rxkenneth

iTrader: (1)

Well my crank pulley bolt became loose and fell out today on my 90 convert with S4 NA motor swap. I followed the s5 to s4 swap directions that i had found in the project swap threads. So to clarify I have a s4 NA block with s5 NA intake front cover a,water pump housing, EGR has been blocked. I ve read up on the importance of the thrust bearings and understand completely. The bolt became loose at low engine speeds and i pray that the bearing is still in its proper location. When the bolt came out so did the eccentric shaft valve and spring. They were in tact but the little needle like tip was bent. I tried to straighten it in my vise but it couldnt take it and snapped. My Question is can i put the bolt back in with the bypass valve and large spring and leave out the the broken tip and small spring. What will happen if i do this . assuming all is well with the thrust bearing and colar. Also i noticed my scrapped 90 engine did not have a bypass valve just the bolt with O ring. Are the setups different between s4 and s5.

AGreen

iTrader: (11)

You probably do need to remove the front cover. I ran into the same issue because of my failure to follow directions in the fsm. It says to use loctite on that bolt, and they MEAN IT!!! After I fished around and found my chopped up thermal pellet (atkins rotary) I called them up for a new one and had it overnighted. Didn't cost too much. The bad part was that I put it all back together without checking behind the cover, and I literally destroyed that damn thrust bearing because it did fall down. Talk about weird noises! After disassembling and finding out what went wrong, I ordered new bearings and thrust washers from Mazda, which only ran me about 50 bucks. That was a lesson well learned. Take that front cover off and verify your thrust washer didn't move. It's cheap assurance to do that and spend a few hours doing so, rather than have your car down for much longer and spend more money, possibly have to buy a new motor!!!

rxkenneth

iTrader: (1)

Thanks for the advice. Im going to check the end play and verify the bearing issue. So your bolt came out also and you broke the bypass valve? What is the thermal pellet? is that the bypass valve and spring setup.

rxkenneth

iTrader: (1)

Reading up on mazdatrix site ive realized they call this the front eccentric thermostat. They also sell a plug to eliminate this. What would be the advantage/disadvantage to eliminating it?

AGreen

iTrader: (11)

DON'T BOLT THAT PULLEY DOWN!!!! You'll F it up man, I'm telling you!! You'll obviously have no endplay when you do it because the bearing will be dropped and pinched, but start it up and you'll blast that bearing. The only way to check that is by removing the cover and visually verifying it. Don't forget the little o-ring on the passenger side when you put it back together.


The thermal pellet I linked you to in the first post eliminates the stock bypass valve. The bypass valve is total bullsh!t. It starves the rotor bearings of oil on initial startup until it warms up, to speed up the warming process. Get the thermal pellet. It's probably cheaper, and it is MUCH more reliable.

rxkenneth

iTrader: (1)

Well i am one of the lucky unlucky ones. My pulley did not move when bolt came loose. The belts were still aligned perfectly. I bought the thermal pellet and bolted down(with loctite of course). No crunching, still have some endplay. 500 miles later no irregular sounds, engine freewheels smoothly and silently. Engine runs great. thanks for your help, and answering my questions.