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Sweet Coolant Smell

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Old 05-23-2014, 10:08 AM   #1
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Default Sweet Coolant Smell

2002 3.0

After my car has been sitting for a while, say overnight, there is a sweet smell when it is first started. I got a low coolant warning about two weeks ago, topped it off with a cup of water and it hasn't come back yet. So I know there is a very small coolant leak and I'm wondering what is a common place for coolant to leak on the 3.0. My water pump was changed with all the seals and everything about 34k ago.
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Old 05-23-2014, 10:22 AM   #2
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Coolant reservoir .. quite common ..

check for cracks.

The fact you smell the sweet smell of coolant when you first start it is disconcerting though. If you smell it in the exhaust you could have a leaking head gasket and coolant is seeping in over night .
Start simple though before we get into deeper diagnosis.
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Old 05-23-2014, 10:51 AM   #3
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I'll take a look at the reservoir. I was worried about the smell, I was hoping maybe it is just leaking onto the exhaust and causing the smell. If it is the head gasket this car is going to have to go, nearly $10k in repairs in less than two years isn't worth it with 176k on the clock.
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Old 05-23-2014, 11:03 AM   #4
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Well I didn't see any cracks in the reservoir, and I don't ever see any leaks. I did notice that my level is about an inch or so under the MIN line, but the level warning wasn't on last time I was running the car.

I should add though that the car is not overheating at all.

Last edited by thall6594; 05-23-2014 at 11:06 AM.
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Old 05-23-2014, 12:09 PM   #5
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okay well that isnt good that there are no visible leaks , but not the end of the world. Remember head gasket leak is worst case .. you could still be leaking some place and dripping on to the exhaust.

There are a few other things you could try but they will require tools. I will list them and you can decide for yourself the path forward.

1. Put a pressure guage on the coolant tank and run the engine .. if you see it " spiking " while the engin eis running your head gasket is toast as you are pressurizin through the head gasket.
2. Pressurize the coolant system through the reservoir to about 12 or 13 lbs and look for visible leaks in the system. There are a ton of coolant lines on this car so look carefully.
especialy around water pump , thermostat, reservoir and pipes running across the front at the bottom.
3. Watch for white smoke as that is what shows if you burn coolant and try and smell the exhaust . if that sweet smell is actually coming from the exhaust , that does not bode well.

4. Remove the spartk plugs and inspect. if you find any strangely clean you are steam cleaning them with coolant . Again a very bad sign. may as well check though . You may find all are normal but one and maybe a neighbouring cylinder are clean plugs . There is your leak.

5. look for oil film in your coolant .

6. Look for intermixed coolant in your oil creating a froth . This however is unlikely at your small amount going in.

7. Your coolant should be Pink .. look for Pink crusting at all the fittings.

8. Make sure your heater core isnt leaking , check the floor for damp carpet while running the heater on high .. if you smell it with the heater on high and the heater valve open you likely have a bad core ... at least you can bypass it to get through the summer ..

Good Luck and report back

BTW keep topping up coolant while cold .. to give you an idea of how fast it is going down.
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Last edited by Airbag; 05-23-2014 at 12:12 PM.
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Old 05-23-2014, 04:28 PM   #6
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Originally Posted by thall6594 View Post
Well I didn't see any cracks in the reservoir, and I don't ever see any leaks. I did notice that my level is about an inch or so under the MIN line, but the level warning wasn't on last time I was running the car.

I should add though that the car is not overheating at all.
Are you getting a fine haze on the windshield along with that sweet smell? It's also possible you have a small leak in your heater core that is draining out your AC drains when you're on the road…you wouldn't necessarily get a puddle under your car although you should with pressurized coolant system.
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Old 05-29-2014, 08:22 AM   #7
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So I have been monitoring my coolant level and it is still dropping a bit everyday. There doesn't appear to be any coolant in my oil, or oil in my coolant. I haven't had any overheating issues. The smell does NOT come out of the vents with the heat on high (no haze on windshield either). I smell the coolant more towards the front of the engine, not really at the tailpipes.

The only leak I have is what I believe is my motor mount. However both fluids are pink...

Where can I get a pressure tester that fits on my reservoir?
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Old 05-29-2014, 08:29 AM   #8
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There should be chalky pink residue where the leak is. If you can't find that, I doubt that a pressure tester is going to help. Look at the Aux Water Pump. Maybe pop the timing covers loose and see if you can get a peek at the main water pump.
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Old 05-29-2014, 08:34 AM   #9
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Look at the Audi OEM crappy quality plastic "T" fitting near the front of the expansion tank. When these crack they will drip on the left side of the engine and the coolant will evaporate creating that smell with no coolant visible.

Good Luck
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Old 05-29-2014, 09:11 AM   #10
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Originally Posted by steveinky View Post
Look at the Audi OEM crappy quality plastic "T" fitting near the front of the expansion tank. When these crack they will drip on the left side of the engine and the coolant will evaporate creating that smell with no coolant visible.

Good Luck
Steve
Just had mine snap on the weekend... pissed me off to no end .. especially after i drove acoss town for a replacement and dropped it in the engine bay ... gone forever .. across town for another .. ..

OP i think if you smell it near the engine you definitely have an external leak .. you just have to keep ooking . If you smell it up front thts where it is .. have someone rev the engine while you are up front looking ( be carefull ) this will kick the water pump into high speed and you may see something.
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Old 05-29-2014, 11:03 AM   #11
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I don't see any pink residue anywhere. The only leak I have is coming from the circled area.

