Discovery 2 Noises - Not Serious, But Would Like To Identify? Help Please!

Dear all

I have two noises and another separate quirk that I am trying to identify in my Discovery 2 TD5 (1999) with an auto box;

1 - When moving off from the stationary, there is a distinct "hiss" which is related to the throttle and throttle use. If moving off from stationary, it will last about 1-2 seconds and then disappear. It won't come back unless I idle and lose speed, and then use the throttle again - when it will briefly (less than a second) re-appear, or if I go back to a full stop and start off again. Should it do this? My 300 Tdi never made this turbo hiss type noise!

2 - When moving at low speed and higher torque, i.e. moving up a hill slowly, there is a rattle coming from underneath the car. It only happens between 1750 & 2500 revs, and only at low speeds. It does happen in the same rev range on the flat, but is less noisy. It dissipates largely when the car is very warm, and has been running for 30 minutes or longer. Any ideas?

3 - Just a niggle - she can sometimes be slow to change up properly to 4th gear. She should move upto 4th at about 55mph, and will should drop down to about 2,000 revs. However, whilst she is cold, she will change up, but the revs only drop down to just below 3,000 revs. It can take anything between 10 - 25 minutes before she is warm enough to fully drop down in revs at 55-60mph. Any ideas?

Thanks so much in advance to anyone kind enough to reply.

Richard

No 2 might be a loose or broken exhaust bracket, or loose baffle inside a silencer.

Can't help with 1 or 3 though.

Ok

number 1.
thats normal, it is turbo hiss you can hear. i've had it on both my td5's
it does happen on the 300tdi but you cant hear it over the engine clatter !

I would agree with mantamad re number 2.

number 3
if you solve this let me know, as I occasionally have the same problem

Derek

With regards No 3 I get this first thing in morning but doesnt normally last that long. I find revving it harder before dropping off the accelerator (where it would normally then drop in at 2000rpm solves this quicker than normal)

no 3 is like this on all Td5's. it wont go into final drive till you hit 53mph or above. indeed this is where she is economical but designed that way as bhp/touque aint needed there. its something we cant change but wouldnt reccommend blasting from cold to 53mph.

jcbdigger1970 said:

no 3 is like this on all Td5's. it wont go into final drive till you hit 53mph or above. indeed this is where she is economical but designed that way as bhp/touque aint needed there. its something we cant change but wouldnt reccommend blasting from cold to 53mph.

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I hear you, but still think it's taking way too long to be able to get the 4th gear lock-out and drop in revs.

The other day I left the village, and go straight onto the Thanet Way. I didn't blast her at all, and gradually built up to 55 - 60 mph carefully. Even at 65, she wouldn't drop down from about 3250 revs, and she sounded awfully high for cruising along on the motorway.

I drove as far as the A249, and she still wouldn't drop down. Came off, and got on the A249, and got back upto 55, and she dropped down to 2,000 revs immediately!

It seems to me that if, at the point you cross over the lock-out speed threshold, and she isn't ready to drop down (isn't warm enough) she will stay like that until you physically and significantly drop down lots of speed and build the speed back up again to go back over the threshold - this is annoying and highly impractical on a motorway, without pulling off and on at a slip road junction or similar service station! Surely, even if she isn't warm enough to lock-out after joining the motorway after 5 mins of driving, this is ok, but should drop down automatically when she has BECOME warm enough automatically, without the reliance being on me as the driver to **** around with the speed to serve the gearbox?!

It took about 25 mins to get to the junction mentioned above, and this has got to be way too long for the transmission to warm up surely, so we can achieve lock-out?

PS - as you're just round the corner, your not a LR mechanic or anything like that are you? If you are, I think I will have just died and gone to heaven.

I didn't want to fill up the thread with loads of individual replies - so thanks very much indeed for all of your suggestions - this is most useful. Any other thoughts remain most welcome!

Dor1s said:

Ok

number 1.
thats normal, it is turbo hiss you can hear. i've had it on both my td5's
it does happen on the 300tdi but you cant hear it over the engine clatter !

I would agree with mantamad re number 2.

number 3
if you solve this let me know, as I occasionally have the same problem

Derek

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Listened to mine today, noticed the hiss as well.

Mantamad said:

Listened to mine today, noticed the hiss as well.

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If only I could post a recording of it on here.... I still think it's loud to be turbo hiss, and think it might be a split pipe somewhere. I popped over to an ex-LR mechanic who lives locally, who now works for himself, and he immediately agreed that it was a noise that it shouldn't be making.

He seemed to be linking it to the ACE system!, but I am sure it is directly throttle / turbo related because of when and how it occurs! Am still trying to work it out!!!

I have a 2001 TD5 and have the same thing with the hiss. Only noticed it as I drive past a wall quite slowly... If you figure out what it may be pls post.

Thanks

Just a thought but you might be hearing the centrifugal oil filter spinning as you increase the revs, some people have reported they can be quite noisy.

Hi
No 2. Is it related to RPM, if so may be the same prob I had. 99 disco 2, metalic grrrratttttle from lower engine front, possible S belt tensioner or lower damper wheel, changed damper wheel noise went, although their's a similar rattle coming from the tensioner at idle and around 2000 rpm, but not as bad.

Russ

Your Auto TD5 won't go into final drive, no matter how you rev up and down, until the temp gauge is up to half way/normal running temp. Keep going on the motorway and it should fall into final drive when the needle gets halfway, without re-revving down and up again. I just knock 10-15mph off my speed until it happens to keep away from 3000rpm.

