Hi! I have a 2005 rx8. So I recently went on vacation for a week and gave a remote start to my sister so that she could warm it up once a day. When I come back, the car doesn't start. Put in new battery, new sparks, still nothing. Mechanic did compression test and says that there is low compression on a motor. What's the best way to go around it? Rebuld the engine or just scrap this one and get another one. But I really want to keep this one. Ive grown very attached to it and I cannot just scrap it. Please tell me what options do I have. Mechanic says that he will need to get into this moyor to see whats wrong with it but I think it will be easier to just get a new motor than trying to fix this one.

 

You almost certainly just have it flooded, probably from something your sister did with the starting combined with the cold and/or weaker ignition, and/or draining the battery.

You almost certainly have fixed the original source of the flood at this point, but you still have to properly deflood to get rid of the result.

Low compression with a flooded engine is very common, because the oil film gets washed away by the gasoline. Compression should rebuild normally. Don't panic over a low compression judgement by your local mechanic, who probably doesn't have a rotary engine compression tester, and probably doesn't really know anything about the RX-8's quirks.

Hook up another car with jumper cable to prevent a battery drain, then holding the gas pedal to the floor, crank the starter for 5-10 seconds, let it rest for 5-10 seconds to avoid overheating the starter, repeat 10 times. Wait a few minutes. Repeat the 5-10 second cranks another 10 times. Remove your foot from the gas pedal. Try starting the car normally. If it coughs and sputters but doesn't start, repeat another two sets of 10 cranks, and you should be able to fire it up at the end of that.

 

My mechanic used to own an rx8 so it leads me to believe that he knows enough. We have tried to deflood it many times already but never did it repeatedly like you said 10 times in a row. We only did it 2-3 times. And I hope it is correct that at the same time Im holding the gas pedal, I also have to hold down the clutch. Am I right? I will try that but if it still doesn't work. What would you recommend?

 

Holding down the clutch has no impact on deflooding one way or the other, but of course you have to either hold in the clutch or put the transmission in neutral, or the wheels on the ground will keep the starter from turning the motor without also trying to roll the car.

Most problems that I see from people not being successful when deflooding is that they are either mixing bits and pieces from different deflood methods, or that they aren't ensuring that the flood is gone before they try to start the car, or that they haven't fixed the problem. In the latter 2 cases, this results in just re-flooding all over again, putting you back to step 1 without you realizing it.

Be methodical and patient and you will get it.

If after a total of 4 sets of 10 you still don't even have a cough from the engine, then there is something else significantly wrong that needs to be addressed. 4 sets is enough to deflood even the worst engine flood, as long as the underlying reason for the flood has been fixed.

 

Okay, thank you very much. Im on a way to a shop right now and I will try to follow your deflooding procedure. I will let you know what happens. Thank you

 

So mechanic said that it was flooded but it is not anymore. He unflooded it. But it still doesn't start and has low compression. So should I just get a new engine or rebuild this one?

 

You are jumping right past steps that need to be taken.

For example:

You need a proper compression test with a rotary compression tester. This will give you 6 pressure numbers and 1 or 2 RPMs. Where these pressure numbers fall in relation to the RPM will tell you whether or not the engine is actually low compression or not. It sounds like he is just diagnosing it on a guess. If he is actually using a compression tester, then if it isn't a rotary engine compression tester, and then normalized to altitude and RPM, then the numbers are worthless.

You also need to verify that you have all the components needed to start, for example verify spark, verify fuel. If you haven't verified them then you are jumping to a $3,000+ repair for something that could be fixed for possible $5.

He may say he deflooded it, but unless the engine has fired since that deflood, you don't actually know if it was deflooded or not without a borescope inspection of the inside of the engine.

Additionally, even if you have low compression, the rebuild vs replace question depends on what the condition of the engine is inside, and you will have to pull the engine and open it up to get that answer.

