My car is peeing coolant. :-(

[slugg]

I put a new radiator in the Miata on Saturday. The old one finally cracked after 13 years.

The new radiator isn't leaking like the old one was, but when I was autocrossing yesterday, my car was definitely still peeing coolant. Well, this morning I took a long drive and revved it high, pulled into my garage, and quickly popped the hood. I found the leak! My terminology might be off (please correct me; I'm learning), but it looks like it's leaking where the upper radiator hose connects to the thermostat housing. See pics:

Now, I remember while replacing the radiator hose that the thermostat housing hose fitting was kinda gunky and nasty looking. I cleaned it and lightly scrubbed it with an old kitchen scrubber/sponge and Simple Green. Could the remaining gunk be causing a bad seal? Also, a friend mentioned that those style hose clamps aren't that great for reuse. Here are some ideas that come to mind, or combinations thereof:

1. Clean the thermostat housing and REALLY scrub it with something like steel wool or a scotchbrite pad.
2. I have some thermostat housing sealant stuff from the parts store; maybe I could apply a small layer to the fitting before installing the hose?
3. Replace the clamp with a "screw type" clamp.
4. Replace the hose (it looks good, though).

What does ATG's vast collective knowledge say?

 

[jlee]

Pull the hose, clean the housing and the inside of the hose, then put it back together with a proper hose clamp. If nothing is cracked or split, that should fix it.

 

[NutBucket]

Replace the hose. New clamp couldn't hurt but probably isn't the problem.

 

[jlee]

Replace the hose. New clamp couldn't hurt but probably isn't the problem.

I've had to replace a clamp before and the hose was fine. I'd throw a clamp at it first, but I agree it wouldn't hurt to replace the hose either.

 

[Squisher]

There is a good chance the hose is split right at the edge of the clamp, where it was pinched.

 

[slugg]

I'm going to try replacing the clamps first. It's easy, can be done without disconnecting the hoses, and thus can be done without dumping my coolant fluid. I'll replace the clamps for both the top and bottom hoses. I'll probably get to it tomorrow.

 

[manimal]

Since you autocross and enjoy your vehicle I would replace the hose and clamp while your at it. Hell replace all the hoses they are
Cheap enough

 

[SpatiallyAware]

Are the hoses 13 years old as well?

On a DD I might say it's ok to risk it, just clean the hose and redo the clamp then keep a close eye on it... But if you're autocrossing then please don't be 'that guy' leaking coolant all over the place.


I think you should replace all coolant hoses AND clamps if they're 13 years old.

 

[waffleironhead]

Take it off, clean it up and get a better clamp.

 

[boomerang]

You need to elaborate on "kinda gunky and nasty looking". If the sealing surface where the hose attaches to the thermostat housing is pitted and cratered, no new hose or clamp of any kind is going to seal it up. If this is the case, a new thermostat housing is the only fix.

 

[slugg]

I don't get it... The hoses look damn close to new. I know the previous owner; I'll give him a call and ask if those hoses were replaced any time recently.

 

[SpatiallyAware]

You need to elaborate on "kinda gunky and nasty looking". If the sealing surface where the hose attaches to the thermostat housing is pitted and cratered, no new hose or clamp of any kind is going to seal it up. If this is the case, a new thermostat housing is the only fix.

I think he means the normal coolant "sludge" you find on any car with old coolant.

 

[slugg]

I think he means the normal coolant "sludge" you find on any car with old coolant.

This.

 

[waggy]

1) roll up the newspaper
2) whenever it pees smack its nose
3) rub its nose in it
4) put it outside

soon your car will be housebroken.

 

[JCH13]

Pull the hose, clean the housing and the inside of the hose, then put it back together with a proper hose clamp. If nothing is cracked or split, that should fix it.

Exactly my suggestion. Just as the radiator crapped out after 13yrs, the constant-force spring clamps do too.

Replace the hose. New clamp couldn't hurt but probably isn't the problem.

Again, good advice. 13 y/o hoses aren't exactly pristine and might be the next thing to shit the bed!

Might also be worth replacing your radiator cap or at least ensuring that it isn't a high-pressure cap if a new one came with your new radiator.

 

[slugg]

Eh, whatever. I'll just replace the hoses AND clamps. Cheap insurance.

 

[manimal]

Eh, whatever. I'll just replace the hoses AND clamps. Cheap insurance.

Good call. The previous owner of my e39 528i neglected their cooling system and almost hosed the engine. Of course I picked it up cheap because of their stupidity.


S

 

[SJP0tato]

Rosenthal Mazda sells a hose kit to replace all of them with OEM parts. Easier than trying to make the "kinda close" aftermarket ones to bend in to fit all the weird angles, etc.
http://parts.arlingtonmazda.com/products/COOLANT-HOSE-KIT-(PKMIAD1006).html
If that doesn't work, it's part # PKMIAD1006 for $105

 

[bbs lm-r]

I hate those style clamps, caught my thumb straight down the middle once.

I'd replace them out of spite alone, but I concur with everyone saying to go with some better screw clamps.

 

[slugg]

Replaced the hose and clamps. All is good now

 

[T2urtle]

So what do you think was leaking the hose or the force that the clamp put on the hose.

In this case i would just take the time to do the upper and lower hoses with new clamps along with a new T-stat and housing (if they were cheap). I know the T-stat,hoses and clamps are cheap, but not sure on the T-stat housing.

You dont want it pee-ing because then you can cook your motor!

 

[bbs lm-r]

More like the lack of force the old clamp was putting on the hose.

Now that you replaced them, I hope you didn't go crazy tightening the new clamps down thinking it'd prevent future leaks.

I've read about this before, but I've seen it once myself where someone cracked the radiator's plastic outlet from over-tightening those clamps.

 

[JCH13]

Stock radiator = garbage. First thing to go IMO, especially when all-aluminum ones can be had for $160.

 

[jlee]

Stock radiator = garbage. First thing to go IMO, especially when all-aluminum ones can be had for $160.

Silly Miatas.






/jealous

 

[slugg]

Stock radiator = garbage. First thing to go IMO, especially when all-aluminum ones can be had for $160.

Stock one lasted 13 years... I got a brand new stock one for $60. I'll gladly pay that every 13 years.