Series Tdi's - refinement and noise levels

[Chicken Drumstick]

Just wondering what other people's experiences are with Tdi's in Series motors?

Have they been nosy and unrefined, even by Land Rover standards?

 

My hunch is, Series engine mounts are just solid blocks of rubber that the engine sits on, which then transfers a lot more noise and harshness through to the chassis and thus the cabin too. A 90 is far more refined by comparison. As they use a large donut style mount, which essentially allows the engine to float and isolates much of the vibration and noise from the chassis.

[Arjan]

I'll know in a few weeks once the Tdi is up and running..

However, all those "in the know" claim the engine mount rubbers need to be top quality for that reason...

We'll see...

[Bowie69]

If it were as simple as that I would expect people would be modifying their Series to take defender mounts, though I've not heard of this happening?

I like this quote from the Glencoyne site: 

Quote

The 200Di is a direct-injection diesel, and it is significantly noisier than the old two and a quarter.  If you fit one of these engines to a Series vehicle you really need to think about soundproofing - floors, transmission tunnel, bulkhead and ideally the underside of the bonnet as well.  There is also a fair amount of vibration - the Discovery has absolutely huge engine mounts to soak up the vibes, but on standard Series diesel mounts you will find that anything in the vehicle that can rattle, will. 

This made interesting reading though, linked to from here: http://www.nickslandrover.co.uk/new-engine-mounts-cure-vibration/

 

 

[GW8IZR]

I was looking at the BMW e46 engine mounts, they use a vacuum and controller valve to significantly stiffen the mount once off tickover. I reckon that's something to consider even in the 90.

FWIW I bought a set of those Glencoyne 'super mounts' and they are absolutely identical to Bearmach units.

[Cornish Rattler]

Noise wise I think you would need to fit some sort of matting / soundproofing to the bulkhead, we have just replaced our bulkhead on the 90 ( 200tdi ) the old bulkhead had factory fitted carpet on the bulkhead which was stuck down well and couldn't transfer it over onto the new bulkhead so atm there is no carpet / soundproofing on the new bulkhead and it is quite noisy in there now.

As regards the engine mounts I have never used the Def mounts but have used 2.25P mounts with a tdi in the past and I have fitted the same mounts on the one I am doing now as I never had a problem with them but have heard bad things if you use 2.25D mounts but would imagine Def mount would be just as good as 2.25P mounts if not better

[Jon White]

In my experience the noise from the tdi is insignificant compared to the whine from the series transmission.

[Snagger]

It is horrible, much worse than a 12J or petrol engine.  The Glencoyne sourced Defender mounts help a lot with cab vibration compared to other sourced rubbers of the supposedly same spec, but not a great deal with noise. Remember to replace the transmission mounts, too.  As Jon says, part of the problem is transmission noise, which is increased significantly because of the engine harshness but also the greater speed attainable with the Tdi.  Even with overdrive, exceeding 60mph is very unpleasant, but below that is OK.  

Discoverys with 200 Tdis used very different mounts tot he Defender, which used exactly the same mounts and brackets as the 2.5 petrol and diesel predecessors.  I suspect they are much, much better than the Defender type for reducing noise and vibration.  All 300 Tdi mounts are the same, irrespective of vehicle, and are very different to either 200 type.  I don't know if they are better or worse than the Discovery 200 type.

I have the whole engine bay lined with Noise Killer sound blanketing, which was entirely ineffective.  I also have a Wright Off Road matting kit, plus his chequer plate patterned matting in the back, and it helps considerably, but is not enough for comfortable high speed long distance work.  It really needs more sound absorbtion under the seat base and around the bell housing and gear box tunnel.

Taller diffs will also help with noise, but I've already mentioned my opinions on 3.54 ratio with a Series transmission.

[Chicken Drumstick]

Thanks for the replies.

Yeah it's not the vibrations so much, it's the noise in general. Tickover in mine is actually ok, although the X-Brake linkage does make a rattle when the brake is on (it didn't with the old drum in place).

But if you have the brake off, the cabin is quite rattle free and moderately smooth on tick over. But when underway, there is just a lot of noise. I've not been able to pinpoint it exactly, but think it's mostly from the bulkhead/firewall and transmission tunnel. I've got a quiet exhaust fitted, so it's not exhaust noise and outside the vehicle it's actually pretty quiet and smooth. Dipping the clutch and coming off the throttle when cruising or going downhill results in a massive drop in noise.