 

When you press gas pedal, the roms don't even move. So how can he get a compression test at 1 or 2 rpms if it stays at zero. Sparks were changed and fuel is there. Quarter tank

 

I live in brooklyn NY so if there is anyone you can recommend that would be awesome. I have the keys from the car and my mechanic is closed for the holidays until monday. So if by monday I can get it to someone who can fix it, I will be more than happy to tow my car there

 

Part of a proper compression test is getting the exact RPM of the test. This is one of the features of a rotary engine compression tester, it will show you the RPMs as well as the pressure for each individual face. If you are cranking at all, there is more than zero RPMs.

Neither of these points confirms that you have an actual spark at the spark plugs when cranking, or if you have fuel being injected while cranking. For example, if your e-shaft sensor is out of alignment or unplugged, you won't have spark or fuel, even with brand new ignition, a full fuel tank, and a working fuel pump, because the ECU won't be telling everything to fire because it needs the ESS. If you have confirmed spark but can't find fuel, then you might have a fuel pump or injector problem. If you have confirmed fuel but no spark, you could have an ignition ground problem. Etc...

Properly diagnose rather than just taking guesses.

 

^+1000

At a minimum tell us what numbers lead the mechanic to believe that the compression is low. If you had low compression, you would have had trouble starting it when warm for a while before this incident. Compression doesn't just insta-fail while the car is being warmed up. So SERIOUSLY doubt it's that based on the info provided. You might be better with a dealer at this point, at least they'll have seen actual cases of flooding before.

It could be something as silly as him having plugged the ignition coils in the wrong way. Are you up for a little troubleshooting on your own?
When were ignition coils changed last?

Also why was it necessary to have the car warmed up once a day while you're away?

 

Ah, that is the big question now, isn't it? Seems like a tremendous waste of fuel, time, and effort; and now he's screwed up his car in some way he's not prepared to fix!

QQ, when you're saying 1-2 rpm, does the needle point to one of those numbers, or are you guessing? How do you get those numbers? If it's flooded a pull start will solve it, but I would be weary of hitting the you're car since brakes are difficult to use with the car off.

 

Considering he has a remote start installed, I'm guessing it's an automatic. They CAN be installed on manuals, but it's rare due to the 'left in gear' risk. So pull starting is a no-go.

So far their diagnosis has been more guess work and assumptions than anything else.

 

Guys, my car is manual and yes it has a remote start and I NEVER leave in a gear. Always beutral. The needle is pointing on a 0. Like hard 0 at all times. It doesn't move. The reason my car was being warmed up once a day is because I read on a forum that these cars have to be warmed up at least once every 2 days. So ti be sure I asked my sister to warm it up once a day by starting it with a remote start. Sparks, plug wires and coils were changed 8k miles ago. We again changed the spark plugs couple days ago when the whole car not starting thing happened. Not sure how my mechanic did a compression test due to needle not even moving from a 0. So Im guessing it's either a rebuild or a whole new engine. I'd rather do a whole new engine cause it'll be faster and I will have a piece of mind knowing that my engine is working properly. Never had a starting problem before and the car worked perfectly fine before. I should also mention that for some reason my remote start doesn't start the car the first time. It usually takes 2 times and since it's cold now, it's 3 times. Maybe that was the problem that led to a car not being able to start at all

 

<mod edit: antagonistic phrase deleted>

A compression test can't happen if the engine isn't turning. When you turn the key does the engine turn over?

 

Hi, this is confusing.
Is the car starting?
You say the needle does not move from 0?
The mechanic says it's unflooded, but still won't start because of bad compression?
Was a Rotary specific compression test done, 2 sets of 3 numbers at a specific rpm, usually 250?
If not, make him explain to you how he checked the compression.
Just because he used to own an RX8 doesn't mean he knows how to fix a rotary engine.
Do nothing until you get a proper rotary compression test with a hard copy of those sets of numbers.

 

You wouldn't have read that on this forum. But if you did, it would have been followed by a bunch of corrective posts. If you're going to leave it for a week, just let it sit. A couple of months, just let it sit but put the battery on a trickle charger like Battery Tender.

