YACT: how can i tell if my heater core is leaking?

[flood]

I've been losing coolant at a slow rate, so i had a pressure test done on the cooling system. they found no leaks, and i recently had the head gasket replaced. my heater has been acting a little funny, but it still works ok. my suspicion is that the heater core is leaking coolant. i dont think they checked it when they did the pressure test. is there anything i can do to confirm this without getting it out (its hard to get to)?

 

[Ronstang]

If no steam is coming out your defroster vents then you probbly don't have a heater core leak....and a pressure test would have found even a leak in the heater core.

 

[HappyPuppy]

If your feet aren't wet you heater core isn't leaking.

 

[Scarpozzi]

Well said. When you have a heater core leak, you'll know it. I had an old truck give me those problems and the cab of the truck was like a sauna.

If you're leaking water, wait until it's nice and frosty outside. Start your car up and then look for steam with a light after it gets warm.

 

[flood]

problem is, its a very slow leak. im losing about a quart every 3-400 miles. the pressure test showed no leak in the engine compartment. i've also had the water pump replaced, so that cant be it. i suppose the only other thing it could be is the head gasket, but it was replaced about 2k miles ago. any ideas?

 

[HappyPuppy]

Originally posted by: flood
problem is, its a very slow leak. im losing about a quart every 3-400 miles. the pressure test showed no leak in the engine compartment. i've also had the water pump replaced, so that cant be it. i suppose the only other thing it could be is the head gasket, but it was replaced about 2k miles ago. any ideas?

Crappy mechanic, possibly?

 

[flood]

Crappy mechanic, possibly?

possibly. would the pressure test reveal a leak in the head gasket?
i also have a new radiator and some new hoses.

 

[flood]

bump?

 

[HomeBrewerDude]

Originally posted by: Ronstang
If no steam is coming out your defroster vents then you probbly don't have a heater core leak....and a pressure test would have found even a leak in the heater core.

 

[flood]

hmk, so if its not the heater core, and i cant visibly spot a leak, does that mean it has to be the head gasket?

 

[HomeBrewerDude]

you could just go ahead any replace your hoses and see if that fixes the problem.

 

hmk, so if its not the heater core, and i cant visibly spot a leak, does that mean it has to be the head gasket?

First off, what is the make/model, engine and year of your vehicle ?


Possible causes of coolant loss ;

Blown Head Gasket
Cracked Cylinder Head
Cracked Block
Leaking freeze out plug
Leaking water pump
Leaking hoses
Leaking radiator
Leaking thermostat housing gasket


A cheap easy way for the home mechanic to check the heater core is to run a bypass hose around the heater core, this will redirect the coolant back to the block instead of it passing through the heater core.
Run the vehicle for a month (DAMN COLD !) and see if you lose coolant.
Now mind you, this is for the cheapskate vehicle owner
Go to a different garage and have it pressure tested again while the engine is fully warmed up.

Does the exhaust produce steam when the vehicle is fully warmed up ?
Does the oil look like chocolate milk ?<-----Blown Head Gasket or cracked head or block
Is there a gooey brown substance underneath the oil fill cap?
Do you have an automatic ?
If you do, look at the fluid closely, is it like a milkshake ?<--Possible leaking radiator(There is a coolant tank inside the radiator that cools the tranny fluid)


The super elcheapo way out is too pour some pepper into the radiator and warm up the vehicle fully, the pepper will find it's way to the leak and plug it.

Usually if your heater core is leaking, you will smell the coolant occasionally and you might experience window steaming.

 

[KMurphy]

If it's your heater core, you will smell it bad on the inside of your vehicle (unless you don't use anti-freeze).

It could be the weep hole in your water pump.

Make sure you have a good radiator cap, one that bleeds off pressure into the overflow container when the coolant is hot and will let the coolant back into the radiator when it cools back down.

 

[Analog]

Originally posted by: HappyPuppy
If your feet aren't wet you heater core isn't leaking.

nice

 

[Vette73]

When the car is warm look for the drain valve on the lower part of the fire wall. If the heater core is leaking it might not leak into the car but leak out the valve. Same lace water comes out in the summer time(AC)

 

[Perknose]

Like Roger and KMurphy both said, if you use antifreeze and have a heater core leak, you should experience that "sickly sweet" smell in your interior with the heater/defroster on.

