Radiator Cap, S4 Cooling System
04-21-2005, 09:11 AM
#1
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I've been losing coolant, I think from the radiator cap. Well not really the radiator, the fill neck by the t-stat, whatever the hell you call it. Mazda says they have one in stock, $22.80. What I was wanting to know is if it would be safe to get a generic one from an auto parts store, as long as it is the proper rating. ???
04-21-2005, 12:12 PM
#7
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Not sure if your cooling system is the same as mine, but I suspect it is. The cap you describe should not be vented. The radiator cap is a pressure-rated cap that bleeds over to the expansion tank. The t-stat cap is just a solid cap. Mine was crap when I got the car, and I replaced it with an off-the-shelf one rated at 13 or 15 psi. It worked fine for a year or so, then started burping coolant whenever the engine got hot, particularly after I shut it off.
I replaced it just a few weeks ago with the proper cap from Mazdatrix. I think it was $18, plus a few bucks shipping. My local dealership has changed hands a lot, and the latest crew says they can't get any parts for the old rotary cars. I suspect they're just a bunch of lazy bastards. If you can get the proper cap locally, I'd go for it.
I replaced it just a few weeks ago with the proper cap from Mazdatrix. I think it was $18, plus a few bucks shipping. My local dealership has changed hands a lot, and the latest crew says they can't get any parts for the old rotary cars. I suspect they're just a bunch of lazy bastards. If you can get the proper cap locally, I'd go for it.
04-21-2005, 12:25 PM
#8
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I picked up the cap from Mazda on my lunch break, $24 and change after tax. I only have 1 cap on my entire system. Any experienced rotary guy who looks under my hood notices that something is not right with my radiator. At the top of the rad there is no cap; there's the coolant level sensor thingy, and there's the overflow tube, but no cap. It looks like someone did something to it, meaning it doesn't look stock. The only cap I have is at the t-stat, and I'd rather have it vent when heating rather than have something pop. I don't know if my overflow works properly coming straight from the rad.
and I confirmed, the mazda cap does say 0.9 on it.
and I confirmed, the mazda cap does say 0.9 on it.
04-21-2005, 12:29 PM
#9
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[quote name='Baldy' date='Apr 21 2005, 12:25 PM']I picked up the cap from Mazda on my lunch break, $24 and change after tax. I only have 1 cap on my entire system. Any experienced rotary guy who looks under my hood notices that something is not right with my radiator. At the top of the rad there is no cap; there's the coolant level sensor thingy, and there's the overflow tube, but no cap. It looks like someone did something to it, meaning it doesn't look stock. The only cap I have is at the t-stat, and I'd rather have it vent when heating rather than have something pop. I don't know if my overflow works properly coming straight from the rad.
and I confirmed, the mazda cap does say 0.9 on it.
[/quote]
Well, yeah. I guess if you have only one cap, it better be vented!
and I confirmed, the mazda cap does say 0.9 on it.
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Well, yeah. I guess if you have only one cap, it better be vented!
