Washer fluid stinks in hot weather

Nutty667

Nutty667

Nutty667

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Sunny Hampshire
Hi,
I have a strange issue with my little Hyundai runabout.

Everytime we get hot weather, the washer fluid starts to smell really bad. Like you can smell it inside the car when you spray it. Smell like gone off milk mixed with sick!
I assume there's some kind of bacterial problem in the tubes or reservoir. I'm pretty sure last year I tried spraying some Dettol in there and ran the whole reservoir out, and I think it's helped a bit, but it still stinks now it's hot again.

Anyone any idea's how to fix it? Is there a product specifically for this? I assume running diluted bleach though it is going to be a really bad idea?
Is it caused by me re-using an old washer bottle when I top up the washer fluid with water?

Thanks for any helpful suggestions.
 
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What are you filling it with?

Any good glycol based screen wash should be naturally biostatic..

If just water, then yeah, bacterial growth will be a potential problem.

I'd get a really good -20C winter screen wash and put that through a few times, the higher the Glycol concentration the more likely to be biocidal and remove the issue, it effectively will clean as it goes..

However, I've bought cars with washer systems so full with algae and black stinky stuff that I've had to pull the tubing off the washer jets and blast it with pressure in reverse, the amount of crap that ended up in the washer bottle was not good, and that was someone presumably just using tap water to refill it the majority of the time.
 
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Have look at TPS - the VW genuine stuff and the BMW genuine stuff has a very high alcohol content (good up to -63 Celsius) and will keep bacteria at bay. It's a very common problem on BMWs when using cheap screenwash. I'd start with cleaning it properly and then using VW / BMW stuff (it's sub £20 per 5L but you can dilute 4:1 with deionised water and it's still very good).
 
Nutty667 said:
Standard screen wash from Halfords or garage, watered down with tap water.

I'll have a look for some high glycol stuff, and put it in neat.
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Most of those screen washes are 'ready to use' i.e. pre-diluted..

The likely hood is you are watering it down below any ability to be biostatic, never mind biocidal..

Nutty667 said:
Last service I guess it was changed. It's not that, it's there when you squirt the washer fluid.
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Haze said:
When was the Las time your cabin filter was changed?
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Good spot!, but I would deffo check for leaks under the washer jets, it's been known for there to be leaks which get in to the ventilation system, i.e. it finds its way to the pollen filter and then stinks the place out..
The reason you might notice it when you use the jets is simply that the damp filter / water droplets let the smell carry further

Tesla Model 3s had issues with rain water getting in to the ventilation system, dripping on to the pollen filter and smelling very mouldy...
 
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Demon said:
Most of those screen washes are 'ready to use' i.e. pre-diluted..

The likely hood is you are watering it down below any ability to be biostatic, never mind biocidal..





Good spot!, but I would deffo check for leaks under the washer jets, it's been known for there to be leaks which get in to the ventilation system, i.e. it finds its way to the pollen filter and then stinks the place out..
The reason you might notice it when you use the jets is simply that the damp filter / water droplets let the smell carry further

Tesla Model 3s had issues with rain water getting in to the ventilation system, dripping on to the pollen filter and smelling very mouldy...
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Cheers, I'll check for any drips under the bonnet when spraying.
I'll fill it with some neat high glycol washer fluid and run that through and see how I get on.

I've always watered washer fluid down. No point in having -10c protection in summer. I do the same on the other car and it has never had this problem.
 
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Nutty667 said:
Cheers, I'll check for any drips under the bonnet when spraying.
I'll fill it with some neat high glycol washer fluid and run that through and see how I get on.

I've always watered washer fluid down. No point in having -10c protection in summer. I do the same on the other car and it has never had this problem.
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Unfortunately once bacteria has formed to a large degree, unless you remove and clean properly, it takes prolonged exposure for the bacteria to die.. just flushing dettol would do nothing..

Must be a lot of it in your case..

Honestly, considering potential health issues, I'd get a garage (or yourself) to remove the reservoir/pump and give it a proper clean.. flush the tubing, and ideally get some sterilisation fluid left in the tubing/reservoir afterwards for 24 hours, then flush it all and only use a good concentration of screenwash for a while to really nail it.

If it's built up this badly, it could take ages to kill it all off and you get a bio mass forming which is just inviting it growing again.
 
Watering down 'ready to use' is a really bad idea.

As said above the biocidal ability will be compromised to the point it may as well be straight water.

Best way I've found to clean a gunked/stinky bottle is to fill it with undiluted Milton (baby bottle washing fluid), leave it 24hrs then drain it. Then use a strong concentration of proper washer fluid, minimum 3 parts concentrate to 1 part water, using a quality fluid like Prestone.
 
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Been some good suggestions in the thread OP.

I had this before on a Rover 214, I cannot remember how I resolved it, but it was more involved than I expected. It's not the sort of thing thats a quick fix, has to be done properly.

Mine smelled of vomit that had been heated nicely!
 
Manbatius said:
Been some good suggestions in the thread OP.

I had this before on a Rover 214, I cannot remember how I resolved it, but it was more involved than I expected. It's not the sort of thing thats a quick fix, has to be done properly.

Mine smelled of vomit that had been heated nicely!
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Yeah that's what mine smells like! Through winter there's no smell, it's just when it gets hot.
I feel it's more the fluid than the pipes themselves.. If I squirt it all out, then replace it, the next lot doesn't smell until the cars been sat in the sun a good few weeks.

I'm gonna try neat high glycol stuff 1st and see what happens.
The car wasn't new, so perhaps this was caused by previous owner only using water or something. Like I say, I'm filling it the same way I've done all my previous cars and my other car and none of those ever had anything like this. Looking at halfords, some of the stuff says fine to dilute 5:1.... I tend to do something like 3:1 on concentrates.

I might use a clean jug to top the water up rather than the old empty fluid bottle in the garage.. perhaps filling that with just water and leaving it is causing some bacterial growth.
 
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I still don't understand why you mess about mixing your own??? Just buy pre mix, used it for 20 years with no problem and use it all year round as it never gets cold enough around here to need something stronger
 
It's not messing around, it's following the instructions on the product. Buying concentrate means you have less big bulky bottles to buy. Premix is for people who live in flats who don't have easy water supply near the car, and is rubbish in the amount of plastic packaging required for the amount of washer fluid you get.

It's also much better value than premix, where you'd paying for mostly water at 100x the price it comes out your tap.
 
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