Hey guys...been having a strange coolant leak that I can't seem to trace anywhere. About a week ago, I started having mild overheating problems, but I was able to control it with the use of the heater and manual fan control. Odd, I thought, and it eventually followed with the distinct smell of coolant, and eventually the coolant buzzer going off when I started the car back up after a few hours. And a few times, there was steam coming out of the passenger side of the hood area, and I figured I would be able to find it then. I popped the hood open, searched all over the place, tried feeling for any wetness anywhere, but I can't find a doggone thing!

I figured it's time to do some coolant hose replacing, but I was hoping somebody had a similar experience that might be able to point me in the right direction. The car runs totally fine otherwise.

Oh, I'm running an upgraded aluminum radiator, evans coolant, no ast.

Any input is appreciated! Thanks!

 

Oops...just did a quick search on scuderia, and came across some information pertinent to my problem.:
http://www.scuderiaciriani.com/rx7/c...eshooting.html

Sounds like it could be either that that small coming off the water pump housing to the firewall, or the hose going to the turbos. (are these the same hose?) Either way, I'll probably buy both of those from mazdatrix as well as new radiator hoses while I'm at it.

 

theck the throttle body hose behind the manifold.

 

I'll pick one of those up too then while I'm at it. I figure if it's time to replace one of the hoses, I'll just replace all the hoses that could possibly go bad soon. Any other suggestions?

 

Take off the airbox and intake pipes and see if you can locate it.

Really, I've managed to make coolant leak from several locations. If you merely forget to replace the hose clamp, it will give you a slow smoking/smelling leak.

Do buy the new hoses and replace them all. The one which is a bitch is the hose from the TB to the block since you have to get under the UIM and around the fuel rail and solenoid rack. It's understandable to procrastinate that one a little bit, but the others just require removal of the I/C, airbox, and maybe the airpump and crossover pipe.

I found that a hose pliers set from harborfreight was a huge help. So does using a utility razor to cut off the old hose, then using a dremel tool with scotchbrite wheel to buzz off the corrosion.

Dave

 

Thanks the tips dave! Yeah I remember how much of a pita it was to deal with some of those hoses...those pliers sound like a great idea.

 

About a month ago, my FD blew the hose under the air pump from the back of the water pump housing. Mine split wide open and had to flatdeck my car home....

 

I'm definitely replacing that one, especially considering the vicinity of that hose to the turbo. Thanks rotorhp!

 

good idea as coolant is actually flammable... in anycase, there are actually a few hoses which goto and come back from our turbos which you might wanna check out. they are very hard to see with out ripping everything out though. ifyou go to mazdatrix, they are pic of all of the hoses. check fsm or parts fiche to see exactly where they are

 

If it's upfront it is a hose going to the overflow reservoir.

 

I had removed the AST so a lot of those hoses were irrelevant for me, but I pretty much got all the other hoses. I had actually replaced the hose going from the coolant fill cap to the overflow reservoir this past weekend bc I was always suspicious of that hose, but it turns out that wasn't the problem.

The frustration stems from the fact that the few times I saw steam, it was very temporary, and when i checked under the hood, I could not tell where the hell it came from...just the passenger side area.

 

Okay I went ahead and tore the hoses apart, and I found that the coolant hose going from the back of the water pump housing to the turbos did indeed have a small slit right where the clamp was! I replaced that as well as the radiator hoses, buttoned it all back together, and voila no leaks!

BUT then after a few days, my coolant light came on again, and after muttering a few choice words, I realized that it might just be another radiator cap gone bad (again!), therefore causing coolant to go out, but not to come back in. I went and replaced the cap, and I *think* all my problems are solved now. Has anybody else had problems with their radiator caps going bad? This is like the 3rd time in the last few years, I've had to replaced them. That being said, however, I noticed that I only need to replace them when I'm continually removing and replacing the cap (coolant changes, etc.), which I guess sort of makes sense.

