CAS o-ring leaking?

Prolly a stupid question, but...

Yesterday I noticed a little oil leakage at the back of the head, driver's (exhaust cam) side. There's some kind of sensor back there which I assume is the cam angle sensor. Is this the sign that the CAS o-ring needs to be replaced? If so, I'll add that to the list when it's time to change the timing belt. It's not a huge leak, but is it something that can blow out and leave me high and dry??? I've seen numerous references to this o-ring, but didn't know where it was, exactly.

Definitely sounds like the CAS o-ring. Since the o-ring is about $4 at town north mazda, I'd replace as soon as you have a chance. This goes hand in hand with replacing your heater hoses as well. The oil from the CAS will leak on the hoses and cause them to become slimey, leading to a hole. (Don't ask how I know this) There are installation instructions on miata.net.

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Originally Posted by johnwag

Definitely sounds like the CAS o-ring. Since the o-ring is about $4 at town north mazda, I'd replace as soon as you have a chance. This goes hand in hand with replacing your heater hoses as well. The oil from the CAS will leak on the hoses and cause them to become slimey, leading to a hole. (Don't ask how I know this) There are installation instructions on miata.net.

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Hes right. If you get oil on those hoses they will sweel up note quite like a balloon but kind of like a balloon. Anyway, bottom line they will bust your car will over-heat and you will be stuck. (Unless you have faith a pair of pliars and a knife)

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Originally Posted by MiataMike

Hes right. If you get oil on those hoses they will sweel up note quite like a balloon but kind of like a balloon. Anyway, bottom line they will bust your car will over-heat and you will be stuck. (Unless you have faith a pair of pliars and a knife)

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That would be crappy! I think that I will add this to my to-do list also. I don't think mine is leaking but I need to change the timing belt soon anyway so I'll just do it then.

Go to Pep Boys, they gave me my o ring for free, plus an extra one!

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Originally Posted by cam76034

Go to Pep Boys, they gave me my o ring for free, plus an extra one!

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Thanks for the heads-up!

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Originally Posted by johnwag

I'd replace as soon as you have a chance. This goes hand in hand with replacing your heater hoses as well. The oil from the CAS will leak on the hoses and cause them to become slimey, leading to a hole. (Don't ask how I know this)

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Been there, done that. ::Rant::

Yup... I stuck my paw down where the heater hose goes into the motor, and it's got a little dusty oil residue on it. Luckily it's not soft, slimy, or swollen yet, but I'm on the case!

Thanks guys!

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Originally Posted by trickyrix

It's got a little dusty oil residue on it. Luckily it's not soft, slimy, or swollen yet, but I'm on the case!

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I hope you're still talking about the heater hose, Rick. ;)

The o-ring is an easy fix with the right tools. I read horror stories about some people taking an hour or more to replace it. Mine took maybe 10 minutes.
Might sound odd, but if you have issues with the CAS assembly not lining up with the cam, grab a dental mirror or something similar. This way you can see the exact orientation of how it needs to "plug in" to the end of the cam.

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Originally Posted by juxt3r

I hope you're still talking about the heater hose, Rick. ;)

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Glad to know I can work it out in about 10 minutes... :rolleyes:

yea...mine did that and it overheated, it sucked something furious. Make sure you mark where the tabs are on the CAS when you take it out, otherwise your car is going to run like hammered ass or not at all :)

Gimme a shout if you want to bring it over here and do it.

I just did a CAS replacement for a guy over on the :batman: board last night to fix his 93.

We can also do the heater hose swapout and when finished we can verify the timing.

RJ

I'll round up the parts and let you know if it looks like too much of a bear. I'm off Mon-Wed so I'll prolly try and take care of it early next week.

Thanks!

Hey, if you guys get together please let me know. My 93 just doesn't seem to have any power until 3500 rpm, so I'm wondering if its the timing. I've never driven any other Miata so I don't have anything to compare it to.

Could use a second opinion.

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Originally Posted by cam76034

Hey, if you guys get together please let me know. My 93 just doesn't seem to have any power until 3500 rpm, so I'm wondering if its the timing. I've never driven any other Miata so I don't have anything to compare it to.

Could use a second opinion.

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I've never driven a 1.6 car, but I understand they're kind of puny in the low end. Does yours jump up "on the cam" at 3500 and then run fine up to redline? Is it smooth or does it stumble under load? I'm going to fetch parts today for the o-ring/heater hose job. If you want to take a spin in my 1.8 for comparison, let me know, and I'd be happy to drive yours and give you my seat-of-the-pants opinion.

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Originally Posted by channelmaniac

Gimme a shout if you want to bring it over here and do it.

I just did a CAS replacement for a guy over on the :batman: board last night to fix his 93.

We can also do the heater hose swapout and when finished we can verify the timing.

RJ

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I feel super-smart. I got the CAS o-ring changed AND did the heater hoses while I was in there. I have to say that the heater hoses were a real mother::Censor:: er! They were really stuck on - esp the one that runs under the CAS.

Everything's lined up and driving like new! ::Banana::

Congrats on the fix

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Originally Posted by trickyrix

I've never driven a 1.6 car, but I understand they're kind of puny in the low end. Does yours jump up "on the cam" at 3500 and then run fine up to redline? Is it smooth or does it stumble under load? I'm going to fetch parts today for the o-ring/heater hose job. If you want to take a spin in my 1.8 for comparison, let me know, and I'd be happy to drive yours and give you my seat-of-the-pants opinion.

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Yeah, that's pretty much how it is on the low end, just doesn't really take off until in the higher range.

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Originally Posted by cam76034

Yeah, that's pretty much how it is on the low end, just doesn't really take off until in the higher range.

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Without driving it I can't say for sure, but it doesn't sound like there's anything wrong with it...

Maybe you're just not driving it hard enough! :burnrubr:

Anyhow, you should drive another one for comparison when you get a chance.

Looks like MiataRoadster is offering a CAS o-ring that is supposed to last longer than the OEM part.