HOW you find out if there is an internal coolant leak in your 2.7T.well you should check this !
10-20-2006, 09:00 AM
#1
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HOW you find out if there is an internal coolant leak in your 2.7T.well you should check this !
what you see is evaporated and then condensated coolant from the PCV system (chocolaty stuff) , there and under the oil cap.
this of course ..esp when your coolant level is going down and NO visible leaks can be found .
<img src="http://pictureposter.audiworld.com/47312/pcvcoolantoil.jpg">
this of course ..esp when your coolant level is going down and NO visible leaks can be found .
<img src="http://pictureposter.audiworld.com/47312/pcvcoolantoil.jpg">
10-20-2006, 09:23 AM
#2
I would add that if coolant is going down and you can't find external evidence of a leak, better get
an oil analysis right away. Also, if your oil level seems to rise for any reason, investigate further. Coolant makes a really bad lubricant for the engine!
I think many people figure that coolant is relatively cheap and just topping off the expansion tank is easy, so they can get lulled into ignoring the issue and the end result can be quite serious. Conversely, many people will immediately complain about a few drips of oil on the driveway, when the reality is this is a mere nuisance.
And if you ever find a bit of oil floating in the expansion tank, this is also an alarm bell to get it checked out - yeah, maybe it's only a one way oil-into-coolant leak, but I wouldn't ignore it if you want your engine to make it through the month. BTW, the only reason I say all this is I don't think too many people will inspect the PVC system on a regular basis, but I could be wrong.
Thanks for the warning and advice!
I think many people figure that coolant is relatively cheap and just topping off the expansion tank is easy, so they can get lulled into ignoring the issue and the end result can be quite serious. Conversely, many people will immediately complain about a few drips of oil on the driveway, when the reality is this is a mere nuisance.
And if you ever find a bit of oil floating in the expansion tank, this is also an alarm bell to get it checked out - yeah, maybe it's only a one way oil-into-coolant leak, but I wouldn't ignore it if you want your engine to make it through the month. BTW, the only reason I say all this is I don't think too many people will inspect the PVC system on a regular basis, but I could be wrong.
Thanks for the warning and advice!
10-20-2006, 09:27 AM
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absolutely ! checking the PCV is 100X easier, cheaper and quiker then an oil analysis
this was my first bell ! next was the oil analysis that confirmed my discovery.
10-20-2006, 09:40 AM
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Typically, if you're getting water in the oil, you'll see it when you drain the oil...
also typically, if there is a coolent leak into the engine, it's through the head gasket.
10-20-2006, 10:14 AM
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NO , not true at all .. i changed my oil 2-3 times (short intervals) and it looked fine
and if that is the case you'd have it blown up in piece by the time you actually see milky coffe colored oil.
10-20-2006, 11:27 AM
#7
In the 2.7t, the oil cooler would be my prime suspect for place where coolant/oil were mixing -
on most other NA engines I would say head gasket is #1 source. Point is, don't blow off a disappearing coolant situation unless you know for sure where its going (and you verify it ain't inside the engine!).
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10-20-2006, 11:48 AM
#8
unfortunately, i believe oil pressure is higher than coolant pressure there and would puke oil into
the coolant instead of vice versa.. still worth checking out though, considering its very easy to do.
10-20-2006, 12:36 PM
#9
Agree, while the car is running. But once you shut the engine down, oil press = 0 while coolant is
still at 14 psi or whatever it normally is. Plus thermal cycling coupled with high pressures (cold vs hot oil) is why I would put my $ on that being the most likely source of a leak. Again - anything is possible, but I would think that head gasket failure is rarer than oil cooler failure.
10-20-2006, 12:59 PM
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surprisingly, common logic doesn't apply with higher oil pressure and the thought that ...
there would be more oil in the coolant system. The opposite is true, however, where more coolant finds it's way into the oil.
Why you ask? As soon as you kill the motor, the coolant system stays pressureized for an extended period of time. Oil pressure? Well, it goes to zero as soon as you shut off the key.
And, the internal leak is, in most cases, a very very small leak that doesn't cause an exchange of fluids while driving. When you have a LARGE leak-- you'll know it right away!
Why you ask? As soon as you kill the motor, the coolant system stays pressureized for an extended period of time. Oil pressure? Well, it goes to zero as soon as you shut off the key.
And, the internal leak is, in most cases, a very very small leak that doesn't cause an exchange of fluids while driving. When you have a LARGE leak-- you'll know it right away!