I have a rattling noise that develops when in high gear and a load is off the engine "coasting". It disappears as soon as I advance the throttle and place a load back on the engine. It sounds like it is coming from the transmission area. The car was completely restored 10years ago and except for this rattle it seems rock solid. Your thoughts please.
I'll be interested to see the comments on this. I haven't found it in the service manual.
Hard to tell.. Maybe it's time to tighten up the rod bearings after ten years of driving?
I had several "rattling" noises in my TT. I've learned that if I leave my hearing aids home when I drive it they all disappear.
Could be a sloppy fitting crank fan pulley.... engine off, if it moves by hand it will make noise.
Sounds like the connecting rod bearings, however if it is coming from the transmission area it could be the triple gear bushings are worn and when in high gear going at a constant speed the gears are rattling around. This is probably not a serious problem but should be addressed if you need to pull the engine and transmission. You can tell by removing the inspection plate from the transmission and try to rock the triple gears back and forth.
Sometimes rattles seem like they are coming from one place but are actually in another. When you are coasting if you grab your Carburettor mix knob does this make a difference or if you grab your "dash" does that help. Is the steering bracket where it goes through the firewall tight?
I had the exact same issue that you describe. It turned out to be the connecting rod knock on two of the four cylinders. I did not have any shims to remove so I filed the caps and reinstalled checking the new tightness by tightly tapping on them to check for side to side movement.
If your motor was rebuilt, then hopefully you have shims that can be removed. It is easy to tell the offending cylinder by placing the car in high idle and removing the spark plug wires one by one until the knock disappears. Do so with insulating gloves or alternatively you can short the top of the plug to the block using a screw driver.
There are several threads on this forum discussing the procedure above in more detail.
The above was from memory, but the procedure" detailed by Royce in the thread below is what I followed.
John, check and see if the noise is in the exhaust pipe, I have found a gland ring loose in one before and will drive you crazy trying to find the noise. KGB
I fixed all the rattles in mine. I turned off the key.
Seriously I hope you let us know what you find.drive safe and often
Dallas: I may try your fix on mine every time I fix one another two let me know they are there, I would try Henry P's method but I don't have the special tool he does.
Interesting about Bob J's comment..I've had a noise bugging me for months, I'm almost positive it was the crank pully, I could practically pull it off by hand. Put on an adjustable non-ridged pulley but have to modify the ratchet a bit as it won't fully engage around the shaft now. I'll get it machined. I bet that cures my noise, and John probably yours too. Another bit of good advice, start with the easy stuff first, then work your way up to the hard stuff. Even if you can't rock/move the pulley by hand, it still may be sloppy enough under engine load to make noise.
Pull plugs, set car on stands transmission cover off and floor boards out and turn crank listening for noise, funny "feel" etc. Pull inspection plate and check rod movement. Recently rebuilt a friends rear end with horrible noises coming up driveshaft and made it sound like the transmission was coming apart. Let us know what you find.
What Dan said. It would be better to short the plugs with a screwdriver to the head than to remove the wires. If you remove the wires the spark can jump somewhere else in the ignition system and burn a carbon trail which will cause a persistant misfire if it happens.
Bob's suggestion is a good one to check. A loose crank pulley can drive you mad.
Thank you all so much for the great suggestions. Upon checking my crank shaft pulley it does in deed have some slop and is a little beat up. I'm going to remove the belt and see if the noise goes away. If not, I'll still replace the pulley and continue my search for that rattle. You guys are the best!!
I guess I spoke too soon. After I diagnosed my problem as being a loose crank pulley, I decided to do the screwdriver test as well. Sure enough the noise stops when I short out #3. So I guess I'll be doing a little tighten-up on #3 and check the others while I'm at it. Question: If I wear a mask and snorkel do I need to drain the oil first? Just kidding!!! A little levity never hurts at times like these. Thanks again for all your help.
Another one that will sound like the transmission is about to come apart is a loose speedometer head, along with the choke rod. I ended up putting a spring on the choke rod.
Sounds like a good reason to pull the engine to me...when I heard that kind of noise, for about the same conditions, I found that two magnet plated had come off the magnets (sheered the heads off the brass screws) and were bounding about inside the engine. You'd think the magnets would hold them, but once you throttle up they get flung off them and go bouncing around...But if you don't find anything wrong with your U Joint, or cracked or loose pulley, pull the hogs head and take a look at those magnet plates...make sure they're all right where they're supposed to be. If not...time to pull the engine, before it blows up. A loose and or broken magnet can take out an entire transmission, your floor boards shred a lot of otherwise good stuff (including you). Don't play with it...check and make sure those bloody little plates are all accounted for.