I have added sound proofing to the underside of the front floors and in the transmission tunnel. Maybe I just need to pile on some more matting on the inside, as it's just metal at the moment. All mounts, engine and gearbox where new last March.

 

And I think I mentioned it earlier, recently went in an 88 coiler with a 200Tdi and LT-77 using Discovery mounts. Despite no sound proofing at all and a noisy exhaust, it's so much more refined and quieter.

[Snagger]

Like I said, I don't think lining the engine bay helps with cab noise, though it should reduce exterior noise.  I saw youtube video the other day of a Defender owner who used Dynamat over the bulkhead and bonnet underside and also the Noise Killer engine blanket, trying each separately (using the same phone and app for reading Db in all instances, internal, external and driving, so even if inaccurate, it'll be consistently inaccurate and so valid for the purpose of the test).  He saw a noise reduction externally from the Dynamat, but not the blanket, and had no significant improvement from either or both together internally when driving or parked.

You need sound absorbtion inside the cab.  I really like Drew Wright's kit (sold by Exmoor Trim as well as Wright Off Road) - it's neat, smart, tough and looks great, and also helps a lot with noise.  But thick carpet over medium density foam has better sound insulation quality than any smooth surfaced rubber or plastic can ever provide.  Unfortunately, they are moisture absorbent (which is why they are also sound absorbent), so you lose the practicality of Drew's kit.  Which works best for you depends greatly on the type of use and how wet or muddy you're likely to get the interior.

What did surprise me in effectiveness from Noise Killer was using their self adhesive grey matting on the sides of the hard top.  It stops a lot of drumming and makes a worthwhile difference.  Other products would work too, the point just being that a surprising amount of noise is generated by those panels, and likewise the doors if they're not covered already.

[Chicken Drumstick]

Thanks. Have windows in the back of mine, so no drumming from the panels. And it's more of a direct noise comparison to how the vehicle was with the 2.25p engine.

[Snagger]

Do you have a headlining?  You'd be amazed at how much noise comes off those panels.

[skirky dave]

If i might jump in here Nick, i was also looking into the Wright off road kit, some 8 yrs ago which , on the face of it looked very good but very expensive and heavy, about the weight of a 750/ 16 tyre, so.. thought i would look into things a little further. A year or so later,and by complete accident, i ended up speaking to an acoustics engineer regarding the sound proofing of recording studio's. We got talking about Landy's and the best way to sound proof one the best we could. His explanation was interesting.

He said, " It's a little more complicated than that, because you have to take into account there are many different materials that create a different tone/noise which cause the annoying interference . Caused by a mechanical wave of pressure. One substance will reduce or stop one sound wave BUT NOT another. To really quieten down the landy, would require 5 or 6 different materials, which, together, would not have to be very thick or heavy but the cost could be a little more"

His explanation seemed to make sense but i'm by no means an expert on this sort of thing NIick.

But it might be a good idea to contact someone who does know about acoustics and what it's all about.

On a more personnel note, however, i prefer to listen to the motor with all it's little foibles. As you know Nick ..i do have a few at the moment !!.

[Snagger]

That's what I'm getting at.  The whole interior needs tackling, not just the front foot wells and bulkhead.  You need something heavy for the high frequency noise, and something with a lot of surface area but essentially soft for the low frequencies, hence foam, felt, carpet and alike.  But those absorbent materials can be impractical as they also absorb water.  The best thing for minimising noise is to minimise its production in the first place, so making sure everything is mechanically correct and properly mounted makes a big difference.

[skirky dave]

As i say to my other half, if she wants quiet, the car's on the drive, but if we have to do a tip run she puts up with the landy, which to be fair, she does actually enjoy as she calls it ,,,,character. The series landy's were never made to be quiet especially the diesels and the thing i enjoy is the fact that if it does get sludged up inside, then out comes the hose pipe and it's done. Carpet stinks to high heaven once it gets covered in sludgy water and the like.

Someone i know bought a Defender and uses it constantly on his farm, it gets covered and i mean covered from muddy boots. He just leaves it now as it took him all day to clean it once and it still stank afterwards. The series land rover , is what it is, but as most things in the world of land rovers, it's always going to be a matter of personnel choice and at best, a very subjective opinion. But you are correct in that if everything is fastened down correctly in the first place, it can be made quieter to a degree.

The best of it is....Once i remove the canvas top, ....( which isn't all that often with the uk summers!! ) all the noise dissipates to atmosphere.

[Gazzar]

I've s tdi200 in my series, truck cab with lasalle headlining.  At 50 you can have a conversation, at 70, less so.