Nevertheless, thanks to all of you guys who suggested all the different possible leak locations!

 

well crap. After driving around for a little bit, I started having coolant steam eminate from the same area. It was disheartening, but after doing some further research on the forums, I realized that I failed to replace the second coolant hose going from the turbos back into the pipe (small 90 degree "L" shaped one). I'm kicking myself in the **** forf that since I was all in there already and I HAD the new hose ready to go in, but I figured it was for something else, and since I had already found a hose with a slit, I figured I was done.

SO...gotta go back in there to replace that hose, hopefully find out that it also has a tear, and be done with this nonsense. Otherwise, I'm at a total loss...

 

Also, a radiator shop with a pressure tester and dye will be able to locate the leak easily.

 

Well look on the bright side. You're getting better at removing the parts in the way, and you're fixing this now, on your terms. Better than on the highway, steam pouring out, dragged onto a flatdeck.

Dave

 

I'm actually cruising ebay to find a pressure tester right now...I figure I should be able to resell a used unit for close to what I paid for it.

And I know what you're saying Dave bc I had this conversation with my friend who's NSX had a radiator hose just blow up while he was on the road. The point I was making, however, was that in a way, it's better that it happens that way since the leak is obvious and the repair is fairly certain.

I dunno...I'm just venting obviously.

=]

 

OKay I replaced the second turbo hose, and it didn't have any apparent problems. I buttoned everything back up, and drove it around, and I'm still having the same problem. I've just about given up on doing anything more, and I'm just going to take it to my rotary mechanic for diagnosis. I have a bad feeling that I've developed a coolant leak within the turbos or maybe even the dreaded o-ring failure.

Crap. This sucks.

 

First, relax.

Second, realize the problem is fixable.

Third, realize you'll learn in the process.

 

San Francisco?

Bring the car over, I'll take a look at it.

 

Clavne where are you located? I'm in the Marina area.

Yeah after wasting two weekends trying to trace the source of the problem, I'm basically just tired of working on the car, y'know? I simply can't figure out where else the leak could come from. It still steams from the passenger's side area whenever I'm sitting at a stoplight, but it will usually go away when I turn on the fans and the heater, which indicates to me that the coolant gets hot at some point, expands beyond some pressure point, and starts to leak out. At cruising, the car runs great with no problems or overheating whatsoever.

I actually just thought of something else that might be noteworthy. A few weeks ago, the car developed a really odd smoking problem where after a cold start up, and driving for about two blocks, there would a ridiculous amount of smoke coming out of the exhaust for about 30 seconds, and then the problem was gone. It was like clockwork...everytime I passed a certain point, smoke would just come streaming out.

 

Hmmmmm... that doesn't sound good.

How many miles on the engine?

Sounds like o-ring seals *possibly* on their way out. The exhaust gas is getting into the coolant system and pushing coolant out the top of your overflow tank on the passenger side --->

 

That's what I'm afraid it is. When I had replaced the first coolant hose, I also checked the overflow tank, and it was pretty full. It wasn't completely filled, but it was like 80% maybe?

 

Well I recommend you take it down to 20% full.

Then check the level again in a week. But before the week is up, do all the standard o-ring seal tests.

 

What are the standard o-ring seal tests? Can you point me in the right direction? I have a similar problem I suspect.

 

Check out Scuderia's Site.

Okay so I got the word from Rick at Rotary Performance, and it turns out I've actually developed a minute leak externally in the gasket between the rear rotor housing and the back housing. At first he suspected that it was the throttle body to rear housing hose, but after taking the UIM off and cleaning everything off, there would be a tiny puddle of coolant that would develop, eventually falling on the exhaust when moving, causing the steam.

SO...Rick's currently taking the motor apart to assess the damage, but no matter what, I'm looking at a complete engine overhaul, so NOW I've got all sorts of other things in mind. Single turbo conversion? Porting?

Have to admit...it's fun thinking about...but jeez...pockets are getting light as air...

=]