P38 2.5 Diesel Tune up

I'm sure this has been done to death already, so sorry in advance if this is a repetitious post.

I'm looking to improve my 2.5 DSE's performance and am considering a plug in box to do this. Mine has a manual gearbox if this makes any difference.

I don't want to have issues with the engine through asking too much of it, but it is soo gutless in the low to mid range. I've fitted a water pump that has a alloy impeller that really seems to keep it much cooler than the OEM plastic one. (Which failed and cost me a another engine but that's a different story).

So what plug in performance boxes work and are sensible and where to buy from?

OldP38 said:

I'm sure this has been done to death already, so sorry in advance if this is a repetitious post.

I'm looking to improve my 2.5 DSE's performance and am considering a plug in box to do this. Mine has a manual gearbox if this makes any difference.

I don't want to have issues with the engine through asking too much of it, but it is soo gutless in the low to mid range. I've fitted a water pump that has a alloy impeller that really seems to keep it much cooler than the OEM plastic one. (Which failed and cost me a another engine but that's a different story).

So what plug in performance boxes work and are sensible and where to buy from?

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Fitting a powerbox to mask an obviously badly running engine is not a very good idea.

I wouldn't put a box on mine but I might be tempted to chip it. Mine is the manual with no box of tricks and it is fine but it doesn't drive like a v8, it doesn't even start to shift until the turbo spools up around 1750 rpm. If you want to shift then you'll have to keep it between 2000 and 4000 rpm.

Before I did that I would flush the intercooler, new air filter, new oil and filter, check lift-pump output, check MAP pipe and stick it on diag and see what modulation I get and readings from sensors. Compression test would also be worth a look. Also, make sure the turbo waste gate is clear and free to move and the pipes from the turbo through to inlet are all sound and clear.

After that, if all is good and you're still not happy then consider a chip. Doing it before is just polishing a turd.

A professional Reprog or chip replacement is the best and guaranteed but only on a healthy engine. If there are doubts on an engines ability any upgrade will soon find its weakness.
Make sure your engine is in good condition before you commit to spending money on a performance mod. You could use that money to repair an unknown fault.
Your call.

Happy with the performance on both mine without a power box, in fact I removed the Power Box and sold it.
As others have said, you need to sort any problems before upping the power on an old engine.
If you then still want to up the power, a remap is better than a Power Box. Have a look at Turner Engineering.

The engine is fine. Its done a lot less than the car. Before I fitted it I took a look inside at the general build up of crud and the block was clean as a whistle which suggested the guy I bought it from was telling the truth when it was from a low mileage vehicle.The old engine by comparison was vile inside.

It has been running perfectly for three years. I change the oil on the dot and there are no issues.

When I fitted it I put in the alloy water pump as the plastic one on the old lump disintegrated causing it to over heat. On the day I said I would not trust plastic water pumps again.

I've just seen on the 'web a lot about these plug in boxes or chip upgrades and not sure which way to jump

OldP38 said:

The engine is fine. Its done a lot less than the car. Before I fitted it I took a look inside at the general build up of crud and the block was clean as a whistle which suggested the guy I bought it from was telling the truth when it was from a low mileage vehicle.The old engine by comparison was vile inside.

It has been running perfectly for three years. I change the oil on the dot and there are no issues.

When I fitted it I put in the alloy water pump as the plastic one on the old lump disintegrated causing it to over heat. On the day I said I would not trust plastic water pumps again.

I've just seen on the 'web a lot about these upgrades and not sure which way to jump

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Where did you get an alloy water pump? I have only seen steel or plastic

Datatek said:

Where did you get an alloy water pump? I have only seen steel or plastic

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Think it came from ebay. It fits a whole load of cars. The impeller vanes appeared to have a bigger surface area than the old one. Its been working fine, the temperature gauge never goes over its normal range. With the old one it would go up to 3/4 in traffic when it was hot.

OldP38 said:

Think it came from ebay. It fits a whole load of cars. The impeller vanes appeared to have a bigger surface area than the old one. Its been working fine, the temperature gauge never goes over its normal range. With the old one it would go up to 3/4 in traffic when it was hot.

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Viscous coupling? ? If you changed the fan when you changed the engine it solved the problem.

I had a power box fitted on my manual diesel and removed it as looked like it aided the head cracking making it work harder than it needs, I still have it as it is one of the more simple upgrades (plug and play), but caution as above, if your interested let me know.

Mine however is the pre-MAF sensor with aluminium inlet manifold.

Me personally for such a big car its not worth the extra 30hp or whatever it provides, I drove mine weekend without the power box, still seems capable enough and if anything runs better without it.

Psi powerbox is the one. There are two with different connectors depending on your model.
It will bugger up an auto box, the manual will handle it so does make difference. They seem to cause premature death of FIPs but not to too great an amount.

I’d fettle it a bit first. You will be surprised. Good clean intercooler, static set, plenty of fuel supply they will shift. Then if it’s not enough for you and your engine is healthy you can plug a box in or fit chip and it will shred your tyres.

What mileage is on the engine?

If you get the injectors recon’d one at a time you will see bit more power each one, can still drive and not too expensive. You need good no4. They can keep going for years but 150k they are not working at full potential.

My friend has a DSE with a powerbox..

I cut it out and thew it in the skip, the car drove much better even though it was slightly slower it felt smoother like at @Lukas018 said himself...

IMO the only way to add power is to chip it, properly..

In my experience the DSE stock isn't bad, compared to a TD5 Disco it is quite peppy.

The DHSE i looked at before getting mine had a Powerbox too, only issue was it was pull of water, the head was cracked too, oh and it have massive blowby..

Keep well away..

OldP38 said:

The engine is fine. Its done a lot less than the car. Before I fitted it I took a look inside at the general build up of crud and the block was clean as a whistle which suggested the guy I bought it from was telling the truth when it was from a low mileage vehicle.The old engine by comparison was vile inside.

It has been running perfectly for three years. I change the oil on the dot and there are no issues.

When I fitted it I put in the alloy water pump as the plastic one on the old lump disintegrated causing it to over heat. On the day I said I would not trust plastic water pumps again.

I've just seen on the 'web a lot about these plug in boxes or chip upgrades and not sure which way to jump

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Pretty sure a company near me in Aylesbury used to do it but can no longer find them guess the M51 is a bit old now.

I think @wammers put a Tornado chip in his.

This might be worth a look: https://endtuning.com/about.html but never tried them.

If I had money it’d be tornado chip in mine.

OK so in conclusion a bit of engine set up might be a better investment.

OldP38 said:

OK so in conclusion a bit of engine set up might be a better investment.

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That would be my way to go.

With any engine you get it running 100% before any tuning or or your wasting your money. learnt that many years ago doing motorsport, brakes right suspension right engine right then think about tuning no good having more power if you cant stop or go round the corners

Just to finish this off, after much fiddling around and trying different things, the two items that made a huge difference were:
Replacing the rubber joints on the intercooler/turbo which had gone like bubble gum.
Fitting a brand new #4 injector

Runs like new, sounds different and has a very decent power output. I won't be chipping it!

Told you won’t need it

But still an option if you want more