I have had a little clang/knock since I bought my 99 Sport. It only does it when I start and on idle, can't heard it when I drive and it does not get faster with rpms. I pulled the access plate today and flex plate was tight and looked good but I did notice some clean/wear spots on the gears of the plate in two different spots. I have a mechanic friend who I trust quite a bit telling me the starter might not be disengaging all of the way or plate could be warped and hitting the starter on parts of the rotation. He said try new starter first. Took pics, any ideas or opinions.

 

Lotsa miles? Can you move the flex plate/crankshaft fore & aft? Mains may be ready for an overhaul.

 

check the play in your distributor shaft. Mine was making similar noise and could not narrow it down. Finally after replacing the distributor, no noise and runs great.

Hope this helps

 

I have been chasing a similar noise for 3 weeks now I think. It sounds like a few rocks in a coffee can tumbling around.
Is that like your noise?
At the 1:00 mark you can really differentiate the knocking sound from the other noises like the exhaust leak.

 

Starters are cheap try one first just to see if its not the problem, if not you have a spare . Your friend may be right if not very little invested in parts or labor.

 

Only on start and idling? The exhaust is a common part for this type of noise also. Especially where is crosses over the crossmember which is near the flexplate and may be mistaken for.

 

One of these in your possession is the best you can do.

Did you check the flexplate bolts to see if they're tight?

 

Check the flexplate bolt tightness first, it is the cheapest thing to do if you own the tools. One of the most expensive things you can do is start throwing money into parts with the hope of making it better. Find the problem and fixing it works a lot better than guessing.

When I bought my XJ it sounded like it had a spun bearing. I bought a oil pan gasket with the intention of dropping the pan and checking it out, $35, but I also knew that it could be the flexplate. I took off the inspection cover and the bolts were visibly loose and the holes in the plate were ovals. If I had looked at the flexplate first I could have saved myself $35

I am sure that down the line I will need the oil pan gasket and $35 is just a drop in the bucket, but it demonstrates the need to figure out the problem before trying to fix it.

 

Well stated, and very true.

 

Flex plate and bolts are as tight as a drum. Couldn't tighten bolts any more than they were and did not move for and aft.


I guess I will start with the starter and see where that gets me. I will check back after that, thanks guys.

 

mine ended up being the water pump, of all things!

 

Yep. Sound travels quite a bit. That's why we all need to go to Harbor Freight and spend under $10 on one of these.

 

Heh. The old phantom knock. I had one that was the tranny mount, then a few months later another developed that was the exhaust on the crossmember. Both felt almost identical under my feet. Now it's back again, but I'm pretty sure its just the exhaust again. I guess I'll have to crawl under there and re-tighten that wire

 

if you see shiny spots on the teeth, that is where I would start. You have the noise down by the flexplate, and starter bendix gears can stick out too far when they are on their way out. You can lay underneath with a good light and have someone start it when cold and watch the gear to see if it goes all the way back in (will be hard to see, but you'll hear the sound immediately from that area). Also, be darn sure to keep clear of that flexplate when turning over / running.

 

I read somewhere that we can identify a broken flex plate step in the accelerator and brake at the same time, noise will desapear. Oviously on D