I Done Did It....

After way too much thinking, I bought a 2006 RX8 on Saturday. Exactly what I thought it would be and a little more. It is the car with the replaced engine due to hydro locking, something that enabled a reasonable negotiation on the price. Has 63,000 km (36,000miles) and a certified 32,000 km (roughly 20,000 miles) on the motor. I want to use it as my DD and a little track time and autocross the Miata. Here's the question, is the Mazdaspeed cold air intake worth retaining? The previous owner blames it for the hydro locking, is this an issue with cold air intakes that are mounted low in the car? Grandson and son approve the purchase.

Hydro locking or carbon locking?

In reply to Knurled:

The story was the po sucked enough water in said intake that it hydrolocked the original engine.

Sorry I could have been clearer. I think that he (previous owner) may have driven through standing water and had the air intake immersed completely. What I'm curious about is whether normal street conditions such as rain and snow are likely to be an issue. The cold air intake seems to wake up the engine. I know that's because it sounds great more than an actual gain.

Why take the risk if you have reasonable suspicion that it cost someone an engine in the same car?

Woody wrote: Why take the risk if you have reasonable suspicion that it cost someone an engine in the same car?

Because this is GRM and we are gluttons for the forelorned and abused.

Stock intake on the RX8 models is already highly efficient so realistically you are not losing anything but sound.

You may want to check for other flood/driving in deep water damage while you are at it.

I would also blame the owner some for not asking about really low intakes and water getting sucked in it, or from him knowing about it and forgetting it is low, or buying one when he lives in a place with heavy rainfall.

I live in an area with moderate to heavy rainfall so I won't get a cold air intake that mounts really low.

Nice purchase, btw. Post pics, too.

Yep there are plenty of CAIs out there that mount low and so long as you are in dry conditions and don't hit a large bit of standing water you should be fine. However hit that and it sucks up some water and...

That is why even though I live on the dry side of my state I still went with a CAI that sits basically were the airbox use to sit. The area is boxed off and sealed from the rest of the engine compartment and is fed the same way the original was. It also so happened that this intake was the best bang for the buck of the about 8 or so that Mopar magazine tested.

I still have all the stock bits, so might be a project prior to winter..I just came from a back to back drive with the RX8 and the Miata on the same little twisty bit. Before I would have said they were very similar, now not so much. Mind you the Miata has Rivals and the RX8 generic Yokohamas. Not at all sure which I prefer so I guess I'll just drive them on alternate days.

Mr_Clutch42 wrote: I would also blame the owner some for not asking about really low intakes and water getting sucked in it, or from him knowing about it and forgetting it is low, or buying one when he lives in a place with heavy rainfall. I live in an area with moderate to heavy rainfall so I won't get a cold air intake that mounts really low. Nice purchase, btw. Post pics, too.

I have a Mazdaspeed CAI on my Miata and it's literally 10"-12" off the ground. Not sure why it was designed to mount so low unless space was a factor. Not an issue for me as I never drive it in the rain or bad weather but still, I can see where that could be a problem.

AEM makes a bypass valve for cold air intakes that opens if the intake gets submerged...

http://www.aemintakes.com/air_bypass_valve.htm

There was a video somewhere of it being tested on a dyno. They stuck the intake into a bucket of water during the run, and the bypass would open before the water made it very far.

I drove my 2006 Miata from Tennessee to Connecticut with the low Mazda/AEM CAI on it through, well, a hurricane. Tons of standing water and by NJ I had to remove and shake out the filter as it was so wet it wouldn't flow air anymore. Even set a check engine light for airflow on the NJ turnike-meaning everyone was doing 90mph through torrential rain. No damage to the engine at all. Unless you submerge it, I think you'll be fine.

Thanks for the responses. Apparently Mazdaspeed intake and wheels was some sort of dealer added incentive in Canada. I do love the sound, reminds me of my Alfa only less mechanical. I think the PO like a lot of people new to the rotary experience was unaware that it wasn't quite like a Honda Civic. Thirsty though, I can watch the fuel gauge drop at 8500 rpm. Not that I really care, although at $1.58 per litre for 91 octane I probably should. Less for the grandkids.

Mind you that if the air filter is of the oil-soaked cotton type, do not let it get wet. If it gets wet, the oil (and dirt) get sucked into the engine. With no oil on the filter, it stops being an air filter.

Rotary engines are highly intolerant of ingesting dirty air. The side of the rotor passes over the intake port, and the grit will get into that area under the side seals with no way out. Then it forms lapping paste. Death is remarkably fast and tends to leave few usable parts behind.

Learned that lesson real quick. I keep two spare air filters on a clean/re-oil rotation and change very frequently.

In reply to Feedyurhed: I hope that Mazda told their customers at purchase time to not drive through big puddles with the Mazdaspeed part on it. That's really low.