Help! I've tried everything.
 

So I finally broke down and bought my dream rx8. It ran well for 2 weeks and its just all gone south.... I have a 2007 RX8 Gt with 80k miles on it. so it was not starting great cold or hot, so I decided lets do the norm and put in new plugs wires and coils. Awesome cold starts are great and now hot starts... I'm not quite sure whats going on with those. I turn the key and it sounds like it wants to start, but it wont fully start... unless i let go of the key and then it will roar to life... 50 percent of the time. Also every time I turn the A/c on it shakes like no other. Symptoms... only when in revers or drive. Conclusion... Has to be engine mounts!!!! "Takes off old engine mounts" they seem fine but whatever I already bought the parts.... this fixes nothing. I am completely lost and need some help. Its like 97 degrees outside today started fine this morning, runs great while its running. It will occasionally die when coming to a complete stop due to the rpms just completely bottoming out. Usually the A/c is on and i forgot to turn it to 0 before I stop.... I did go ahead and clean the MAF, and that maybe helped the idle a small amount. I have not done a compression test but in all honestly the compression is fine. It does have a small knock that sounds like the SSV valve so I guess if we can't come up with something else next week that will get cleaned.

Thank you for any help!!!

If you have done the compression test, how do you know it's fine? You have the symptoms of low compression. :/

How are the coils and spark plugs? Get that comp test, if it checks out, the coils and spark plugs are next up.

A newer/faster starter might help as well, but it won't fix the cause.

sorry to be redundant but sadly I have the new started and I literally just changed coils plugs and wires. I mean the engine seems to run fine, it gets up and goes.

Sorry I missed the coil question. A rotary with low compression will run fine at speed, but struggle to idle or restart when warm. They are not like piston engines. So. Get that test. Usually we recommend to do that before buying, but at least you'll know what you're working with. If it's fine, we can look elsewhere for the cause.

Yeah, you should have it done before you bought it. You can't just think it's fine.

What's the previous owner like? Does he/she seem like an enthusiast that told you everything you need to know about the car or someone with a beat-up Civic sitting there?

The symptoms you described sound like low compression. Get that tested before throwing away money for more parts you don't need.

Remember, you need a special rotary compression tester. A piston one won't give anyone any useful feedback. You need to go to a Mazda dealership, a rotary shop or a member with one near you to get your engine tested. Expect to pay US$150 for it at a dealership.

Your results should look like these, with 2 cranking RPM numbers and 6 compression numbers, 3 for each rotor:

https://cimg9.ibsrv.net/gimg/www.rx8...70d041f562.jpg

For an AT(since you said Drive), it's more likely to have carbon issues due to the AT keeps the RPM too low(MT drivers keep our RPM above 3k RPM; I downshift if it drops below 2.5k RPM). These cars like more spirited driving, and hates granny driving and punishes you for that. Also, check your AT fluid if you haven't already. That also can make a difference.

Haven't had the time to go into get a compression test yet, but I did try a hot start that wouldn't start, and then connect my other car to it and it fires up no issue. The battery in it is brand new so I may try to get a red top. Also now there is no check engine on but it throws a code for p0443.

https://www.rx8club.com/new-member-f...t-here-202454/


P0443 Purge solenoid valve circuit problem ON 2 CCM ´

Starting the Engine
• Starter
• Battery
• Engine Compression
• Grounding Wires
• Ignition Coils
• Spark Plugs
• Spark Plug Wires
• Fuel Pump
• Fuel Injectors

Keeping the Engine at an Idle
• Ignition Coils
• Spark Plugs
• Spark Plug Wires
• Engine Compression
• E-Shaft Sensor (ESS)
• Mass Air Flow Sensor (MAF)
• Front O2 sensor
• Catalytic Converter (Cat)
• Intake Vaccum


RX8 Club’s recommended maintenance schedule, more comprehensive and proactive than Mazda’s schedule.
30,000 miles:
- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.


every 60,000:
...all 30,000, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.

90,000:
...all 30,000, plus any 60,000 not yet done, plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.
At 100k, anything original in the cooling system is really suspect and failure prone. It represents the biggest threat to your engine.
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