got slightly dislodged and slowly leaked water out years ago.

I fitted a new O ring and to be on the safe side sealed the whole lot with Permatex sealer.

In my case I could see the slight leak though.;)


I was thinking the reservoir may have a crack or something, but never thought about the sensor O-ring... I'll check this afternoon if it doesn't storm today.
 

William Waddy

New Member
Joined
Jul 19, 2011
Messages
8
Reaction score
0
Location
St. George, UT
I've been having a similar problem and hope you will keep posting as you work through this. Thanks! I did run some head gasket sealant through the system and it has slowed down the leak, but not stopped completely. Just like you, no milky oil, no apparent leaks, no white exhaust, etc.
 

Latest posts

Members online

Top