Engine won't turn over... used to run fine!
 

I have just encountered a problem with my 88 RX7. It has not been driven this past winter, but I have been starting it up about once a week, with no problems. With the good weather I have just put it back on the road and been driving it around town for just under a week. I then took it for a good 3 and a half hour drive, which also went fine. Shortly after the drive I attempted to start it and the engine turned over about twice and then died because of a faulty positive connection on the battery. I fixed that only to realize that the engine seemed to have seized. The starter, which I checked and was fine, tried to turn over the engine without success and just "clunked" each time I turned the key. I wasn't sure if the engine had got stuck on some sort of compression stroke, and removed the spark plugs, but that didn't release any pressure. I also tried turning the main lug nut on the front of the engine, counter clockwise to try and free the engine. I had no luck here, as I couldn't budge the engine.

I'm desperate for advice on this problem. I know that rotaries do seize and carbon build up can be a problem but I always thought that it was only if they were left sitting for a long period of time. I had just done an oil change and everything was fine for the 3-hour dive. I even stopped for gas in the middle and turned off the engine. The car started up just fine.

Any suggestions? What should I do?

Sounds like a "spinned" bearing... Was your oil pressure OK before this happened?

I was watching the oil pressure most of the trip and it was fine, but didn't as much toward the end.... so I could have missed something. What is a "spinned" bearing exactly?

A spinned bering is when a bearing gets "stuck" to the ecxentric shaft and spins along with it either in a rotor or a stationary gear depending on which bearing got stuck or welded on to the shaft. This damages the shaft and the rotor or gear (once again depending which bearing seized). Hope this is not your case, I really hope I'm wrong here... It happened to me once and I had to replace the shaft and a gear...

Where should I go from here? Is there any other option then to take the engine apart? Also, why would this just randomly happen after the engine had been running problem free?

Make sure the starter drive is still not "stuck" on the flwheel teeth. Pull the starter and try turning it over by hand.

I did take the starter out... thinking the same thing as you, that it was jammed! The engine is still seized for some stupid reason!

Can anyone help?

Drain your oil and look for metal flakes in it... Also check for metal in the oil filter... I am assuming that you also tried to turn the engine by hand and have veryfied that it in fact is stucked...

this is what happened when my motor died...it made the clunk noise and seemed to be seized...it wasnt a bearing for me tho...i got a new starter and kept cranking it and tapping it till it it turned the flywheel...(while jumping the car at the same time)...when it finally started over i swear i heard it detonate (popping from within the block) then alot of afterburn and a super hot converter and that was it for my motor...hope your motor is aight good luck with it

I've been trying to turn the engine over with a 19mm socket on the main lug nut off the engine. I've been trying counter-clockwise without any success. I also tried spraying anti-seize compound in the spark plug holes to free it up but even after it sat over night I still couldn't budge it with the ratchet! I will have to check the oil.

I still really need advice on what I should do.... please help!

check the oil first and report back
spun bearing doesnt sound too out of reach.....

heh push the car put it in 5th and let off the clutch?/? lol

Okay... so I drained some oil and checked the filter as well. The oil seems perfect... no metal shavings at all. I just changed it about two weeks ago (20W50). So no metal visible in itl; or in around the oil filter!

I'm hoping this is a good thing.... Now why is my stupid engine still seized! This is stressing me out here. It is just such a wierd, random thing to happen out of the blue like this for no reason!

Any more suggestions of what the problem could be, or what to do!

Well when my bearing seized the oils was fine... Spraying anti seize in the housings will do no good if the bearing is welded to the E-shaft. The only thing that makes contact in there are the apex seals and side seals... Try another starter, if that does not work then it may be time for internal surgery... And no... it is not weird, bearings do get spinned out of the blue for whatever reason either poor lubrication or vodoo... Since you are working on the front bolt... go ahead and take it out and test the thermall pellet...

If standing in front of the engine, you need to try turning her clockwise (normal rotation direction), not counter-clockwise. Just a thought, doubt it will help much...

You could try taking all of the belts off of the accessories, then try turning it again. If she turns, one of the belt-driven components is seized...That's a reach too, though...

How many miles on the engine internals?

I've tried turning the engine both ways just in case... but it's totally stuck. I'm pretty sure it is a seized bearing. The engine has 190,000 km on it so obviously that's a fair bit!

How big of a job is it to fix this seized bearing... does the engine need to be completly taken apart? I just want to know what I'm getting into, and what's involved? Thanks!

according to him, youre gonna have to replace a gear and the e shaft...which requires tearing the engine apart.

Ya I've been looking at the diagrams of the engine internals, and it's definitely clear that the engine will have to be totally taken apart if this is the actual problem.

Since it does have high miles what else should I be looking at replacing? Or can I get away with just replacing the eccentric shaft and needle bearing?

Complete tear down and rebuild, probably...All seals, whatever the bearing damaged (if that's it), etc...

Is there any way to know if it is something else... or do enough signs point to it being the needle/pilot bearing seized to the eccentric shaft?

