The Mysterious Case of the Disappearing Coolant

[jhknight56072]

The coolant reservoir on my 1999 4.0 seems to empty itself. It only takes a few trips before I have to add to the tank again. I never see it more than half full when hot and I never see any liquid leaking anywhere, though sometimes I smell hot coolant aroiund the front end after parking in the garage when engine is hot. If I opne the hood at that time I can smell coolant but see nothing wet.. what's going on????

 

[Big Jim M]

The coolant reservoir on my 1999 4.0 seems to empty itself. It only takes a few trips before I have to add to the tank again. I never see it more than half full when hot and I never see any liquid leaking anywhere, though sometimes I smell hot coolant aroiund the front end after parking in the garage when engine is hot. If I opne the hood at that time I can smell coolant but see nothing wet.. what's going on????

What is going on is YOU! You ain't looking good enough!! You obviously have a small leak.. Your job is to FIND IT! Lay down under the vehicle with a flashlight and look closely for ONE SMALL drip. It IS THERE! You simply havn't looked good enough. The coolant ain't going UP to the top of the engine!! It is going down (gravity you know) and dripping on to the street. So get under there and LOOK!
Big JIm

 

[fordwheelinman]

even looking underneath doest do a whole lot sometimes

 

[almostclueless]

Intake manifold (hopefully, because otherwise likely a head gasket or cracked head/block).


It needs to found much sooner than later, or a hopefully simple problem will kill the engine.

 

[jhknight56072]

You simply havn't looked good enough. The coolant ain't going UP to the top of the engine!! It is going down (gravity you know) and dripping on to the street. So get under there and LOOK!
Big JIm

The bottom of everything is dry too smart guy and my garage floor you can eat on.



How do I tell if it's leaking in the manifold or head gasket? I notice the engine will start and run rough sometimes, is this why?

 

[Big Jim M]

The bottom of everything is dry too smart guy and my garage floor you can eat on.



How do I tell if it's leaking in the manifold or head gasket? I notice the engine will start and run rough sometimes, is this why?

One must be smarter than the LEAK!! One might have to lay on his back with a flashlight and crawl under the vehicle and LOOK FOR ONE SMALL DROP of coolant! The coolant doesn't need to coat the complete underside of the engine... ONE DROP is what one is looking for.
As a child did you do well on Easter egg hunts?
Big Jim

 

[rboyer]

Pressure test the thing to the max and then take a look. I had a similar problem with my 4.0 Ranger. It was emptying the reservoir every 1000 miles or so which wasn't too bad but it bothered me because I could smell coolant but couldn't find any leaks. One day I finally got enough time to mess with it so I hooked up the pressure tester and pumped it up to like 25lbs and low and behold it was pissing a tiny bit of coolant out of the end cap on the passenger side of the radiator. There was a really small dark spot on there so I could tell that it had previously leak from that spot and my assumption is that being such a small leak and being subjected to the air moving through there it never had any time to form drips. That's just one scenario out of countless so i'm not saying that's your problem, but it wouldn't hurt to pump it up with a pressure tester.

 

[289-tiger-]

I agree with rboyer. The endcap to core seal would be my first thought especially if the leak got worse as the weather got colder. My 94 had a small leak also at the upper a/t line into the drivers side endcap that never dripped to the ground.

Also the overflow tank to cap hose will bleed coolant over time. Check all hoses and connections also.

Good luck

 

[koda6966]

I had a rotten hose. It leaked pretty bad.
12 dollars at Advance, along with some clamps, and problem solved.
So check your hoses, one could be rotten or loose.
That could also explain why it got worse with cold, rubber shrinks when its cold so a rotten hole could get bigger.

 

[100890]

Lay off the guy Big Jim!

Come on big jim, jh knight asked for help and you want to chastise him. Is there something personal here or what. If we get new members in here and they see what is going, they won't contribute. I don't know about the rest of you but i don't know everything about the ranger and they might know or give input on something that we have a problem with but now if they ask a question about something and they might get treated like @#$! Thats not the way we should be doing business in here!


Knight, check out everything on top and underneath. If you have a small leak, it's not going to drip to the floor all the time. Just my 2 cents worth!

 

[KELLY88]

With ya 100% 100890. Take it easy Big Jim, he's got a genuine problem and raggin on him won't help solve it.

As for the coolant leak, does the exhaust come out white all the time? That would indicate it's leaking into the combustion chambers. There's also another trick for finding an elusive leak. There's a UV dye that can be poured into the coolant system, run for about 50 miles or so then check with a UV light to try and find the source. My dad had to use it once but the mechanic gave it to him. Not sure if you can buy the dye at a parts store but you probably could. If not, try talking a mechanic into selling you some, should only be a couple bucks. Good luck.

 

[jhknight56072]

thanks 100890, will take a closer look at the radiator after I borrow a pressurizer. I hope that is where it is. I should have stated a rate of leak too, which is the overflow tank was noticeably lower after each 17 mile commute to work and home. After just a few trips it was pretty low. I filled the thing once and now I figured I'd ask some knowledgable folks who know Rangers . ( I didn't ask for B***S***!)
kelly88; I don't think there's any unusual amount of visible exhaust. I've seen the steamy exhaust on a car that lost coolant through the head gasket and this truck isn't steaming. No, I have not been able to aquire any dye.

 

[100890]

No problem knight, hope you fing the problem. I agree with MOST of the guys on here. it could be a number of things. Just hafta take am one at a time. As for Big Jim, I don't know what his deal is but thats not the way business should be done in here. Let me know what you find out about the leak and we'll use the info for future reference.

Mike

 

[289-tiger-]

Like your attitude 100890. Lets help keep our members on the road.

 

[Roadkill]

What about adding the UV dye to the cooling system? Then run it a few days, one time at night take a black light and use it to inspect the engine. If it's dripping or running out a hose or on the block then it will show up. If it's a cracked head or gasket then a leak down pressure test is in order to find it.