01 Blazer Possible Distributor Problem

2001 Blazer 4x4 with 105,000 miles

A few months ago me and my wife were leaving Dallas heading back to NW Arkansas. Her blazer had been parked for two days after driving down to Dallas (no noises go down or when we got there). After leaving her brother's house (traveling about a mile) we kept hearing a knocking/thumping noise from under the hood. Stopped and I noticed the distributor was moving. Placed my hand on top of it and could feel the distributor rise and fall regularly. Being on the side of the road we decided to continue on. After we picked up speed (say above 60), the noise went away and did not come back. She has been driving daily since then and no reaccurance of the problem. We were thinking about taking her blazer on another trip, but was concerned about the distributor.

I could not see anything that was broke, but did not attempt to take anything apart in the distributor and the distributor seems to be "fairly" tight/secure. Any thoughts as to what caused this or indication of breakdown ahead? It has not had any work done on the distributor (maint.)

thanks

john

2001 Blazer 4x4 with 105,000 miles

A few months ago me and my wife were leaving Dallas heading back to NW Arkansas. Her blazer had been parked for two days after driving down to Dallas (no noises go down or when we got there). After leaving her brother's house (traveling about a mile) we kept hearing a knocking/thumping noise from under the hood. Stopped and I noticed the distributor was moving. Placed my hand on top of it and could feel the distributor rise and fall regularly. Being on the side of the road we decided to continue on. After we picked up speed (say above 60), the noise went away and did not come back. She has been driving daily since then and no reaccurance of the problem. We were thinking about taking her blazer on another trip, but was concerned about the distributor.

I could not see anything that was broke, but did not attempt to take anything apart in the distributor and the distributor seems to be "fairly" tight/secure. Any thoughts as to what caused this or indication of breakdown ahead? It has not had any work done on the distributor (maint.)

thanks

john


There is a hold down clamp on the right bottom side of dist that holds it down tight.
It will have a no 15 bolt straight up in the middle of clamp.
Get a no 15 wrench or a extension with a wobble socket and tighten it down.
Then see if you can pull dist up and down any.
If it has not been done at 100K is a good time for new plugs and check over.
MT

MT-2500,

Thanks for the advice.

I finally got around to putting new plugs, wires and cap/rotor on the blazer. The bolt holding down the distributor was tight. I am leaning towards the problem being with the one or both of the screws that hold down the cap. Here is what happened: After I put the new cap and rotor on (boths screws on the cap "seemed to tighten up") and I went to start the vehicle, I heard the same "knocking" noise. It would go away when the engine was revved up and would not come back while it was running after being revved up. If I put my hand on top of the distributor cap and slightly pull the cap towards the front of the vehcile, the noise/knocking gets worse. If I push towards the cab of the vehicle, the noise completely goes away. In my opinion, it feels like the rotor is bumping up against the inside of the cap.

My thoughts were that the hole that the screw on the cab side is cracked or is not completely being grabbed by the screw. The screw did get tight when I put it in, but it might just be getting tight in the hole that is part of the cap and not the distributor.

Any thoughts or suggestions would be appreciated!

Also, anybody reading this that hasn't replaced the plugs yet. The tip on getting to that # 3 plug is a life saver!!!!

thanks

john

The ears on the dist housing are plastic.
Watch and check them real close.
They tend to break out or off which means another dist housing or dist.
Also hold down screws have locktite on them which makes them hard to get out or in.
I always clean off all of the old locktite.
Good luck
MT