 

When I put the engine in I lined the bulkhead engine side with "flashband" bitumen sheet - several layers, and then with some camping mats.  I also did the bonnet underside.  It's bearable, but the transmission whine noise from the overdrive is a problem.  When I redo the cab I will  do the underside of the seatbox and the floor boards, I expect this will help a great deal.  A rebuild of the overdrive is probably the next major job.

 

Also, the glencoyne engine mounts are very worthwhile, the keys don't rattle anymore!

 

G.

 

 

[Cliffordtdi]

On 7/13/2017 at 6:50 PM, Gazzar said:

I've s tdi200 in my series, truck cab with lasalle headlining.  At 50 you can have a conversation, at 70, less so.

 

When I put the engine in I lined the bulkhead engine side with "flashband" bitumen sheet - several layers, and then with some camping mats.  I also did the bonnet underside.  It's bearable, but the transmission whine noise from the overdrive is a problem.  When I redo the cab I will  do the underside of the seatbox and the floor boards, I expect this will help a great deal.  A rebuild of the overdrive is probably the next major job.

 

Also, the glencoyne engine mounts are very worthwhile, the keys don't rattle anymore!

 

G.

 

 

Are the Glencoyne mounts just the expensive better quality Bearmch items part number BFM 560G?

[Cornish Rattler]

What do you recken to using that thick rubber matting that they use in a gym for the engine bay, I've seen it in Homebase's and son says he can get me a load free and it's thicker than homebase's 

[Maverik]

I've been chipping away at the noise/rattling thing for years now and I reckon I've done an alright job. Taking some info gained from sound attenuation measures on some old ships, where you have to change resonant frequencies of big flat panels when you see the stuff on the market now its basically doing the same thing, its all about changing frequencies and blocking frequencies. I'm no expert but I looked and thought and tried very hard to improve my 90 (1986 200tdi Van) and its a posetivly warm and generally quite Land Rover with a bit of potential for to eek a little more out of it too I hope.

Phase 0

Cut down a rubber engine cover that you find on 300tdi's, to cover the rocker cover.

I hacked up an old (I think D2) gearbox insulation cover and zip tied it around the gearbox and bell housing.

Phase 1

So I started off with covering areas on both sides of the bulkhead with foil/bitumen based matting material, I then covered this on the engine bay side with a closed cell foil backed 10mm foam type stuff (not unlike the foil stuff that was fitted as standard to trucks around the late 80's early 90's, I covered the inside of the transmission tunnel and seat box in a similar manor as well as the front floor, but I left of the closed cell foil. On the inside of my cab I then stuck a few bitumen pads in the centre of the front roof sections, then covered it with the 10mm foil foam then the teddy bear headliner went on top of that. Under the bonnet I've got a standard 300tdi black felt type bonnet linear.

Cab side of seat box and footwells I have standard Td5 type moulded insulation.

Other than a bit of carpet in the back the panels where bear in the back...

Phase 2

I bought some MUD van panel finishers, they come with a 8mm heavy foam bad that you put on the panel then cover with the plastic outer, I sourced some pyramid foam sheets that where a lightweight open cell foam stuck them to the roof, they improved insulation but didn't do much for the sound.

Phase 3

Took the crunch and ordered some Noise Killer eggbox roof panels and rear tub load area lining... now things start really improving, should have done that much earlier, that stuff is very impressive and gave instant results, after the NK insulation was installed I could then start to hear where sound was almost leaking into the truck.

Phase 4

MUD rear door card cover, again first line with bitumen matts then cover with 10mm closed cell foam with foil, then door card on top. New rubber load space matt with a layer of astro-turf lining rubber under it with a piece of carpet over that.

Phase 5 (yet to do)

Remove bonnet insulation and fit NK self adhesive insulation then re-fit standard bonnet insulation. Install foil backed foam inside doors. Convert Engine and Transmission mounting rubbers to later 300tdi/Tdci 45 degree rubber block type rubbers mounts. Potentially fit a NK engine blanket... but I'm not keen on this as I like to be able to see the engine.

 

[tuko]

I have a 300tdi in my series which uses the 300tdi motor mounts, these mounts transfer very little vibration in the vehicle.

As for noise control I used "silent coat" over all panels from the seatbox downwards. Plus on the floor panels I have 10mm high density foam. The one thing that helped the most with noise control in the cabin is plugging or sealing all the holes in the body panels. This took a long time but effective in the end. The one area that I would like to point out that created the most noise is the lack of sealing between the bulkhead and the transmission tunnel cover. Solve that and you'll enjoy quieter motoring.  

