Hey all ...

Last year, I bought a 2004 RX8 with about 80k miles on it. It had low compression, so I had the engine replaced.

Everything seems to have been fine, up until recently. It was hard to start when just sitting there. Like, I drove to work, it sit outside all day, I went to go home and it was hard to start....

I didn't get any CEL's or anything though... I did go ahead and take it back to the dealer, who said everything checked out ok. I asked for the #'s of the compression test, and they said they machine didn't give a print out. The tech may have written it down somewhere, but I never got the #'s.

Last week, during a hard rain (if that matters) my car threw a P0037 code. I have not reset the ECU, nor have I replaced the O2 sensor yet. I'm debating on getting a new exhaust, but haven't pulled the trigger yet.

This morning, I go to go to work, and the car won't start. It sat all weekend, and I did not move it. I tried to start it, and it would crank, but wouldn't fire. I let off the key. I tried again, and it finally started, albeit with a bunch of white smoke. I assume the engine was semi-flooded. The CEL was blinking during this. I have not gone to get the new codes off of it yet. After that, the car ran fine for the drive to work, although it did sound like, after I got it started, water running? If that makes sense.

Right now the car has 97k miles on it. When they put the new engine in, it looks like they replaced the spark plugs (I still have the invoice, it lists 4 plugs and a gasket set). I assume that maybe I should look into replacing the plugs and ignition coils? Or maybe having my battery tested.

Also last week, when I was on the interstate, I stopped at the off ramp and the car died while stopping. I was able to start it back up just fine. Some research leads to maybe motor mounts?

Like I said.... the car sat from Friday at about 6:30pm until this morning, at 8:30am ...

I'm grasping at straws, and before I start buying up stuff to fix it, I figured I'd ask for pointers. I figure it's either Battery, Coils and Plugs, Starter, or maybe the fuel pump?

Thanks everyone. I appreciate it.

~wangel

 

Your coils and wires are shot if you have no idea when they were replaced. They should be replaced about every 30,000 miles, often sooner, sometimes they last a bit longer but it's not common. Flashing CEL is a misfire every single time.

Water running is the coolant moving through the heater core, completely normal.

Motor mounts won't stall a car, just make it a vibration heavy idle.

Fuel pump would be a culprit if it just suddenly shut off while driving, more-so if it was higher fuel demand at the time, and wouldn't start at all until it cooled off for 20-30 minutes. So I wouldn't jump at fuel pump yet.

Get an oil sample tested for coolant. The white smoke might just be gasoline burn-off from a semi-flood, or it could be coolant in the housing that is leaking there while the car sits. An oil test for the presence of coolant will confirm this, or rule it out.


My money is on your ignition though, it's been neglected and will cause all of these problems.

 

Awesome. Thank you for the reply. I was leaning toward ignition... as I said I don't know when the coils where replaced. I know when the spark plugs where done... but not the coils. I figured it wasn't the mounts. I thought I'd bring it up, because a google search led to one guy talking about his car dying on the interstate after getting off the ramp and he replaced motor mounts and it stopped. Seemed odd to me, is why I mentioned it here.

I will order some plugs and a coils today.

Should I go to the dealer to get an oil sample done, or do places like Autozone, O'Reilly's etc do that? I assume the dealer.

Thanks again for the reply =)

 

You can check the oil yourself actually. If there's coolant in the oil, it will produce a milky looking substance on your dip stick. You can also change your oil and check it manually (if you're equipped to change your oil).

 

Incorrect.

The milky substance on your dipstick is indeed moisture, but it is incredibly common, especially in colder weather. It is moisture condensing from the air into the oil. This is present on every RX-8 that hasn't had the very expensive and largely pointless ventilation system installed. If the test for coolant was to simply check for the milky substance, then every RX-8 would be diagnosed with a blown engine every winter, probably being more specific and calling it a "blown head gasket" by an "expert".

You need an oil test to test for coolant, as it will detect more than just water, but also the other chemicals that are present in coolant.

 

Yes, I was going to say this was incorrect. I know about the milky substance on the dipstick.

I change my oil myself, every 3k miles.

If it was truly coolant in the oil... wouldn't something else be going on also? And really, this engine was put in last year... the fact it's "blown" or has a blown head gasket... well wouldn't they have picked that up when I had it in for service a few weeks to check for compression issues?


Regardless, do I need to take the car back to the dealer for an oil test, do I just drain some oil and take it to them or do places like autozone etc do the tests?

