The case of the disappearing coolant.

[MuddFlapp]

As you can surmise this is about having to replenish my coolant frequently. I can find no leaks anywhere, the oil is black, the coolant is green and there is no steam coming from the exhaust. This brings me to the radiator cap. I replaced the cap with a Stant OEM 16 psi. cap. So my question is two-fold:

1: Are all caps created equal? Is my Stant cap at $7.53 as good as another vendor's cap at $19.99?
2: Where the heck is my coolant going?

Thanks

 

[petersonj]

The quickest and most direct way to diagnose for a coolant leak is to use a coolant pressure tester. If you don't have one, you can usually get one from a local auto parts store (borrow or rent). Tracking down coolant leaks can be elusive as the leaks may not occur all of the time and if the coolant from a leak runs over hot engine parts, it just evaporates.

Perform the test on a cold engine. Then pressure tester will check your radiator cap as well. Almost every time I've used the coolant pressure tester, I have found the source of the leak quickly.

- John

 

[Darkbloodmon]

I second getting a pressure tester, I got the chemical coolant test kit but with all the mixed reviews on how well it works on diesel, I just returned it and got a pressure test kit. It's more accurate in my opinion.

 

[GCroyle]

Any recent cooling system repairs?

 

[MuddFlapp]

Any recent cooling system repairs?

Approx. 18 months and 10,000 miles I replace the two small cabin heater hoses on the engine. Maybe one of them is leaking and as John has said, the coolant is evaporating on the engine/exhaust manifold. I guess it's time for a pressure tester. Or maybe I'll tighten the clamps a see if that stops the loss.

Thanks to all.

 

[Tuesdak]

Or maybe I'll tighten the clamps

Replace the screw clamps with the proper constant tension spring clamp. Screw clamps are known to randomly leak when cold on this engine. I believe it's the PIA one by the oil filter that there is a TSB out to use spring clamps on for this exact random leak reason.

More info and updated hose here:

https://www.turbodieselregister.com/threads/coolant-leak.247208/

 

[gsbrockman]

2: Where the heck is my coolant going?

It might would help if you specified xx number of ounces, cups, pints, quarts, or gallons over yy hours, days, weeks, months of loss.

 

[MuddFlapp]

Replace the screw clamps with the proper constant tension spring clamp. Screw clamps are known to randomly leak when cold on this engine. I believe it's the PIA one by the oil filter that there is a TSB out to use spring clamps on for this exact random leak reason.

More info and updated hose here:

https://www.turbodieselregister.com/threads/coolant-leak.247208/

 

[bcbender]

the oil is black, the coolant is green and there is no steam coming from the exhaust.

Why is the coolant green?.....

 

[Wayne M.]

The water pump is a tricky one. Sometimes they won’t leak when they’re not turning, and when they are, the engine is warm and the coolant evaporates. If it is the WP, it’ll eventually start slinging coolant onto the side of the air cleaner box.

 

[Ozymandias]

The connections Radiator to Radiator Hoses on mine leaked once slightly. Leaving very little white traces.

 

[JR]

If it is a small leak and is leaking on something hot it will quickly evaporate as it drips on the hot surface and generally leave a stain as evidence.

Being a new cap its likely OK but I wouldn't bank on it lasting as long as your OEM. Aftermarket parts ain't what they used to be, with a few exceptions.

 

[AEdelheit]

There is a small section of rubber coolant line between 2 hard lines behind the turbo that are notorious for leaking enough for the level to go down but not enough to make a puddle on the floor, you can see it with a flashlight from the bottom or through the fender well, I would check that even if you found other issues as if its not leaking yet it will at some point.

 

[bcbender]

Aftermarket parts ain't what they used to be, with a few exceptions.

Agreed!!! Leak down / pressure test is best for these situations.

 

[MuddFlapp]

Turns out it's my radiator. Thanks for all the input.

 

[bcbender]

Lost mine suddenly (tank cracked) about 6 months ago.. Glad you found it, leaks are a PITA to chase down