I have a 2002 Dodge Durango First Generation with the 4.7L 8cyl engine (220K Miles)
Recently I am loosing cooling fluid over a period of two weeks.

No External Leaks of Cooling Fluid
Engine runs fine
No check-engine light.
No water in the oil
Cannot find any leak with dye and a black light.
No rough Idle
No missing
Getting 15 MPG
No Stalling
We pressure tested it and it loses pressure at a rate of 1lb. per 20-30 Min.
I had some fluid in my tail pipe. I taste tested it it is Coolant (Sweet) I just checked it again 3 times and no sugar taste at all i think i had some on my finger from working with the coolant : )
Gas tested the cooling system and the color remains blue
No loss of acceleration
Brake fluid tested manifold with no acceleration
No Water in the oil.
Does this engine have cooling fluid going through or near the intake manifold on the 2002 Dodge Durango? Answer Found = No cooling fluid does not go through intake manifold. 10/02/2020 cw

What are your thoughts?

How can one discriminate between a bad intake manifold gasket, Blown Head gasket or a cracked cylinder head?
I seem to be getting conflicting information!

Thanks for your interest.

Chris

 

It's gotta be going somewhere...... Not as familiar with the 4.7 as I would like to be, but, an intake leak isn't going to make it to the cylinders, the passages are simply too far away. If the intake were leaking, it would either be external, or, into the oil.

If you are seeing coolant in the exhaust pipe, then likely what you have is a cracked head. Though in that case, I would expect that the test you did would actually SHOW combustion gases in the coolant. The fact that it doesn't, is puzzling.....

And just to throw a monkey wrench into the works...... I have seen coolant leaks that drip onto a hot surface, and pretty much immediately boil off, so you never see anything hit the ground...... I would expect that would show up under a UV light though, with dye in the coolant......

Yer gonna have fun finding that one. I wish you luck.

Welcome to DF!

 

Thank You DF! I edited the post a little that the liquid in the tail pipe i tested it three times and I found no coolant taste today just now.

 

Is it possible the heater core has something to do with this? Is it the radiator? i put a piece of paper in front of the radiator (not the cooling unit) and it barely pulled the paper to the Radiator. I will try to back flush the fins on the radiator in the am.

 

If the heater core was leaking, your passenger floorboard would be wet, and the defroster for the windshield would actually fog it, not clear it.

 

Liquid coming out the tailpipe is normal. Water is a byproduct of combustion.

Jack up the truck and put it on stands. Pump up your pressure tester to 21 psi, get under the truck, lay there and wait for the drips or put a clean sheet of cardboard so it is easy to spot. Sometimes it takes a while. Last time I was losing coolant, it was a loose clamp on a heater hose.

 

tasting exhaust liquid? You can clearly smell coolant if it's getting in(or even past the combustion chamber) or in the exhaust. It will have a sweet smell, It's definitive if you know the smell. I would look at the the hose clamp locations for leaks as Dodgevity mentioned.

 

I have a coolant smell all over because it over heated and I did not take time to wash it off. It is sweet to the taste and condensation is not so I was a little goofy and tasted it from my finger touching it.

 

No coolant smell inside the vehicle. No moisture fogging the windows or standing on the floor.

 

Do you have a rear heater??