I just finished up my post here under ejected cam seal. The motor ran normal this morning except very bad oil leak on drivers side cam cover. I took it apart and the lower drivers side cam seal was ejected from it's bore. There was a lot of oil over the bottom of the car, but the motor was never run out of oil. I replaced all four cam seals today and cleaned it all up. New timing belt and a fairly good job all in all. The drivers lower cam really jumped back when I undid the belt. It banged back much harder than they usually do. I was able to get it all aligned and assembled and no other problems. There was an oil change done but I forgot to partly fill the new filter before installing it. When I started the motor, it ran normal for about twenty seconds, then started to miss and stalled fairly quickly after that. It now will not start. It acts like it wants to start, but can't quite make it. I pulled the covers and the timing marks are all lined up correctly. It was turned over by hand at least five or six times before I tried to start it and the marks all lined up good. The wires to the crank and cam sensors are undisturbed and the only new pieces used were the cam seals and the timing belt. The sprockets were not interchanged. This is a 99 OBW 2.5 auto with about 190,000 miles. My only two thoughts were somehow it messed up a valve when the lower cam snapped back, or something triggered the knock sensor with the empty oil filter and the timing pulled back hard. I'll be doing a compression test tomorrow unless somebody can think of something. Thanks in advance.

I would bet a tooth off on the timing.

 

I never have done one of the DOHCs, but have done the SOHCs many times - it is easy to get things just one tooth off and it will cause all kinds of issues.

Absolutely recheck your belt timeing.

I didnt see this thread before leaving a reply in your other thread.

Double check the timing marks. If anything jumped it would likely be the crank.

 

The cams snap out of place all the time. If all of the timing marks are lined up properly before removing the belt there is no chance of bending valves if the cams slip.

If they were not at the proper marks, then only one cylinder could be affected by that one cam snapping out of place. One cylinder with bent valves will not prevent the other three from firing and the engine from starting.

But if the crank sprocket slipped after-the-fact (while it was running) that will affect timing on all 4 cylinders and could lead to the current problem.

The reply Fairtax4me made in the ejected cam seal thread was absolutely what happened! Everyone else was right to question the timing being off, and that was what happened. The timing was correct initially, but the tensioner did not survive being recompressed. That's why it ran OK for maybe twenty seconds, enough time for it to slip a couple teeth at the crank sprocket. Very happy with the help I got here as usual. The notion of the tensioner failing in that way didn't occur to me, but once suggested, that explained everything. The tensioner came from the import experts and was put on 5 years 50,000 miles ago, and still looked brand new. I did squeeze it slow and vertical, probably close to an hour to get it squeezed until the pin could be inserted. It was just something I didn't do right. I would buy that tensioner again, my fault somehow. Again, thanks, these familiar little jobs can make you crazy when everthing seems to go right, and then it won't run.

Hopefully you have no bent valves because of the slip. I think the interference on the 25D is valve to valve, so there shouldn't be any chance that the pistons and valves made contact, but I've never seen a conclusive write-up saying where the interference is on that engine.

 

I'm not even sure of the correct way to compress those newer style tensioners, but I know that using a vice is a big no-no because its way too easy to overload the tensioner and damage it.

Final report, got the motor running without any more drama. I finally got it all properly timed and back together and it's running with no misses and no leaks. Glad to have this job finished and thanks again for the help!

I did one two days ago that belt was  striped and when we putt new belt on. One tooth from old belt found its way between new belt and crank gear and jumped 4 teeth had to reset belt ran for about 10 seconds then dead stop

The tensioners are very touchy. You have to compress them extremely slow or you will blow them out. I've only ever lost one so far. 

Also the tensioners don't always extend on there own.

 

I always take a large flathead and wedge it in above the tensioner and pry down to tension the belt and let the tensioner pin extend.  Sometimes that helps set it