Timing Chain Hell

[Kaisar]

:wtf: Why would my timing chain tensioners keep coming apart?

I am having lots of problems with my 1991 2.5L Iron Duke making excessive engine noise. I have replaced the timing chain, gears, tensioner assembly (tensioners) and the gone through the whole mess associated with the timing chain cover re-install as well as the fun involved in getting the oil pan off, clean, and back on.

Here is the deal- My noise problem went away after all of that for about 3.5 months, and then the chain tensioner came apart again. I have replaced it a second time this week, sealed it all back up, and within 10 minutes of having been started, it sounds like the tensioner came apart again. In addition, there are still really bad grinding noises. I have removed and inspected the water pump to find that was not my noise maker. I am really stumped. I am trapped in "Timing Chain Hell"! Please help!

Any suggestion will be appreciated!

[p8ntman442]

ok, on the back of the cam there is supposed to be a spring that keeps tension on the cam, if that is not in or was installed improperly you are probably getting a ton of cam walk and causing the chain to move back and forth breaking the tensioner. Also, **** timing chains. get a replacement set of gears, their noisy but whatever thats the 2.5 for ya. never worry about the chain again. good luck with it, and I hope you didnt bend any valves when the tensioner broke. If you need any valves or springs let me know, i have a good set thats used, but wtf there free if you need them.

[Kaisar]

Ok, great! a few more questions...

When the timing chain broke about 3 mo ago, I repl the cam sprocket and drive sprocket you referred to, as well as the chain and tensioner. The chain broke a link, and both of the tensioner guides were in little pieces. I did not think much about it, except that it was about time. It broke while idling in my drive, and am not sure if I have any related damage. Prior to the chain break, it was making a ton of clatter. I mean excessive noise, like I thought she was about to grenade! After the replacement it seemed quieter, and ran smooth and powerful. Has never burned oil and has always gotten about 20 mpg.

Regarding the cam-walk, how much play are we talking about? I pushed and pulled on the cam while I had the oil pan and timing cover off, and it was solid. It did not seem loose at all, and if there was a spring to compress, I did not notice any slack, like a ball bearing connection only, and no spring. I assume you mean the back of the cam is the opposite side from the timing chain? If so, do you know how to get to the spring? Does the cam have to be pulled to do this?

On another note, my Haynes manual explains that this cam can not be removed without pulling the engine!?! Is this right?

Also, how would I know if I have bent any valves? Thanks!

[p8ntman442]

shit 20mpg is horrible, i get atleast 26. and i drive hard. you cannot remove the cam shaft without pulling the engine, I have never done it though. I have only heard stories about the spring never seen one, or been able to buy one. Although johhy mac told me about the spring, and since he blueprinted and supercharged a 2.5 i think he knows what hes talkin about. i dont know how much the cam will walk, but you can hear a machinegun tick when the car is running, and that is the sign that the car needs a new spring, probably the cause of your broken link.

[Kaisar]

Thanks p8ntman442. Your replies are very appreciated! Yeah, the it may have been more like 22-24mpg, no biggie for me, unless you are saying this indicates something really bad. I always thought its performance was pretty good for it's age.

It sounds like your saying its time to pull the motor, or, give up on this one. The timing chain project was my biggest shade-tree mechanic undertaking. So, I am not set to pull an engine, and not sure how hard it will be to get it all back together (or most importantly, if it is worth it). Super Frustrating!
:dead:
Anyone else have any experience with this cam spring, and what is involved in replacing it? How about Johnny Mac, we know you have been there, are you still around? Any feedback would be appreciated.