growling noise

[aupickup]

on start up everything is fine no growl when revved hard
on warm sounds like a growl when driven hard, this is at speeds of 30, and 50 when driven hard through the gears, also when revved hard at standstill

no knocking or anything at tickover, no smoke from engine, oik pressure and compression is good

i can time the noise out, but then teh timing is wrong

have checked big end bearings in engine and they are all good, no vibration

could this be clutch or gearbox related, the gearbox was changed for a gold seal before i got the car

(been like it for 3 years) just thought i would try and find the answer

[chickenjohn]

Check the joint between exhaust and manifold. These are prone to slight leakage on the Minor. I have had a simmilar growl (without hearing it of course!) on my cars when the joint is blowing just a little bit. You may need a new clamp, and a cleanup of the mating faces and fresh exhaust paste.

The car can pass the MOT for years like this (not bad enough for inspector to notice) and give no other symptoms other than the growl.

I have had this on all my Minors.

If not this, check compression, a very slightly blowing exhaust valve can give odd symptoms like this.

If the noise occurs at standstill and is rev related then it is not likely to be drivetrain related- most likely engine exhaust.

[aupickup]

manifold joint is good and tight

will check valves tho

does seem to be coming from low down in engine gearbox
and it seems revs dependant
when revved slowly all is ok, same as driving, when driven slow all is ok, but still get it at 50, seems like a knocking at 50, 60 is ok and 70 is ok

[Leo]

Both my 1969 Traveller and before that 1969 Convertible have what sounds like a similar noise. Also a friends 66 Saloon has the same
I have been asking fellow Minor Owners for years about this, and it always has been put down to the gearbox, but my suspicions are that it may we something such as the exhaust vibrating or touching the body

Leo

[chickenjohn]

Manifold joint might be good and tight but can still leak if the exhaust paste is old and tired and cracked! I still think it is exhaust related (though hard to tell without seeing/ hearing the car first hand).

Oh, and another source of growl could be corroded exhaust baffles inside the silencer. The exhaust can appear good and leak free outside but can be noisy/ growly due to corrosion inside the silencer- no baffles left means more noise.I had this exact problem on my Traveller about 10 years ago. A neighbour used to complain about the noise late at night. New exhaust made the car much quieter. Exhaust was not leaky.

[aupickup]

well the exhaust system is old and on its last legs i guess

but why can i time the noise out on the dizzy
timing is correct and car has plenty of zip

but agreed is difficult without hearing or driving the car

[bmcecosse]

Is it still there if you take the fan belt off ? And - is the vacuum unit working properly?

[aupickup]

just changed the dizzy for a new old stock one and timed and it seems better now, and good performance will see how it goes during the week

[bmcecosse]

May be main bearing 'rumble'.

[aupickup]

would main bearing rumble occur all the time

[bmcecosse]

Seemingly it was a problem on Marina/Ital at one point in production. They 'cured' it by fitting a dizzy with no vacuum advance How that was supposed to help - I have no idea!!

[Leo]

Cleaning and refitting the exhaust to manifold joint worked for me
Who would believe it, so simple when you know how
How many owners have changed their gearboxes unnecessarily when this simple measure would have done the trick

Leo 69 Traveller

[MarkyB]

Always a good plan to start with the cheap easy fixes then try the expensive, difficult ones.