Older 110 hdi goes better than newer 110hdi?

[azazel]

I had two 406hdi, one was 6 months older than the other, both 110... The newer one had lower road tax. The older one was a saloon and always had better MPG and nicer drive than the newer one which is an estate. Anyway, the estate had a head gasket problem about the same time as I wrecked the saloon so I decided to fit the older nicer engine into the estate which now goes as well as the saloon did. My mate at the garage recons that the newer engine has all sorts of enviromental related things which is why the tax is cheaper but it doesnt go as well. I used to get about 550 miles out of a full tank but with the better engine I get 650.

Also, does anyone know what that flap is for in the air intake just after the airfilter? My older saloon glx didnt have it and the newer estate gtx did. My theory is that it is so the cruise control can use engine braking to maintain correct speed down hill by obstructing the intake of air.

Anyone got a view on all this?

[Busman]

err, no.
It's the air dozer and helps with the reduced emissions that get the lower tax band. It's also prone to leak a bit of oil from the turbo.
With reference to your comments about the mpg, my two 110s behaved exactly as you describe. The newer low tax one has never been as good as the old one, either in power or mpg.

[Welly]

My theory is that it is so the cruise control can use engine braking to maintain correct speed down hill by obstructing the intake of air.

Anyone got a view on all this?

That'd be the wrong side of the engine to have any 'braking' effect, in fact it would probably speed up as there's no new air to compress. Something in the eggsauce system would do a job like this (buses/coaches/lorries have an exhaust brake to strangle the engines breathing and create a brake).

Not too sure how the Doseur works but it may throttle down at low engine speed to increase EGR? or it may create a 'swirl effect like the BMW's? I think it also slams-shut when you turn the engine off to stop that judder (bit of a free party trick really).

[azazel]

thanks for the replies. This dozer thing was only fited to the newer car with the less mpgs and performance. Interesting how they think that significantly less mpg is "green".. wonder how many here realise that the better 406 hdi is the older one, pre 1999 I think. The better, older one was V reg.. It some how drives much nicer too, it rolls along after you come off the gass much better.

[rwb]

Do they have different numbers (2 and 3) of vac control solenoid valves on the bulkhead? The third is present if and only if an air doser is fitted. (The other two are EGR and boost limit.)

I don't know what the air doser does on the 2.0 110. It's a flap in the air intake, IIRC it's after the intercooler and before the EGR.
On the 2.2 this flap is used to "improve" EGR and for particle filter regeneration.

[scotty73]

Here's abother one economy wise for you.

my mate has a 307sw same engine as mine but newer (it's had the dpf bashed out with a 140ish map) 53 plate i think, mine being the older engine he has said to me he gets about 45mpg and not much more but my best recorded is 58mpg so i couldn't understand it.

Just before Christmas i had to drive his back from chepstow it drives lovely but sure like he said i didn't see more than 48mpg all the way home, on the same stretch of road mine would probably show late 50's and not be far off the mark on fill up.

From a newer car I'd expect better, like said above less miles per tank is probably no greener than my old taxi at full price tax.

[azazel]

I removed the older engine from the car as I crashed it sadly, and fitted it in the newer car. The vacuum hose I blocked off with a screw as I decided not to have the dozer thing that was on the newer engine which had developed a head gasket problem. My mate who is a mechanic recons its to smooth out deceleration but im not so sure. Ive also blacked off the EGR thing as it got bent when the engine mount snapped. Car still drives the same with out these parts.

[dirtydirtydiesel]

I had two 406hdi, one was 6 months older than the other, both 110... The newer one had lower road tax. The older one was a saloon and always had better MPG and nicer drive than the newer one which is an estate. Anyway, the estate had a head gasket problem about the same time as I wrecked the saloon so I decided to fit the older nicer engine into the estate which now goes as well as the saloon did. My mate at the garage recons that the newer engine has all sorts of enviromental related things which is why the tax is cheaper but it doesnt go as well. I used to get about 550 miles out of a full tank but with the better engine I get 650.

