DamonB

Tonight on the way home from work I noticed steam coming from under the hood while at a stoplight. 15 seconds later the low coolant buzzer went off and I pulled over and shut her down. I could see I had a massive coolant leak from the turbo area. I was only 1 mile from home so I walked into a gas station and bought four gallons of water. I topped it up and could make about a 1/4 mile before the buzzer would go off; pull over add water and repeat until I made it home. It took 3 gallons just to make it that one mile; the water would just pump out onto the ground.

I suspected one of the turbo coolant lines so I removed the airbox and the air pump to have a look; sure enough the upper line on top of the primary turbo had ruptured. It was a long time coming too because it was inflated like a balloon, then finally failed. Only a couple bucks to replace, but this could have been bad.

The perfect time to replace the turbo coolant lines is when you do the silicone hose job, as you'll be there already. Once the airbox and air pump are out it is simple enough to do. I consider myself lucky. It is impossible to see or feel these lines without removing the airpump; I recommend checking them the next time you are doing any work like changing belts, or the hose job. Rob Robinnette's site has a good pic of the lines; search for "turbo coolant".

misdbman

I agree. I blew one of mine off. No warning that there was any problem. Luckily it did not lose enough coolant to raise the motor temps. There are a lot of small coolant hoses on an FD. I believe that the MazdaTrix web site lists all of them. Just do it and change them all.

RonKMiller

Yep, they usually balloon, or cook until they are as hard as a rock and leak past the clamps. This is also the cause of lots of mystery leaks and suspected water seal failure since they are tucked away out of sight. I wonder how many engine rebuilds/turbo replacements have been caused/undertaken as a result of not replacing these inexpensive (by Mazda standards) OEM hoses?
This is a must do - resist the urge to only do the top one. The bottom one is a struggle. A pair of long, curved, needle nose hose pliers makes the job a snap. While you're at it, bite the bullet and replace ALL the hoses.

REDLINE

Aaaaaccckkkk!! I think I have the same problem. One cold night, after working on my car, I started driving around slowly. I saw white smoke come out of the engine bay and smelled coolant. Looked like it was coming from somwhere inbetween the turbos and motor. Well, somewhere deep atleast! I knew I was leaking coolant somewhere in the engine bay since I was loosing coolant and could smell it everytime I pop the hood and could hear it slurrping sometimes. I couldn't really see it drip out near the radiator or from any major coolant hoses. Right now its about a pinhole size, but I guess I better get them repalced. HOw ard is it to remove the airpump and to measure the belt tension and all? I''ve never removed it before.

REDLINE

ooohhh!! I forgot to ask! Since the Turbos are water cooled, why do they still glow orange after a short hard drive? And some people said that with our stock water cooled engines, we don't really need to "cool" the car down after a drive. I still do anyways, just in case.

DamonB

Sounds just like me last week; then POOF! Replace them now. Getting the airpump off is not hard; just three bolts to remove. Loosening/removing the belt is the difficult part. You have to loosen the alternator to relieve the tension and then unthread the belt. You have to remove the airbox of course before you can get the airpump out.

I smelled coolant last week a couple times but cound no leak and was not loosing coolant that I could tell. The little drips hit the turbo and evaporate, so you never see them until the hose completely fails like mine did. You can PM if you want some help.

badass7

Same thing happened to me about a month ago. I was racing around the city doing about 4 WOT runs in total. When I got home let her cool down and shut her off. The next morning on my way out...I see that ALL my coolant had leaked out and there was a huge puddle underneath my car. Luckily this happened while my car was sitting!! If it would have happened during one of my WOT runs I'd of been screwed bec. I was out in the middle of nowhere!! Anyway, changed the hose out the next morn. and has run fine since. The bad thing about it was that this upper turbo coolant hose only had just under a year of wear on it!! So, go ahead and do it if you have not in a while.

whitelight7

iTrader: (5)

More turbo coolant hose symptoms: after my 7 warmed up after driving a few miles, some steam would come from under the hood sometimes. But then the steam would stop after a while. Closer inspection showed steam coming from the passenger side of engine, somewhere around the turbos. The coolant level was fine everytime I checked it. Never saw coolant puddles or coolant dripping from under the car, just steam - sometimes. Replaced both turbo coolant hoses and solved the problem, no more steam. The hoses were very hard, and bloated as mentioned above.
I bought OEM hoses from Mazdaformance (http://www.mazdaformance.com).
N3A1-13-54X $8, N3A1-13-536 $4

whitelight7

iTrader: (5)

Also, I HIGHLY recommend that you get long-handled angled needle-nose pliers to get the lower hose clamp.

kleinke

I recommend you do not use cheap hose clamps. I just repaired major mess caused by hose blowing off--cheap hose clamp on a good hose.

KevinK2

Those hoses have a rough life. When idling or in traffic with rpms low, temps hot, coolant flow through those hoses may stagnate, or even reverse. Could be locally boiling egw coolant, with very hot coolant rising through the hoses.

Turbo coolant flow is normally from back of the t-stat (after full loop through the block), and returns at the wp inlet, by passing the rad. With t-stat wide open, not much pressure drop there to induce flow thru turbo loop. Big rads, drilled t-stats, and underdriven wp's further reduce the pressure drop, and flow.