300Tdi question

This does seem to be a very common problem with 200 / 300 tdi Discoverys mostly prob due to the extra waight from the seating and carpets compared with a Defender , On there own they do drive ok , But towing or under any adverse towing comditions they lack grunt. This is why a very lot of people tend to uprate the intercooler and fuling to improve towing capeability.

Note : on some auto's to adjust the fuling you may need either the ecu chipping of a addon power box.(doing this alone would improve the car tremendiousley) a further intercooler upgrade would also help a lot.

If you need any advise on either option i would gladly try and help you

On or around Wed, 22 Jun 2005 14:58:47 +0100, "Richard Brookman" enlightened us thusly:

24-25 sounds a bit heavy - we reckon about 30 on the manual 300 TDi.

is yours EDC? If not, then I can give advice about tuning it...

so bellautos was, like...

Yep, a chip and vast intercooler seem to be very much on the cards! Thanks for the advice.

so Austin Shackles was, like...

A bit disappointing, especially as one of the reasons for chopping the RR was economy! Even my Td5 Disco (manual) returned almost 28 overall. However, I have heard (since the change!) that the autos are noticeably juicier than the manuals.

Sadly I think it's EDC (haven't poked about enough yet, been too busy, but it's a 97). Thanks for the offer anyways. Chippable, though...

:-)

so Paul - xxx was, like...

Thanks for the info, although I hear the autos are a lot heavier on fuel than the manuals. Unfortunately, Di has to have an auto (2 big spinal ops), which was the main reason for getting rid of the Td5 Disco (28 mpg manual).

I think the gearing setup is a lot of the problem. At about 53mph the autobox goes into direct drive (I assume this is the same as on the 3.9 RR), where it drops to under 2000prm and has no guts at all. It spins along lovely at 60, but the first sign of a hill and it starts to wilt - then it drops to 53mph, changes to 3rd, and it's foot to the floor to stop it slowing further. I think that's where all the fuel is going. If I try to dawdle along at 50, it never gets into top gear, at least not with a weight on the back. If I hit a hill with the Td5 (OK it was a manual), a bit of right foot kept the speed up and it sailed up long inclines.

If an intercooler upgrade would give it some more at 2000prm or so, it could hold top gear much longer and may well help the economy. I always knew that

111bhp would not tow as easily as the 225 of the RR, but I wasn't prepared for how much like hard work it would be! Funnily enough, there are some short sharp hills round here, and the Disco will climb them more easily than the Rangie did - there seems to be plenty of grunt when there isn't a ton-and-a-bit hanging off the towbar.

I would expect the auto to actualy be slightly less on mpg that a manual they do tend to rev a lot b4 actualy setting off , so this is where the fuel goes :( .

I have put one of my large intercoolers on a 1997 disco auto b4 , I was lucky tho it was NOT a (EDC) pump, so you may be lucky :)

On or around Wed, 22 Jun 2005 20:00:02 +0100, "Richard Brookman" enlightened us thusly:

I suspect you're right. On the V8, you drop to 3rd and apply welly but you then have enough revs to pull hard. The V8 will go into *2nd* if you floor it at 50...

Problem with the TDi is it has a relatively narrow power band, from about

2000 up to about 3000 revs. Chipping it would presumably improve that though - what you really want is a chip that gives a lot more torque at 1500-2000 - the converter stall speed is about 1800 ISTR; this means that under load it'll drop off the bottom of the decent power/torque on the standard engine, and then have to change down, whereupon it'll be revvign hard and losing grunt at the top end. I spose a chip that boosts the top end would solve the speed thing but that would require the use of much welly.

Worth chekcing everything is in good order first though. Replace all filters regularly, and check the valve clearances, check that the intercooler is clean inside and out.

By a bit of judcious tweaking, out TDi is significantly better to drive than when we first had it. Mind, subjectively, my non-turbo transit-engined bus goes about as fast up to 60.

You're in a very similar position to myself but see an even worse effect.

I changed from a 3.5Efi auto RRC to a 300Tdi auto RRC and in so doing gave up a third of my horsepower. You've given up even more.

Simply we're just short of that horsepower. The torque is there but not in combination with engine speed. Changing the gearing is not going to help and the engine's not ill.

An intercooler upgrade would certainly help but let's not kid ourselves it won't get us back to square one.

But we are better off in the pocket - though I suspect that neither of our driving styles is going to result in some of the heady fuel consumption figures that we read about here!

