Diagnose my nasty knocking sound

[95atxsho]

I live in Scituate Massachusetts, Is their anyone on there way home or in the area that may be able to stop by and tell me what it is, after 4pm tomorrow?? Any help anyone can offer would be greatly appreciated.
1989 Titanium 90,800 miles, Driving around, car was driving great, slowed to about 20mph and all of a sudden knock and rap galore, drove it home and parked it, afraid to drive it now.
Please help.
Paul

 

[TYSHO]

Get a stethascope(sp?) and pin point where the noise is coming from and tell us at what rpms the noise exist, or not and ect.

 

[gbizzle27]

Is it RPM relient, meaning the noise increases with RPM's? and is it a heavy thump that you can feel in the gas pedal? If so watch out for a spun rod bearing.

 

[SHOlocke]

if it's knocking like what you are saying, don't even bother starting it up to listen for the sounds. order up some rod bearings and oil pan gaskets and go in there and look around. Worst case you can just slap some new bearings in there and go. You'll be out $75 and a few hours on your back.

The more you run it with a bad, spun, or otherwise questionable rodbearing, the more chance you won't be saving that engine. Period end of story.

 

[TYSHO]

if it's knocking like what you are saying, don't even bother starting it up to listen for the sounds. order up some rod bearings and oil pan gaskets and go in there and look around. Worst case you can just slap some new bearings in there and go. You'll be out $75 and a few hours on your back.

The more you run it with a bad, spun, or otherwise questionable rodbearing, the more chance you won't be saving that engine. Period end of story.

I do not think that is always the right thing to do. I did this and changed the rod bearing when I didn't need to. After installing them, I pulled out the stethascope and it turned out my timing belt was loose. I wish I would have done that at first!

 

[95atxsho]

I never worked on an engine internally. Replacing plugs, wires, starter and small stuff but never engine internal. I'm a computer guy. I wouldn't know what a rod bearing looks like. Anyone want to make some money? The knocking/wrapping is consistent (all the time) from start up to shut off.
Thanks for all your responses.
Paul

 

[Racer X]

I never worked on an engine internally. Replacing plugs, wires, starter and small stuff but never engine internal. I'm a computer guy. I wouldn't know what a rod bearing looks like. Anyone want to make some money? The knocking/wrapping is consistent (all the time) from start up to shut off.
Thanks for all your responses.
Paul

Ah jeez man, it's computer guys like you that make it hard for the rest of us!

http://www.shoforum.com/showthread.php?t=46736

I did mine last weekend, and the hardest part was dealing with the exhaust manifold studs that broke. And I'm a little computer guy at that!

 

[95atxsho]

After listening to this for a couple minutes. The noise actually sounds like a typewriter coming from what seems to be the back of the motor on the firewall side.
Any ideas now, does that change anything?
Thanks.
Paul

 

[TYSHO]

Check by your timing belt cover, next to the battery. Put your hand on there and see if you can feel it while it's running.

 

[95atxsho]

I held my hand on the cover, nothing, no vibration there at all, but you can hear that it's coming from the other end under the intake on the firewall side.
Thanks for all the help.
Paul

 

[95atxsho]

Yo TYSHO were did ya go

 

[TYSHO]

Start up to shut off is the same rpms, did you give it a little rpms, like maybe to 3k? Knocking at all times? Only when rpms rise or fall?

It's kinda hard, a lot of things can cause knocking. Bad valve clearance, timing chain tensioner, rod bearings and ect. The easiest to do would probably be the rod bearings.

You might want to go buy a cheap stethascope from an auto store or so and put it to use. I wouldn't mess with the car anymore, unless you have that to diagnose right then and there.

 

[95atxsho]

Thanks again. You guys have been a great help.
Paul

 

[TYSHO]

The sounds of where you said it's coming from sounds like the valves or rear chain tensioner, but I don't get how it would just pop up out of nowhere.

 

[95atxsho]

I know. The car was running, driving and shifting perfect before this. I just changed the oil and tranny fluid over the weekend. (Mobil High Mileage 10-30) and (Mercon V fluid) I just got the car and the oil and filter were spotless. Tranny fluid was slightly dirty. Very puzzled.

 

[fohengr]

Mine done the same removed the rear valve cover and found a bad cam chain tensioner thanks to the advise of some members. I ordered the new tensioner from my ford dealer for 86.00 he done a nationwide parts search and it came back that there was only 8 left in the u.s. 7 now none for the front. hope this helps.

 

[fred79]

if the sound is tinny make sure your flexable exhaust joint is tightned correctly. I had a tinny noise that I couldn't find and it turned out to be the spring loaded exhaust joint bouncing on its self.

 

[95atxsho]

Chain tensioner would be nice. Exhaust even better. Sounds just like an old electric typewriter. Weird stuff. I will rip it apart this weekend.
Thanks

 

[Racer X]

Isn't Mercon V in a Gen2 AX4S a big no no?

 

[95atxsho]

This is an 89 Gen 1. The Autozone DONKEY told me Mercon V. Is this wrong?????