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Sweet Coolant Smell

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Old 05-23-2014, 10:08 AM
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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.
Old 05-23-2014, 10:22 AM
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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.
Old 05-23-2014, 10:51 AM
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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.
Old 05-23-2014, 11:03 AM
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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.
Old 05-23-2014, 12:09 PM
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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.

Last edited by Airbag; 05-23-2014 at 12:12 PM.
Old 05-23-2014, 04:28 PM
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Originally Posted by thall6594
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.
Old 05-29-2014, 08:22 AM
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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?
Old 05-29-2014, 08:29 AM
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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.
Old 05-29-2014, 08:34 AM
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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
Steve
Old 05-29-2014, 09:11 AM
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Originally Posted by steveinky
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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