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MG TD TF 1500 - NOISE IN ENGINE BAY

I’ve got this strange noise coming from the engine bay. It’s a rattleing/vibrating sound, and can be compared to a few things,like;
>Holding a sheet of newspaper in the wind as you drive at 60MPH,
>A rotating shaft vibrating in a loose bushing,
>A relativly loud sparking sound,
>Like the fan blades were just grazing the rad fins,
>At times it sounded like a squeal.
First time it happened was on the NJ Turnpike on the way back from Cape May in 2007, it lasted only about 10 seconds, but it was loud enough to hear at 65MPH with the hood down. Then a few miles up the Turnpike it happened again,, I stopped figuring I would change ou the distributor, but it was tight. Started the car, and the noise was gone. Since then, it has appeared only a few times,, we’ve even gone through a few years with no sign of it. We have gone a few thousand miles till it happened again.
Last year it happened on the way to Auburn GOF, stopped checked under the bonnet, started the car and it was gone,, continued for another thousand miles, and now it’s back again. But it only lasts 10-15 seconds or untill I shut it off and start up again,
Things I’ve checked;
Generator movement, dizzy wobble, water pump movement , fan fins.
Things I am going to look at; (although highly doubt if it is tha cause)
Starter bendix some how loose and occasionaly touching ring gear?
Water pump impeller some how loose and occasionally touching the casting?
Speedo cable?
Engine has 62,000 miles, Tach drive is disconncted. No loss of power when the noise is present.
Any ideas?
Gotta fix it before Strausburg GOF
TIA,
STEVE
SPW Wincze

Generator bushing? Generator fan? Engine ping? (Knock) sticking lifter? What is the engine doing when this happens? Under load? Certain speeds?
D. Sander

Dave,
last week it happened as I was coming to a stop,, from about 25, down to stop,,It has also happened under load(on the turnpike at 65). It doesn't seem like the engine misses, but it happensd so unexpectidly, it's hard to think of what everything is doing at that moment,,,
Gen seems tight and charges ok,,
SPW
SPW Wincze

I have had fan belts make sudden and brief unexpected squeals. Like electrocuting a cat I imagine. Usually gone when the engine is warmed up though. Starter bendix would be #2 for me.

Matthew.
M Magilton

Hi Steve,
have you checked your manifold nuts.If slightly loose the exhaust gasket can act as a reed. Never had it on a T Type but regular on B's.
Ray TF 2884
Ray Lee

Steve; might look closely at the fan blade tips. Had the engine shift positions and the tips just touch the lower coolant pipe - was a come and go issue that was tough to find and easy to fix. Dan
D Craig

If using after market air cleaners make sure the tops are tight to the body. I had a K&N that was loose and it made sounds similar to what you're describing.
Gene Gillam

Dan,
I got excited when I read your reply, That would make the exact same sound !!! Ran out to the garage and found 1/2" clear between the tip of the blades and the lower pipe,,,
The fact that noise is sooo inconsistent,, sometimes we can go 1 thousand miles without hearing it,,, The last time we heard it, we only covered less than 100 miles between instances,, When we do hear it, it sounds loud!!!! If I get a chance this weekend I'm going after the starter, to see if something is amiss in there with the bendix.

Thanks,
STeve
SPW Wincze

Steve,
I've had instances of strange vibrating/squeal type sounds from the engine compartment over the years which turned out to be the following: loose intake/exhaust manifold nuts (the newspaper rattle in the wind sound), loose radiator (what a clatter from time to time), a wire touching the distributor shaft (high pitched), distributor cap center post disintegrating, starter gear touching ring gear, water pump and belt, tack or speedo cable. The sounds you describe reminds me most of loose manifold nuts as Ray Lee described.
Charlie
Charlie Adams

Steve, I had a strange noise that was really loud with various squealing sounds and very intermittent. It drove me crazy because it was something I could not get to repeat when I drove under the same conditions trying to find the problem. It happened only a couple of times at first, then later began to occur more often.

Just by pure luck, I happen to notice my speedometer needle jump when it occurred on one occasion. After quite a bit of trouble shooting of the speedo, cable and pinion connections, I decided to pull the transmission. While removing the drive shaft in preparation to pull the transmission, I noticed the tail shaft yoke had quite a bit of play in it. The nut on the tail shaft drive yoke was slightly loose.

