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Topic # 240280 30-Aug-2018 16:51
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Yesterday there was a "FairGo" TV show. It featured a woman who dropped off her RX8, with rotary engine of course.

https://www.tvnz.co.nz/shows/fair-go/clips/a-mechanical-horror-story-has-put-motorist-on-a-collision-course-with-a-panel-beater


Fair Go – A mechanical horror story has put motorist on a collision course with a panel beater.

They fixed her car, but stuffed the motor and have steadfastly refused to fix it or apologise.


The panel beater moved the car several times, but didn't know that RX8 is prone to flooding

Unlike a piston engine, once a rotary engine floods, it's extremely hard to unflood. There have even been class-action lawsuits in the US against Mazda over this issue.

So the panel beater wants to return her car, but she's refusing to take it because it won't start (it's flooded)

Here's a good explantion on a rotary forum


The reason why the rotary is easier to flood than a piston engine has everything to do with total chamber surface area and the distance that the fuel needs to travel before it gets ignited. In a rotary, we have an awful lot of surface area that the air and fuel see. In a piston engine, for the most part the air and fuel stay in the same place and just get compressed there. This is minimal surface area and hardly any distance traveled before combustion. Since air and fuel have to travel to the opposite side of the engine in a rotary before it gets ignited, this is a lot of contact with a cold surface. The fuel will stick to the sides easier. It is harder to ignite and there is lots of waste that didn't get completely burned. This is why cars run rich until they are warmed up. They need to in order to get enough fuel into suspension long enough to get burned.

Since we have the possibility of more fuel getting unburned and falling out of suspension, this means that we have seals pulling the fuel along the walls. The shape of the apex seals is rounded slightly. This means that this liquid can get underneath the edges of the apex seal tips. Cold temperatures and slow engine rotation don't help compression at all. Some of this small amount of fuel under the apex seal can cause the seal to move up just slightly. This causes a pressure leak which further reduces compression. It does not take much fluid at all to make this happen. When we don't make compression, the engine doesn't want to start and we keep cranking it. This dumps more fuel into the engine which makes the problem worse and so forth and so on.

Once a rotary gets flooded, it is extremely hard to unflood it. You can not just wait long enough for it to dry out. You'll be waiting a VERY long time. A flooded rotary might not start after months or even years of waiting! You need to get the fuel out. The factory recommendation is to hold your foot to the floor while cranking. This shuts off fuel delivery and allows the fuel to escape through the exhaust. At least it's supposed to. This too is hit or miss as just enough fuel may continuously stay in the engine as opposed to getting out of it and this will keep compression low. You need to get the engine spinning fast enough to overcome the compression loss. You also need to pray that your plugs will still fire as they may be all gummed up and wet. You can pull start any flooded rotary engine and get it to run. If it can't be done with a simple push start and popping the clutch, pull it behind another car. It will start. Depending on the severity of the flooding, it might take a few feet, it might take a few blocks but it will start. Do not take your car to a dealership to fix it. It is easy and you don't need a tow truck.


So while I feel sympathy for the lady, she should have done the research and probably bought a more robust, less sporty car.

She can't realistically expect a panel beater to know you have to warm-up a rotary engine, even if you're moving it 1 meter.

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  Reply # 2081594 30-Aug-2018 17:45
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Is the motor really "Stuffed" as the headline claims. Seems to me there is a simple remedy in the info from the rotary forum.

 

I'd be inclined to whip the spark plugs out, make sure they are dry and clean, spin the engine over for about 30 seconds with the plugs out and the throttle wide open, refit the plugs and try to start it. If that failed I'd try towing it as suggested in the forum info.

 

Rotary engines get hard to start once tip seals wear. Who's to say whether this engine wasn't a bit worn anyway.





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  Reply # 2081600 30-Aug-2018 18:00
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I had mechanics and AA WOF people do this to my RX8 almost every time I took it there, I would even pre warn them about doing it and they still did it.

 

All you need to do when its flooded and wont start is remove the fuel pump fuse from the fuse box, crank the starter for about 20 seconds, replace the fuel pump fuse and it started every time for me.  If that's all they did, no way this broke the engine.  The main issue with the RX8 is the apex seals inside the engine which break down over time or if the oil is not regularly kept topped up.


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  Reply # 2081613 30-Aug-2018 18:18
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One of the few episodes of Fair Go I actually saw.

 

After Fair Go got involved and made a few phone calls, the Panel beaters drop the car off at a rotary specialist mechanic, who got the engine going again.
It just needed the plugs removed, the engine cranked over a bit to dry it out properly.

 

All is well, and right with the world :) 

 

I don't no why the panel beaters just didn't do this to start with. They broke it, they should have fixed it, with out Fair Go getting involved.

 

I would expected any competent panel beater to know how to treat a Rotary engine vehicle, or just not take the job. I know of a few places that will tell you to go else where if you have a rotary.

 

 




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  Reply # 2081615 30-Aug-2018 18:26
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The panel beater was "MJ Breen" / "M J Breen" in Papatoetoe. I don't know them, and never used them.

While they probably could been more sensitive to the, frankly ignorant and confused, owner, I think the FairGo should have talked to an Mazda RX8 mechanic.

For anyone reading this in the future, removing the spark plugs on any flooded RX8 is dangerous, unless you also disable the crank sensor

spark + fuel = bad.