 

[NikPreviousAcct]

If your heater core is leaking, like mine did, you'll spew coolant all over the windows as a mist and it will drip down on the passenger side all over the floor and floormats leaving puddles eventually. Ever tried cleaning antifreeze film off of the windshield!? :frown: Bypass the heater core like I had to do or get it fixed. Trust me, you'll be sorry. It's been four months since I disconnected mine, and the passenger side floor is STILL wet. I don't know how to clean it up. There aren't puddles or anything, but that coolant has coated everything and it's a bitch on anything you lay on the floor other than shoes.

 

If your heater core is leaking, like mine did, you'll spew coolant all over the windows as a mist and it will drip down on the passenger side all over the floor and floor leaving puddles eventually. Ever tried cleaning antifreeze film off of the windshield!? Bypass the heater core like I had to do or get it fixed. Trust me, you'll be sorry. It's been four months since I disconnected mine, and the passenger side floor is STILL wet. I don't know how to clean it up. There aren't puddles or anything, but that coolant has coated everything and it's a bitch on anything you lay on the floor other than shoes.

Not entirely true, if he has a very small pinhole in the heater core, it will not produce puddles or even mist the windows, it depends on the size of the leak



ffmcobalt

Want a sure fire way of cleaning that mess up ?

Soak the floor of your vehicle with a garden hose, then wet vac it up, do this at least once a day for a week, this will dilute the antifreeze stuck in the fibers of the carpet and carpet backing to the point where it will be mostly water and it eventually dry on it's own.


Do not under any circumstance allow it to stay soaking wet, mold will form and then you will have a mess that you will not be able to clean up.

 

[flot]

It sounds like you have a very small leak. That could be anywhere - even a hose with a small crack that only opens up when the engine is warm.

A pressure test should have helped spot a leak /anywhere/ in the system.

The big symptoms of a heater core leak are the smell of antifreeze in your car (kind of sweet/syrupy) and/or visible leaks and/or fogged windows when you turn the heater on.

Honestly... it sounds like a relatively trivial problem... unless you have some particular attachment to the car and keeping it at 110% all the time.. buy a bottle of radiator stop leak. Don't go overboard and get one of the ones that has big chunks of solid crap - go for the ones that look like a vial of pepper, or some I believe are entirely liquid. I'm pretty sure prestone makes two kinds, one which is all liquid and one which has solids in it.

Someone can jump in and correct me, but back when I was in high school I had a 13 year old car that sprang leaks in various places, and I must have kept the cooling system together for at least 3 years by adding various stop-leak type additives. If you start small, I really doubt you'll do any harm and you might just solve your problem permanently - for about $3.

 

[flood]

i have a 91 bmw 735i. its an auto.
the atf looks ok. i took a look at the dipstick, and there appears to be cream at the top of it. is this a sign of a head gasket problem?
if so, can i use some of that stop leak stuff until i get it fixed?

 

i have a 91 bmw 735i. its an auto.
the atf looks ok. i took a look at the dipstick, and there appears to be cream at the top of it. is this a sign of a head gasket problem?
if so, can i use some of that stop leak stuff until i get it fixed?

That's a sure sign of coolant making it's way into the oil, you have either a blown head gasket, cracked cylinder head or cracked block.

The Stop Leak will most likely not work, you can try to retoque the cylinder head bolts, this might stop a slow leaking head gasket but it will not help if your cylinder head or block is cracked.

I wouldn't sweat it, just keep adding coolant.

 

[resinboy]

find a mechanic who uses ultra violet dye- we have used it for years- add a bottle- drive it for a week or so, hit it with the light- shows up bright puke yellow- can't miss it.
All you case modder boyz should have some sitting around for your water cooled rigs!
Resinboy

 

[N8Magic]

and i recently had the head gasket replaced

he atf looks ok. i took a look at the dipstick, and there appears to be cream at the top of it. is this a sign of a head gasket problem?

Did they check to see if the head was warped when they replaced the head gasket? Did they machine it?

If the head was moderately warped and they just replaced the gasket, you will still have a leak.

 

[kevreilly7]

A creamy dip stick does not always mean it is a head gasket,,,On some models it could be a leak at the intake manifold.....before anyone spends ALOT of money on a head gasket you should have a postive outcome on the radiator gas test!!!!