AQ171C Timing issues

[AQ171C270SP]

Okay here we go.Don was correct as usual. MY timing belt failed and he suggested removing head and inspecting for damage.Well my worst fears came to frutation.I have at least 8 bent valves,I am not a happy camper although there is no piston damage.The bad thing is I have yet to find the root cause of my timing belt failure. It didnt break it lost cogs.Has anyone experienced this type of failure on a belt that was not that old and shows no other signs of wear or fatigue other than cogs falling off.I have checked the seawater pump.the tensioner,Out drive still able to move in forward and reverse,and the engine turns over.The day it happened I was at about 3000 rpms and had no noise when it just stopped.I really hesitate to put this back together with new valves, gaskets and time involved to reinstall everything if I cant find the cause for the belt failure. So my question to all is, have you heard of a belt failing like this or am I missing something that caused it. Engine is an AQ171C DOHC with an SP-A outdrive 1990.

 

[AQ171C270SP]

Re: AQ171C Timing issues

anyone with any thoughts on this. also I am pulling the engine I think as I want to change the bearing On this year and model I dont believ it is called a gimball bearing I am looking for pointers or instruction on how to change the bearing.Don posted a link for a manual but for some reason I can not download it.I guess it is just not my week LOL

 

[bruceb58]

Re: AQ171C Timing issues

Timing belts fail and that is why they are supposed to be replaced after a certain amount of time. I would certianly replace the tension roller when replacing your new timing belt.

 

[AQ171C270SP]

Re: AQ171C Timing issues

Thanks for input.This belt was replaced in June.I did not change the tensioner .I am still looking for direction as to how I change the bearing.Cant even open the manual that Don sent the link for.

 

[ispurpleafruit]

Re: AQ171C Timing issues

It sound like you already changed your belt but I had a Camry once that had the same problem. what ended up being the problem was the water pump bearing burned out and caused the water pump pulley to move just enough to allow the timing belt to slip teeth. Lucky for me it was not an interference engine. But when I took it apart there was an in tacked belt which appeared to be in place and functional so it took me a while to figure it out. I dont know what kind of engine/drive combo you have but when I changed my "gimball bearing", I had to pull the drive off and the bearing was pressed onto the outdrive shaft.