How much coolant loss is normal?

[Jedi Knight]

So I'm curious. Since I've bought my Jeep I've had to fill the coolant reservoir one time already (about a year ago) and now I have to fill it again as the coolant is below the MIN line. This will be the second time i've had to add coolant and I have 56,000 miles on the Jeep. Is this a normal thing or do I have a leak somewhere? I do my oil changes and the old oil looks fine and i've not seen any spots under my Jeep when I park of something leaking. So what do you al think. Normal or not?

[PhantomRescue]

You are just filling the reservoir, not the sealed cooling system. More than likely that at least 50% water you put in last time has since evaporated. It's just a "extra" reserve tank.

X2

It's just for overflow and the only time you should worry is if your jeep 'drinks' more than one of those tanks dry when you run it. You'll likely get a temp light LONG before that happens.

[Mark Doiron]

... I do my oil changes and the old oil looks fine and i've not seen any spots under my Jeep when I park of something leaking. ...

Just want to add a couple thoughts:

1. Make certain you get the right coolant. There are a couple threads about it, but Chrysler coolant is Chrysler coolant. GM, Ford, Toyota, etc are NOT. Make certain your new mixture is for Chrysler cooling systems.

2. There's another way to lose coolant: Blowing out the tailpipe. You'll see/feel this as a smoke/dampness at the exhaust. Oil may appear fine, but you're losing coolant through a blown head gasket.

As others said, you're probably fine, but just wanted to bring out those two points.

[goaterguy]

NO coolant loss is normal coolant loss. The reserve has two lines, the lower one is for when the engine is cold, and the higher one is for when the engine is hot (coolant expands with heat)

All modern cooling systems are sealed. Check your coolant level based and judge based on the engine temperature, if it drops, you have a leak.

If you are under warranty, let the dealer find the leak, if not have it pressure tested.

In my experience, leaks never get better and it's cheaper if dealt with them earlier.

[Mark Doiron]

NO coolant loss is normal coolant loss. ...

I topped off my coolant to the max fill line before hitting Moab this year. During my Moab trip I had a problem with coolant loss--could smell it and see it below the reservoir. I thought I had a leak. In fact, it was simply draining out the overflow tube because of maneuvers like this ...



and this ...



Now I let my coolant remain an inch or so below the max fill line.

[goaterguy]

The coolant reservoir is not sealed on a JK, therefore the water in the coolant mixture is allowed to evaporate. It actually has a giant hole in the top of it. Without that, you could not suck coolant into the sealed system, and the top would blow off when the coolant enters the reservoir. The last time it was topped off was over a year ago according to the original poster, not quite the last tank of gas. I would not be concerned.

You can completely run without an external reservoir, just as every domestic vehicle on the road at least until 1980. The JK system is no different.

You are kinda contradicting yourself here. I never said that the reservoir is sealed, I said that the system is.

The JK cooling system is sealed, and sealed systems have overflow reservoirs. The reservoir is not the deciding factor on how to determined if the system is sealed or not, what seals the system is the radiator cap and it's seal.

When too much pressure builds up in the radiator it pushes the cap spring and lets the pressured coolant release into the reservoir, when the engine gets cold, the system vacums coolant from the reservoir into the radiator. This happens constantly.

You could run without an external reservoir but the coolant would spill on the road everytime the engine warmed to operational temperature and you would have to top it off every day.

All modern liquid cooled vehicles on the road have a sealed cooling system and reservoirs.

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[goaterguy]

The Plymouth Barracuda was made from 1964 - 1974, not my definition of "modern".

Where does the hose on the picture goes?

I saw the reservoir of my JK yesterday while installing a clear bra and it's huge!

If the OP had to fill it within a year (under normal driving conditions) it is an abnormal loss.

[CerOf]

40K miles in one year and I've never had to add coolant to the reservoir.

I would say this is NOT normal.

I live in texas and temperatures range from a very dry and cold winter to a hot/humid summer.


My vehicle idles a lot and drives a lot.


Again, not a single drip of coolant/water has been added.

For that matter, the wife's Kia Sedona minivan has not required any additional coolant in over 2 years.

yes, different vehicles, but today, a cooling system is a cooling system. They are all similar enough.


I'd take it to the dealership (if under warranty) and inquire.

[CerOf]

The Plymouth Barracuda was made from 1964 - 1974, not my definition of "modern".

Where does the hose on the picture goes?

I saw the reservoir of my JK yesterday while installing a clear bra and it's huge!

If the OP had to fill it within a year (under normal driving conditions) it is an abnormal loss.

As for where that tube goes...on a lot of older vehicles it merely pointed "down" and terminated towards the bottom of the vehicle. If the coolant expanded and needed to go somewhere, it simply "spewed" out of the hose to the ground.

[Bob_O's Jeep]

Living here in South Carolina it gets pretty hot. About a year ago I had to add a fair amount of coolant to the reservoir. Never had to add any since. I kept an eye out for leaks but never seen anything, figured it just evaporated.