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SUDDEN coolant leak - not while driving

I took my 2009 VW Tiguan (which I purchased last week used from the VW dealership in Barrie Ontario) out for a drive earlier today. When I left, the ground under where it was parked was clean and dry. I came back after about an hour of driving and parked it. Then, this evening, after it sit for about 6 hours, I went out to put something in the car and noticed a puddle under the wheel. It hadn’t rained and I could see/smell that the puddle was red engine coolant.

I checked the engine coolant and it was low. It’s like it sprang a leak all of a sudden while it was sitting there - like someone cut a hose or something. I did a look over the engine with a flashlight and couldn’t see any slashed hoses or anything.

Tomorrow I’m going to call the dealership and see what they say. I’ll update here with what I learn.

Here’s a picture of the puddle

Presuming it is actually engine coolant that’s leaking, it could be the radiator sprang a leak, or the water pump decided it has had enough and wants to be replaced. That’s what I’d guess the most likely culprits are. Good idea to make sure the radiator cap – if your car has one – is screwed on the radiator properly too. Engine coolant goes all around the engine in various hoses and tubes, so it could leak pretty much anywhere, but you got to start somewhere.

An alternative theory, it’s not engine coolant, but instead just the condensation from the AC unit. Has it been really hot & humid there and you’ve been using the AC?

Of course you don’t know if it developed the leak while you were driving. Coolant could have leaked out while driving and puddled on a frame member, then on the ground. The other thing is that the cooling system is still under pressure when it is hot and running, so it could have continued to leak out while it sat. You really need to get under it and follow the puddle up to try and determine where the drips come from but at this point probably best to go back to the dealer.

Sorry. Should have said hot and NOT running.

IF it is coolant, the water pump seal could have blown; the pressure builds up when you shut off the engine and then the leak starts.

This is a not uncommon failure; it happened to me with a Chevy Impala in the mountains, when I shut the engine off at a truck stop after a tough climb. Unfortunately this type of failure is impossible to predict, unless there is a very small leak initially.

Day #2. Any leaks today?

Agree with DocNick. Same thing happened with my '02 Impala: drove it 900 miles up the East Coast, pulled into the driveway, turned engine off, and out came the stream of coolant out the water pump weep hole forming the puddle underneath.

Paid $32 at Autozone for the replacement (Duralast). Just checked my records: happened July 2006 at 80,360 miles on the clock. Car now has 192k+ and that Duralast pump is still in there. I’ve seen people on some of these auto forums bashing Duralast water pumps but maybe that’s not a fair label??

U got the 1 good water pump they made. Must of been a mistake.

Yeah I never got more than one or two years out of a replacement water pump, rebuilt or brand new. Really not a whole lot to them-bushing, shaft, and housing, so don’t know how they screw them up.


You must be buying some LOUSY parts :wink:

Because every water pump I install lasts for several years, before it’s noisey and/or leaking

Can’t imagine what brand your’e buying, if they only last 1-2 years :fearful:

Yes, my original water pump lasted 10 years on the Impala. The replacement is still on the car to my knowledge. In the last 50 years I’ve only replaced 5 water pumps.

If the coolant is replaced on time, the water pump lubricant in it is not depleted.

NAPA and Champion and whatever Midas put in when it went on the way to work at 20 below. I’ll have to say not always leaking but rather the bushing wearing and cocking the pulley so that the serpentine belt won’t stay on. The Midas new one lasted only a year. Of course when we are talking years, I was doing 40,000 miles a year, not just to church on Sunday.

I use to replace the water pumps every other timing belt change (about every 200k miles). Our last 3 vehicles all had chains so now I only change when needed. My 05 4Runner had original pump when we sold it last yes with over 300k miles. I was disappointed that I had to change the pump on wife’s Lexus at 110 k miles though.