OK, bought a RX8 with a "bad motor...
#1
OK, bought a RX8 with a "bad motor...
Hello guys,
This is my 1st RX8... we bought it as a project car for me and my son to work on (he's 14 and it would be his car when he turns 16)
owner's story: Original owner,Car doesn't start, he was told by his "rotary mechanic" that it needed a new engine(no compression test done). Car has 90k on it, meticulously maintained at the Mazda dealership I have a 2" thick folder of receipts for everything... negotiated him down to $1200
Plugs, coils, and wires were done 2yrs ago (aprox 10k miles) all Mazda OEM items.
Fast forward to yesterday so we got it home and bought a new Bosch Platinum battery.. it would not start.. cranks but nothing...
Went through the de-flooding procedure for about 2hrs... and BOOM! Car starts up! I have never seen so much white smoke and the smell of raw gas was terrible... Amazingly after letting it idle for 10 minutes (feathering the throttle, it kept wanting to stall) and then reving it to 9-10k a few times (huge plumes of white smoke and good exhaust crackling) it dropped down to 850 RPM and idles just fine... no smoke no CEL, no missfire... nothing. Drove it for 10 minutes..runs PERFECT no more smoke, no studder, revs to 10k no problem. Tried the dreaded "warm start issue" a few times, no excessive cranking, it starts right up...
so Whats the next step?
should I get it compression tested? (shows no signs of low compression)
change the plugs, wires, and coils?
drive it for a while and see what happens?
I wasn't expecting to have a driveable car so soon...lol
Ryan
This is my 1st RX8... we bought it as a project car for me and my son to work on (he's 14 and it would be his car when he turns 16)
owner's story: Original owner,Car doesn't start, he was told by his "rotary mechanic" that it needed a new engine(no compression test done). Car has 90k on it, meticulously maintained at the Mazda dealership I have a 2" thick folder of receipts for everything... negotiated him down to $1200
Plugs, coils, and wires were done 2yrs ago (aprox 10k miles) all Mazda OEM items.
Fast forward to yesterday so we got it home and bought a new Bosch Platinum battery.. it would not start.. cranks but nothing...
Went through the de-flooding procedure for about 2hrs... and BOOM! Car starts up! I have never seen so much white smoke and the smell of raw gas was terrible... Amazingly after letting it idle for 10 minutes (feathering the throttle, it kept wanting to stall) and then reving it to 9-10k a few times (huge plumes of white smoke and good exhaust crackling) it dropped down to 850 RPM and idles just fine... no smoke no CEL, no missfire... nothing. Drove it for 10 minutes..runs PERFECT no more smoke, no studder, revs to 10k no problem. Tried the dreaded "warm start issue" a few times, no excessive cranking, it starts right up...
so Whats the next step?
should I get it compression tested? (shows no signs of low compression)
change the plugs, wires, and coils?
drive it for a while and see what happens?
I wasn't expecting to have a driveable car so soon...lol
Ryan
#2
Registered
iTrader: (1)
Flooding shouldn't occur on a healthy car unless someone seriously abused it, so I'd still recommend a compression test to have a baseline of what condition engine you're working with. Maybe nut and bolt the ignition, fuel and vacuum system to make its happy. Get an OBD reader on it and check for excessive fuel trims.
I would run Seafoam through the fuel system to get moisture and other junk out of it. If it has been sitting, who knows what condition the fuel is in.
The white smoke was probably gas and moisture, but just in case, see if there is coolant on the spark plugs, or if the coolant level is down.
But oherwise, nice find! Enjoy it
So did the previous owner let it sit for a while, let the gas go bad, and then started it for a brief driveway hop or something? That could have flooded it.
I would run Seafoam through the fuel system to get moisture and other junk out of it. If it has been sitting, who knows what condition the fuel is in.
The white smoke was probably gas and moisture, but just in case, see if there is coolant on the spark plugs, or if the coolant level is down.
But oherwise, nice find! Enjoy it
So did the previous owner let it sit for a while, let the gas go bad, and then started it for a brief driveway hop or something? That could have flooded it.
Last edited by Loki; 03-25-2018 at 08:00 AM.
#3
Yes, it sat from October to January, he moved it out of the garage to "get some stuff" and it never started again... I'm assuming he shut it down cold and flooded it..
I plugged in my ODBII scanner and I have torque PRO... I saw nothing unusual... what would I be looking for?
I plugged in my ODBII scanner and I have torque PRO... I saw nothing unusual... what would I be looking for?
Last edited by SaabViggen; 03-25-2018 at 08:18 AM.
#4
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What year, mileage, etc?
#6
Registered
iTrader: (1)
Oh yeah that'll flood it. It was probably a minor flood even after he shut it off cold, but he probably made it a lot worse trying to start it after that.
The coolant level light giving false positives is a known issue. If that coolant bottle (including the sensor) is original, you may want to inspect it for cracks and replace preventatively.
As for OBD, check the short term and long term fuel trim on a warm idle. They should be near zero.
The coolant level light giving false positives is a known issue. If that coolant bottle (including the sensor) is original, you may want to inspect it for cracks and replace preventatively.
As for OBD, check the short term and long term fuel trim on a warm idle. They should be near zero.
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Williard (03-25-2018)
#7
Dark Moderator
iTrader: (18)
Dump a bottle of heet into the fuel. It removes water but doesn't cause the same smoking as seafoam.
Remove your plugs and clean them. Disconnect the Ess while the plugs are out and crank it 3 times for about 5 seconds each. That will clear all the crap out.
Reinstall the plugs and see if she starts nicely.