I'm trying to think good thoughts and maybe it will be something really easy to fix! Wishful thinking probably but does anyone know what else it could be... I've ruled out carbon lock!

Is there any way to know if it is something else... or do enough signs point to it being the needle/pilot bearing seized to the eccentric shaft?

I'm trying to think good thoughts and maybe it will be something really easy to fix! Wishful thinking probably but does anyone know what else it could be... I've ruled out carbon lock!

Probably not the pilot bearing at the back of the e-shaft, that's a fairly puny guy...

Take the exhaust manifold off of the side of the engine, and look into the ports for damage to the rotors or apex seals, that's about as good as it gets unless you have a boroscope handy...

Haha, it seems like people on this forum just make up answers as they think of them...theories, I guess. Here's the reality.

Most rotaries, especially mid to high mileage nonturbos, die from apex seal failure. The apex seals are thin wafers of metal that are spring loaded and slide in and out of a slot at each tip on the rotor. Stock seals have 2 long, thin pieces that form the seal, the upper of which does the compressing, and is the only one that wears. With time, the upper part wears down quite a bit, sometimes almost half it's original height. As this happens, the top piece tends to wiggle around, since it sits closer and closer to the open end of the slot as it's pushed up. Finally at some point, without warning or reason, it'll either break (*due to being weak and thin) and the pieces will fall out of the groove and do damage to everything else in that chamber (rotor, housing, and subsequent 2 seals), OR it'll fall out of the groove as a whole and do the same damage on subsequent rotations. Normally this happens at speed, with the momentum of the car (in drive) forcing the seal to break, tear off chunks of the soft rotor and rotorhousing, and get pushed on out the exhaust and keep on going (albeit with a large loss in power due to loss in compression).

However, on rare occasions (like this one apparently) these same events occur on shutdown or startup. Anytime you accelerate, decelerate, start, or shut off an engine, the top edge of the seal tilts one way or another (the engine is either applying power outward such as during startup or acceleration, or power is being applied backwards into the engine from the flywheel or drivewheels when decelerating or shutting off). So this tilting action just so happens to coincide with the seal finally coming out of the groove. However, at low rpm/low momentum times such as startup or shutdown, there isn't enough force to make the seal break and get pushed out, so it just wedges in place between the rotor and housing, and locks the engine up. Even if you do apply enough force (for instance, rolling and clutch dumping) in either direction, and make the engine break loose and turn again, you will have done the same damage that was started anyway...you'll break the wedged seal and force it out of the way, but the engine still requires rebuild.

Thanks a lot for the great advice! Now in this fairly rare case, will there be very minimal damage to the rotor housing etc? If the engine were to be re-built what would have to be replaced besides the apex seals? Would the re-build require faily little new parts since there probably isn't much damage and therefore not cost as much?

Ageman,

Listen man. Almost the same identical thing happened with me last year. Car ran fine, then, out of no where, I went to start it, and it was seized. In other words, the motor seized but not while it was running. Bottom line-I had to rebuild. Cant get around it. And from the sounds of things, I wouldnt attempt this yourself. Youre looking at (realistically) 1200-2000 for complete rebuild (all parts, labor, and install). Eventually most of face this...but there's no way around it :)

Thanks for the advice, I appreciate it! And I was figuring about the same price range for the rebuild (1200-2000).

This might sound stupid, but I might try and take it apart myself. It seems that lots of people have done it, maybe with the rebuild video and the diagrams of the engine, as well as if I take lots of pictures of what I do so I can put it all back together I might be able to pull it off!

Think that's still a bad idea??? :-)

As far as rotorhousing damage, one gouge is one too many, and you WILL have at least one. Now, sometimes you can get by with using that rotor if you do a bit of filing on it, or mill them both to 3mm...but I wouldn't PLAN on that, either. Plan on replacing both with parts from another used engine, and if you somehow get lucky enough not to need to, then you just got a bonus.

People don't realize that rebuilding a rotary isn't just taking it apart and cleaning and putting it back together...there is very often internal damage that cannot be repaired and requires replacement of one or more of the 8 major hard parts inside.

Thanks again for taking the time to give me such great advice. I figued I would have to replace some stuff and not just clean it all and put it back. I just wasnt sure what exactly would need to be replaced. I guess I will figure that out for sure when I take it apart.

Would you be a good place to get these replacement parts?

No offense please Age...but it sounds like you are fairly new to the rotary world. I would *highly* discourage you from doing rebuild yourself, especially if this is your daily driver. True, the main block only has 8 moving parts, but the electrical and vacuum lines will make you crazy. Also, there is SO much involved in the tuning (i.e. getting air/fuel mixture correct) you wouldnt believe it. I have had only 2 rotaries, and have done quite a bit of reading on everything from tuning to mods...and I wouldnt even think ONCE about trebuilding myself. I was lucky enough to find a guy who let me come over and watch through the rebuild process so I could learn more. I still dont know that I would attempt it on my own. Just be careful man.

