Was crusing at about 70 when my battery light came on. Soon after a guy next to me signaled that something was wrong w/ my car. Checked the temp gauge and it was nearly maxed. Pulled over, probably within about 1/2 mi of when the batt. light came on.

Popped the hood, engine was smoking, coolant had sprayed onto the underhood. Main belt was nowhere to be seen. Left the hood up until the tow came hoping it would help cool the engine. No words on the damage yet cause its the weekend, but my guess is that its probably terminal. Car has 14k miles on it, belts inspected about 2k ago.

Of couse, I suppose this could happen to anyone, at any time, but I was certainly surprised at the rapidity of the heat increase in the engine. Probably took less than 20 seconds to overheat, even traveling under light load at 70 mph. Ambient was about 78.

 

Ouch! I hate to say it, but it sounds like a severe enough overheating to toast the engine. At least with past rotaries; it doesn't take much.

I wonder why the belt broke or bailed in the first place? Just inspected? Could it have been overtightened, or maybe the bolts weren't tightened after the adjustment?

At any rate, sorry to hear about this. I hope you get some good news!

 

Oh my goodness . I am very sorry to hear that.

At least there is not many moving parts in the rotary that - like the piston - the parts flies out and damage other things.

Hope all goes well in the repair (if there is going to happen). <MA is going to give you another car?> Keep just informed.

Now go and sit down and have a drink :o

 

They gave me a 4-door auto. Neon right now. Let me tell you, its every bit as agile and rewarding as my eight.

Seriously, I have never driven a newer car as completely worthless as this thing. Seats are terrible, interior quality is terrible, steering is over-boosted, suspension is ultra soft, and the tires brake away at basically walking speeds in the corners. :D No wonder domestics can't outsell the Japanese cars in this segment; you'd have to be nuts to buy one over the Civic. Now I want to drive an SRT-4 and see if it manages to surpass the lackluster qualities of the base car.

What really surprises me is that the whole incident, from batt. light to stopping the car probably only took 40 seconds or so. But I'm pretty certain the engine is toast. Maybe I'll get an ever better engine. I've always felt that my car felt slightly more powerful than the two other 8's I've driven.

Luckily my gf's got a 95-M edition Miata I get to drive on weekends that's nicely tuned, with a sensational exhaust note.

 

My condolences as well to you on this most unfortunate incident.

Please do keep us posted on the outcome, as well as the likely root cause if ever they figure that out.

 

that sucks man... that really sucks

 

ditto.

 

When rotaries overheat, some weird things can happen. Just like detonation you may kill it or you may not. I had an old 2nd gen that I overheated on at least 2 separate occasions. The engine was still fine afterwards. You never know. It's weird that a belt broke after only so few miles. I wonder what happened to it. Was there something that got down into the engine bay that rubbed on it and frayed it? Was it just a defective belt? You never know. At least you aren't blaming this on the fact that it is a rotary. This can happen to any car with the same results.

 

tuj, any mods on your car that the dealer was upset with?

 

Didn't hear from the dealer yet today. I had just topped up the oil right before I left on the trip that the belt broke on. I don't recall actually looking closely at the belt, but I think I would have noticed if anything was dramatically amiss in the engine bay. I am in the MW, where it has been unseasonably hot the last few weeks, but no where near Vegas temps.

Only mods on my car are RB front sway, RP short-shifter, HPS pads, and a MS wing. Someone who looks very much like me (but is NOT me) with a car very much like mine (but NOT mine) regularly autox's and does trackday's with his/her 8. This person is quite respectful of letting the car warm up before rev'ing it or shutting it down, and always rev's the engine to 3k as he/she cuts the ignition. Fluids are properly maintained.

I didn't look real close at the engine post-mortem (cause of the coolant fumes), but I didn't see anything strange around the pullies (other than the total absense of the belt). There shouldn't have been any work near the belt that the dealer performed, and I haven't done any work around there either.

I seem to have bad luck with over-heating. A few years ago my Miata decided to drop its coolant load via a spontaneous rip in one of the heater hoses - right onto the headers - on the highway! It felt like I was in one of those old WWI movies when the engine of a plane got shot: my vision was totally obscured with smoke (the top was down too). I had time to get that car stopped before the temp gauge was pegged.

 

Just got off the phone w/ the dealer. They said the belt took out one of the oil seals, so they are having to replace that. I had them test compression; they did it twice to be sure, here's the numbers:

f: 7.8, 7.4, 8.1
r: 7.2, 7.6, 8.0

Since I didn't have a compression test done before this, these probably aren't too meaningful. I have to say I am a little dissapointed at the numbers, especially the rear rotor.

 

why? from what i've seen on there, those numbers are good compression numbers.

 

the 7.2 is a little close to the edge but what was the cranking speed for that one?

 

Dunno what the cranking speed was, but I assumed that all faces of the rotor were done at once and that the Mazda tool made sure the cranking speed was correct.

I was thinking people were seeing compression numbers around 9 on each face, but looking thru the archives I've had a hard time finding good sets of compression numbers. I know that spec is 6.8 - 8.5, but I'm not sure what the average engine gets.

 

avg i have seen is in the low to mid 7's

 

Which oil seal is this?

 

No idea, but he said the belt hit the seal and damaged it? Apparently they don't stock belts or oil seals either since they had to order the parts...

 

sorry to hear about your misfortune man. Hope all ends well. Sounds like the dealer is trying to make things right.
The compression numbers raise a question for me. I know on recip engines the numbers are as close together as possible from cylinder to cylinder. I would assume that on the rotor you would want the same. Each rotor face as equel as possible. You list a 7.2-8 range. Does the compression build on this engine as each face goes by? Why such a varience? Also the engine is listed as having a compression of 10. Is the way the engine is tested and the particular grading system in that tool the reason it is saying 7's and 8's rather than numbers closer to 10?
puzzled olddragger

 

Olddragger, the figure there are readings in kg/cm2...not a compression ratio.

 

Great info, Tuj -- keep it comin'. Sorry to hear of your loss.

Hang in there -- maybe that guy who looks a lot like you but isn't you who drives a car a lot like yours but isn't yours will let you take his 8 out once in a while -- er, uh, unless he too is having trouble with his! :p (Ahem... )

 

the numbers mean nothing without the cranking rpm

 

My assumption is that the numbers were taken at 250 rpm or corrected to that.

 

Doesn't anyone think that the engine may have overheated thus melting the belt enough to break it?
Hard to say what the cause was, belt breaking and then overheating, or visa versa.

But the compression numbers aren't too bad.

 

Gomez...wouldn't want this engine.....................even though the rotors are all equal....seems a bit low :D

 

I wouldn't assume that. Generally the dealer just tells you the figures the tester put out and for some strange reason (Lack of experience?) neglect to list the cranking rpms. As I've said here before this addition or omission is everything. The figures do not have proper meaning without them.
Paul.