Well i found out about this problem after i bought my beater (89 mercury tracer) for a cheap price with some small issues which pretty much have been fixed. But when just looking at my engine while running which i do once in awhile (bad habit?) and i notiched my crank pulley wobbling alittle. And i was alittle ohoh about it. As i remembered about the mazda 323/miata 1st gen crank key problem. Well my car has 114k on it now and when i bought it, it had 107k and the guy did do a timing belt job on it BUT i don't know if he took off the crank pulley or not himself, etc. BUT from what i found. If the crank pulley wasen't put on good enough the problem would happen within a few hundred miles. Well its been 7k. It said degraded performance and wobble are symptoms. Performance has always been "okay" since day 1. Better some days then others slightly which i assume depends on the air quality (humidity, etc.). But i have seen nothing odd EXCEPY my idle dropped a smidge and it goes up and down alittle randomly more then usually. So 2 questions. #1. Am i f**ked? #2 Starting when did the newer cranks get used? According to what i found its 92+ for the miatas. What about the 323/proteges? LMK whatever input you have. Thanks in advance!

 

Yes and no. Found at Miata.net is a fix using some sort of Locite product. It seems to have been met with a fair amount of success. I'd suggest visiting the forums over there and searching for Locite, crank, pully, short nose....any and all of those combinations. Short of that, there's really not much that can be done short of replacing the crank itself.

Mazda moved to the long nose cranks about half way through the 91 MY with both their BP and B6 series engines.

My '90 Miata with 128k Mi. has the infamous short nose crank, but to this date is not exibiting any symptoms of the problem. Until I build a spare motor to drop in, I'm too scared to investigate, heh.

HTH and good luck.

 

My 1990 Protege had the crank problem. Unfortunately I let it go and did not have the benefit of reading the Miata Locktite idea. Well the problem gradually got worse until I had to get a new crank.

Before it was diagnosed accurately the engine would knock when cold but would quiet down when warmed up. No loss in power for the first while.

It took a few thousand kilometers but the noise gradually got worse and then I started to feel a power loss.

I believe 1991 and up were the newer cranks, in fact I was told that part way through 1990 they were put into service.

As far as I know none the Escort GTs ( came out in 1991) received the short nose crank.

Was this not supposed to be a problem only with the DOHC engine? As far as I know the 89 Tracer had the SOHC.

 

Then as far as protege lxs go with the dohc motor. Is it a safe bet to say that 92 and up are fine? 93/94 are hard to find but 92s seem to be around. LMK asap thanks!

 

Yes

 

take a good look at the rubber dampner part of your crank pulley...the rubber deteriorates with high mileage..could be why your crank pulley wobbles

 

I have only 114k on that car but will check tommorow when i also intend to do the bolt. Thx.

 

also when inspecting crank pulley look for rust around crank pulley bolt ... this is the 1st sign that the crank key way is starting to wear.......... if caught in time before crank keyway slot is too worn....clean up real good, install new crank key and reassemble with locktite (red) in keyway slot and on all sides of key...and hope for the best......good luck G