# Coolant leak



## Navyman1 (Jan 31, 2010)

I'm have been losing coolant in my VW Passat VR6 engine for some time now. I cannot for the life of me find the leak. There is never anything on the ground. I'm not sure if it's burning it or not. Oil looks good. I'm on a low budget right now. Is a pressure test nessesary if i already know it's leaking? I'm thinking not. What can I do next?


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## Giles (Jan 25, 2010)

You didn't say how much coolant you are replacing, but any amount would be of concern.
A pressure check , in most cases, is relativly inexpensive and will give marginal results. The pressure check will be done with the engine at a given temperature and the leak could be when the engine is cold or at a higher temperature then when pressure check was done.
(1) Is there any abnormal moisture on the inside of the car?--leaking heater core.
(2) Is there any signs of steam in the exhaust, white smoke, with engine at operating temperature?
(3) Have you ever had any work done on the car?

I asked this last question because when I was buying and selling cars, I would always ask if any repair work was done because many many times, these repairs had to be redone or something else was damaged during the repair.


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## Navyman1 (Jan 31, 2010)

There are no signs of moisture on the inside of the car.

If I let the car idle in the driveway, the coolant level will drop from max to min in say....1 hour.

I had the heater core replaced about 4 yrs. ago.

About a month ago, I used some radiator stop leak...it worked for maybe a week, then I started losing coolant again.

Appreciate the help.


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## Bondo (Dec 8, 2007)

> If I let the car idle in the driveway, the coolant level will drop from max to min in say....1 hour.


Ayuh,... How much is from Max to Min,..?? A Quart,..??

If it's loosing that that much in an hour, there's gotta be signs on the ground under the car...


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## Billy_Bob (Sep 11, 2008)

On all cars I've seen...

There is the radiator and a radiator cap.

Then a hose going from the radiator to a coolant reservoir.

And you fill the coolant reservoir to "MAX". As the engine heats up, coolant flows into the coolant reservoir. Then you shut off the engine. Then as the engine cools, coolant flows from the reservoir back into the radiator.

So are you saying that as the engine is idling for 1 hour, the coolant reservoir goes from MAX to MIN with the engine still running????


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## spark plug (May 5, 2009)

Navyman1 said:


> I'm have been losing coolant in my VW Passat VR6 engine for some time now. I cannot for the life of me find the leak. There is never anything on the ground. I'm not sure if it's burning it or not. Oil looks good. I'm on a low budget right now. Is a pressure test nessesary if i already know it's leaking? I'm thinking not. What can I do next?


As Giles (Poster #2) asked "Do you see any Steam in the exhaust?". sometimes, there is an internal leak in the Cylinder, which will leak and end up in the exhaust as steam! Or, the (Anti)-Freeze plug/s might be leaking! Either cause should show up in the Temperature Gauge with a higher than normal Temp.:yes::no:!


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## Dieseltech (Jan 22, 2010)

If you are having to replace that much coolant (a quart for every hour of operation) and there is no signs of leaks under the car....running or not....no signs inside the passenger compartment and no signs in the oil....that only leaves one place for it to go....into a cylinder. Does the car run normally or do you see a lack in power, temp changes?? Sounds like maybe you have a head gasket leaking...this would explain the stop leak working a day or two and then the compression blowing it back out, there is an inexpensive check that can be done for this as well...i believe you may even be able to buy a cheap DIY version at some auto parts stores, it basically is a chamber you put over the radiator with some fluid in it and hook the top side to vacumn and it turns color if exhaust gas is present in the coolant. Does this car have a turbo?


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## Navyman1 (Jan 31, 2010)

How much is from Max to Min,..?? A Quart,..??

probably about a good pint.


So are you saying that as the engine is idling for 1 hour, the coolant reservoir goes from MAX to MIN with the engine still running????

Yes. If I drive the car for 1 hour, The reservoir is empty and my low level flashes on the dash.

I don't think this engine has a radiator cap, I've never seen one. It's cold out so I'm not sure if i see steam in the exhaust or not. I have put my hand in the exhaust and I don't smell anything unusual. I do have a slight miss in the engine though making me think it's leaking past the gasket. There is no turbo. I like the test Dieseltech talks about. But what about having no radiator cap?


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## Billy_Bob (Sep 11, 2008)

It seems that this vehicle has a direct connect to the radiator and thus no need for a radiator cap!

And the reason that the level goes down while the engine is running.

BTW - I think this is a better design than the rest of the vehicles out there!


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## brons2 (Jan 25, 2010)

You can do an oil analysis and see if you've got ethylene glycol in your oil. I get analysis kits from my local CAT dealer. They're $11 each.


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## oldrivers (May 2, 2009)

hmmmm could also be a possible water pump failure , alot of times the waterpumps have a weep hole thats really hard to see cause everything is in the way of seeing it. also if its getting hotter than normal because the pump is bad the coolant could slightly steam its way out of the radiator etc where you cant really see it ... those coolant components only hold so much pressure and if its overheating they can leak steam if pressure builds up to high ... im putting my money on the waterpump ...


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## spark plug (May 5, 2009)

oldrivers said:


> hmmmm could also be a possible water pump failure , alot of times the waterpumps have a weep hole thats really hard to see cause everything is in the way of seeing it. also if its getting hotter than normal because the pump is bad the coolant could slightly steam its way out of the radiator etc where you cant really see it ... those coolant components only hold so much pressure and if its overheating they can leak steam if pressure builds up to high ... im putting my money on the waterpump ...


Yes. One of the major signs that it's the Water Pump, is, when the Temp. goes up, but no heat comes out of the heater in car!:yes:!


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## twink288b (Feb 2, 2010)

oldrivers said:


> hmmmm could also be a possible water pump failure , alot of times the waterpumps have a weep hole thats really hard to see cause everything is in the way of seeing it. also if its getting hotter than normal because the pump is bad the coolant could slightly steam its way out of the radiator etc where you cant really see it ... those coolant components only hold so much pressure and if its overheating they can leak steam if pressure builds up to high ... im putting my money on the waterpump ...


Agreed 100%... put it under pressure and you will see it drip from the weep hole on the water pump...


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## Navyman1 (Jan 31, 2010)

Alas, I have found the leak.:thumbsup: This engine, a VR6 has an auxiliary electric water pump. And that is the culprit!:thumbup:. I am so glad it's not the head gasket.


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## oldrivers (May 2, 2009)

yes that is good. glad it wasnt worst than it could have been . $$$$$ saved


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