HDi 90 performance and "Good Mechanical Husbandry (TM)"

[bytecode]

Hi Everyone,

So I've successfully replaced my timing belt (+ the tensioner & roller), pulley wheel & accessory belt - so I'm feeling a little more confident in my car now.
I've still got to replace the water pump - I would have done this with the timing belt but I just COULDN'T afford it until payday.

I've started using the 406 for my daily commute now and I really notice the lack of power from the supposedly 90BHP engine. I know from readin posts such as this one viewtopic.php?f=1&t=4340&hilit=underpowered that it is to be expected - but I suspect that a little more maintenance is due to bring out a little more "life" - I can barely overtake the lorries that are in the crawler lane on the Cornish A38 at the moment - even with a run up in 3rd gear.

I've heard of this business of cleaning the F.A.P. - would this have a performance impact?

What about EGR? Can this be cleaned? would it deliver economy OR performance benefits?


What other "non-modification" "Good mechanical husbandry" items should I look at BEFORE more drastic options are considered (let's face it - even chipping is limited IF the other areas of the engine are not being looked after).

Any suggestions welcome,
thank you.

PS: I haven't looked at the airfilter yet - but OIl, Oil Filter, Air filter and Diesel filter changes are my next "trick" for this weekend.

[rwb]

"HDi 90 performance"

That's life with 90HP dragging round 1400kg and with a usefull rev range of only 1500rpm (boost from 1800, and then runs out of puff at 3000 -- look at the power and torque curves).

Admit defeat.
Accept it.
Then you can move on to a higher plane and start obsessing about economy instead of speed -- that's what the HDi 90 is for.
You should be able to get 40mpg going up that hill.

[Welly]

It's important to respect the way a diesel engine wants to work and (without being disrespectful to the OP) some people try too hard to eek power out of them and end up getting the opposite.

You have to work with a diesel and follow what it wants to do, it won't be rushed, and if you sit back and learn to ride the torque wave you will find you will need very little throttle input and start progressing better than you imagined. Diesels of less than 100bhp feel very flat but keep an eye on the speedo and you'll see you aren't going as slowly as you thought

Of course, if the car is hopelessly slow for some reason you'd need to diagnose what might be wrong but the 90bhp is usually well behaved.

[DiscoPol]

Hi there, you shouldnt have a fap on a 90 so that ones out,

a damn good service and blocking off the EGR would be my next step but remember it is a 90 so no intercooler i think you might just be expecting a little too much from the thing if you want something quicker flog it and buy something else.

is it your first hdi diesel? if so maybe just a bit more practice driving it might bring out a few more horses for the overtake, in my old 90 you had to learn to play with the power band and after 3200rpm it was all out of puff, its not a typical turbo diesel its a HDI

3rd gear from 1800 rpm to 3200 rpm was cracking fun with the torque but again it takes a while to get used to this.

Good luck with it, but first get that service done with some decent oil (10/40 semi synth) and have a play about with different gearings and soon enough you will have it drivable at least.


EDIT : damn you welly

[Welly]

EDIT : damn you welly

[highlander]

Remap that HDi 90 and you might get it to about 110 HP.

But yeah, what those guys said - diesels are funny beasts and behave differently to petrol cars. You can't, and shouldn't, try to drive them the same way.

[steve_earwig]

See what changing the air filter does, you might have a medium sized sheep stuck in it.

[DiscoPol]

See what changing the air filter does, you might have a medium sized sheep stuck in it.

Has Dai been disposing of the bodies again??

[Doggy]

I've not tried a HDi 90 406, but my Xsara had this engine & was pretty nippy once you mastered the technique. For me this amounted to a heavy right foot, changing up at the right point, ( 3k max. but more important to get the right revs in the next gear) and change up quickly so the boost doesn't die off.

There are a few things that will slow it down - clogged air or fuel filter, leaky egr or maybe a partly-blocked cat, binding brakes, low tyre pressures, carting lots of stuff about, (like 75 litres of fuel if you're rich), etc.

[Blubayou]

Hi bytecode,

I'd agree with all said above, especially about the sheep in the air filter box, mine was pretty horiffic.

My HDi 90 goes well and certainly has plenty of torque at 60 on the motorway. Two things you might also want to look at if you have the SIEMENS fuel system like mine. Check the fuel pipes on top of the engine for any air bubbles. Mine had plenty, a good pump of the hand bulb on top of the engine with it running cleared them & made the car smoother and better at top end (you may have a blocked fuel filter too?). I've also dissed the EGR plug, no fault codes show, when driving it's much more responsive at small throttle openings.

It's no ball of fire but given the good handling maintaining a good average speed is easy. 50mpg too

[bytecode]

Ok, thank you all for hte replies - it's been a long day - so I'll post a proper reply tomorrow - thank you all

(And no - that doesn't mean that *FURTHER* good suggestions aren't welcome ;-) - I just wanted you all to know that I appreciate the feedback before I go to bed and dream of smooth driving, wipers that come on when it rains and lights that come on when I enter the Saltash tunnel...)

