Replacing engine - what else should I do at the same time?
 

Hi everyone,

Long time member here but I only recently was able to finally pull the trigger and buy my first RX8. I found a crazy deal on a clean car with 50K and a low compression motor.

I'm going to be replacing it over the next month or two and was hoping I could get some advice on other common parts I should be doing at the same time. Searching 'things to replace along with motor' didn't get me much, so I thought I'd better ask.

So far I am planning to do the clutch and of course ignition coils, wires and plugs. I was thinking maybe motor mounts too? Are they a common failure point? Given that the car only has 50K on it, I feel like there shouldn't really be much I should have to do, but if there are any common things to need replacing early, now's the time.

Any help appreciated!

Are you replacing it or having it replaced? Check the cat very well. normally bad ignition causes a bad cat and that cooks the engine.

If you're doing the work I would not worry about engine mounts. That takes a hour when they do go bad. probably around 100K. you'll know if they're bad when you get to them. Clean your ground points well.

Next I'd get mazdaedit and an openport. Getting into tuning can be a bit complicated but not to bad. The primary reason is to lower fans and give it some more oil. it can be good for blocking codes if you modify anything else.

Good advice, thanks. Yeah I'm doing the work myself. I don't want to get into tuning just yet though, as I plan to compete in the SC autocross class. I do have a Sohn OMP adapter though, so that ought to help with oiling.

clean and/or replace the SSV valve.
check the OMP lines and connections.
Throttle body clean.

Get your injectors cleaned.

Clean the LIM (SSV). Lotsa carbon is going to be there.

Also a good time to replace oil cooler lines if they are marginal.

Just off the top of my head. Think of anything that otherwise is a PITA with the engine and transmission in the engine bay.

Fuel filter and fittings.

Most common thing with rebuilds is FIRE!

Replace your clutch slave cylinder and bleed the clutch hydraulics thoroughly. It's a bitch to do with the motor in the car. Also visually inspect the clutch master (where clutch rod depresses piston) for leaks, replace if any oil is dripping or on housing. This would also be the time to install an SS clutch line if you so desire (if you're going to run an aftermarket, non-stock clutch I've heard this is good to have).

I don't know what your budget is, but if you're patient and thorough in your searching you can find lightweight flywheels for ~$200. Good time to add that as well if you're replacing the clutch.

You mentioned motor mounts and I agree that you may as well do them now. It's $30 to cut, drain, and fill them with 80a urethane from McMaster Carr. I did this mod to my mounts before they blew and it really enhances the driving experience (no more driveline lash). There is a DIY here. Do a good job prepping and cleaning the mounts before you fill them though.

You can replace the fuel filter or the fittings in a S1 RX-8....................

You can replace the whole fuel pump assembly to get a new filter and replace the entire fuel lines to get new fittings.

I am on my 4th build right now. To be honest the external stuff is the hard/expensive part. New fuel pump, cleaned flow tested injectors, new clutch, upgraded starter, new 02 sensors, new engine mounts, etc. The engine is relatively easy.

I would highly suggest upgrading and replacing these other components.

Sure you can do these things with the engine in the car, but its much easier doing them with the engine out.