Also, does anyone know what that flap is for in the air intake just after the airfilter? My older saloon glx didnt have it and the newer estate gtx did. My theory is that it is so the cruise control can use engine braking to maintain correct speed down hill by obstructing the intake of air.

Anyone got a view on all this?

Interesting, mine is a 2002 110 Hdi estate with manual box. I allways get 750 miles from a tank give or take 25 miles & that is all on B roads & through town & I have been told it'll be even better on a run. It should drive nicer with the EGR blanked / removed & give a bit better mpg but take a bit longer to warm up, the air doser on the 110 I beleive is just for anti-shudder on shut down also de-cating gives a bit better pick-up, better mpg & a bit smother running / more poke

[Doggy]

For some reason, HDi 90 and 110 307's don't return mpg figures akin to a good 406.

(Maybe the air itself is affronted by the appearance of the 307 and so resists it's passage).

[rwb]

I can well believe it Scotty. The 406 is an amazing piece of kit -- although you have to accept that the game is MPG not MPH.
My HDi 90 averaged 60mpg. The 407 puts out 180 and so far is averaging a rather embarrassing 47. Am I saying that my time is more valuable than diesel ?!

ddd: I disabled the EGR on my 90 by pulling and bunging the vac supply to the control solenoid. Before it was a complete bitch to drive when cold and afterwards it was normal when cold. From the second oil change afterwards the oil was still golden after 5k whereas before it would be black. (The 407 oil isn't just black, it's downright sooty!)
It is also my belief that the air doser on the 90 and 110 operates only on shutdown to reduce clatter and, potentially, prevent run-on.

Doggy: if they're the 1.6s then say no more. I believe the 2.0 90 is the same Siemens system I had in my 406, so that is surprising. Perhaps puggy can comment on the 307's passage?

Bit of a thread hijack there. Sorry I can't add anything more to answer the (very interesting) question

[scotty73]

Perhaps puggy can comment on the 307's passage?

Oh f*ck....

[azazel]

The older better engine that was fitted into the newer 406... I didnt change the ECU so the difference is in the engine not the ECU. Also the two big main connections on the engines wiring loom were different on each engine so I had to swap wiring looms too. There was one connection left over for a sensor located by the injectors. To be honest, Im suprised that it worked but ive covered 30,000 miles since the engine change and it runs great with no problems whatsoever.

When I first got the older better saloon 406, the best economy I got from it was about 900 miles from a full tank. Typically, it was about 750 on a decent run. Now I get about 650 driving around Devons hilly country roads, same engine in an estate. I think the estate has a smaller tank than a saloon so that explains some of the difference. The estates original engine did about 550 miles to a tank.

[steve_earwig]

one connection left over for a sensor located by the injectors

Water-in-fuel?

Did you swap the injectors over?

[Rolebama]

I wonder if the cats, pdfs and other emission rubbish has changed and also the weight of the car. I was gobsmacked some years ago when I took a bog-standard Fiesta Mk 4 to the local weighbridge. 960kgs! Some of the later ones are even heavier because of added bits and pieces, and the weight of the ST170 seats has to be tried to be believed. I wonder how many differences of this type there are between older and newer HDIs?

[Welly]

I've been reading up about Diesel engine emissions and it's interesting:

Diesels have lower C02 but much higher NOx and Particulate Matter emissions than petrols. The Government has had a hand in encouraging Diesel cars (which now outsell Petrols) but there are no standards set to test or govern the amount of NOx (NO + NO2) emitted from a car. NOx (particularly NO2) has been proven to be a culprit in Ozone depletion and global warming (if you believe in that) but is also hazardous to human health, and air/water quality in general. It seems crazy that everyone goes on about CO2 from cars but it is not checked, neither is NOx

To come back to the HDi, the leaner-and-greener version uses 'cooled EGR' to reduce emissions on tickover and partial loads, I think this leads to more throttle input from the driver and lower MPG's..........and THAT'S progress for you