Get a comp test done. I would bet someone in your area has a tester and is cheaper than Mazda.
Other than that. Looks like Loki has you pretty well covered. Welcome and enjoy.
Travis
Remove your plugs and clean them. Disconnect the Ess while the plugs are out and crank it 3 times for about 5 seconds each. That will clear all the crap out.
Reinstall the plugs and see if she starts nicely.
Get a comp test done. I would bet someone in your area has a tester and is cheaper than Mazda.
Other than that. Looks like Loki has you pretty well covered. Welcome and enjoy.
Travis
#8
Yeah.. since the plugs coils and wires are 2yrs old I think I'll change them to be safe.. change the oil...
I'll check fuel trim today...
should i change ge the rear diff fluid?
I think I'll swap out the original starter as well..
I appreciate all the help guys!
I'll check fuel trim today...
should i change ge the rear diff fluid?
I think I'll swap out the original starter as well..
I appreciate all the help guys!
#9
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If you don't know the history of the fluids (like what fluid is in there and when it was put in), I'd replace all of them, so you have a known baseline for your period of ownership. Trans, diff, engine, coolant, brake. But that's just me. Won't hurt to send the used engine oil for analysis, it'll probably have more than the normal amount of fuel in it given what's happened to the car, but you get an idea of what's going on in there. You can go far with preventative maintenance and health assessment if that's how you roll
I would just suggest getting the compression test done before spending too much on starters and other replacements.
I would just suggest getting the compression test done before spending too much on starters and other replacements.
#11
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check out BigCajun's growing list here: https://www.rx8club.com/rx-8-discuss...ilders-265177/
Thanks BC!
Thanks BC!
#12
I don't see rear dif fluid was ever changed... I have receipts for brake and coolant about 3yrs ago (15k miles)
I looked at the fuel trim and it was basically 0...
How long is a "hard warm start"?(the low compression start issue).. I got it up to operating temp and let it sit for about 5 minutes cranked for a count of 2 and it started..
let it sit 10 minutes and cranked it and before I got to two it started... just curious
So my lower door sills are RUSTY(i can break a piece off).. less than ideal.. passenger rear wheel arch is starting to bubble.. the underside frame, etc.. looks good.. should i be really concerned about the lower sill area? if it crumbles is it an issue?
I looked at the fuel trim and it was basically 0...
How long is a "hard warm start"?(the low compression start issue).. I got it up to operating temp and let it sit for about 5 minutes cranked for a count of 2 and it started..
let it sit 10 minutes and cranked it and before I got to two it started... just curious
So my lower door sills are RUSTY(i can break a piece off).. less than ideal.. passenger rear wheel arch is starting to bubble.. the underside frame, etc.. looks good.. should i be really concerned about the lower sill area? if it crumbles is it an issue?
#14
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That wheel arch looks like it was repaired already. They probably fixed the outside, but not the inside, which is where the rust starts. So I mean it's not going to get better. Those parts aren't structural, but whether you want to accept holes in the car is a bit up to you.
#16
Registered
Wow! This looks like a good find! If everything turns out good with your motor, (Not sure if cleaning the ESS and MAF sensors should be considered here, air filter cleaning, or if you should check the catalytic converter......)
Do you plan on doing any modifications? New intake, Ignition coils, Exhaust ect?
Do you plan on doing any modifications? New intake, Ignition coils, Exhaust ect?
#17
Air filter needs changed.. but I'll do an intake..
I'll go over the exhaust.. if it's time I'll replace it with something nicer
I'll do the upgrade on the coils and wires when I replace them..
I know this all sounds stupid before I get a compression test..
but
I anticipated putting a new motor in this car.. so the fact that it runs at all is a borrowed time bonus!
it's got 97k on it so I'm sure it's close to motor end of life..
not bad for $1200!
I'll go over the exhaust.. if it's time I'll replace it with something nicer
I'll do the upgrade on the coils and wires when I replace them..
I know this all sounds stupid before I get a compression test..
but
I anticipated putting a new motor in this car.. so the fact that it runs at all is a borrowed time bonus!
it's got 97k on it so I'm sure it's close to motor end of life..
not bad for $1200!
#18
Registered
I.e Drop the cat, check it, if it's good keep it. if it isn't... options are Replace, Use a mid-pipe, or punch it out. Then you'd want to Check and/or Replace the coils and then get the plugs changed to OEM NGK Iridium plugs.
OEM wires should be fine from what I've heard.
If you want the ultimate OEM coils (If you are unwilling to buy aftermarket performance ones like BHR or do LS2 coil conversion / various others) Revision "C" coils are what went in the 2012 Spirit R RX8.
A full fluid flush while pricey, would be valuable just in the fact you would then know the maintenance basis thereafter.
Mind you, I'm not entirely certain this is the correct course of action (Loki would have a better idea of what to do after the compression test)
#24
Wow, very nice, congratulations!
I would run a can of seafoam through a tank of gas to clean the injectors. Do the usual coils, plugs, wires, fluids, decide whether to premix. At that point you'll have increased your investment in the car 50% (!) but it should keep it reliable for a while. leave the stock intake alone, it is excellent, repalce the filter with an OEM filter. Stock exhaust is excellent as long as the cat has not been damaged from a poorly running engine. good luck!
I would run a can of seafoam through a tank of gas to clean the injectors. Do the usual coils, plugs, wires, fluids, decide whether to premix. At that point you'll have increased your investment in the car 50% (!) but it should keep it reliable for a while. leave the stock intake alone, it is excellent, repalce the filter with an OEM filter. Stock exhaust is excellent as long as the cat has not been damaged from a poorly running engine. good luck!