The speedometer gear was slipping just under certain conditions like when slowing down coming down a hill. other times it didn't make any noise. At that time, I just re-torqued the nut and the problem was gone. After looking in the work shop manual, I found that my transmission did not have a key in the speedo gear on the main shaft because it was an early model. Years later I rebuilt the transmission and I could see the main bearing snap ring had been bent a little because someone previously tightened the tail shaft nut so much that it bent the snap ring at some point in time.

If your transmission has a keyed speedometer gear this wouldn't happen.
Richard Cameron

Steve, I once had such noice and it turned out to be the generator fan. Re-fastening that pulleybolt fixed it.
Good luck, Huib
Huib Bruijstens

huib,
What was the fan hitting to make such a noise?

Steve
SPW Wincze

Actually, hitting nothing particular but it was loose so, that made the rattling noise. I found it when i checked the pulley :pushed it around to feel if that bearing had some play and than I noticed that the fan was loose. After starting the engine and playing a bit with the trottle I could see and hear that fan wobbling around.
Huib Bruijstens

Steve,
This was an article that explained about a loose fan the generator on Buds TTalk site. It is mentioned down at the bottom and is possibly in a lot generators this way.

http://www.ttalk.info/Holcombe.htm

Rod




R. D. Jones

My generator screached from the rear bush after a long, hot drive (and pack of lubrication....). Horrible sound that was.
Willem van der Veer

I pulled the starter yesterday,, and much to my dismay, the gear and spring looked in fine order,, no wear marks on any thing including the ring gear,,
Another noise that would be similar to the noise that I am occasionally getting is,,,
.
Remember the noise you got when you put a NEW card in the spokes of your bicycle?? That's the noise that we hear,, but only for a short time,,,,

SPW
SPW Wincze

When was the last time you put a load of grease in your tach reduction gearbox mongrel to the back of the generator. I had mine do that once and then the car stalled. I thought I had spun a bearing, but it started back up again just fine. Turned out the stall was caused by the box rotating around and contacting the low tension lead on the dizzy which killed the spark. Give it a few pumps and drive it for a while to see if that helps.

Alex
Alex Waugh

Alex,
thanks for the suggestion, but the Tach Drive is not installed,,,
This noise is LOUD!!
Spw
SPW Wincze

What about your carb bowl overflow pipes rattling?
DLD

DLD,
It is MUCH louder than the overflows could ever make,,,, Loud enough to hear at 65mph on a busy highway,,,

SPW
SPW Wincze

Alex: This happened to me at the GoF West this week. I was constantly cleaning oozing grease from the sides so I convinced myself that could not be the reason I was getting so much noise and constantly having to reset the tach reduction box to keep it away from the connector.

Finally discovered it when just trying to start the car the last day it would spin it into the distributor and the best I was getting was one quick fire. I took off the reduction box and it started right up. I just drove by the tone of the engine from there :-)

I greased it up when I got home and put it on the car again. Hope its OK and I did not damage it. It seems to turn OK by hand but I cannot remember how easy it was to turn before.
Christopher Couper

Check engine mounts, and the welds on the tranny mount. Perhaps it is shifting causing something to hit or rub. Loose baffle in the exhaust? Just guesses, a video recording would help.
George Butz

Spigot bearing.
mog

MOG,,, That's got to be it !!!!!!!!! Brilliant thought!!!!!!!

I'll try to get a video of it,, but by the time we R 20, 30 50 or so miles into a drive, and it starts making the noise, I'm not sure that I can get the phone turned on and set it to record before the sound disappears,, but I surely will try,,
We are expected to get quite a downpour tomorrow, so it will have to wait till Mon, tue,,

Chris,
Go to Bud's great t-talk for this method of stopping the tach drive from rotating

http://www.ttalk.info/picture_this.htm#Tach Box Stabiliser

SPw
How about a loud muffler bearing???

SPW Wincze

SPW: That's a clever solution for a poor design. But I have to blame poor maintenance for mine drifting somewhat. Steve Simmons also suggests putting in an o-ring on the coupling at the dynamo. My real slippage was at the clamp where it has worn a bit and is not as tight as it was originally.
Christopher Couper

can't be the spigot bearing. It is only in use while clutch is depressed.
Sandy

This thread was discussed between 15/06/2015 and 21/06/2015

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