Click the image to open in full size.

There was some on the bottom which is where the leak is coming from. The fluid is pink, but I think it is motor mount fluid. What is over there that could be leaking?
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Old 05-29-2014, 11:24 AM   #12
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so if i understand this correctly ....

you smell coolant ..
you notice your pink coolant is going down ..
you refuill it and you see your pink fluid still going down
you see Pink Fluid at the bottom of your car
and you think it is motor mount fluid ..
hmmmmm.....

gotta think it is coolant after it has run past all the oily bits..
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Old 05-29-2014, 11:27 AM   #13
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Originally Posted by Airbag View Post
so if i understand this correctly ....

you smell coolant ..
you notice your pink coolant is going down ..
you refuill it and you see your pink fluid still going down
you see Pink Fluid at the bottom of your car
and you think it is motor mount fluid ..
hmmmmm.....

gotta think it is coolant after it has run past all the oily bits..
The reason I think it is motor mount fluid is because I have been leaking motor mount fluid for a while now, and only recently noticed my coolant level.
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Old 05-29-2014, 04:16 PM   #14
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Just had mine snap on the weekend... pissed me off to no end .. especially after i drove acoss town for a replacement and dropped it in the engine bay ... gone forever .. across town for another .. ..

OP i think if you smell it near the engine you definitely have an external leak .. you just have to keep ooking . If you smell it up front thts where it is .. have someone rev the engine while you are up front looking ( be carefull ) this will kick the water pump into high speed and you may see something.
Seems to happen when I release the expansion tank and swing it up to get to the back two spark plugs on my V8. Just happened today. And that little hose from the expansion tank to the T? $86 list but google the p/n and you can get it for like $45-50. The damn audi T is like $14 at the dealer or you can wait a few days and get it online.
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Old 05-30-2014, 04:14 AM   #15
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Seems to happen when I release the expansion tank and swing it up to get to the back two spark plugs on my V8. Just happened today. And that little hose from the expansion tank to the T? $86 list but google the p/n and you can get it for like $45-50. The damn audi T is like $14 at the dealer or you can wait a few days and get it online.
wow .... got a vacuum T for 5 bucks to get me running.. another thing to grab the next time at the wreckers ... and lets face it ,.. it wont be long
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Old 05-30-2014, 06:31 AM   #16
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You could kluge a tester using a MityVac if you have one for brake fluid flushing or bleeding. They have pressure and vacuum ports…just clamp the mityvac pressure port into the expansion tank tubing and cap the expansion tank port and pressurize to 15-20psi or whatever is printed on the reservoir cap. This also has the advantage of testing the pressure cap...

Stahl makes a pressure tester. The only problem is you'll need to buy the adapter(s) for your coolant reservoir and reservoir cap. They're not cheap (ask me how I know this). I have a kit that I've had since the 70s and only had to buy the adapters. FWIW, the adapter for the reservoir cap was more expensive than simply replacing the cap….

Here's one source for automotive cooling system pressure testers…
http://www.etoolcart.com/pressuretesters.aspx

Last edited by SloopJohnB@mac.com; 05-30-2014 at 06:42 AM.
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Old 05-30-2014, 06:39 AM   #17
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wow .... got a vacuum T for 5 bucks to get me running.. another thing to grab the next time at the wreckers ... and lets face it ,.. it wont be long
I also could have purchased a plastic vacuum tee for even less…like $1.88 at Advance auto…and that would have got me back on the road for an undetermined amount of time. However, I looked at the vacuum tee and it was about ½ the wall thickness of the audi part and made of an indeterminate plastic that may or may not survive the under hood hot coolant environment. (Although the OEM tee wasn't that good either!) In any case, the vacuum tee appeared weaker than a new OEM tee and would likely have broken the next time I moved the reservoir.

The best solution would have been to install a brass tee, but I couldn't find one quickly and I didn't want to kludge one with a triple female thread and three male threaded adapters. That would have probably worked out to $20 worth of brass at Home Depot.
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Old 05-30-2014, 08:20 AM   #18
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You could kluge a tester using a MityVac if you have one for brake fluid flushing or bleeding. They have pressure and vacuum ports…just clamp the mityvac pressure port into the expansion tank tubing and cap the expansion tank port and pressurize to 15-20psi or whatever is printed on the reservoir cap. This also has the advantage of testing the pressure cap...

Stahl makes a pressure tester. The only problem is you'll need to buy the adapter(s) for your coolant reservoir and reservoir cap. They're not cheap (ask me how I know this). I have a kit that I've had since the 70s and only had to buy the adapters. FWIW, the adapter for the reservoir cap was more expensive than simply replacing the cap….

Here's one source for automotive cooling system pressure testers…
http://www.etoolcart.com/pressuretesters.aspx
Ahh I'd be better off bringing it to the shop and having it done for that price...
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Old 06-01-2014, 04:20 AM   #19
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Ahh I'd be better off bringing it to the shop and having it done for that price...
The kluge or the stahl tester? Kluge is free. LOL!
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Old 06-01-2014, 09:26 AM   #20
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The kluge or the stahl tester? Kluge is free. LOL!
I don't have any of those tools laying around. I'm only just starting to do my own work lol.
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Old 06-01-2014, 09:26 AM
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