TR2/3/3A Mysterious knocking?

[karls59tr]

I'm hearing a knocking sound coming from the motor. The motor is running fine and drives no problem. I thought it might be a rod knock? I put a stethascope all over the motor but do not hear this knock? Put the scope on the water pump but it's fine. What els could be loose. Very disconceting. I don't think I've ever changed the motor mounts on the car and I've been driving it for 20 years. Would that cause a knock?

 

[mezy]

I would think bad motor mounts would be more of a vibration than a knock.
I find that a piece of tubing like a garden hose help to pinpoint strange noises,
place it to the ear and follow where it sounds loudest. Works better than a stethescope.

 

[karls59tr]

I would think bad motor mounts would be more of a vibration than a knock.
I find that a piece of tubing like a garden hose help to pinpoint strange noises,
place it to the ear and follow where it sounds loudest. Works better than a stethescope.

I'm beginning to think that maybe it's the exhaust pipe that goes thru the cruciform under the car that is making the knocking noise? Maybe a clamp let go/ I'll have to get underneath to check it out.

 

[TR Tom]

I’m having the same problem. Mine also runs fine, but in the back of my mind I’m thinking I have a ticking time bomb.
You can tell if it’s the exhaust by driving a short way with the center tunnel removed. That convinced me my noise is coming from the front somewhere. Just be sure to put a piece of cardboard over the u joint so you don’t spray yourself with grease (ask me how I know)

 

[Stevenry]

I had a vexing knock at higher rpm and under a load. I suspected the exhaust, and nearly everything else, and drove around with the tunnel off, used a stethoscope and my kids ears, etc. Eventually, while adjusting the valves, I discovered two rockers were hardly moving because of two worn cam lobes (bad tappets I think, they were all pitted). That would be an easy check. Just roll the car in 4th with the valve cover off, or someone could crank the engine while you watch the rockers.

If it is the camshaft, hopefully it’s not, Rusty Beauties YouTube channel has excellent step by step videos of replacing and degreeing the camshaft. And you may have an excuse to buy a few new tools.

Steve

 

[CJD]

Need more info. Is it all the time or only while moving? Is it different whether the engine is cold or hot? Does it change from coasting to under load?

 

[sp53]

Have you ever had the timing chain tensioner out of the car? They can make unfriendly sounds.

Steve

 

[karls59tr]

I.m pretty sure the problem is with the deteriorated rubber motor mounts which I am in the process of changing. I'll report my findings.

 

[karls59tr]

Need more info. Is it all the time or only while moving? Is it different whether the engine is cold or hot? Does it change from coasting to under load?

Seems to be quite steady at idle and driving. The sound goes away when I grab the intake manifold and pull the motor towards me. I' changing out the motor mounts that are only 60 years old.

 

[CJD]

I agree...