C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

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skycat61
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Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by skycat61 »

Anybody that tries this needs to be aware that it will likely screw the FAP regeneration but I reckon it should be ok for a couple of hundred miles to prove the point.
How exactly? Is this a bad or permanent thing?

Anyway I will move on to trying disconnecting the throttle valves in a bit, but at the moment the car has developed another problem. It keeps failing to start by popping the 20A starter fuse. I know this is off topic but any ideas what the root cause might be?
cachaciero
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Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by cachaciero »

Hmmm! 2005 to 2016 is 11 years, you don't say how many miles but starter motor brushes would be a possibility but first check the heavy current cable (+ve supply) to the back of the starter motor can you hear the starter solenoid pulling in, (a very definite click!)?
skycat61
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Joined: 18 Aug 2014, 19:17

Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by skycat61 »

Its got 58k on the clock Cachaciero. Its been deteriorating and now I get about one or two starts out of a fuse. I've had the lexia on it and it says starter relay short circuit. I decided to take it to an auto electrician tomorrow.
skycat61
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Joined: 18 Aug 2014, 19:17

Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by skycat61 »

It's now had a starter motor and things are back to normal. On the subject of MPG I've been doing a little digging on the government's website:-


Code: Select all

Car                                    Urban               Extra Urban        Combined
C5 2.2HDi Auto                         28.8                 51.4                   39.8
C5 2.0HDi Manual                       36.2                 56.5                   47.1
Skoda Octavia 1.9TDi Manual            41.5                 65.7                   54.3
BMW 320d Manual                        36.2                 62.8                   49.6
BMW 320d Auto                          31.0                 53.3                   42.2
It would seem the C5 2.2HDi Auto has never been known for good fuel economy...
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Paul-R
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Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by Paul-R »

Yes, it's well known that the 2.2 is poor for economy and the figures show that the auto box gives an added twist to the, err, poorness as it also does for the BMW.

The only other observation I would make is that the other cars you've chosen are all smaller, and presumably lighter, than the C5 which would exacerbate the comparison.

Good news on the starter motor though.
cachaciero
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Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by cachaciero »

skycat61 wrote:It's now had a starter motor and things are back to normal. On the subject of MPG I've been doing a little digging on the government's website:-


Code: Select all

Car                                    Urban               Extra Urban        Combined
C5 2.2HDi Auto                         28.8                 51.4                   39.8
C5 2.0HDi Manual                       36.2                 56.5                   47.1
Skoda Octavia 1.9TDi Manual            41.5                 65.7                   54.3
BMW 320d Manual                        36.2                 62.8                   49.6
BMW 320d Auto                          31.0                 53.3                   42.2
It would seem the C5 2.2HDi Auto has never been known for good fuel economy...
Indeed the 2.2 has always had a poor reputation for economy but the above figures have two omissions viz a 2.2 manual and a 2.0 auto, I suspect that those details would put a slightly different perspective on it and ensuring that it was an estate not a saloon as the estate is heavier than the saloon.
The 2.2 manual estate is a rare bird hence most of the complaints about the 2.2 are for the auto version, similarly the auto version of the 2.0 was not so common as the manual so again when people say the 2.0 is more economical it is but maybe not by so much.
One should compare apples with apples :-).
Having said that even in manual version the 2.0 litre is nowhere near as good as the VAG 1.9 in the Octavia and I can confirm that the numbers for the OCtavia are easily achievable and often exceeded.
Interestingly I have just done a journey which was essentially a 140 miles of Extra Urban at 70 + the economy was as near as makes no difference 39.8, however I am sure if I had reduced speed to 56 mph the economy would be better though I doubt it would have reached 51.4.
cachaciero
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Re: C5 2.2 HDi 136 Facelift - poor MPG and no bottom end grunt

Post by cachaciero »

Another little test that you could do, check that there is no leakage around the injectors.
Remove the Plastic covers over the engine and fill the "wells" around the injectors with WD40 or some very thin oil. Then start the engine and check that there are no bubbles in the liquid, did that on mine last week and was somewhat horrified to discover that I had leaks on two injectors, not only that but the bolts were loose as well. There was no other obviuos indication of leaks, no "chuffing" sound, no smell of combustion products, the only thing that drove me to looking was the fact that the idle appeared to be a bit rough.
Much smoother now they have been tightened :-)
Would be better to remove them and fit new seals, however on the 2.2 just getting the injectors out could be another can of worms:-( at the moment they appear to be sealed so I shall leave well alone.