Mazda RX8 - hot start problem - ideas wanted
Mazda RX8 - hot start problem - ideas wanted
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Discussion

frottage

Original Poster:

37 posts

214 months

Thursday 29th May 2008
quotequote all
My mate is getting desperate - his RX8 has been off the road for 5 months now due to a huge hot start problem. The car starts fine from cold and drives very well but as soon as it is hot it will not start even though the starter is clearly turning the engine over apparently fine. The car has been put on diagnostics 3 times and has shown no sign of a fault, the coil packs have been replaced as well as all HT leads. It has been into 2 Mazda main dealers - and has even had the ECU completely reflashed, all to no avail.

Where do we turn now ? is this a known fault ? (internet searches haven't turned up much) is there an RX8 guru we might take the car to ? we are based in South Yorkshire.

Any suggestions gratefully received.

buckman63

89 posts

238 months

Thursday 29th May 2008
quotequote all
Did the dealer do a compression check ?? What mileage is on the engine. Poor hot starting is a classic symptom of low compression in a rotary ( worn or damaged apex seals ). Not always the cause but very common.

Holst

2,468 posts

244 months

Thursday 29th May 2008
quotequote all
I had a similar problem with my Honda and it turned out to be bad solder joints on the relays that turn on the injectors and fuel pump.
I was lucky that this problem is well known with old Hondas and it was easy to find a fix on the net.

I dont know anything about these cars but is it easy to check you are getting fuel and spark?

uk_vette

3,336 posts

227 months

Thursday 29th May 2008
quotequote all
I had a similar problem on a Maxda rotary i had years ago,

Turned out to be the apex seals, that when I got shut.

For a while, I had a spare 12 volt battery in the boot, and some times I had to connect them in SERIES, to get 24 volt, to spin the engine over fast enough to fire.

Brilliant engine when running well though, i could rev to some thing like 9000rpm, and just as smooth as an electric motor.

Guess that what done the seals in.

Good fun while it lasted.

iamthatm8

5 posts

214 months

Thursday 29th May 2008
quotequote all
Tis my car and they as i have have dismissed any compression issues because the cars only done 26k and drives like it should no performance issue's once started but having said that i've no confidence in these part swapping run up a big bill monkeys, so i'll get them to do a compression check tomorrow. £500 for a starter plus fitting is just rediculous when they can't guarantee that it will solve the problem. I'm already £400 down and the car has the same problem i took it in with frown Thanks for the comments though guys, will let you know how i get on !

*Kosta*

911 posts

226 months

Thursday 29th May 2008
quotequote all
One of my colleagues at work bought a used Mazda RX8 off a Honda dealer and was experiencing identical problems.

Turns out the engine needs rebuilding. Can't remember what the problem was exactly, but when hot it loses a lot of compression.

So he rejected the car last week.

frottage

Original Poster:

37 posts

214 months

Thursday 29th May 2008
quotequote all
god i hope thats not the problem in this case

Vixpy1

42,697 posts

287 months

Friday 30th May 2008
quotequote all
Sorry chaps, the dreaded hot start on a rotary usual means bed news. Get it compression checked.

buckman63

89 posts

238 months

Friday 30th May 2008
quotequote all
iamthatm8 said:
Tis my car and they as i have have dismissed any compression issues because the cars only done 26k
Just goes to show how little knowledge of rotaries these Mazda " main stealers " have. The first thing any rotary specialist would do is a compression check, takes 10 minutes and is THEE classic cause of poor hot starting. There are a few small issues which can cause premature wear of the seals so it is always the first thing to check. This issue is not half the problem in RX8'as it is with the RX7, RX8's are generally good for twice the miles ( 80 - 100K )on a well maintained engine but it still happens.

iamthatm8 said:
i've no confidence in these part swapping run up a big bill monkeys
You ain't on your own there mate !!!


If the worst is diagnosed ( apex seals ) its always worth harrassing Mazda Central for some compensation , even out of warranty, as they are desperate to restore / maintain the good progress of the rotary and I know of a few people who have had engine failures on newer, lowish mile RX8's and got free engine replacement once diagnosed as component failure rather than owner neglect.

Good Luck !

anonymous-user

77 months

Friday 30th May 2008
quotequote all
Depending on the cost of a rebuild/replacement engine, drop me a line as I may be breaking an RX8 in the near future. Not as low mileage, but ran sweet as until I crashed it.

iamthatm8

5 posts

214 months

Friday 30th May 2008
quotequote all
Another ting that just struck me. Ouch !

If compression was low at normal engine temperature then emissssions would be way out too, and they def aren't !

BigWithey

565 posts

253 months

Friday 30th May 2008
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Pop over to the RX8 Owners Club loads of help/info on this known issue.

Jon

iamthatm8

5 posts

214 months

Friday 30th May 2008
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Oye BigWithey used to be a member, never noticed anything about this particular subject though !

BigWithey

565 posts

253 months

Friday 30th May 2008
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4 page thread going the moment....

iamthatm8

5 posts

214 months

Friday 30th May 2008
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Yeah just read ! Will post over there too !

Surely though as i said above if compression is down performance would be down & emisssions would be up ?

Silent1

19,762 posts

258 months

Saturday 31st May 2008
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What about the fuel system? Is it a deadhead system or does it have a return? Cooper S's suffer the same problem as the fuel rail doesn't have a return meaning it gets vapour locked, are the injectors flowing correctly?

frottage

Original Poster:

37 posts

214 months

Monday 16th June 2008
quotequote all
Quick update to this

The car is now fixed - it was not compression - that checked out fine - the problem was the starter motor which was replaced.

Now working better then ever. The Mazda diagnostics and new starter did cost over £800 so not the greatest testimonial for a car with 26k miles on the clock.

Thanks to all those who contributed.


RobDickinson

31,343 posts

277 months

Wednesday 18th June 2008
quotequote all
Wasnt theer a recall/update on dodgy starter moters at one point?

papercup

2,490 posts

242 months

Sunday 22nd June 2008
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Good to see the usual internet bks being rolled out

Q: When i sit in my RX-8, sometimes i get a little back-ache so i adjust the seat.

A: OHMIGOD ITS THE ROTOR TIPS OHMIGOD ROTARIES ARE SO UNRELIABLE OHMIGOD BUY SOMETHING GERMAN AND DULL RIGHT NOW

smile