Jump to content

Drone at 70mph


Recommended Posts

I have a drone at 70-75mph on my 200tdi 110 that sounds like it is the exhaust blowing. Thing is, i cannot find anywhere where gas is leaking from the exhaust. Put my hand over the end when it is running and the pressure quickly builds up and blows my hand off. If i cruise at 80 or 65 it goes quiet again. Any ideas what could be causing it? I replaced the rear box recently (Britpart item) - is there any chance that the rear silencer could be faulty? I dont remember it being there before i changed that box.

The only other thing i have done to the exhaust recently is to weld up a couple of holes on the first section of pipe after the downpipe and the only other thing i can think that might have caused this is if some of the weld had caused an uneven surface inside the pipe causing turbulence of the gases and causing the drone - does that sound at all likely?!

Link to comment
Share on other sites

Some new exhaust boxes I have had had a very bad drone, was just down to poor manufacture.....

hmmmmm i was hoping someone wouldnt say that! How does one prove that to get it returned and replaced?!

Link to comment
Share on other sites

Cruise at 80 mph!? :o

Is the noise not just tyre or running gear resonance with it being speed affected?

It never did it before i did those two jobs on the exhaust. I've got an overdrive and on the flat it will cruise at 80 (will go faster as well.. :P ) - soon loses puff on the hills though and needs to go down a gear but cant complain about that!

Link to comment
Share on other sites

I have a drone at 70-75mph on my 200tdi 110 that sounds like it is the exhaust blowing. Thing is, i cannot find anywhere where gas is leaking from the exhaust. Put my hand over the end when it is running and the pressure quickly builds up and blows my hand off. If i cruise at 80 or 65 it goes quiet again. Any ideas what could be causing it? I replaced the rear box recently (Britpart item) - is there any chance that the rear silencer could be faulty? I dont remember it being there before i changed that box.

The only other thing i have done to the exhaust recently is to weld up a couple of holes on the first section of pipe after the downpipe and the only other thing i can think that might have caused this is if some of the weld had caused an uneven surface inside the pipe causing turbulence of the gases and causing the drone - does that sound at all likely?!

I just tell her to shut up I'm driving and can go at whatever speed I want.....biggrin.gif

On a Serious note, I had this on one of our work land Rovers turned out to be Exhaust baffels not fixed correctly got the box changed noise went.

Jason.

Link to comment
Share on other sites

Think its gonna be a new back box then. Dug out the invoice for the exhaust just now and i bought it at the enf of January this year. Might have left that a bit long to get it re-funded. Doh! <_< Cant beleive i've been putting up with the noise for that long, but with all the snow i didnt use the car on the motorway much for the first month or so after fitting it.

Link to comment
Share on other sites

Just spoken to the supplier. If there is a rattle from the back box, they reckon there will be no probs replacing it. If no rattle, they think it might be difficult to get the money back on it. Its gonna have to come off anyway as i'm sick of the noise, but its sods law it wont sound broken and rattly!

Link to comment
Share on other sites

  • 7 months later...

I put up with the drone for another 6 months after this thread. Then i cut out the centre box to see what a straight through pipe with just a rear silencer would do for performance ont he 110. Performance went up, very nice too - much better acceleration, BUT, more noise and the drone was still there.

Over christmas i contacted a company local to my parents and they fitted a very nice stainless system to my 110 from the turbo back, 2 inch downpipe into a 2.5 inch system and two straight through silencers. Really nice, much quieter than the 2 inch system with the straight through pipe and much less restrictive, but the drone was still there. I went back to see the company yesterday and (FOC) they re-jigged one of the silencers and the exhaust mounts in the hope that would fix the drone. Its better (i think) but still there. Its like a bass tone occurring under acceleration between 65-75 (or other gears at about 2500rpm) - come off the gas and it goes away.

Now it has done this with two completely different exhaust systems I'm coming round to wondering if it is indeed something like Anderzander suggested above and want to rule other things out before/if i pester the company about the exhaust again. Any more thoughts welcome............

I'm off to grease my prop UJs and check oils again now....

Link to comment
Share on other sites

I get a drone at around 60mph when accelerating in my RRC. It's from the front transmission, and having replaced the brake discs, wheel bearings, tyres, swivels and prop UJs (the prop itself is mint), I have come to the conclusion that it's the front diff. There is a small oil leak from the pinion, which while any play seems absent, seems to corroborate the theory.

Given that you have had several exhausts, all with no significant change, and that the drone is road speed related rather than engine rpm, I would suggest you look at your tyres and transmission and forget about the exhaust.

Link to comment
Share on other sites

If it does it at 2500 rpm does it do it in neutral (either main or transfer neutral)? If so that would point strongly to some sort of exhaust reasonance. But if not, and it goes when you lift off, maybe a pinion bearing or something thust bearing-y that gets unloaded when the load switches direction. I admit it's not under much load so that might affect things.

Nigel

Link to comment
Share on other sites

he he I cruise at 55 and the noise is pretty bad at those speeds :lol:

The fastest I've gone is 75 and I had to rev the living poo out of the engine! At 80 the tyres must be making a lot of noise even if you are on AT's. Is it possible that the tyres are the source of the noise or a wheel bearing?

Link to comment
Share on other sites

It is on ATs, but the thing that made me think exhaust was that before the old backbox dropped off in Jan 2010, i dont remember this drone (on these tyres then too). But as has been said, two exhausts and no significant change. Greasing it up today, i discovered wear in the rear UJ on the front prop shaft, so next step is to replace that and see how we go from there. Worryingly, the swivel oil resovoirs were both sirtually empty, so the seals are a job for when it warms up (any metal i touched was bitter cold today!). New swivel ball also required on the driver side - all good for learning i suppose!

Reving it to 2500 in neutral doesnt seem to replicate the noise. Its only when under load.

Link to comment
Share on other sites

It is on ATs, but the thing that made me think exhaust was that before the old backbox dropped off in Jan 2010, i dont remember this drone (on these tyres then too). But as has been said, two exhausts and no significant change. Greasing it up today, i discovered wear in the rear UJ on the front prop shaft, so next step is to replace that and see how we go from there. Worryingly, the swivel oil resovoirs were both sirtually empty, so the seals are a job for when it warms up (any metal i touched was bitter cold today!). New swivel ball also required on the driver side - all good for learning i suppose!

Reving it to 2500 in neutral doesnt seem to replicate the noise. Its only when under load.

What AT's are you running?

Link to comment
Share on other sites

Did they put a flexi section in the exhaust? I had a drone that came about 2000rpm in 4th and the same in 5th. Once I fiddled with the exhaust to allow it to move more, the noise went away.

Yep. Its between the downpipe and the next section where the downpipe points rearward under the clutch slave. I am wondering if i might fiddle with the mounts - these are the type of ones they used (i thought they looked pretty good really though):

http://cgi.ebay.co.uk/Austin-Morris-Universal-Exhaust-Rubber-Mount-/140456656651?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b3de7f0b

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy