JorgLaw3083

Hi all, had the 54 plate rx8 for a few month now and still trying to get my head around the hot start issue, engine rebuild is the ultimatum but I just wanted to ask, if it bumps I.e push starts when hot is this still a hot start problem? I have had the starter off and cleaned her up and she did sound livelier but still, wouldn't start when hot unless bumped. Can I have a true honest answer please, new engine not financially possible, so if that's the case I will put up with the half n hour waits at petrol stations but for how long lol.

Williard

iTrader: (18)

With a hot start issue it usually means it's time for a rebuild. How long the motor will last is anyone's guess. It starts better cold because everything contracts back. Once the motor is warmed up the housings expand leaving you with less compression. How old is the ignition system? How many miles on the engine? Honestly your driving around with low compression and all that is going to lead to is you being stranded somewhere..

RIWWP

iTrader: (2)

The key variable when starting is the engine compression, assuming your ignition and fueling is fine.

There is a minimum compression threshold on the air/fuel mix that needs to be achieved in order to get a solid combustion. The engine's ability to seal, the battery's charge level, the starter's health, and the temperature of the engine are all factors that determine if you can meet the minimum compression.

A stronger battery spins the engine faster (for more compression)
A stronger starter spins the engine faster (for more compression)
The faster the engine can spin the better a compression score can be achieved
The colder the engine is, the better the compression will be

So being able to start when cold means your battery and starter can spin the engine fast enough by themselves, and the weak point is that your engine's natural compression is too low, so that when hot, you can't achieve the needed compression of the air/fuel mix. Let the engine cool off, and you can achieve it.

OR push/pull starting the car allows you to spin at a much faster rate.


So the straight answer is that you need a new engine. You can patch the issue in the short term by upgrading to a faster starter, but it's only a patch.

Williard

iTrader: (18)

If your planning on keeping the car then yes i would go with RIWWP and replace the starter with the upgraded one, if you havent already. If your not going to keep the car or can't afford to have it rebuilt, sell it. Your wasting money for a bandaid.

JorgLaw3083

Hey, nice words! I have had the starter off and cleaned it with brake/clutch cleaner, greased her back up and refitted the standard N3H1, this in effect has brightened her up and when hot she does try so hard but nothing, I have upgraded to truck coils and have a new battery now and still the same issue but infact longer cooling down periods, I'm thinking performance plugs then and a new starter possibly the N3H1. My girlfriend wants to part with it and sell it once she starts when hot, if this solves the issue which as I can see it just patches things up then maybe selling individual parts would make more money starting now lol, rebuild is to expensive for us for it to possibly happen again, she will have to go, the rx8 I mean.....

Khurram

Ohh i smiled for a second thinking the gf gotta go hahah jus joking.

Im sorry to hear that you are thinking of parting with ur 8.

Here's another solution.

upgrade the starter to more powerful one.
Pop ur hood when u pull up for gas
This will only patch the issue not make it disappear
save some money on the side each month and later get the engine rebuilt.

by the way, what are the truck coils where you get them from??

Khurram

I think removing the battery in the trunk, and removing the stock intakke box will also help engine cooling dramatically.. Not sure though just my thought can be wrong..

RIWWP

iTrader: (2)

Cooling off the engine bay will only have a tiny fraction of a difference in cooling it down faster. You need to get >100lbs of cast iron from 500F+ down to more like 200F+, without any flow through the cooling or oil system. It simply takes time.