g-mack wrote:

is it the exhaust that is noisy? also presume when he says "chipped" he probably means tweaking fuel pump, as 300tdi isn't computer controlled

Exhaust and engine is noisy and he did mean tweaking yes

Ramsay wrote:

An '87 90 would not have had a 300 TDi orginally. So when was it fitted and how was the exhaust run then.

Is the noise problem one of when you are outside it or inside driving?
The standard 90 exhaust is not too bad. However the engine noise is pretty loud on the TDi. Is there any sound reduction in place on the timing cover or under the bonnet?
Have you any sound proofing in the rest of the vehicle. The flat panels do like to resonate.

LandRoverAnorak wrote:

Do you know what year your 300tdi engine is? I ask because if it's pre-'97 then there isn't anything to 'chip' as it's an entirely mechanical system. A rudimentary electronic management system was introduced in '97 that can be tinkered with although those offering the service seem to be few and far between these days. Regardless though, I can't see how it would make it any quieter Confused

To be honest, unless you think there's something physically wrong with it (and a fresh MOT suggests not), then normal operating noise can be relatively easily reduced by soundproofing the interior. There are lots of threads about it on here and a quick search for Dynamat or Silentcoat will bring up lots of entries.

I'm not sure about fitting bits of Discovery exhaust. I guess it may help but it's not a modification I've heard of before. If my 200tdi is anything to go by though, the biggest sources of noise are the engine itself and road noise, both of which can be reduced by soundproofing as mentioned.

Mash wrote:

My 300tdi runs a normal defender manifold, a straight through mid section and a normal tail pipe and that isn't loud I wouldn't of said.

For the engine check your tappets (0.008 in) as they can lead to noisy running, I purchased a standard 300tdi engine cover off eBay for 15/20£ And it made a noticeable difference in the noise.

Will do my friend. It's booked in next Wednesday to have the new SVX wiring loom I had installed previously in the last place done right so the sidelights come on without the main lamps so i'll get the new guy to check that while it's in

shaggydog wrote:

First things first,

Check for any leaks in the exhaust system.
Check the timing is correct
Check tappet clearences

Assuming the engine is running well and has no obvious leaks then you can start looking for other things.

There is no ecu to tweek and its pointless tweaking an engine which may have issues.

No leaks in the exhaust and I know the timing is correct as it was done less than 6 weeks ago so i'll do as you and Mash suggested and get the tappets checked. How is your restoration going by the way? I need to check up on your post.

Many thanks everyone