Just swapped in a rebuilt engine into my 88 TII. Engine is S5 with FD rotors and housings on a Microtech LT8 ECU.

Engine started right up and runs quite well, however, the CAS is making a noticeable vibration/noise. So we pull the CAS, and found that it is getting banged up on the gear (see pic below).



Anybody have any clue what could be going on? My first thought is to remove the front cover and inspect, so I will be doing that sometime this week. Just looking for thoughts or if anyone has experienced this issue before.

Thanks!

 

unfortunately someone probably dropped the CAS gear on the floor and mushroomed the gear face somehow, which is causing the wear.

shine a light through the CAS hole(lol) and try to find the damaged portion. crappy part is if this is the case the front cover has to come off to replace it. for the hell of it i checked to see if it could be removed by pulling just the front seal but nope.

 

^ Thanks Ben, I was afraid of that. I figured there was no fixing this issue without taking the front cover off, so I went ahead and just ordered a used gear anyway since they were cheap enough from Atkins.

Also if your curious, reason why I threw this engine in is because I cracked the rear iron on the previous one. I had new intercooler piping made and it fixed the issue of not holding boost until redline (it also made boost a few hundred RPMs earlier). Well I took it out on a cold dense night and at the top of third it crept to 17psi and predetonated, cracking the rear iron. I lost all my oil within a matter of seconds lol. Not 100% sure if it's because I lost/didn't have the fuel pressure, or the fuel/timing map just wasn't described to handle 17psi.

Anyways, I'll get that front cover off and update this thread with new info.

 

ugh, that sucks.. intercooler upgrades alone are enough to warrant a retune so it was probably already borderline unsafe running the tune to the prior boost level.

wish i could make it out sometime, but there's always the kan sessions in the meantime. they may not be the best but they usually work for the time being.

 

Well, got the gear off. Found this on it:


I should have the stuff to put it back together by Wednesday, and hopefully once I do, the problem will be remedied; as I really want to break this engine in already

 

be sure to show it to the overhaul shop/person who did the work. looks sort of like someone whacked it with a hammer.

 

What is the CAS? just posted a thread about my car making weird noises while coasting and in gear at the same time.

 

CAS is the crank angle sensor.

 

99.9999% unrelated to this thread. this is a build issue and something almost no one would ever come across.

 

I'd also check the bottom of the CAS where the shaft comes out to make sure that as the gear was revolving over the damged part it didn't push the shaft back and forth it the housing and damage it.

 

the CAS is cheap enough that it should just be replaced. the gears are already damaged and that will create more slop than usual. the CAS is already rather sloppy with an average of 10 degrees of unintentional advance on misfires.

 

Ok so I got the engine back together with the new distributor gear, and the noise is completely gone now.

I now have other issues that can be found in this thread here: https://www.rx7club.com/microtech-11...-blip-1056423/

I reused the CAS, which I hope is not related to the other issues I am experiencing. For safe measures, I will throw in another CAS.

Thanks everyone for your responses. The car is almost ready to be driven and broken in, just want to sort out the other issues first.