If you are determined to take project on, as far as rebuild kits, videos, etc...all I can say is Google is your friend :)

RR: These are the simptoms of a seized bearing and also the simptoms of what you are talking about... In the end the engine will have to be taken out and that will be when he will know which scenario happened... Bottom line is time for a rebuild...

Has no bearing on his mechanical capability

This is not his daily driver; I would highly "ENCOURAGE" him to rebuild his own motor.

Vac lines and electrical lines are easy....unless you pull every component off the motor and completly dis-assemble every little part. Your basically pulling off a componenent (leaving any vac lines attached where the are) and laiying it aside until your ready to re-assemble. The vac lines/electrical connectors should still be sitting just where you left them.

Tuning.......again if you just remove the components that make an engine run( and his ran fine....) and then replace the components during reassemble.......who changed the settings on the TPS???? or the BAC??? or the mixture ratio??? All those components that are set properly today will still be set properly in two months when he starts to re-assemble......unless the componenents where broken down to there very core, which, nobody should be doing for a basic rebuild of the internals.

Google???? what do you mean google??? What are you looking at right now?? RX7club.com is exponentially greater in resources than google ever thought about being for RX7 info. I'm not trying to bag on you.....I am not.....really. Just I think your giving poor info.

My take on it???

Yes you should attempt the rebuild.

Yes you should buy the videos that are available, they are great.

You need to look at the archives and read them all twice and you'll have most of your answers (such as where to get parts). You will spend 600-800 on parts for the rebuild but if you don't have extensive mechanic tools you could spend another 500-700 on tools, oils, rags, hoists, stands, special sockets, impact wrenches, etc.

Lastly, once you do this to your car....your will find it hard to think about selling it.

I think Kevin would be a good source for parts. There is also a good amount of parts for sale on this forum. Look in the for sale section for second Gens. There is always somebody taking apart a car that will have the parts you need.

If Kevin is right, you'll need a new/used rotor housing. New ones are $500 aprox. Used ones can be had as cheap as $50 depending on the seller.

If angel guard is right then your going to need a new e-shaft and stationary gear. MOST engine blows do not stem from this problem so those two parts should be easily found.

The Good used rotor housing is the holy grail. that is the one you'll have to search for.

Wow... okay this is great info! Thanks for the very helpful posts! And thanks for the encouragement on doing the rebuild myself. I definitly don't think it will be a piece of cake by any means but it isn't my daily driver and I'm willing to do as much research and question asking as needed in order for be to do a "basic" engine rebuild.

I'm going to take a chance on it and VERY carefully label everything and take pics and all that. With the help of the video and repair diagrams I'm hoping it's possible!

Also, thanks for the info on used parts etc! Greatly appreciated!

The main thing that you are going to find overwhleming at first is getting the motor pulled out and apart. Below is a word document guide that I used. I made some changes. pring it out.

You'll need to look at "13b rebuild parts list" form Karack in the archives. You need to decide these issues for replacement, look in the archives for titles of disuccusions for the following
PD replacement called "skeptic of the banjo....."
Thermal pellet replacement
front cover housing and oil pressure. Found at www.mazdatrix.com
Water pump replacement
OMP or also called MOP oil line replacements. the old lines are brittle and will break when you try to remove the OMP.
vacuum line replacement, you want nice new supple rubber vac line everywhere.
removing the flywheel and 2 1/8" nut.
You need to search out a thread about 5-6 pages long discussing apex seals from two months ago.
You need to read the treads from felixwankel88 and his coolant seal problems. (about 30 gazillion pages long)

While you are gathering info you need to familiarize yourself with those items listed and why I mention them.

Skip all the stuff about how to port/polish or turbo related issues, Mod issues as they are just a distraction at this point.

I think you'll have fun. If you like learning new things and challenges you'll be amazed during this rebuild.

Double post Sorry.....mods please delete this post if you see it.

I can't thank you enough... this information will help me out so much! I hope I can have fun too. I'm always up for a good challenege and I do like learning new things... so hopefully all goes well!

Thanks again! I will start my researach on all these topics!

keep us posted. We (I) like to see the progress Felixwankel88 is like a TV show...you can't wait to see what happens next. He post everything with lots of pics.

Have FUN my friend!!!! It ain't that bad... If you need help or get confused at any point, feel free to ask... ;)

You guys are great! I'll keep you posted and will probably shoot questions at you as they come up! I'll have to take pictures of my rotor housing and rotors and check the damage. Since the car died after two turn-overs on startup, I'm hoping there is less damage then if it happened when it was at full speed! I'm crossing my fingers!

I just posted about getting the rotor housings "lapped" Anyone know much about this... it's new to me? Have you guys got this done when you did your rebuilds?

Thanks!

The rotor housings don't get lapped, it is the side housings. I have never lapped my side housings, I'm not gonna lie and tell you they are not ported but first you must find out what's wrong and buy the parts before thinking of anything else... Pull that engine and find out what's wrong with it...