engine noise - drooning noise

J

johnuk

New Member
1968, 2000 sc auto. I have had this car for many years, it has a "drooning", sort of inbalanced noise that comes in at 60 mph and levels out at 80 mph. I changed the engine and gear box many years ago for a 1976 2200 sc auto unit. This may have been when the noise started but I cant remember if the original made the noise or not. Since then I have changed all of the following parts, engine mountings, engine for a 1977 2200 tc, auto gearbox, flex drive plate, ring gear, torque convertor, diff and diff mounts, de dion tube, trailing arms and bushes, all four wheel bearings, rear springs, all four shock absorbers, balanced prop and half shafts, removed fan and belt. Is there any thing else? Please help as I am going mad, (not joking!). The car has visited many specialists including MGM motors (Carlisle), Paul Atkinson (Birmingham) and Vibration Free, (Oxford), and many hours in my own garage where the car was sold new, to name a few. As you can see many of us have tried and failed to stop this noise, so if you can suggest anything that fixes it you will get a very large feather in your cap,
Many thanks, J C Gates :angry:
 
John,
is this noise present at rest with the engine turning at the equivalent of these speeds? (i.e. confirming noise from engine) or does it only happen at these actual speeds? (i.e. could it be a tyre problem?)
I'm sure that you have considered this but I am clutching at straws!
Regards, John.
 
Only other thing I can suggest is possibly a wind related vibration, e.g. a loose body panel, grill, door mirror etc, even a vibrating brake hose could cause similar effects.

At 60-80mph the wind is quite considerable.

Richard
 
John. From my experience with P6s (this is the third I've owned) they are just not that quiet. My 2000 manual gets pretty noisey above 50, and starts drooning at between 60 - 80. I believe this is a fairly well-established feature of the P6 design, and does get commented on in some of the old Rover reviews I've read. My car smooths out above 80, and I recently drove it for a few miles at 90mph+ and it was happier at that speed than a motorway limits! Compared with my daily ruabout (a 10yr old zetec engined Escort) my Rover really is very noisey, but has nothing like the character or pedigree. Hope this helps, even though it will not solve your problem. Adrian
 
The drooning noise at 60-80 mphs is quite normal on the 4 cylinder cars. I have owned 5 2000&2200s over the years and they have all been the same, except for an amazing 1968 2000 tc with very low miles.. which used to purr.. but even this was noisy at 65+mph. The only way to get rid of this noise is to buy a V8, you may not have the exhaust noise, but you still have a lot of tyre and wind noise.
Having just replaced my V8 auto with a 1972 2000tc.. I find the TC is a good match between speed and economy. Plus the 2000s do not over heat like the V8s tend to in hot weather and there is none of fuel vapour issues.
I am really fond of the 2000s... but the V8s do make them seem like tractor engines. So there is not much you can do about this noise, learn to live with it... or buy a V8 auto.. The 2000 auto is very slow and the engine has to work hard so fuel economy with this car is not much different to the 3500 auto.
 
Anybody with a 5 speed conversion (4pot or v8) add any comments on this ? does the extra gear reduce noise and vibration at motorway speeds, I suspect it does, but opinions from the horses mouth are better than my guesses !

Richard :)
 
Thank you for all your suggestions everybody, i have not given up yet! But I thought I should reply to you all. I had already changed the tyres john and they do spin true. I have thought of wind noises aswell webmaster but have discounted it as the noise is so "throttle" related. The more throttle you give it, the louder the noise gets. It used to completely stop when the throttle was released, but now it just gets much quieter. I have also thought of a higher gear but rather than fit a five speed box I have fitted a V8 3:1 ratio diff but it didn't help. My dad and a family friend who both have 50 years in the motor trade have both suggested it may be a characteristic noise, but after road testing my car and every other rover 2000 we could borrow in the area, the three of us are satisfied it is not characteristic. If it was, Rover would only have sold about 100 of them to people with bad hearing before the word got round how noisy they were! I am now changing all the mechanical parts from my car into a car I have bought. If it runs as quiet as it does with its own parts I will then change the interior and all body panels as we now feel the noise must be in the shell. This may seem extreme and probably is, but the car was sold new from my family business by my grandad who founded the business in 1935. So the car has immense sentimental value to me, otherwise I would have given up long ago! I will let you know the result.
 
Today i had the first real drive in my 2000 TC since i drove it to work. It is mostly motorway for about 50 miles.
Impressions?
Well, not too bad, but rather noisy, maybe more than my Austin!!!
Engine wise it should be OK, it got fairly easy up to 100 mph and perhaps it could do more if i insisted. The oil pressure was fine hot or cold.
The road was really smooth and the car drove nice and straight. Even at 100 mph i felt safe and relaxed (wearing earplugs!!!). In uneven surfaces due to worn out front upper arm rubber bushes, worn steering idler bush and rear springs that are down it tends to wander.
Other things that i liked are the very comfortable seats and the fact that even with the window down it still is draught free.
So, a nice cruiser apart from the noise. Ok, i had too much wind noise because the door and quarterlight seals are due to a change, but the car is noisy. Not too bad at 60 mph, rather worse at 75, it got smoother above 80 - 85 but still noisy.
So, i rolled the window down and kept going anyway.

