What looks like was once a coolant leak (pics)

Hi everyone!

I recently purchased a 2004 Hyundai Sonata that under the hood looks to have evidence of a coolant leak. I’ve drove the car around 500 miles including a few trips of over an hour on the highway and haven’t actually seen anything dripping from the car after parking. The temperature gauge does not move once it gets up to temp. Those of you that have experience looking at this type of thing, what could have caused this? Could be a prior issue that was fixed and the mess was just not cleaned up? It looks like the white marks have almost worn off a bit.

I brought the car to a mechanic before purchasing and he said something about a minor “power steering or something else leak” but that it was generally a good car. I’m not sure what to make of this. Any comments are appreciated.

It looks to me like that someone removed the radiator cap (or attempted to) under pressure. That will create a mess and may create a nasty burn at the same time.

I agree with @missileman. Looks like someone opened the radiator cap while the system was hot and pressurized. Hopefully, there were no burns. If you are not losing coolant from the reservior, I doubt you have a current leak.

After I did a head gasket in my car I decided to have a machine flushing of the cooling system - too much junk falling into the cooling jackets while cleaning up for the new gasket. I’m not a veteran of the “flushing” as I normally just drain and refill. But I’d say that the mess I found under my hood after that job had some resemblance to that. In any case - if you’re not losing coolant, you needn’t worry.

Ehh, I’m going to disagree a little bit. Looking at that battery cable and the color of the mess under the hood I’m going to say that someone tried to clean a bunch of corrosion off of the battery using some chemical or a baking soda mix and splattered it all over. Just my guess.

I could go along with the battery cleaning mess. Some dried up splatter of baking soda and water, for instance, would pretty much look like that.

Or I’m actually starting to think that justishar is a grad student in psychiatry trying to revive the relevance of the Rorschach test, and trying to find out what people “see” in ambiguous patterns.

I’m going with the battery cleaning guess. You might want to lift that little rubber battery terminal cover and check to see what the level of corrosion is. If it’s covered with white crap, I’d suggest having it cleaned and having some corrosion prevention grease smeared on it. If you do it yourself, the terminal brush and grease is really very cheap at any parts store. It may prevent your being stuck with a car that won’t start.

Thanks everyone. I’m leaning towards the radiator cap removal because I get a smell of burned coolant every now and then. I will certainly check out the battery terminals for corrosion additionally.

I’ll have my eye on the coolant level just in case I’m actually leaking a little bit somewhere, but for now I’m optimistic that both the smell and visual evidence are explained by an ill-timed radiator cap removal.

I’m guessing that the radiator had some type of stop leak added to the coolant and the radiator cap was loosened when hot.

^ Why do you say that (about the stop leak)?


The white film seems to originate at the radiator cap and many of the stop leaks have a white coagulant that dries to a white, hazy, difficult to wash off film.