Vladee

Had my first oh **** moment today since purchasing my car earlier this year. Was driving home from the gym and as I turned into my neighborhood, got a low coolant light. Coasted into my garage, and suddenly white smoke came out of engine bay.

Pfc showed coolant temp at 107 as I shut the car off. Stepped out and coolant flows out from under the car, my heart sank. Popped the hood to take a look released pressure from ast cap, nothing. Opened the filler neck, no more coolant. Panicked, I grab my coolant bottle and pour some in, it keeps flowing out.

I get it up on the quick jack to inspect, could not find a noticeable source. I let it sit for several hours so it could cool down enough for me to inspect some more. What I found was the coolant hose on the heater core line on the driver side ripped. This brings me to my question, has anyone used this kit from HPS?

HPS Coolant Hose

I’m planning to purchase this to replace all the lines, unless there’s a better option.

Hoping nothing else was damaged in the process.

scotty305

iTrader: (2)

The factory hoses are pretty good, but 10-20 years ago people were advising that they should be replaced every 10 years. If your car has any of the original coolant hoses it's probably a good time to replace them. I don't remember if Mazda still sells a kit with all the cooling system hoses, but Ray Crowe can get you the ones you need at good prices. If you race your car (even HPDE or Autocross), the prices from the Mazda Competition site might be even lower than Ray but you'll need to navigate the parts catalog yourself.

SETaylor

iTrader: (4)

Be very careful when removing the old hoses from the barb on the heater core. They will be baked on due to their proximity to the exhaust manifold(s) and the heater core fitting is very easy to accidentally bend and not be noticed. I would suggest you just cut it off with a sharp blade instead of trying to pry it off with pliers.
I made that mistake back when I did my engine replacement and it ended up leaking from the fitting and under the carpet. Ended up having to pull the carpet to have it cleaned. Was probably a good thing because I found out I was driving a very fast mouse nest and had several pounds of ballast in the form of mouse droppings...

Vladee

Thanks for the info, are the ones from Mazda competition of better quality?

Thanks for the heads up, will just cut them off. Did you go with OEM replacement?

SETaylor

iTrader: (4)

Thanks for the heads up, will just cut them off. Did you go with OEM replacement?[/QUOTE]

I went with the OEM hoses. I don't recall the part number(s) but I got them through Ray Crowe. IIRC one of them was like $10 or $12. If you email or call him and just tell him you need the heater core hoses, he'll know what you're talking about.

scotty305

iTrader: (2)

I got the name wrong, it's actually Mazda Motorsports mazdamotorsports.com .


I don't think they have upgraded coolant hoses available, but the original ones for the RX7 aren't too bad aside from wearing out eventually. There are some upgraded suspension and drivetrain parts available, like engine mounts or suspension bushings.

mobash

iTrader: (4)

FWIW I have all the cooling hoses from Mazda, ordered those Mazda Motorsports this winter just sitting here. I could have them shipped out this week if you need.

Send me a PM and I can get some photos once I work on my car tomorrow.

Vladee

Started taking the hoses off today and noticed some heavy corrosion on the hard line.




Is this still reusable? I’m not able to find the hardline anywhere online. Going to try Ray tomorrow. Any other recommendations?

Howard Coleman

iTrader: (6)

i always like to drive the brand of car that i race so when i switched to Mazda in 1983 i bought a wonderful 1983 GSL. about 3 years later i am doing 74 on the highway when i smelled coolant. i immediately shifted out of gear and coasted to the shoulder. the driver's side heater to block coolant line had ruptured from vibration. the engine was toast!

i would absolutely consider these lines to be a maintenance item on all RX7s and keep a careful watch on them. i, also, would only replace them w genuine Mazda hoses... just my two cents.

Pete_89T2

iTrader: (4)

I probably would not reuse that hard line. Hard to tell from the pictures, but if the end where the hose attaches to it is so buggered up that it won't make a good seal, it's done. If Mazda no longer sells these new, check the classifieds here for a used one.

DaleClark

iTrader: (55)

Yep, OEM coolant hoses 100%.

Mazda did improve the material they are made out of some time back, it's possible that hose was original from when the car was first made.

And yes get a new steel heater pipe for sure.

Dale

marksae

iTrader: (1)

I got the HPS heater hoses on my car. They are pretty good quality. Nice and thick. I am also using them in my E46 M3 as well.

Vladee

Thanks everyone for the input. After taking everything apart, I’ve decided to just bypass the heater core for now by capping at the thermostat and rear of engine. There was just too much corrosion on the hardlines to reuse and Ray informed me they no longer sell them. I did find the rear hard line used, but will just wait till I go single turbo and purchase the single turbo hard line, to put the heater core loop back in service.

Sgtblue

iTrader: (16)

I’m also considering stopping the coolant to the heater core. Haven’t really looked into it for options but initially thought I’d use a valve on the hose. I just never drive the car in cold weather and can’t remember the last time I needed the heater.

Sorry if this side-tracks the thread but didn’t see the value in starting a new one and welcome discussion and tips…. pro and con.

Vladee

If your lines are in tact and in good shape don’t see a need to bypass it.

Sgtblue

iTrader: (16)

Except my blender door has never completely blocked warmed air since nearly new, and it’s a 30 year old core.