From indide, during the recent recarpeting i fitted as much soundproofing as it will get (to allow the gloveboxes to close).
Perhaps it will get better when i will add soundproofing from the engine side, but it will never be a quiet car, it was never meant to be anyway.
Only the V8s should be better but i had not such a choise.
 
When P6's were new we followed a '65 2000sc with a '71 1/2 S2 2000TC. The TC lasted barely a year on complaints from Mother on the throaty noise and was again replaced in favour of a '72 3500S.

Your current setup will have the TC fabricated exhaust manifold. This seemed to be the main culprit for noise in our TC. How about lagging the manifold with exhaust tape? This will have the secondary benefit of also reducing underbonnet temperatures.

The other popular source of noise (and of fuel vapourisation) would be a defective / missing carburettor heat shield. Again, why not replace with a steel or aluminium asbestos composite? The asbestos layer will tend to damp any "zingnig".

What you describe does sound throttle related. Perhaps another avenue would be to play tunes changing silencer / exhaust setup? You could have a middle silencer with loose or non existent baffles. Also were there not several iterations of the 4 cyl exhaust? Some may well be better than others! My Father and I kept a complete spare exhaust with blown silencers being swapped and taken down to the local blacksmiths (the what?!!) for repair.

Our experience would suggest the early SC system may well have been superior to the experience described by others above. I have a feeling that after introduction of the TC with a deliberately more sporty exhaust Rover may well have standardised the SC onto this sytem as well??

I seem to remember a thread on here which pinned a similar problem on gearbox rear thrust washer / gearbox rear mounting / diff mountings - I can't remember the detail and a quick trawl failed to show it up. Do you remember that webmaster?

Best of luck

Chris
 
A tubular mild steel exhaust manifold will certainly produce more noise in comparison with a cast iron one, as it does not have the sound damping qualitites of cast iron.
Wrapping the manifold will certainly help, i have done this in my Austin in the past, although the difference was not that much, it just removed the high frequency rasping, which for some people is not a totally bad thing.
To be honest i like the sporty exhaust note, but perhaps i will have to compromise for a quieter cruise.

Contemporary tests wrote that of the 4 cylinder cars the 2200 TC was noticeably quieter in comparison with the 2000 TC.
Now i am learning my 2000 TC but i am not familiar with the anatomy of the 2200 TC.
Can anyone who has experience of both 4 cylinder models tell us why the 2200 was more quiet than its predecessor? Different exhaust cans? Different exhaust mounting? More soundproofing? If yes in what areas? Different engine mountings? Or is it just down to the 2200 engine being more balanced?
Opinions?
 
Just had a bit of luck looking through old posts. Diff nose mounting is the aledged culprit! Or have you already renewed that?

Chris
 
Today i did another drive, a longish one, about 360 Km (approx 225 miles) round trip, a combination of motorway and mountain roads. I do this almost every Friday in my Austin to get to the college where i teach.
This time i took along the Rover to see how it compares. I tried to restrain myself and not get above 65-70 mph. Results? I was impessed with the economy as it achieved overall well over 30 mpg!
It was rather comforatable even if until i sort out the suspension it is a little annoying to try to keep it on a straight line on bad surfaced roads.
The engine actually was not noisy, probably thanks to the modest speeds and the extra soundproofing. But wind noise was way too much. And no, it's not the door seals. I was tempted twice to remove the door mirrors to see if it would be any better.
So, is this typical for a P6? Wind noise around the A pillars?
Road noise was high too, but i think that i have to blame the old tyres for this.
 
johnuk said:
1968, 2000 sc auto. I have had this car for many years, it has a "drooning", sort of inbalanced noise that comes in at 60 mph and levels out at 80 mph. I changed the engine and gear box many years ago for a 1976 2200 sc auto unit. This may have been when the noise started but I cant remember if the original made the noise or not. Since then I have changed all of the following parts, engine mountings, engine for a 1977 2200 tc, auto gearbox, flex drive plate, ring gear, torque convertor, diff and diff mounts, de dion tube, trailing arms and bushes, all four wheel bearings, rear springs, all four shock absorbers, balanced prop and half shafts, removed fan and belt. Is there any thing else? Please help as I am going mad, (not joking!). The car has visited many specialists including MGM motors (Carlisle), Paul Atkinson (Birmingham) and Vibration Free, (Oxford), and many hours in my own garage where the car was sold new, to name a few. As you can see many of us have tried and failed to stop this noise, so if you can suggest anything that fixes it you will get a very large feather in your cap,
Many thanks, J C Gates :angry:
Click to expand...
I agree with what's been written above. I ran a 1972 2000 auto for many years and can catagorically state that at about 60 the droning did cut in, and on the odd occasion when I got the car to 80mph it did quieten down. It's a characteristic of the cars, nothing more sinister than that.

Cheers
Nick
 
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