I'm aware of how many RX-7s came to the USA.

What you're implying is that Mazda only put ASTs on cars bound for the US market. I'm thinking they put them on every RX-7 ever built....

 

All this arguiing us useless. For around the price of a new plastic AST you can get an aluminum one. Why not do it?

 

Not sure what exactly is included in the "kit", but as for the OEM turbo coolant hoses, they are pre-formed to fit. Even then, they're a minor PITA to replace with the motor in the car.

 

Maybe he just wants to replace things as he goes along and keep everything under the hood as OEM as he can.....you can look at like this too, why spend 100.00 or so on a aluminum one when you can just get rid of the AST all together

 

Exactly. Its needed. Anyone who buys a Plastic AST new, to replace a Broken one, needs to check their priorities. If keeping their 7 running is one, then a new aftermarket AST is in need.

 

Well I have an AST in place so I dont have to worry as much about bubbles. Trust me, if I could I would be rid of it. I want to keep my car as STOCK as possible but I wont forego reliability. The only reason I can see for keeping things stock is for resale value and if thats the case, you can just replace the aftermarket part for the OEM one before you sell.

 

Well any informed potential purchaser, would wonder why you didn't replace the AST. And second guess your knowledge and judgment in the FD and rotaries. At least i would.

 

If a more novice owner had started this thread, all these comments about a metal AST might be warranted. But the OP is a long-time, experienced owner whose car is probably better taken care of than the majority. I'd venture to guess he knows the risks. While I might not agree with his choice, he has his reasons... and doesn't need the lecture. My .02.

 

Yes - but novice users may get the sense that there is some close level of debate here and that there are some valid reasons for keeping the plastic AST.

 

Bubbles? I've been running without an AST for years with no issues. We also delete them on customer's cars if that is what they want, and we still warranty the motor.

 

Not if they start with reading stickys and searching like they should. Besides, there are VERY FEW things are absolute/universal about these cars, because each owner brings a different set of priorities and uses. No accounting for stupidity if they make decisions on any of them after reading one thread.

 

This has happened twice during this car's lifetime, and it ain't dun-fer yet. Our rule is to pull it over and park it if temp goes up. Thank you; I think I do. I lobbied for an aluminum AST to my wife (it's her car), but failed to convince her. She wants it as OEM as possible, and it's really her choice. I was lucky she accepted a Bonez downpipe and Viton hoses! Anyway, it was not possible to convince her that something which lasted 98K miles is an inherently defective item.

 

i think the chance of losing an engine to a broken ast are pretty slim. its gonna crack and leak, not explode imediately draining your coolant system and overheating the engine.

 

Come now, you've met me in person. You know how poor my car skills are and how lazy I am. For those that dont know, Im very lazy, and know nothing about cars except to let other people fix mine.

 

I PREFER THE OEM AST VS AFTERMARKET

Not if you understand why the plastic one broke. Was it age or was the hose applying stress on the nipple? Two easily solved problems. Always make sure the AST is black (not green) and that the hoses are connected straight into the nipple(s), meaning not coming in at an angle thus creating stress on the connection.

FYI most of people's "leaking coolant out of the over flow tank problem" is due to leaky aftermarket ASTs. Not a bad radiator cap, which is a band aid. The quality control just isn't there IMO that is why some get lucky and get good ASTs and some don't.


so to both of you: all I'm saying is that there are reasons why it isn't a bad idea to stick OEM.

+1 I'm currently taking steps to remove mine. Tired of dealing with the subpar quality aftermarket AST's, and always watching the OEM one. Burp the system correctly and don't look back.

M-

 

So, if I told her that I had a relative who smoked 2 packets of cigarettes per day and lived into their 90s would she conclude that smoking was not dangerous? Making conclusions based on outliers is not a good idea.

It is pretty common, for example, for people on this board with 100k mile+ original engines to attribute its longevity to their superior maintenance skills that - whereas it should be pretty clear that they got lucky.

 

I agree, but some people dont watch their gauges carefully, and might not notice your engine overheating. i would suspect some one who buys a OEM AST, that are prone to cracking and leaking, might be one to not to watch their gauges carefully.

Not saying the OP dosent know anything, just saying, that the majority of FD owners, know the risks of owning a rotary, and why put it in more jeopardy then you need to?

 

The low coolant alarm would sound long before enough coolant has been lost to overheat the engine, steam and a burning coolant smell would also likely be present. not to mention there would be a pool of coolant underneath the car while parked.

 

ok i think we all get the point

 

I agree, but we have all heard those stories, about "Coolant light was on, but i thought i would just drive it home". Im just saying,m taking precautions isnt a bad thing, and how hard is it to dish our 20 moe dollars to limit the things that could go wrong )Stock AST to Aftermarket one is $20.

 

Goodfellafd3s ,good point . I deleat them on customers cars with no problems reported .

 

Installed the new AST today. It is a N3A1-15-35XB, which looks identical except for the printed numbers on the side to the -35XA that broke. Color is maybe a little blacker, but not much. The new unit went in with no trouble at all. Refilling the coolant is time-consuming; don't know when all the air will finally be out of the system. If/when this one breaks I will offer to all who recommended the aluminum aftermarket units.

 

It should last a while. Other than temps, the AST is not a highly stressed part. It just sees a lot of temp changes and pressure from the coolant system being pressurized while running.

Automakers have been steadily making as many parts out of plastic as they can. If you think the Mazda AST was a bad decision, think about the fact that BMW makes their waterpumps out of plastic. They usually break at 50k miles.