- My model of MX-5 is: Mk3.5 1.8 (2009)
- I’m based near: Basingstoke
- I’m looking for technical help or recommendations on: Unknown Fluid Leak
Hi all,
I noticed that I’ve got a minor fluid leak on my NC.
It’s very slight. The car hasn’t been driven for a couple of months and there was perhaps a puddle the size of a 2p piece on the garage floor.
I quickly lifted the car and noticed a small amount of fluid on the corner of the undertray, below the right hand side inner tie rod end (pic below). I had a feel around (as much as I could without dropping the undertray), but everything seemed as dry as a bone.
The fluid is a very pale yellow colour and is greasy to the touch. Definitely not engine oil, I think it’s too far forward to be brake/clutch fluid and I don’t think it’s coolant either, as it doesn’t smell like dead fish!
My thought was therefore power steering fluid (as it is in the vicinity of the rack), but it all seemed dry.
Any thoughts/things I should focus on when I get a chance to properly get underneath?
Hmm, Power Steering fluid is usually reddish, same as Auto Transmission. It has a distinctive smell.
The ABS etc control box lives just about above that point, behind the screenwash. What colour are the brake fluid and screenwash? Again distinctive smells.
Did the fluid have a vinegary smell? The battery lives about there, but the tray should take any leaks out forward through the cooling duct.
Brake fluid is light yellow. It’s definitely not screenwash - it’s too viscous.
Smell wise, its a slightly musty/oily (definitely not acid). I did take the caps off the various fluids in the engine bay and had a good sniff, but no obvious match.
I’ll have a good feel around the ABS module and see if that reveals anything…
It might simply be an oil spill from when the engine was last topped up.
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Fingers crossed - I’ll drop the undertray and have a good look around when I get a chance and report back!
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Dropped the undertray and found a drip of fluid on the bottom of the power steering cooling pipe, at the point where it goes under the radiator.
I think it was just engine oil, as there was a slight stain on the radiator directly above (and I did have a spillage 2 oil changes ago).
Working hypothesis is that the extreme heat in the garage over the past week made the oil really runny and finally make its way out.
I’ll keep an eye on it and see if anything reappears.
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Ollie
You might consider the free option of thanking Richard for his excellent advice. I can see historically, you have used that option once before but perhaps not de rigueur in modern life 
No faux pas intended, I just thought that as Richard had taken the time to offer a suggestion, I would quickly respond with an update (whilst at the time covered head to toe in MX5 underside filth).
I am of course grateful and apologise if I have caused offense. The car is currently sitting in the garage with white paper under the area in question. I was intending to report back in a few days as to whether Richard’s helpful suggestion is correct, or whether there is potentially another issue at play.
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Not a problem for me. Ollie had replied with an update and I ticked his like button.
Sometimes people can seem a bit distracted if thinking of other things as well. I have enough trouble keeping track of things myself so I understand.
It always takes me a bit longer to reply, checking nothing stupid said. Even then I miss things, only seen later!
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Thanks Richard, I think you were spot on - I had a look under the car tonight and it was as dry as a bone.
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