Car ? For The Auto Mech's

[Roadkill]

If your burning coolent (50/50 mix antifreeze/water) from a blown gasket or cracked head, can you tell by checking the exhaust? ie: sweet smell, white smoke, ect.?

[StandrdDev]

I'd bet it would smoke a bit, but another way would be to do an oil change and look for coolant/water in the oil. If it is a gasket or head then I'd bet it would seep down into the oilpan.

I'm not a mechanic though, maybe one will come along with a more definitve diagnosis.

Sigma

[BBA]

You can also tell by checking the spark plugs. The one with coolant in the cylinder will look brand new and the rest will be chalky, carboned or blackened.

[draboo]

I had a Chev 350 with a bad head. Massive amounts of white "smoke" aka steam coming from the exhaust.

A mechanic told me to wait till morning and check the oil. If there is any white stuff on the dipstick,then there is water getting into the oil. Or take off the oil cap where you add motor oil to the engine. It may have whitish glop on it,also

[Cruez]

If there is white smoke (steam)... it is leaking into the combustion chamber and turning into steam out the exhaust.

If the oil looks like a type of chocolate milk... it is leaking into the crankcase...

[BBA]

FYI: Just in case... Trans fluid will also burn with a very white smoke. If you have a vacuum shift modulator design trans ( TH-350) the diaphragms will go bad and allow the motor to suck trans fluid into the intake manifold. This really confuses a lot of people.

The rule is: A little white smoke, with a semi sweet smell...probably water getting into the cylinders. If the smoke is pure white and intermittant...with no real smell, it's trans fluid.

[jad1097]

If your burning coolent (50/50 mix antifreeze/water) from a blown gasket or cracked head, can you tell by checking the exhaust? ie: sweet smell, white smoke, ect.?


Yes.

[Roadkill]

Thanks guys. I guess I'm not burning it. Oil is fine, No smoke, no sweet smell to the exhaust. So I get to try and find out where a gallon of coolant per 100 miles is going. After driving a bit, I can smell it, but I can see no leaks. No wetness on the floorboard under the heater core, no spots on the ground, no drips, nothing. Arrg!

[Roswell_NX]

can it evaporate?...maybe there is a hole somewhere where it can escape when it heats up...i'm not exactly a car-literate person since i don't own one yet, but i still wanna help

Roswell :)

[roadtech]

Yes, The best thing you can do is check all your fluids to start with.
Sound like a headgasket.
What year is the car or truck

[Cruez]

You might want to find someone who can do a compression check on the cylinders. That is one way to see if the head gasket is in fact leaking.

There could be a small leak that could be evaporating... but a gallon over 100 miles is quite a bit.

[BBA]

I'd start with a new radiator cap. :)

[Roadkill]

It's a 91 Ford Explorer with the 4.0 L V-6.

This fluid has to be going somewhere. I'm not saying that I've lost 1 gallon in the last 100 miles, I'm saying I'm losing a gallon EVERY 100 miles (or less). I have to top off the radiator and refill the tank every other day. I've gone thru about 5 gallons so far. It's not going in the oil, it's not coming out the exhaust, it's not coming out of the heater core into the cabin, It's not coming out of the A/C drain hose, it's not dripping out onto the ground.

I'm beginning to wonder if that plastic radiator has a leak that only leaks when under the pressure of high RPM's while driving down the road. So when it idles and when I shut it off, it doesn't leak, but leaks when I'm moving.

[MDS]

They make a coolant dye that you can put in and run the engine. If it is or has been leaking somewhere you will see it with a blacklight.

[TwizComp]

Best Bet: Take it to someone who has a pressure tester for cooling systems. (local pepboys, etc...) Have em pressure test it to the specified LBS/PSI and you should easily find your leak, big or small. Definately gotta do this BEFORE replacing anything to properly diagnose your issue. Could be as simple as a cap, pinhole in a hose, or worse. Dont trust yours or others "guesses" as it could be a fatal mistake for your vehicle.

Brian

[halfwatt]

check your oil also for a milky color, it could be leaking internally into your oil

[TwizComp]

I'm beginning to wonder if that plastic radiator has a leak that only leaks when under the pressure of high RPM's while driving down the road. So when it idles and when I shut it off, it doesn't leak, but leaks when I'm moving.

It shouldnt cost you much if anything to have someone pressurize your cooling system. Its very imple process that takes maybe 1 minute to detect the leak if any. As per your quote, the highest build up of pressure would be right AFTER you shut of the hot egine, as there is no fan or other cooling components cooling the antifreeze. This is when the pressure is at its max. Imagine this:

~Boiling a pot of water with a fan blowing over it. it will cool slowly as the air ciculates.

~Boiling a pot of water with NO FAN. It will gradually build more pressure as the heat rises and boils off the water.

Just something Ive learned in my years of mechanics here in PA. Im definately not an expert, but i know the basics, and know you should always pressurize a cooling system before swapping or dying, or quessing the reason your loosing the coolant.

Brian

[TwizComp]

I also agree with HalfWatt. If your oil filler tube, or cap has a yellowish/white foam, then your most likely into a much bigger problem. Internal leaks are a main cause of engine failure, and severe damage.

Brian

[roadtech]

A gallon or so every 2 day is alot.
And it's got to be going some where.
Just because you don't smell it doesn't mean it's not coming out the exhaust.
The cataltic converter may be doing a good job of cleaning it.

The problem is if it not a clear cut thing it's hard to help you.
I know halfwatt and I carry just about every tester there is on our service trucks. I even have a laptop to work on or set up elec. forklifts.
If I could put my hands on it I could tell you whats going in no time.

At this point the best you can do is a leak down test with a coolant pressure tester.

[caddmannq]

One possibility that hasn't been mentioned is a loose intake manifold. Check all your mainfold bolts for looseness.

Often manifolds have coolant passages through them, and if the manifold becomes loose or the gasket leaks, coolant can be sucked right into the intake valves. Many "V" engines have a seperate valley cover, but if the bottom of your manifold forms the valley cover also, then coolant could show up in the oil as well, yet a compression test won't indicate a bad head gasket.

Anyhow, if you pressure test, this leak will leak, but it just might not be obvious where it's leaking from if it's running out from under the manifold, or simply filling up the manifold/cylinders with coolant.

[Roadkill]

Found the problem, a previous owner installed one of those coolant flush kit tee's, and it was loose. The coolant would leak when I was driving and stop leaking when the engine dropped down to idle. Replaced with a new hose, as the old one looked a little sad, and all is well. Thanks for the help!

[brainchild]

A bad cap will loose a lot of fluid.If there is no smoke,smell or leaks,I'd start withthe cap.