How much does coolant evaporate?

[The motor guy]

It seems my truck has lost about 5 ounces of coolant over the last 7 months or so. This is about 4,000 miles. I've started driving it more over the summer than I did in the winter. Now this isn't that much considering the entire capacity of the vehicle is 27qts. Should I be worried about this? The level in the bottle goes up and down like normal and it isn't bubbling or anything like that so I don't think it's a head gasket issue. Do you think the coolant just evaporated a little bit? It has been over 100 degrees outside the last three months or so. The cap they put on the degas bottle isn't really the best so there is a way for it to evaporate. Is 5oz of coolant not much to lose sleep over?

 

[jorton]

I hope that's ok. My small cars lose about the same in around double the miles.

 

[Trav]

Coolant has water content so I'm sure there could be some evaporation under the conditions you operate in.
I wouldn't panic at this point, keep an eye on it and check the obvious e.g. milky oil or anything external.
If this happens again at lower ambient temps do a UOA to get a better idea of where the loss is.

Keep in mind that the smallest of external weepage can just be burned away on a hot pipe or manifold.
Thay can be hard to find under normal operating conditions, as they tend to weep more at high temps and pressures.

 

[demarpaint]

I'd pressue test the system to be sure. Under normal conditions I never add coolant between changes.

 

[The motor guy]

Originally Posted By: demarpaint
I'd pressue test the system to be sure. Under normal conditions I never add coolant between changes.
How do you do that?

 

[Trav]

With a pressure tester.
The problem is with it being such a small amount over a 7 month period the tester may not be able to duplicate the condition too easily.

A small air bubble may have been hanging around in the system for a long time also. especially if the coolant has been changed.

 

[The motor guy]

i'm gonna get the oil analyzed. Then I will see what's up. I just changed the oil a few days ago and took a sample so i will send it in. The oil looked normal. It wasn't milky or anything.

 

[Smokefan1977]

Check behind the turbo. There is a coolant coupler behind there that is notorious for leaking small amounts of coolant. Often not enough to reach the ground before evaporating. Also check the hoses on the pass side of the truck. Coolant leaks are common of these trucks

 

[The motor guy]

Here is a picture of the exhaust manifold. This is right where a couple coolant hoses are from the egr cooler. You see those dots on the manifold and also that brownish looking stuff? Isn't that coolant? That's been there for a long time. Atleast since the dealer replaced the turbo which was a couple years ago. Wouldn't that stuff burn off? Or do you think I have a leak occurs while moving. I figured it would burn off and disappear. But it's been like that for a couple years as far as I know. http://i1176.photobucket.com/albums/x328/bigoledodge07/Picture153.jpg

 

[Smokefan1977]

That sir is where your coolant is going!! It appears the dealer didnt not replace the hose or the clamps. i would replace both and go from there. Coolant leave a residue behind when it dries. How much is based on the ratio. In a sealed system I have never seen coolant evaporate.

 

[The motor guy]

I'm just wondering if that's just where the dealer spilled it from unhooking the hoses. Wouldn't that dissapear after a couple years if that's all that happened or do you think there might be a hose seeping slightly when the engine is under load? This is actually an old picture but that residue on the manifold is still there currently.

 

[Smokefan1977]

yes with the amount of coolant loss and the time it is a very slow leak. Put it this way it's so common I keep about 20 of the kits instock at all times.

I cant say if that where they unhooked and didn't clean it. if they didnt that pretty poor on their part.

 

[The motor guy]

Well hopefully thats what it is. It's not that big a deal if that's the case. I'm gonna send off a sample for the oil and I'll see what turns up. There are so many hoses and clamps on these new diesels it's just a disaster waiting to happen. Wait until these trucks are 10 years old and these hoses are rotten.

PS: I think if they just spilled some there would be big spots. This looks like it's being sprayed from one of the hoses.

 

[Smokefan1977]

Yes and the coolant comes out with great force when disconnected. There would be spots on the chassis parts aswell. Im confident you have the right issue here. let me know how it ends up and if you need any advice just let me know

 

[demarpaint]

Originally Posted By: motor_oil_madman
Here is a picture of the exhaust manifold. This is right where a couple coolant hoses are from the egr cooler. You see those dots on the manifold and also that brownish looking stuff? Isn't that coolant? That's been there for a long time. Atleast since the dealer replaced the turbo which was a couple years ago. Wouldn't that stuff burn off? Or do you think I have a leak occurs while moving. I figured it would burn off and disappear. But it's been like that for a couple years as far as I know. http://i1176.photobucket.com/albums/x328/bigoledodge07/Picture153.jpg


If there is a leak where there's traces of coolant left behind, the pressure tester should find it. I'd give pressure testing a shot.

 

[HTSS_TR]

I had to add approximately 4-5 oz coolant every year or two to all my cars.

 

[ltslimjim]

^So, that's an 'evaporation' of about an ounce every 3 months at least?

 

[HTSS_TR]

It seems like an ounce a quarter, but I didn't bother to add water or antifreeze until the level on reservoir was at or below the minimum line.

 

[The motor guy]

Alright so I got the oil report back and everything looked normal. Except for lead which was at 13. Normally at 3 but that doesn't really have anything to do with coolant plus that's very minor wear. Could have been a spec of dirt that got in the bearings. So it must be leaking slightly from a hose. It's such a small amount i'm not going to mess with it. Probably just make it worse.

 

[bullwinkle]

My '06 Cummins Ram had a leak in that same spot, put blue Loctite on the hose clamps and tightened them up, it has not lost a drop in the THREE YEARS since then (although it is time for a coolant change anyway)!