My 200 TDI disco gets about 32-34 solo, 32-34 towing a small trailer,

30-32ish towing my old dears caravan or SWMBO's SJ on its trailer. I used to get about 16 towing the GLASS exhibition trailer (over 2000kg, 15 ft tall, and makes a Defender look aerodynamic). Turbo started howling a fortnight ago, fitted a new one and now get 20 towing the GLASS trailer, and still the same solo, but better pickup....

On or around Wed, 22 Jun 2005 21:05:44 +0100, Dougal enlightened us thusly:

a gearing change might improve matters WRT the lock-up of the converter.

but you really want a wider torque curve which gives more at 1500 and doesn't lose any at 3500. Should be do-able.

Wow. After Austin's tweaks I had no difficulty towing a 2.5 ton boat on a half ton trailer at any speed I cared to do in the 200TDi manual. I wouldn't say I didn't know the boat was there but I could pull up to 60 no problem, didn't dare to go beyond that. Fuel was around 25 ish which I was more than happy with. My opinion is that some are set to burn so lean that it actually destroys the fuel consumption rather than aiding it. With a bit more fuel in the system everything improves. I'm still grateful Austin! TonyB

On or around Wed, 22 Jun 2005 21:33:43 +0000 (UTC), "Simon Isaacs" enlightened us thusly:

I believe there's some evidence that the 200 TDi, properly tuned, is actually slightly more economical, if less refined.

This is probably the way to go. I have a replacement intercooler and Allard turbo pipework on my 200TDi auto RR and this has made a big difference to the performance, with and without a trailer, and hasn't made a noticeable difference to the economy.

In particular, it seems to change down a lot less than it used to. I got my intercooler from John Norman at Brunel Performance. He uses standard headers and puts a bigger mesh on, so it fits in the same place next to the radiator. No connection other than as a satisfied customer.

-- Pete

so Dougal was, like...

Hmm - not sure you could count me in there. :-)

I tend to drive pretty steadily, only rarely use max revs, and always have an eye on the economy. I learnt to drive when "mechanical sympathy" was regarded as a virtue, not a waste of time for a throwaway product. On the France trip, the cruise control was thrashing the car more than I was! On long hills, I was deselecting the CC out of sympathy with the engine. I don't regard trying to maintain 50-60mph on a motorway with gentle hills as unreasonable. As to better off in the pocket - well, yes, up to a point. But the Scottish guy in the caravan on the next pitch reckoned he got about

40mpg towing a similar (medium) caravan at 60+ behind a diesel Rover 75. I got below 20.

I take your point about the bhp, though. 111 will never be 225, no matter how you figure it!

so Pete Young was, like...

I think if I keep it, that's the way I'll go. BUT...

I have the offer of a swap (same independent dealer) to an early auto Td5 for about the same money (price to change) as I would spend on an intercooler and chip upgrade for the Tdi, and I am seriously considering this. The Td5 is in excellent condition throughout, but has been pressurising the coolant. Dealer reckons it's the head gasket and will fix it, but will replace the head if necessary. Otherwise, it's a peach with just over 100K on the clock. I've had a Td5 before and know it has enough power for what I need (and it's an auto, so no off-idle stalling issues that so p*ssed me off with the manual). I'm sorely tempted.

Which is going to be the better deal - a straight and clean Td5 with enough grunt but a possible issue with the engine, or an older, less tidy Tdi with a big intercooler and evil chip?

Oh dear, decisions... Help, someone!

I find that mine (96) is very much as you describe. I think the biggest issue is the gear ratios which are very far apart. (3rd and fourth) You find yourself either labouring in Forth or screaming in 3rd. I am in km/h but I won't exceed 80km/h in third as the engine seems quite unhappy above this. I find the max I can get comfortably in lockup forth is about 110km/h. Much over that and you are again in the uncomfortable zone.

I find that dealing with hills is particularly poor. It just about manages to get itself up with me in the car, but throw a few more bods in and your hillclimbing tends to be done in the truck lane. As for towing, I only tow a light trailer +-500kgs, and this is enough to virtually slow you to a crawl. On the plus side I usually return about 9.5l/100km in normal driving and slightly over 10l/100km with a trailer on. The engine has just been rebuilt so it is not old and tired.

Regards Stephen

Just a thought, maybe the gearbox has been replaced by one not out of a Tdi as the gearbox control unit on the Tdi is listed as SFC1582 and the ones for the 3.9 and 4.2 are listed as STC930 and STC907 respectively, maybe the gearing *is* wrong in that the changing speeds are different.

Martin