mk1 very loud 2.5di, any thoughts?

[jenningsroadranger]

Hi, I have a 1975 Jennings Roadranger, it had a 2.5di fitted by the last owner, it runs really well, and has been really reliable, but it is ridiculously loud in the cab.

I have fitted foil backed insulation under the bonnet, on the firewall, and covered the floors and front arches, its better, but it is still too loud to have proper conversations!!

Is there something that stands out as being a likely cause?

thanks

[Neil]

di s are noisey it would have been petrol at one time

[Keef]

Have you checked the timing (preferably with a dial gauge)? They do clatter badly if they are too advanced.

[1949bug]

Ear plugs I'm afraid!
I have a Di in my mk2 tipper, you could throw £500 at insulation and it's still going to be loud.
I religiously use ear plugs. They are the disposable 3M ones -39db, though you can wash them daily and they last about a month.
I tried ear defenders but looked very stupid lol.

I'm currently torn because I've done a lot to my Di, timing belt,injectors, mk2.5 water pump and fan, and lots of other bits and it runs like a dream, but I still remember how quiet and torquey the pinto was......and its sitting in my shed waiting

[Keef]

Just had a thought .....

Has it got the old Lucas injection pump? They are a fair bit noisier than the later Bosch pump.

[jenningsroadranger]

Thank you very much for the replies, it has the later Bosch pump, and an aftermarket K and N type cone air filter, i was speaking to someone recently who said that the air filter will not be helping.

We have just got back from two weeks in France, and ear plugs made a massive difference, next stop is going to be to get more insulation in the cab and bulkhead.

Thank you again for your replies

[FredTransit]

Another thing to try is two stroke oil in the tank. It has been known to quiet down clattery pumps. We use a dose (marked on the 500 ml bottle, 100ml) in a tank. Well worth a try and not much outlay. It doesn't matter what pump you have, and use up the whole bottle (over time) before you decide if it makes a difference.

[bortaf]

If it has a cone filter instead of the ford airbox it wont be doing anything other than anoying you with extra noise, Mk1 & 2 were never the quiestist by design but having converted a few Mk2 recovery trucks to diesel i have to say they aint that bad but i depends what your used to ?

[sidewaysjas]

Hi,
I have a Di in my MK2 LWB and it is so loud I am thinking of changing to a petrol. You can't have a conversation at 50mph, so long distances are just deafening.

Jas

[1958 harry]

If you've got a low ratio rear diff it could be revving high at speed which won't help the noise issue.

[Neil]

just throw that dirty smelly old smoker in the bin and fit a v6 power smooth silent

[Muttley]

Put a proper air box on it I have several if you need one

[Mfr]

I suffer from CFS and have bad headaches and earache so its been a priority for me to quieten the Di, I followed Andy's how too except for removing the dash. Did the engine bay, headliner, floor up under the dash, doors (Huge improvement in stereo sound quality! and gives a wonderful Rolls Royce "wump" when you close the door ) Also been testing a gearbox and had a spare in for a while without the gearbox sound insulation surround (not sure if have an MT75) and it makes a noticeable difference.

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