The image I am posting, is our standard coolant overflow reservoir. But I have a question. Why would there be coolant coming out of the black rubber hose to the right of the cap? I have been smelling a faint coolant smell for a couple days, and have been trying to track it down. I was under the car, and don’t see any coming from the water pump, which was recently replaced, and don’t see any coming from any hoses, or anything connected to the radiator, except this little black hose. It is splattering on the side of the Revi housing, and it is around the lip of the overflow reservoir. It is not a lot, but why did this start happening, after almost 60K miles. I just want to make sure there is not another problem, that is causing the overflow bottle to leak out of this little hose.

Any advice, tips, ideas, or possible problems/solutions, would be greatly appreciated. Thanks in advance.

 

Does it to me too. Turning fast seems to do it... Tracks make you turn fast Also, the coolant mixture expands when heated and thus seems more prone to coming out the overflow tube.

Why was your water pump replaced?

BTW--you are missing a nut on that bolt...

FS

 

well, I have noticed the smell after just street driving, and then this weekend I noticed it a lot more after some alleged late night autocross sessions, but it was too dark to look for the evidence. and today I saw all of the splatter that had not been there before, since I had just cleaned everything on Friday.

Water Pump was replaced because it was leaking.

and Mazda lost that nut when they did the water pump, don't ask me how, and I just have not gotten a new one. It is secure where it is, and is not going anywhere. But i do need to get a replacement nut.

 

Hmmm... I've had it over-spill out but I could never smell it. Is the smell inside the cabin or from the engine bay? Maybe your heater core is leaking?

 

mostly the smell is outside the car, most noticeable when in the garage, but sometimes it is perceptible in the car, because the windows are open, or the climate control is using outside air, and not the recirc function.

 

Well, sorry, I'm outta ideas!

At least it smells sweet. I have to inhale tranny fluid!

 

The black hose is there to relieve pressure if the car is overheating. The possibilities I can think of:

1 - the overflow tank was overfilled with coolant

2 - the cap is leaking/not holding the proper pressure

3 - the car is actually overheating


1 is easy enough to determine. If that's not it, then I'd try a new cap, and make sure to clean and inspect the seating surface on the tank to make sure it's not damaged. Hopefully that will take care of it.

 

Another possibility is that you have a blown internal coolant seal that is causing over pressurization of the coolant system which results in coolant blowing out the overflow pipe. Probably should have that possibility checked out as well.

 

Thanks for the ideas, I will be taking it in soon, and I will see what the dealer says.

 

I only got rid of it by changing to Evans NPG-R

new caps, new coolant etc won't do it, they all do it

 

I know exactly what your problem is....................

Lokk on the right.

Your missing the nut. You think it's tight but it ain't.

Go around a track or spirted driving and you will see what I mean.

 

How do I know?

Samething happened to me! Doh!

 

I just had this problem. I was told the thermostat was screwed so coolant wasnt circulating properly. Now I think about it I dont see how that causes pressure to build up though.

 

I am not doubting you, as you know what you are talking about, but if you say switching coolant won't help, how did it help you to switch. I just want to fix the problem, I am tired of smelling coolant. And am willing to try anything.

I know, I am going to get one this weekend. But in defense of that nut, it has been gone for a while, and this issue only surfaced recently. And if anything, the bottle only shifts about 1/8" or less, at most, and that is with me trying to move it. But I will try the bolt, and see if it helps.

This I can see being the culprit. It makes sense, if the T-stat is not functioning properly, and circulating fluid at the rate it should, then you would have increased pressure, and fluid in the reservoir. But, I have not yet opened the hood after driving to work, to find coolant flowing at high pace into the reservoir, like it does right after coming off the track. So, I am stumped.

 

1 - are you sure it is still actively leaking from the overflow?

If you recently had the water pump replaced you could simply be smelling whatever was spilled/spread around during that repair.

Might help to pull off the overflow hose, clean all traces of the coolant from the area and wash out/dry the hose then see if the "leak" returns.

 

I've been finding a lot of coolant on my garage floor. I checked my level, and it's beyond Full. Wondering if I should take it out (a syringe maybe) or just let it all leak out. any suggestions?

-Cody

 

I had frequent over-boilings here in the desert.
I switched to a 1.1 BAR overflow cap from the Millennia S/626/RX-7 and that fixed it.

I also extended that hose so that if there was another purge, it wouldn't spill all over the power steering connections like it does in its OEM configuration.
Now it vents straight to the ground.

 

that was my first thought, that it was spillage from when the pump was replaced. so I did not worry too much about it, but it has been 6 months now. I thoroughly cleaned everything around the reservoir last week, but have not driven the car much at all since, so I have not had a chance to see if it is still actively leaking.

that is a good idea, also the switching caps too. If the problem persists, I might do both of those things. Thanks for the tips.

 

you could put a small container under the hose & see if it collects any water ?

Really though - all cars will expell water from that hose if you put too much water in the reservoir . You do realise there is a hot / cold fill line ?

 

yes, I am aware of that, although, I would suggest not opening the reservoir cap while it is hot. Today was the first day I drove the car since last week, so, I am going to see if there is anymore coolant spilling out. Might be a good excuse to go out and drive it at lunch.

 

are you having to add coolant to maintain the proper level? Just trying to get an idea of the volumne you are seeing.
olddragger

 

not that I can tell. The fluid level is less than 1/8" under the maximum fill line. and the splatter I am seeing is minimal. The only reason it has my attention is, it never used to do that, and I hate the smell of coolant, it makes me paranoid.

 

I had this problem here when going on mountain road drives. I switched to a higher pressure 1.3 bar cap I bought from ebay and have not had the problem since.

It was this exact one.

http://cgi.ebay.com/ebaymotors/MAZDA...QQcmdZViewItem

 

The Evans NPG-R doesn't boil until 400 degF so the cap doesn't blow off and release coolant. The tank discharge hose drops the blow-off right down onto the radiator/electric fan where it slowly burns off, that's what you're smelling

 

Thanks for the extra info. I don't know a lot about coolant types, so any extra info is great. Is there any extra maintenance, or concerns to be aware of when using that type of coolant. And, at what temp does regular coolant boil? TIA.