MGB & GT Forum

Cannot for the life of me find the rattle/noise

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Kumiteking Avatar
Kumiteking Sean Turner
Perth, Western Australia, Australia   AUS
1969 MG MGB "Harold"
I really hope someone has also had this same rattle/noise happen to them so that I can learn what it is - totally driving me barmy!

So, if I take off normally, I have this weird rattling noise from, I believe, underneath and behind the seats. I think it's underneath and behind the passenger seat (RHD car), but it's hard to really pinpoint where it's located. I change in to 2nd gear and if I give it some herbs the rattle remains. If I take off really, really slowly, there is no rattling noise and if I change up a gear really gently, I can ensure the rattling noise doesn't appear. I've put the car on stands and started it up and ran through the gears quite vigorously, but I can't replicate any noise. It only seems to be apparent under load.

Any ideas?

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ozieagle Avatar
ozieagle Gold Member Herb Adler
Geelong Victoria, Australia   AUS
1958 Wolseley 1500 "Wooly"
1966 MG MGB "Bl**dy B"
Hi Sean,

I had a similar one. Turned out to be the exhaust pipe hitting the rear shock drop link. Very hard to spot on stands, because the axle etc is not near this link, when hanging. Look for a small spot of bright metal, on the bulby end of the link.


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Kumiteking Avatar
Kumiteking Sean Turner
Perth, Western Australia, Australia   AUS
1969 MG MGB "Harold"
Hi Herb,

Thanks for the hint - I'll pop out now and have a quick squiz. I'll let you know


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Mgcarma Silver Member Kevin Richards
Culpeper, Virginia, USA   USA
1960 MG MGA 1600
1960 MG MGA 1600
1960 MG MGA 1600 ~ For Sale ! ~
Check for a loose exhaust hanger or muffler clamp. I had the same thing and it was an exhaust clamp that was buzzing because it needed to be snugged up.

trmgb Avatar
trmgb todd martinez
littleton, co, USA   USA
I'm going the other way if the other suggestions don't work .
Put you hand on the top to give it weight,.

72 engine, hif carbs, black od, rest of car stock

mdubash Avatar
mdubash Silver Member Manek Dubash
Lewes, East Sussex, UK   GBR
1968 MG MGB "Odysseus"
Check your hard fuel line isn't rattling against the bodywork anywhere, eg the front firewall. This foxed me for a while.

- If duct tape doesn't fix it - you haven't used enough duct tape

Ex-Calif Avatar
Ex-Calif Gold Member Dan D
Cincinnati, Ohio, USA   USA
1968 MG MGB GT "Bart - Yellow And Naughty"
1977 MG MGB "Red Betty"
2012 Jeep Liberty "Tank"
2014 Hyundai Accent "Skate"
Also check the clearance between the exhaust cans and the floors. Mine was rattling against the floor under load.

The goal - Reliable summer driver interspersed with mechanical tinkering...
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Bart -

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mworland Mike Worland
Tampa, USA   USA
1978 MG MGB
Had a very similar problem, baffled me for months, noise only under load, in every gear...turned out the stainless muffler wasn't stainless on the inside. Remove the mufflers and shake, any rattling will cause that problem.
Good luck

Wachtmans Avatar
Wachtmans Wouter Strodijk
OVERVEEN, Noord Holland, Netherlands   NLD
1974 MG MGB "The Bee"
1974 MG MGB "The Bee"
1974 MG MGB MkIII "The Bee"
I also have an occasional rattle at idle. It is inside the back of my driver seat. When jiggling a bit with the seat adjuster on the side, it disappears.

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DrewM Avatar
DrewM Silver Member Drew Maddock
74 MGB roadster, Southern California, USA   USA
My "noise that came and went" as I drove the car was a loose muffler hanger that was buzzing against the bottom of the car. The under-the-car "back there somewhere" noises you get when driving often seem related to the exhaust pipe, mufflers, or exhaust hangers which come loose or don't fit correctly. My exhaust hanger was loose but looked just fine until the guy at the exhaust shop played with it. The weld had come loose. So it was buzzing at certain speeds. The location you describe is where the exhaust pipe and mufflers are located.

You might take your car to a good exhaust shop and have them look it over and re-weld anything that looks suspect. Or maybe your muffler has shifted location and is contacting the bottom of the car? It could also be something inside the exhaust pipe or muffler buzzing. Then maybe it's time for a new pipe and muffler?

Drew Maddock, So. Calif.

oleanderjoe Avatar
oleanderjoe Silver Member Joseph Baba
Fresno, Ca, USA   USA
Install 18" Glass Pack Bigger Stereo Speakers, Maybe an Amp ... British Leather Pilots Hat. Smile a lot.

dipstick Avatar
dipstick Kenny Snyder
La Center, Washington, USA   USA
1941 Ford N-Series
1958 MG MGA 1500 Coupe "Rosie"
1970 MG MGB GT "Pat's GT"
1971 MG MGB "Gifted To Me"    & more
My rattle turned out to be inside the driver's side door mirror.

Be safe out there.

rj horizon Avatar
The internal baffles in the muffler could also be rusted loose. My car vibrates/rattles at specific rpms.

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