Hi guys. A new sound coming from my engine alarmed me. It is a high pitch squeal that fluctuates. Upon close inspection I determined the cause. The main pulley is literally sliding forward and back (very slightly), periodically making contact with the block.

I have circled the point of contact on this picture from another car.

I mentioned it to my shop via phone and they said they didn't think it was possible. But I can visibly see there is play on this pulley.

 

E-Shaft thrust clearance is controlled by a collar in the front stat gear stack.
If this was not put in or other spacers or the bearings left out, then they would cause that.

Or maybe the front bolt that holds the pulleys to the e-shaft is loose and was not torqued.

APPEARS TO BE AN ENGINE REBUILD ASSEMBLE PROBLEM!

 

Wow. Got a video? That sounds bad.

 

the engine was built by RP and has run for 60k miles with no issues around this. It has never been opened since that time. Could excessive wear or a broken part cause the contact to manifest?

 

I had the same problem with the S4 13B in my FC. It turned out that the one torrington bearing was completely gone. It had been completely chewed up and it had also worn into the retaining plate. It was actually so bad that the front counterweight would hit the inside of the front cover. I started a thread about it.
There might be some usefull info there. https://www.rx7club.com/showthread.p...+shaft+endplay

 

If any of the torrington assembly collapses, first point of contact should be the pulley striking the crank angle sensors....wearing away the stainless steel outer cover.....something else going on there!

 

Check torque . . .

 

off topic: but what idler and waterpump pulley is that?

 

The water pump pulley is SR, the idler is from this group buy: https://www.rx7club.com/forum/showth...=807734&page=6

Dan

 

It's either one of two things.

- The crank trigger wheel is bent and hitting the front cover. It's thin metal and isn't hard to bend.

- Your endplay on the motor is hosed. Usually caused by a crushed needle bearing during engine assembly. Have a friend work the clutch pedal while you watch the front pulley - if it moves in and out as the clutch is operated, there's your problem.

First one is easy - replace the trigger wheel. Second one involves pulling the front cover, and you might as well pull the motor to do that.

Dale

 

uhhh, what??

Dale - I'll try that with a friend tomorrow.

I can spray WD40 on the spot I have circled and the sound goes away for 5 seconds until the WD is worn off again. The pulley does not look bent at all.

 

lol i was hoping so. I was like TheWird usually has pretty intelligent posts....

Id check the torque like stated above. I have never heard of this before. learn something everyday. Keep us posted, id like to see what the cause of this was.

-Mark

 

http://www.mazdatrix.com/faq/pulley.htm

 

Very odd, RP builds some stout motors. Have you called up Chris and Ari to ask them what they think?

 

No, but I honestly don't think it has anything to do with the quality of RP motor builds. I have been very happy with the motor.

The car has seen a lot of track time in the last 60k miles, really it has lasted longer than my expectations considering the way I drive the **** out of it.