Looking at a particular RX-8, could use some input on possible red flags
 

Hey guys,

Let me first say I'm really glad such a great forum exists for these cars. It's been very helpful for me to read up on them with such detailed information available! I'm very mechanically inclined, do all my own car work, but I've never owned a rotary before..

I'm looking at an 8 right now, and before I go any farther, I wanted to ask a couple questions. I already called my local dealership but the guy I spoke to wasn't all that up on rotaries and couldn't answer all my questions.

The car is an 06 and has about 35k km (21k miles) on it, and is a Canadian car. It spent around half its life in a small town, so it likely has a lot of short trips and a lot of highway mileage..

Things I noticed are (roughly in increasing order of severity):

-Car shakes more at idle than I remember the last RX-8 shaking. I know motor mounts can be an issue, but at this low mileage?

-According to Mazda, the recall for the clutch and oil cooler lines has not been done yet. I assume if it wasn't a problem, the previous owner(s) didn't know there was a recall or didn't care to fix it?

-Highbeams don't work. Are those the bulbs in the middle of the headlight housing, between the projector and whatever that small, innermost light is? The guy at the dealership said he thinks if one burns out, the other won't work. Is that true?

-Side markers on the front fenders light up, but don't blink with the turn signals. Not sure if they are supposed to or not? Guy at Mazda didn't know, lol..

And lastly, most seriously, hot starting. It started from cold almost as easy as any piston engine. After the test drive (engine ran fine on the test drive, pulled smoothly to redline), I shut it off, investigated the highbeam issue, and then tried to start it again. It took 2 tries and a bit of cranking before it fired up.. I guess what I'd like to know is if even a perfectly good rotary engine will be slightly harder to start when fully warmed up? Given the mileage I'm sure it most likely has its original coils/plugs/wires.

So, what do you think? Should I bother going any further with it at this point? Of course I will be taking any car I buy for a compression test and full inspection from the dealership, but I don't want to waste the money on a car with obvious warning signs.

Thanks in advance!

I cant comment on all the issues but these few I can.

Motor mounts can be an issue at any mileage.
If recalls have not been done the owner didnt care enough to know or take care of it
Side markers dont blink, they are just running lights
Hot starting is almost always a bad sign. Signs of poor start on hot start are usually a sign of low compression.
I would look for a better example unless the price was excellent and it passed a compression test.

Hmm, good point about the recalls. I did find that kind of odd. At least they weren't for anything major though?

As for the hot starting.. Yeah, that's exactly why I wanted some input. I know low compression isn't the ONLY thing that can cause that, but at the same time I want to make sure my expectations aren't unreasonably high or something. I don't think I've looked a car yet that started perfectly when hot. :(

Yes.

If the engine and everything is in good health then it will start hot fine. It is always possible that the problem is not low compression but I think that is the most likely thing.

The hot starting problem is a red flag; it's never taken mine a couple of tries to start whether hot or cold. Def get a compression test. Also, make sure the MSP-16 reflash has been done.

Kudos for reading and researching before posting!

Hmm, ok well it's good to know I didn't just have unreasonably high expectations or anything, but that also means every 8 I've looked at so far has had some kind of hot start issue. :(

Ok, so it took maybe 3-5 seconds to cold start, ran smooth, and then took maybe 8-10 seconds across 2 tries to hot start.. Is is reasonable to think that if it was related to an ignition issue, it would most likely miss or otherwise misbehave while running (high RPM, high load, etc)?

Reason I ask is because I don't want to spend $250 on a compression/safety inspection on a car with an obvious compression issue to begin with.

Thanks for the help guys! Much appreciated.

Maybe. I think the 06 should have the upgraded starter already but you never know. It might be as simple as changing and plugs and coils or possibly the starter it is hard to say. If you just go in for a compression test at first then that should run you $100-150.

Maybe I missed it but where are you located? There are members here that have rotary compression testers that will either let you use it or charge you much less than Mazda would to do a test. I know theres one in vegas and one in new york somewhere.

The thing about ignition is that it's not necessarily alive one day and dead the next. It dies a little with each revolution, and often you'll have no noticeable symptoms of a weak (but not dead) ignition until your cat is clogged and glowing. That's why coils are preventative maintenance, not repair work.

So whatever RX8 you end up getting, if the coils/plugs/wires are not verifiable fresh, be prepared to change them right away.

Starting problems can be an indication of bad compression or bad ignition, but you won't know for sure until you do a compression test. It can also be caused by other things like bad gas or weak battery or starter (there was a TSB on these in 2k6-ish), especially if the car has been sitting. Note also that all RX8s have a 160,000km/8 year warranty on the engine core, so even if the compression comes up back, you can have the engine changed if the car is within that timeframe. You may need to prove that regular maintenance has been performed, so be sure to choose a seller who has their service receipts, or a record of each with the dealer.

Long story short, if you like the car get the comp test. Guessing why it's having problems starting is really just guessing until you look at the test results. And, by the way, make sure they give you the actual comp numbers and the rpm at which the numbers were read. Some dealers will just say "yeah it's fine" which could mean "it's in spec" or "it's barely in spec" or "it's below spec but we don't want to deal with it" etc.

Alright, good advice. I will report back soon. Thanks.