Blubeasty22

A couple of days ago when i pulled into my parking lot, i put my car in neutral and revved it for a while slowly increasing the rpm. When it got between 6k and 7k rpm it had hard misfires but as i went higher it revved fine. I held it a little below 8k for around 30 to 45 seconds then let off and turned off the car after letting it idle a little. Looked under the car and found that some antifreeze had leaked out but not much.

After i did that my CEL was off when i started it the next day. I did it again when i got home and i noticed that antifreeze only leaks out after revving it high. Probably just a small leak somewhere.

Today i tried it again to see if it would start to get rid of the rough idle and revved it to a lil over 8k and held it there for about 15 seconds then let off and dropped the rpm between 6k and 7k and held it there for a few seconds. Again it started misfiring and out of nowhere it started bogging down when i gave it gas. i let off the gas and it didn't die. I revved it again after a few seconds and it revved fine.

Any ideas? I might have a vac leak but haven't been able to find it yet. Any suggestions?

Harlan

iTrader: (3)

Busted coolant seal. Coolant is coming out the overflow due to combustion gas in the cooling jacket. Sorry but you need a rebuild.

Quick way to check for sure, with the engine cold take off the reservoir cap and start the engine. If bubbles come out the skinny line at the top, or you see a oily sheen then it's for sure.

Blubeasty22

What do you mean by oily sheen? and how much is a rebuild? good thing i have some money saved up...

Harlan

iTrader: (3)

A sheen like this:
New inexpensive method to clean oil from water

A good rebuild is around $2k if you remove/replace the engine yourself. It gets more costly if you have a shop do it. You can also find low mileage engines from about $1500-$2000, but then you don't know the maintenance history. The choice is yours either way the removal/replacement of the engine is going to add 500+ to the cost. Oh and Mazda remains are also available although their history is hit or miss.

I changed my first engine myself and it wasn't too terrible a job. Just take your time and have something else to drive as you do it.

Blubeasty22

OOOhh ok yeah ik what you mean by sheen now. I gotta wait for it to cool first. i cant check the reservoir quite yet. hmmm well if i really do need a rebuild i would prefer to drop it in myself the only problem is i don't have a chain hoist to pull it out and put it back in with. Looks like i'm gunna have to bring it back to good ol' Hallettsville and rig a up a crank lift to it.

Ill most likely get a rebuilt/new engine. I wouldn't risk putting that kind of money into a used one if it could blow in a short time.

Blubeasty22

K sooo i just went to check the reservoir. the engine was still a little warm but not hot. no bubbles and no sheen in the antifreeze. theres probably just a small leak in one of the hoses or maybe the radiator but there definitely is a leak. Starts fine too. Didn't gallop or anything. took one crank. I could be wrong but i don't think a new engine is necessary just yet. What do you think?

Harlan

iTrader: (3)

Hmm. Did you check for bubbles with the engine running? No oily sheen is good news. Don't know where your misfires are coming from without more info.

Blubeasty22

Yeah no bubbles. I could't see a sheen, just regular green antifreeze. I shined a light on it from like every angle and couldn't see one. it is starting to run low on antifreeze but i'll put some more in there tomorrow. I think misfire is coming from cylinder 2 cuz i got a P0302 code when i got the CEL checked before it turned off but whats causing it is what im having a hard time figuring out. It has had a rough idle ever since i got it but it misfires really hard between 6k and 7k rpm now and im not sure why. I'm in the process of making a stethoscope because i can hear a knocking noise coming from around my intake manifold but it doesn't always do it. When it does do it i can hear it in the cab... I also think i have a vac leak because of the inconsistent misfire. Could maybe be a stuck valve? Other than those things it starts good, drives good, and has some pep to it when you gun it. It's been a great car. Those misfires is really the main thing thats been giving me hell.

EricB

iTrader: (7)

make sure the wires are FULLY seated onto the coil packs

do you have an aftermarket intake?

there arent that many vac lines, especially if the stock airbox is out.

check to see where the leak is coming from, there should be yucky residue below the tube that is leaking..

Blubeasty22

Yeah its a K&N intake. i do need to clean the filter soon. The intake manifold does have oily residue on it. not sure if thats what its from though

I changed the coils, plugs, and wires. double checked the wires. and good to go. Still have misfires...

Harlan

iTrader: (3)

Here's this thread:
https://www.rx8club.com/tech-garage-...t-here-222280/

Also if you see oil in your intake you might want to clean your maf. They get dirty easy and cause a lot of problems.

The knocking noise could be a stuck ssv. That can also cause some serious problems. Good luck.

FungsterRacing

iTrader: (4)

Hopefully my thread as posted by Harlan can help you out. You are still getting the misfire codes?

The 'skip' around 7k, it's funny because I also have that. I also have the K&N Intake (Been trying to find an AEM for a long time to replace this K&N POS, I suggest you find another one as well).

My car has been in storage for months, but I'll be pulling it out in a few weeks to find if I have a vac leak or something somewhere. Unlike you, I don't get the misfires (anymore), just that I'm running lean, which the K&N Intake is famous for.

If I come back with anything that I think can help you I'll be sure to post it here for you.

Blubeasty22

Well my CEL hasn't come back on. It used to flash at high rpm but not anymore after i held it at high rev like that.

One thing that i am a little confused about is why my CEL hasn't come on because of the punched cat. Bad O2 sensor maybe? it does look like an aftermarket POS that the last owner put on it.

For my intake ill just clean the filter until i have the money for a new one. Ive cleaned the MAF before but that didn't do anything but ill clean it again. I havnt noticed oil in the intake but on the outside on the manifold.

Ill keep checking for vac leaks and ill see if that sound is coming from the ssv. i recently made a pretty legit stethoscope so if that's the problem ill be able to hear it out and get it fixed.
Thanks for the help! ill keep yall posted!