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  Reply # 2081616 30-Aug-2018 18:31
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GRISDALE:

 

I had mechanics and AA WOF people do this to my RX8 almost every time I took it there, I would even pre warn them about doing it and they still did it.

 

 

I'm not a rotary fan boy, I personally think they are a stupid engine to put in a vehicle.

 

But it still amazes me that mechanics don't have the basic knowlege and understanding of how to treat a rotary engine.


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  Reply # 2081617 30-Aug-2018 18:32
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djtOtago:

 

One of the few episodes of Fair Go I actually saw.

 

After Fair Go got involved and made a few phone calls, the Panel beaters drop the car off at a rotary specialist mechanic, who got the engine going again.
It just needed the plugs removed, the engine cranked over a bit to dry it out properly.

 

All is well, and right with the world :) 

 

I don't no why the panel beaters just didn't do this to start with. They broke it, they should have fixed it, with out Fair Go getting involved.

 

I would expected any competent panel beater to know how to treat a Rotary engine vehicle, or just not take the job. I know of a few places that will tell you to go else where if you have a rotary.

 

 

 

 

I don't agree they broke it. The car needed special handling. I wouldn't expect a panelbeater to know all about the idiosyncracies of an RX8 but I would expect the owner to be aware of them and advise the panelbeater.

 

I didn't see the show, but it does seem the panelbeater could have handled it better.





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  Reply # 2081620 30-Aug-2018 18:37
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If it was my car I would have collected it and towed it somewhere to have it fixed, and then sent the panel beaters the bill for the expenses.





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  Reply # 2081622 30-Aug-2018 18:41
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Thinking about this some more. 

 

It's not impossible the panelbeater, not knowing the starting issues of the rotary engines, was afraid they'd been "set up" to help fund an expensive repair on the engine. That would make anyone gun shy.





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  Reply # 2081653 30-Aug-2018 20:24
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djtOtago:

 

One of the few episodes of Fair Go I actually saw.

 

After Fair Go got involved and made a few phone calls, the Panel beaters drop the car off at a rotary specialist mechanic, who got the engine going again.
It just needed the plugs removed, the engine cranked over a bit to dry it out properly.

 

All is well, and right with the world :) 

 

I don't no why the panel beaters just didn't do this to start with. They broke it, they should have fixed it, with out Fair Go getting involved.

 

I would expected any competent panel beater to know how to treat a Rotary engine vehicle, or just not take the job. I know of a few places that will tell you to go else where if you have a rotary.

 

 

 

 

Agree fully. A panelbeater is not an engine expert, but they do need to know, as they need to move many cars. Rotaries are a niche, but they are not rare


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  Reply # 2081702 30-Aug-2018 22:52
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I feel for people who buy RX-8's, without reading up on the engines, and hence not aware of issues with oil consumption, and short trips.

RX-8's have desirable styling, and relatively practical Coupe setup with the rewards opening rear doors. Also 2003 era ones are relatively cheap now, so I can see how people pick them up to be a commuter or shopping car, without knowing they are better suited to higher speed applications.

 

djtOtago:

 

I would expected any competent panel beater to know how to treat a Rotary engine vehicle, or just not take the job. I know of a few places that will tell you to go else where if you have a rotary.

 



Panel beaters are experts in paperwork, and car exteriors.

Unless they happen to be performance car enthusiast's, I wouldn't expect them to know that an RX-8 has an unusual engine, or that it needs to be treated in a special way. 

I am aware that an RX-8 is has a rotary engine, but had no idea that you couldn't start it, drive it for a minute, and shut it off again.

That said, I seen a 4 cylinder outlander get flooded when it was started, moved 5m, and immediately shut off...

Sadly, I think it is up to the owners of exotic cars to tell service people of any qwerks.


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  Reply # 2081729 31-Aug-2018 02:00
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What does the owners manual say? Does it say anything to do with how long you need to run the engine for, or any other special running procedures? Does Mazda publish any documents or run any training courses on starting and running the RX8?

If there is nothing official, then you can't expect every single person who works in an automotive related business to know things that some mechanics have only discovered via personal experience.

Can you even leave an RX8 idling for long periods of time? Or will the spark plugs fowl up from doing so, which would also cause a no start problem.

Leaving a car running also causes safety hazards inside a building, Especially around things like flammable paints. And leaving it running outside often has security issues. If the car needs to be driven, Instead of just left idling, Then there might be insurance issues with staff driving it on a public road. As opposed to only moving it around the yard.

Does the flooding issue occour in good condition engines? Or only engines that have some worn parts? Have also heard that the RX8 can be difficult to start when hot, if the apex seals are worn. Maybe the panel beater knew that, but not the flooding issue. He might have thought that only running it for short bursts was actually better.

How is this different to a car that has a weak battery. Which is OK if you run the engine for long enough each time it is started, to get enough charge for the next start. But which would fail if the car is only run for short bursts.

The issue could be as simple as someone who is not maintaing their car properly, and is blaming others for their mistakes.





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  Reply # 2081756 31-Aug-2018 07:23
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Aredwood:

 

<snip>

 

Or will the spark plugs fowl up from doing so, which would also cause a no start problem.
<snip>

 

 

Yeah, once you get feathers growing on the spark plugs, you can expect the engine to be stuffed. (Sage and onion most likely.) :)

 

 




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  Reply # 2081762 31-Aug-2018 07:55
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Here's Why You Should Buy The 'Unreliable' Mazda RX-8


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