 

My "blown head gasket" was pointing a joking finger at the people that have no idea what they are talking about when it comes to rotaries, which don't have head gaskets (or a head).

No, the dealer wouldn't have picked up on it. Coolant seal failures (the rough equivalent of a piston's blown head gasket for a rotary) aren't always going to show up on a compression test.

A dealer most likely can't / won't test the oil, and local parts stores certainly can't. You have to use an independant oil laboratory, Blacstone Labs is one of the most well known in the car enthusiast community. They send you the free sample kit, you take the sample, and send it back with $25. They get you a report within a week.

 

Right, ok. I knew the engine didn't have a head gasket, but I didn't pick up on the joke. I suck. Is why I'm a newb.

I'll send the oil sample off. In the meanteam I'll get a new ignition kit.

Anyways. Thanks for the info. I appreciate it.

If it turns out there is coolant in the engine ... I assume, new engine again huh. Ught

 

I wouldn't get concerned about the oil sample unless the white smoke continued. Like I said in my first response, it was probably due to the semi-flood. Gas cooking off like that can look similar.

Here is a shot of a deflood on my 8 years back, all gas:


If it does continue, get the oil sample. The Mazda remans that fail way early typically fail due to a coolant seal failure, unfortunately. Just an FYI bit though, I don't have any reason to believe you have anything but failing ignition at the moment.

 

Yes! That's exactly what it looked like, and it sputted like that when I gave it gas, that's why I figured it was "semi flooded".

Thanks for all the insight RIWWP ...

 

Hey RIWWP,
this got me thinking (oh oh), is there any reason to get oil analyses other than checking for coolant or other contaminants?
Jus wonderin.
Thanks.

 

Sure. There is a whole thread on used oil analysis results. Lots of discussion of what can be found

 

Ok, thanks.

 

So I replaced the coils, wires, and plugs....

1 of the coils had a big white spot on the top. 1 of them had nothing and the other 2 had some white on them. I understand this doesn't mean they are bad, but I just happened to notice them.

The first L plug I took out, was HORRIBLE looking, here's a pic:


That was probably the worst one, and then this one:



All in all, I replaced all 4 plugs with NGK plugs, NGK wires, and new coils (Sorry, I didn't have the $ for the BHR coils ... gunna start saving for them next :P).

Here's what they look like now:



I did notice, that there was oil in the air filter and in the bottom of the air box. I searched and just by looking at the engine, can see that this is probably normal...

I'm going to buy a new air filter. I cleaned the one that was in it, but need to replace it. Any suggestions, or should I look at replacing the whole thing with another intake?

Anyways, just thought I'd post some pics of how bad the plugs where :D


Thank you RIWWP for all the help and info :P

 

Ok well. After installing the new plugs, coils, and wires ... I thought everything was ok.

I drove the car home Saturday ... it sat all day yesterday.

I get up to go to work this morning, it started, although poorly. The rpm's where sluggish and the CEL was flashing (Yes, I know, misfires, WTF). I gave it some gas, and it again blew out tons of white smoke. The CEL stopped flashing it ran normal.

I drove it on in to work, it ran fine. No CEL, engine sounded normal, everything sounded fine.

I got to work, turned the car off. Waited a few seconds, restarted it. Fired right up, no problems.

My questions now are:

1) Fuel Pump? Although, it has never stalled or anything when giving it gas or under high demands ...

2) I did notice oil on the air filter and in the the bottom of the air filter box etc. Even the rubber gasket going around the air filter had oil on it. I blew the filter out, and wiped off the oil from the gasket ... but I did see in the Misfire thread info about the MAF needing to be cleaned etc. I dunno if this would cause it tho.

3) Battery? This is dumb I guess. I don't know how old the battery is, and it was pretty dirty/corroded when I had it unhooked while changing plugs. I cleaned off the leads tho.

I'm at a loss now I guess. The car sit for a whole day and it was hard to start this morning. Maybe I should go ahead with getting an oil sample done? I've only ran 5w20 in it.

I don't think it's compression. I head the dealer check that last month when I thought that's what it was. It doesn't seem hard to start when hot ... only after sitting for a day?

Suppose replacing the air filter and cleaning the MAF would be a good start now?

thanks,
~wangel

 

Let the car sit for another day, then crank it over with the gas pedal to the floor, as if you are deflooding it, to cut the fuel. Then pull the spark plugs. Do they have coolant on them?

That sequence of symptoms is right in line with a slow leak of coolant into the housing while the car is just sitting, making it hard to start and the rough idle for a short time after, plus the white smoke.

This won't really show up on a compression test.