When I accelerate on the highway the engine pings or makes a knocking sound when it shifts from 2nd to third. Some times it shifts back down again right after it shifts(it also happens between first and second at times). I have had this problem before, but I thought that it went away when I changed my plugs a couple weeks ago. I drove to Grand Forks yesterday and this sound came back.
Recently, I have done the timing, the idle has been set, spark plugs changed (old plugs showed normal engine operation), plug wires changed, oil changed. Last winter distributor cap was replaced.

Any ideas?

What did you set the timing at? It could be detonation, which is uncontrolled combustion, that can be caused by improper timing. Did you use the same part number spark plug?

I think your shifting problem is connected to the hard shift problem you talked about in another thread. For the sake of clarity, I will respond over there, so that we don't get confused-

Andrew

hmmm... The timing is set to 15 degrees which is what is placarded on the VECI label under the hood. The erratic shifting doesn't explain why the engine knocks for a few moments during acceleration. Does it?

I don't believe so.

You have two (if not three) other live threads going at this time. There is a good possibility they are all directly related to the following:

http://www.oldsconnection.com/forum/vie ... 2582#22582

We need to deal with the state of tune before proceeding here.

Norm

hello everyone,

I am resurecting this thread hope you guys don't mind. I'm still having the same problem with some engine noise. Basically, the knocking type sound is most pronounced when i am coasting foot off the pedal about 25mph, and when i step on the pedal quickly to about 3/4 throttle the engine makes a weird knocking/girgling sound while hesitating slightly and then the car picks up and the sound almost goes away completly and I get a smooth acceleration.

I recently had the tune-up of the car confirmed by a mechanic but he didnt have time to go for a test drive.

Any thoughts? Thanks,

p.s. my other issue of the temp light has been solved.

Im not sure but could this also be a vacum advance problem? check all of your vac lines anyway to make sure you have no cracks or broken hoses running anywhere.

to be honest some of the vac hoses are in poor shape. (the one going to the advance is cracked). I was planning to get some hoses this weekend and replace them. Hopefully that's the problem. Thanks!

Have him recheck everything, then test drive it, when he does have time.

Norm

Part of the normal "tuneup" that his “mechanic” already checked.


Also, part of that same normal “tuneup” that his “mechanic already checked..

Norm

Thanks

Obviously, that was my point.

Norm

zzzzzzing!

mmm...and the attitudes begin.

Well, I replaced all the hoses and although it seems a little more responsive it didn't fix the problem. Seems to get worse after the car has been driven for awhile. I will try some high octane fuel to see if that might help to rule out a detonation problem. Any other suggestions?

Thanks