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Hello everyone im back it colo-lady1, i have a question I have a 2004 Mazda rx8 and after driving it for a while i shut the car off and it wont start. unless i wait maybe 1/2 hr or hour then it will start or if i get a jump.Now it seems that the battery is draining while i drive it. The alternator is good and if i change battery it will start but after awhile it to will go down, could it be not enough volts in the battery?
1. Electrical / charging system. Dirty or loose ground connections, dirty or loose battery connections, weak battery, weak alternator.
2. Weak starter. The starter could be turning too slowly to start the engine. There is an updated starter that turns faster. The updated starter can prolong the useful life of an engine with low compression, if everything else is good.
3. Weak ignition system. The ignition coils, wires, and spark plugs should be replaced every 20K miles in this car.
4. Low compression. Hard hot starting is a classic sign of low compression. Compression must be tested with a proper rotary engine compression tester. Mazda dealers and specialized rotary repair shops are the only places that have the correct tester. The only solutions to this are to rebuild your engine or replace it.
We usually recommend you spend the ~$150 to have the compression tested at a Mazda dealership before spending money on any of the above to see if those things are worth replacing.
1. Electrical / charging system. Dirty or loose ground connections, dirty or loose battery connections, weak battery, weak alternator.
2. Weak starter. The starter could be turning too slowly to start the engine. There is an updated starter that turns faster. The updated starter can prolong the useful life of an engine with low compression, if everything else is good.
3. Weak ignition system. The ignition coils, wires, and spark plugs should be replaced every 20K miles in this car.
4. Low compression. Hard hot starting is a classic sign of low compression. Compression must be tested with a proper rotary engine compression tester. Mazda dealers and specialized rotary repair shops are the only places that have the correct tester. The only solutions to this are to rebuild your engine or replace it.
We usually recommend you spend the ~$150 to have the compression tested at a Mazda dealership before spending money on any of the above to see if those things are worth replacing.
Hi Steve,
Which Koyorad are u using? the 53mm core or the 36mm one?
See, Koyorad is produced in Indonesia and they have 2 options for rx8.
Hi Guys, I've my 2004 manual rx8 for nearly 11 years now, had my engine rebuilt 46k miles ago (4 years ago) due to the hot start issues. I've also found this forum great over the years to solve minor issues. Just replaced my coils and spark plugs last week and she's running allot smoother but the power is still not great below 6,250rpm (more sluggish when pushed hard), above 6,250rpm she just takes off like a bullet. Occasionally she gives me some hot start issues but not all the time. Should I be getting a compression test done given the great power above 6,250rpm or what else should I be looking at? I'll check engine management code within next 2 weeks to see if anything else is on in there. I hope to keep the car for another couple years as I like her.
The Koyo 36mm one is for the Series 1 RX8s 2004-2008. The 48mm one is for the Series 2 RX8s 2009-12. Koyo does make a 53mm one, but it does not fit the RX8.
I have the HyperVcore Koyo 36mm in my 2008 40th Anniversary Edition. It is a beaut and adds improved cooling over stock rads.
The 36mm is for your 2003/4 . Just be sure to get the latest HyperVcore, not just the VCore one. The HyperVcore is improved. They both have the same part number, so be careful when you buy it.
Last edited by gwilliams6; 05-07-2017 at 12:55 PM.
Mine is 48mm. The other is 36mm. There are 2 radiators listed on Koyo's site for RX-8s.
Originally Posted by gwilliams6
The Koyo 36mm one is for the Series 1 RX8s 2004-2009. The 48mm one is for the Series 2 RX8s 2009-12. Koyo does make a 53mm one, but it does not fit the RX8.
I have the HyperVcore Koyo 36mm in my 2008 40th Anniversary Edition. It is a beaut and adds improved cooling over stock rads.
The 36mm is for your 2003/4 . Just be sure to get the latest HyperVcore, not just the VCore one. The HyperVcore is improved. They both have the same part number, so be careful when you buy it.