Just piling on with everyone else: have your mechanic give you the numbers (six pressure values and an rpm) from the compression test. If he doesn't have that, or looks puzzled, take it to a dealer for a proper test.

BTW - I believe the pedal to the floor deflood procedure was introduced as part of the reflash with emission recall 4206f. Presumably you had that done. Without that, you need to follow an earlier procedure of pulling the fuel pump relay.

Ken

 

If you were to verify fuel and spark first, I bet you will find that neither is firing when you crank. No fuel injected or no spark firing = no start.

STOP jumping to conclusions based on flawed assumptions. I'm pretty much done trying to save you money though. Feel free to waste as much as you want.

Posted From RX8Club.com Android App

 

That's not how the test is preformed. To test a chamber they replace a spark plug with a pressure sensor. The motor is cranked but never fires up. The test measures compression at cranking speeds usually around 250 rpm. The gas pedal isn't part of the equation. You would have gotten a print out with 8 numbers. 6 numbers representing the pressure generated by each rotor face, and 2 different cranking speeds.

So you have trouble cranking? How exactly is the car "not starting?" What happens when you depress the clutch and turn the key from On to Start? Is there a clicking noise? Is there a cranking noise? Do the lights dim on your dash? Because even an engine with low compression should start while cold.

You should get a new mechanic before you consider getting a refurbished motor.

 

Just add, @OP, folks here can help, but you gotta help us help you. Make a video of what happens when you try to start the car, and history of what's been done to the car in the last couple years. Let's just start from scratch and we can start figuring stuff out from there. But if you need the car running pronto, get to the dealer, ideally one with a good reputation in rotaries.

 

Name calling was not called for, but pales in comparison to the impatience some of us have been showing.

QuiQuik's next move is really to find out just what the compression test showed. Then follow the path Loki laid out.

Ken

 

Finally back at a computer, and posts edited/deleted. Keep it calm and clean people.

 

Ok...Time to get down to some serious diagnosis. Questions need answers as follows:
1) when you turn the key or use the remote starter, does anything rotate on the engine?
2) How was the compression test done? Screw-in guage or digital analyzer?
3) If digital, there should be a print-out containing 2 sets of 3 numbers plus 2 RPM readings. Is this the case? If so, what were the readings?
4) Who did the deflood and how was it done?
5) When you turn your key to the "ON" position, does everything inside the cabin work?
6) If anything seems not to work, were fuses checked in case one or more blew?

If you have any mechanical ability at all, try the following;
1) Check the main fuse and make sure it is still intact. Then check fuses for starter, fuel pump and ignition
2) Pull one of the lower spark plugs and see if it is gas-soaked

If the main fuse is intact, power should be available to all other circuits including the starter, provided no other fuses are blown.

Once fuses are checked and found ok, try turning the car over with he hood up and you are watching to make sure there is enough power to crank the car over normally.

If the plug pulled was gas-soaked or smelled of raw fuel, a deflood is needed. If that is the case, be certain to hook the car, via heavy cables, to either a running vehicle or a shop battery charger with a start cycle, then proceed with the deflood procedure.

If any of this is beyond your ability/experience level, proceed directly to a Mazda dealer and bypass the local mom & pop garage, former RX8 owner or not. Ownership doesn't always denote full comprehension and ability. Only experience can provide the services you will need competently thereby maximizing the positive effect your dollars will provide.

At the dealer, you should request the following:
1) Electrical check if the car refuses to turn over
2) Deflood if/when it does
3) Comprehensive rotary compression test with printout

Lastly, please stop screwing around and get down to brass tacks. It sounds as though your engine might be OK, just in need of knowledgeable TLC. Only the compression test will tell you that for certain, though.
Best of luck.

 

Guys, thank you very much for all your help. It finally started. It was very heavily flooded. It took us an hour to unflood it. As of right now, it seems to be havinga problem starting when it's hot. It still starts, but takes a while. What do I need to do?

 

Get a compression test, from a rotary specialist with a rotary compression tester.