We now can drive long distances without the need for ear plugs.

 

Todd. 

[Daan]

I have a 300 tdi, on 300 mounts and 0 sound deadening. Interestingly, the noise at speed from this is quite ok, the only problem is tickover; this is truly horrific. I have never been able to sort this. At speed I also have to deal with simex tyres, which makes the engine noise sounds like a whisper. But basicily i generally cruise at 70 MPH. this is with 4.75 diffs and a 1.2 transfer box (lt77 with lt230 box).

I have to have decent speed, as a weekend offroading in Wales involves driving there after work on a friday night and come back on a sunday night.

 

Daan

[Cornish Rattler]

On ‎9‎/‎19‎/‎2017 at 10:21 PM, Cornish Rattler said:

What do you recken to using that thick rubber matting that they use in a gym for the engine bay, I've seen it in Homebase's and son says he can get me a load free and it's thicker than homebase's 

Sorry just realised what I wrote, I meant to say cab not the engine bay

[Snagger]

On 20/09/2017 at 11:01 AM, Maverik said:

I've been chipping away at the noise/rattling thing for years now and I reckon I've done an alright job. Taking some info gained from sound attenuation measures on some old ships, where you have to change resonant frequencies of big flat panels when you see the stuff on the market now its basically doing the same thing, its all about changing frequencies and blocking frequencies. I'm no expert but I looked and thought and tried very hard to improve my 90 (1986 200tdi Van) and its a posetivly warm and generally quite Land Rover with a bit of potential for to eek a little more out of it too I hope.

Phase 0

Cut down a rubber engine cover that you find on 300tdi's, to cover the rocker cover.

I hacked up an old (I think D2) gearbox insulation cover and zip tied it around the gearbox and bell housing.

Phase 1

So I started off with covering areas on both sides of the bulkhead with foil/bitumen based matting material, I then covered this on the engine bay side with a closed cell foil backed 10mm foam type stuff (not unlike the foil stuff that was fitted as standard to trucks around the late 80's early 90's, I covered the inside of the transmission tunnel and seat box in a similar manor as well as the front floor, but I left of the closed cell foil. On the inside of my cab I then stuck a few bitumen pads in the centre of the front roof sections, then covered it with the 10mm foil foam then the teddy bear headliner went on top of that. Under the bonnet I've got a standard 300tdi black felt type bonnet linear.

Cab side of seat box and footwells I have standard Td5 type moulded insulation.

Other than a bit of carpet in the back the panels where bear in the back...

Phase 2

I bought some MUD van panel finishers, they come with a 8mm heavy foam bad that you put on the panel then cover with the plastic outer, I sourced some pyramid foam sheets that where a lightweight open cell foam stuck them to the roof, they improved insulation but didn't do much for the sound.

Phase 3

Took the crunch and ordered some Noise Killer eggbox roof panels and rear tub load area lining... now things start really improving, should have done that much earlier, that stuff is very impressive and gave instant results, after the NK insulation was installed I could then start to hear where sound was almost leaking into the truck.

Phase 4

MUD rear door card cover, again first line with bitumen matts then cover with 10mm closed cell foam with foil, then door card on top. New rubber load space matt with a layer of astro-turf lining rubber under it with a piece of carpet over that.

Phase 5 (yet to do)

Remove bonnet insulation and fit NK self adhesive insulation then re-fit standard bonnet insulation. Install foil backed foam inside doors. Convert Engine and Transmission mounting rubbers to later 300tdi/Tdci 45 degree rubber block type rubbers mounts. Potentially fit a NK engine blanket... but I'm not keen on this as I like to be able to see the engine.

 

Forget phase 5 - it won't achieve a thing but will cost plenty.

[Snagger]

On 20/09/2017 at 10:27 PM, Daan said:

I have a 300 tdi, on 300 mounts and 0 sound deadening. Interestingly, the noise at speed from this is quite ok, the only problem is tickover; this is truly horrific. I have never been able to sort this. At speed I also have to deal with simex tyres, which makes the engine noise sounds like a whisper. But basicily i generally cruise at 70 MPH. this is with 4.75 diffs and a 1.2 transfer box (lt77 with lt230 box).

I have to have decent speed, as a weekend offroading in Wales involves driving there after work on a friday night and come back on a sunday night.

 

Daan

300s are a fair bit less harsh than 200, and the mounts are considerably better.  But you're also avoiding the LT76 transmission noise, which is a considerable pat of it and is worse behind a Tdi than an earlier engine (petrol or diesel).