Takes a long time in the morning when fully cold.

James W said:

Your Auto TD5 won't go into final drive, no matter how you rev up and down, until the temp gauge is up to half way/normal running temp. Keep going on the motorway and it should fall into final drive when the needle gets halfway, without re-revving down and up again. I just knock 10-15mph off my speed until it happens to keep away from 3000rpm.

Takes a long time in the morning when fully cold.

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Thanks alot for the suggestion, but I think it's more than this.

I live fairly close to a fast piece of dual carriageway that is the main London link. The car is virtually at normal operating temperature, when I get onto this carriageway, but if the car is not ready, she will not go anywhere near final drive.

The other problem is that despite cruising along at something like 60mph, and sitting at over 3,000 revs (which sounds bloody awful), no matter how long you give her, she will not drop down when she does get warm enough - nor can I simply drop her down to about 40mph, and gather speed back up to overcome the problem.

Once she is in the high rev mode, she will not come out of it, unless I come down to a virtual stop, and THEN gather the speed back up. This involves leaving the carriageway, as you just can't do this safely on a busy fast road!

If however, I was drive round the houses for ten minutes before joining the carriageway in the first place - then she would be ready, and there would be no problem.

I am pretty sure now, that this is going to be cured by a transmission filter and fluid change, which is going to happen when it goes into the garage next week....

Thanks to all for the suggestions for the No. 2 rattle. I think that I might have sourced the cause.

I was tapping away underneath the car, looking for something that sounded loose, and virtually the last thing I tried was the exhaust. I initially tapped it round the 1st box area, then towards the back, and it made a very "tinny" hollow sound with a rattle sounded like something was loose or some sort of shield was loose.

I got under the bonnet, and tapped the downpipe, and it seemed to be worst there, particularly around the flex element. I popped over the garage where it is going in next week, and he was pretty confident that this was the cause of the noise that I can hear. It appears to need a new downpipe.

The noise is actually pretty loud when she's cold, to the point where pedestrians sometimes look round. It does get better (quieter) when she's warmer, which would make sense to me, as the exhaust is one the hottest parts of the car when running, and it seems to calm down, but never go completely.

Anyway - hopefully, this is the cause.

As for the hiss, the mechanic had a quick gander and drive, and seemed to think that it might be the ACE pipes?! It seemed like a strange suggestion to me, as the "hiss" definitely sounds to me like escaping air, and is directly throttle related.

He suggested, that it might be fixed (if indeed this is the cause) by binding the pipes together to stop them rattling! It still doesn't sound right to me as a suggestion - however, I ought to give him his due, as he is a LR main dealer trained mechanic who has now gone private..... What do others think about this suggestion about the ACE?

stuartc said:

I have a 2001 TD5 and have the same thing with the hiss. Only noticed it as I drive past a wall quite slowly... If you figure out what it may be pls post.

Thanks

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For those that read this thread - all three problems have been identified and resolved (well sort of!)

1 - Hiss was caused by a leak / crack in the flexi-joint on the old exhaust downpipe. Hiss has gone completely with the new pipe that has just been fitted.

2 - Rattle has been identified as also being the downpipe as I suspected. However, I got a replacement from a salvage specialist, and whislt it cured No. 1 - it still rattles (which you couldn't tell until fitted), therefore still have the torque rattle. At least I know what it is now though.

3 - Completely cured by fitting a new transmission filter kit and new gearbox fluid. It will happily change up to final lock-out at 55mph, when still only a quarter of the way on the temp guage on the dashboard clocks - which is excellent news.

Anyone got a good downpipe for a non-cat TD5?

PS - I get about 75 miles of range from £15 worth of diesel - circa 95p per litre. Does this sound about right, or a little low? I was on the yellow light in Richmond last night - chucked in £15, and drove home to Canterbury - about 75 miles total. She just hit the yellow light again by the time I had got home! I would have thought she would do more than this.... I'm sure the old 300tdi did more!

PS - I get about 75 miles of range from £15 worth of diesel - circa 95p per litre. Does this sound about right, or a little low? I was on the yellow light in Richmond last night - chucked in £15, and drove home to Canterbury - about 75 miles total. She just hit the yellow light again by the time I had got home! I would have thought she would do more than this.... I'm sure the old 300tdi did more![/quote]

Glad you got it sorted but please please please
Can you explain to me why you take the time to stop at a garage, get covered in diesel and only put 15 snakes in???? And then had to go back again today I bet

Lifes to short and I know it's a killer putting 100 squides of petrol in yeh car but it safes you going to the garage at least 7 times a week

Is it a auto if so make sure you have enough oil in the in the gearbox for the torque converter to work properly.that mite be the trouble your having changing up or even replace the oil it might have been in there from new.

I was waitin behind a wimmin at the petrol pump last week. she were drivin a V8 Disco. after she pulled away, i drove up and looked at the pump - she had put in £5 worth!

Glad you got it sorted but please please please
Can you explain to me why you take the time to stop at a garage, get covered in diesel and only put 15 snakes in???? And then had to go back again today I bet

Lifes to short and I know it's a killer putting 100 squides of petrol in yeh car but it safes you going to the garage at least 7 times a week

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I know, I know - it was 11.30pm at night on a Sunday, with no choice of petol stations! If I'm going for a big fill - I'll only use certain stations for their prices (and collector points!) - there was no choice....

Anyway's - does that sound like about right economy considering the almost all the driving was at motorway cruising speed, with no town stop / start nonsense??!!