Thank u guys so much for the insight! Now i know what to get! Thanks alot seniors!
The Koyo 36mm one is for the Series 1 RX8s 2004-2008. The 48mm one is for the Series 2 RX8s 2009-12. Koyo does make a 53mm one, but it does not fit the RX8.
I have the HyperVcore Koyo 36mm in my 2008 40th Anniversary Edition. It is a beaut and adds improved cooling over stock rads.
The 36mm is for your 2003/4 . Just be sure to get the latest HyperVcore, not just the VCore one. The HyperVcore is improved. They both have the same part number, so be careful when you buy it.
So i was asking the local Koyorad factory and they didnt know about hyper v core nor v core. I went to their website and search for rx8 koyorad and it states that they only have vcore for rx8 36mm..
Quite confused how to explain the difference to them as they keep saying it's full aluminium all the time. We all know it's full aluminium but is it Hyper Vcore or not?!
Designed for applications where engine configuration/size cause clearances issues for thicker core radiators. In this case, the 36mm V-Core Series will suit your needs. Intended for both circuit and daily use. Unless noted otherwise, all Koyorad V-Series All Aluminum Radiators are Nocolok brazed, designed as a factory fit, direct bolt in with no engine modifications necessary, and retain mounts for the stock fan shrouds and fans. See notes in individual item descriptions for details.
HYPER V SERIES 36mm Core Thickness with Hyper Fin and Tube Pitch
The Hyper V-Core Series is the newest to the Koyorad | Koyo All Aluminum Racing Radiator line up. An engine's cooling system in many newer vehicles are suffering due to limited space and crowding which affects air circulation. Our new ultra efficient Hyper V core was developed specifically for vehicles which see extreme heat, are limited in space, and where the factory inlet/outlet locations eliminate the option for a proper N-FLO design. The Hyper V Series radiators have a specially designed fin and tube pitch which significantly increases its surface area while still allowing for excellent air circulation through the radiator. The Hyper V-Core series is the perfect solution where space savings and high performance is a must. Unless noted otherwise, all Koyorad Hyper V-Series All Aluminum Radiators are Nocolok brazed, designed as a factory fit, direct bolt in with no engine modifications necessary, and retain mounts for the stock fan shrouds and fans. See notes in individual item descriptions for details.
I bought and installed the Hyper V-Core 36mm Koyo in my RX8. It is a direct bolt-in for the Series 1 RX8
My research of suppliers found both the V-Core and Hyper V-Core being sold with the same part number for the RX8, but I made sure the one I bought came with Koyo badge and sticker on the outside and inside of the box as the latest Hyper V-Core one. It is truly a beauty of quality workmanship, it is a shame it goes mostly hidden from view.
Last edited by gwilliams6; 05-08-2017 at 07:33 PM.
Designed for applications where engine configuration/size cause clearances issues for thicker core radiators. In this case, the 36mm V-Core Series will suit your needs. Intended for both circuit and daily use. Unless noted otherwise, all Koyorad V-Series All Aluminum Radiators are Nocolok brazed, designed as a factory fit, direct bolt in with no engine modifications necessary, and retain mounts for the stock fan shrouds and fans. See notes in individual item descriptions for details.
HYPER V SERIES 36mm Core Thickness with Hyper Fin and Tube Pitch
The Hyper V-Core Series is the newest to the Koyorad | Koyo All Aluminum Racing Radiator line up. An engine's cooling system in many newer vehicles are suffering due to limited space and crowding which affects air circulation. Our new ultra efficient Hyper V core was developed specifically for vehicles which see extreme heat, are limited in space, and where the factory inlet/outlet locations eliminate the option for a proper N-FLO design. The Hyper V Series radiators have a specially designed fin and tube pitch which significantly increases its surface area while still allowing for excellent air circulation through the radiator. The Hyper V-Core series is the perfect solution where space savings and high performance is a must. Unless noted otherwise, all Koyorad Hyper V-Series All Aluminum Radiators are Nocolok brazed, designed as a factory fit, direct bolt in with no engine modifications necessary, and retain mounts for the stock fan shrouds and fans. See notes in individual item descriptions for details.
I bought and installed the Hyper V-Core 36mm Koyo in my RX8. It is a direct bolt-in for the Series 1 RX8
My research of suppliers found both the V-Core and Hyper V-Core being sold with the same part number for the RX8, but I made sure the one I bought came with Koyo badge and sticker on the outside and inside of the box as the latest Hyper V-Core one. It is truly a beauty of quality workmanship, it is a shame it goes mostly hidden from view.
This is the reply from Koyorad asia :
Hi Okki,
It could be KV061615R (no hyper core available for this model).
You need to provide OE number of plastic tank aluminium radiator so we can be sure about correct KOYORAD p/n.
Regards
=====================================
Effendy Wong
They are sometimes sold as Koyo "Racing" aluminum radiators. I have been owning, driving and modding RXs for over 44 years and I know what I am putting in them. In the US several suppliers have the Hyper V-Core for the Series 1 RX8.This one came from Importtuned. Click on the link and see for yourself. The radiator came with a metal badge on it that confirmed it was a Hyper V-Core. Not able to show that after it is hidden from view in installation. But here are my receipts.
Note: In the US, the Hyper V-Core Koyo is only available for the Series 1 RX8. For the Series 2 RX8, Koyo only offers a V-Core one
Maybe the Hyper V-Core one for the Series 1 RX8 is not available in Asia.
They are sometimes sold as Koyo "Racing" aluminum radiators. I have been owning, driving and modding RXs for over 44 years and I know what I am putting in them. In the US several suppliers have the Hyper V-Core for the Series 1 RX8.This one came from Importtuned. Click on the link and see for yourself. The radiator came with a metal badge on it that confirmed it was a Hyper V-Core. Not able to show that after it is hidden from view in installation. But here are my receipts.
Note: In the US, the Hyper V-Core Koyo is only available for the Series 1 RX8, the Series 2 RX8 ONLY has a V-Core one available from Koyo.
Maybe the Hyper V-Core one for the Series 1 RX8 is not available in Asia.
In the US it lists for around $275.28 (after a discount of 96.72), so yes around $372 list price. Lots of price competition in the US, so several suppliers had it discounted to around $275. So a $350 price there in Indonesia is not out of range.
Im having the same problem. I purchased an 04 without researching. smh. Runs great. Starts when cold. Holds idle well. But wont start hot until I wait about 15 min. Frustrating.........TodaY, i saw I still ahve the original starter, so Im praying the upgraded one will fix this issue..
I'm sorry but I have a friend in US who bought the Hyper V Core one for his rx8 2004 MT. and he is sure that he got the Hyper V core instead of the V core one. Is the production different for koyorads in US and Asia?
Thanks,
Okki
Last edited by Okki-Jakarta; 05-09-2017 at 09:20 PM.
It is ok if they say this is not hyper vcore. In the US it is badged and sold by more than one supplier as hypervcore. Either way, the vcore radiator would still be an improvement over stock. There are some, even more expensive custom radiator options for your RX8. This Koyo Hyper Vcore one was recommended to me by other longtime RX8 owners, and was more affordable than some others which can cost upwards of $600 and more.
Time to put this topic to bed. Best to you !
Last edited by gwilliams6; 05-10-2017 at 10:19 AM.
It is ok if they say this is not hyper vcore. In the US it is badged and sold by more than one supplier as hypervcore. Either way, the vcore radiator would still be an improvement over stock. There are some, even more expensive custom radiator options for your RX8. This Koyo Hyper Vcore one was recommended to me by other longtime RX8 owners, and was more affordable than some others which can cost upwards of $600 and more.
Time to put this topic to bed. Best to you !
I'll just take it as Not available in asia and i'll just get the available v core one, it's coming this friday, can't wait!
04-29-2017, 05:20 PM
car wont start after driving
