Is the 96 4CLY engine an interference engine? My son's friend thought he broke his timing belt but it looks like the tensioner just gave way. It happened while idleing at a stop light and then he tried to restart it. I am wondering what the odds are there was not any valve damage. I only had time today to pull the valve cover and the belt is intact but loose. If ther is no valuse damage I don't mind putting $200 in parts into it to help the kid out but if valve damage well.............

 

Did he mention if it made any noise when it stopped running? You could hand crank the engine and see if the valves are all still operating.

Not sure if it's an interference engine or not.

 

Non interference.

 

Thanks, I got a Haynes manual today, I have one for just about every Nissan going back to 69 but no Mazdas. I will get into it Sat. i figue if I can rotate the cams and the valves operate I should be in good shape. If all goes well i plan on replacing all the belts, and the timing belt tensioner. What elese is a good idea to replace while I am in there? Water pump?, seals? and hard to get hoses or sensors?

 

Looks like the tensioner spring broke and the cams got out of sinc. The belt cover is also warn through in one area above the water pump. Is this common?

 

Pretty common,there was a recall on the spring/tensioner on earlier models due to the spring wearing through the eyelet of the tensioner. I would not worry much about the hole in the cover unless it's huge but i would put new cam/crank seals and waterpump in it if it has 100k miles or better on it.

 

Even if the tensioner spring broke the timing belt would still be under tension. The tensioner pully bolt keeps the tension applied. Only if the tensioner pully bolt worked loose or was never tightened would a snapped spring cause loss of tension on the timing belt. I'm suspecting the timing belt was replaced some time in the past and things were never put back together correctly.

 

Yeah my thoughts exactly the tensioner retaining bolt was not tightened as it is just sliding back and forth. The spring broke at the base of the hook section. Looking at the cam marks the cams are out of sinc about 1/4 turn.

 

The tensioner bearing does not lock down. The spring keeps the belt tensioned. Mazda used to use the spring for initial tension then lock it down but when Ford took over that was done away with.

 

Wow what a dumb idea to rely only on the spring that just hooks on a small stud. I am learning how cheaply an engine can be made from working on this car. It is amazing to me they are so durable. 185K on this one and little maintenance.