[bytecode]

It's important to respect the way a diesel engine wants to work and (without being disrespectful to the OP) some people try too hard to eek power out of them and end up getting the opposite.

You have to work with a diesel and follow what it wants to do, it won't be rushed, and if you sit back and learn to ride the torque wave you will find you will need very little throttle input and start progressing better than you imagined. Diesels of less than 100bhp feel very flat but keep an eye on the speedo and you'll see you aren't going as slowly as you thought

Of course, if the car is hopelessly slow for some reason you'd need to diagnose what might be wrong but the 90bhp is usually well behaved.

Thank you for the response; I have driven Diesel before - so I know not to expect the power curve & torque curves of petrol - used to love my XUD7TE Rover - but that was a regular "non-HDi" Turbo Diesel with intercooler (the turbo wastegate did stick a couple of times and the car was an absolute dog to climb hills with whenever than happened) it really flew along.

I have been experimenting with the powerband and keeping the turbo "spun up" as it were - but even then - trying to overtake a lorry doing 50 on the A38 is proving tricky - it just doesn't seem to "pull" - it's fine on the flat - I was just expecting more Torque - like my rover.

That's why I wonder whether the regular service items are desperately in need of some love - (oil, air filter etc..) as I'm SURE it should have a /little/ more pull when in the zone. It was a shock the first, second and third time that I've attempted to build speed to overtake a "slow" moving vehicle (lorry/bus/etc) and finding that I have to pull back in behind it because I'm "only just" keeping pace.

It's not that I'm looking for a "boy-racer - petrol head go-cart" from this car - but the current behaviour isn't as I'd expect.

[bytecode]

See what changing the air filter does, you might have a medium sized sheep stuck in it.

I'll check out the filter over the weekend.

I like your description "..sheep.."
Incidentally:
Has anyone tried the K&N Panel filter? I wonder whether there's any "mileage" in the K&N over the regular disposable filters?

I've an old friend who was a ship-board mechanic in the merchant navy and used to fiddle with diesels all of the time - he runs his without a filter at all - his attitude being that we don't live in a dusty environment such as a desert. Personally I find that a little too gung-ho for my tastes though.

[bytecode]

I've not tried a HDi 90 406, but my Xsara had this engine & was pretty nippy once you mastered the technique. For me this amounted to a heavy right foot, changing up at the right point, ( 3k max. but more important to get the right revs in the next gear) and change up quickly so the boost doesn't die off.

There are a few things that will slow it down - clogged air or fuel filter, leaky egr or maybe a partly-blocked cat, binding brakes, low tyre pressures, carting lots of stuff about, (like 75 litres of fuel if you're rich), etc.

Yeah, I've always found that my preferred technique with diesel is to take an essentially "binary" approach to the accelerator, modulating it with the clutch (but not so much as to glaze/burn out the clutch ( Hence getting into a petrol car resulting in plenty of wheel spin until I re-developed the "finesse" required with petrol)) and keeping within the boost range.

I do tend to spend a fair amount experimenting with driving styles, so I hope that I can improve my approach - I'm predominantly on an "economy" drive at the moment though - so tend to aim for lower revs and higher gears, unless I know that a hill is looming of course...

I've checked and set the tyre pressues so I'm happy with them.

I can't detect any binding as far as driving goes (I've experienced the sensations and symptoms of binding on some of my other cars over the years).

I'll do some searching to find out more about diagnosing EGR faults I guess - even if everything is fine, it's good to have the knowledge :-)

(like 75 litres of fuel if you're rich), etc.

Yeah, I filled the tank for the first time on the way home last night -OMG! £89 for one tank - I'm not going to be doing that very often. But I want to monitor the consumption and mileage vs the trip computer. (Plus it was "pay-day" - so a good opportunity).

[bytecode]

Hi bytecode,

I'd agree with all said above, especially about the sheep in the air filter box, mine was pretty horiffic.

My HDi 90 goes well and certainly has plenty of torque at 60 on the motorway. Two things you might also want to look at if you have the SIEMENS fuel system like mine. Check the fuel pipes on top of the engine for any air bubbles. Mine had plenty, a good pump of the hand bulb on top of the engine with it running cleared them & made the car smoother and better at top end (you may have a blocked fuel filter too?). I've also dissed the EGR plug, no fault codes show, when driving it's much more responsive at small throttle openings.

It's no ball of fire but given the good handling maintaining a good average speed is easy. 50mpg too

I'll take a look at my fuel and EGR over the weekend - thank you for the tips, where do I look to determine whether it *is* Siemens? Is it the pump on the accessory belt or do I look elsewhere?