C5 2.0 HDI LX no power and low mpg

[UXDEV]

Hi folks

Got myself a 2003 C5 2.0 HDI with FSH and 260k on the clock. Seems really low on power. I know it's a big car but feels like there's just no oomph at all. Struggles to reach 70 but no warning lights on. I do 47 miles to work with 90% of empty road and last few miles bumper to bumper. I'm not expecting it to be super fast, but I have to drop into 4th or even 3rd to even consider overtaking.

I've read a few posts about it possibly being the MAF sensor, but revving over 3000rpm has no noticeable difference. Feels like it's really being held back, like something is too tight, but when I drop the clutch it's runs free so no issues with brakes or seized wheel bearing etc.

Also, trip computer has me averaging 32.4 mpg, I've not been driving it hard, pretty much cruising along at 65. Is this not a bit low, even for a diesel??

Put £40 diesel in this morning, which gave me 1/2 a tank, ran to work and back (100 mile round trip) and its down at almost a quarter - at this rate is gonna cost me about £20 a day to get to work. I do 500 miles a week and if it's going to cost me £100 per week to fuel the beast, I'd be better off getting a petrol

Any thoughts would be greatly appreciated.

I'm going to check the air box for water, as it's been pretty wet in sunny Scotland, anything else I need to check?

Thanks folks.


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[Hell Razor5543]

OK, well, first, I would suggest you get her onto a Lexia to see what is happening. Until you do so, it will be guesswork trying to find the problem. Fortunately there are forum members who have Lexia clones, and are prepared to help out (OK, you are a little far north, but there are members there in the Highlands who have Lexias). Here is the link;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;

[lexi]

Your journey to and from work with a light foot should be round about a tenner? Scottish money even less
Until you get Lexia you can check for stuff like a blocked air filter, no oil filled intercooler, split or disconnected turbo hoses, blocked egr, and that the turbo is spooling up

[UXDEV]

Thanks HellRazor @ lexi.
Should I be able to hear the turbo spooling whilst revving with bonnet open? Noob question but only 2nd diesel I've ever owned and not too familiar with engines.


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[daviemck2006]

You should get near 50 mpg from it, and although it won't be a ball of fire it should be ok and not feel too slow. I would try to cross someone's hand with a beer token or two to get a lexia session. Don't go to a citroen stealer, they will try to rip you off. I would also be changing air and fuel filters unless you know they were done recently.

[Peter.N.]

The 2.0. 8 valve Hdi engine in your car is about the best one they have made but yours obviously has a problem, the low mpg is probably being caused by the same problem as the poor performance.

You can check if the turbo is working by disconnecting the manifold air intake pipe and checking for a good draft from it when you rev the engine.

As suggested, find someone with a Lexia that can run a check on it.

Peter

[UXDEV]

Fab. Thanks for this guys. I was just reading a post about a possibly blocked cat. Hope not as low on funds having just bought the beast. Will check the pipes, turbo operation and give it a service for peace of mind


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[UXDEV]

I'm guessing that a normal OBDII reader doesn't work on these?


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[Hell Razor5543]

Unfortunately not. The French are a law unto themselves (as we can see when they go on strike and blockade everything!), and this includes cars. However, the Lexia (or, in the case of later PSA cars, DiagBox) can do so much more than just read fault codes.

[myglaren]

Also check for slack in the throttle cable, had that on both mine and tightening it up makes a significant improvement.

Mine also did a miserable 32mpg until fairly recently when it has been creeping up gradually and is now around the 40mpg mark depending on how it is used.

[RichardW]

Low power with no other symptoms is usually the MAF gone west. If you can Lexia it you can check the reading from the MAF to see what it says. Cheap replacements are best avoided as they are often rubbish - genuine ones are north of £100 though. A scrappy might turn one up, but it may be no better than the one you've got.

[simon123]

Wondering if any one can help just bought a 2004 c5 estate hdi 110bhp doesnt seem to have much boost also only geting 110mile to 20quid any ideas no warning lights or smoke

[myglaren]

The MAF is the usual first suspect with these symptoms although there can be other reasons - check for leaks in the intercooler and turbo hoses before spending any money.
Both mine were like that and the first one eventually had all the hoses and EGR valve removed and cleaned, plus a new MAF.
The difference was borderline frightening.
Current car was the same - in fact far worse when I picked it up, got the same treatment and also the throttle wire tightened up and a new intercooler. Again, a whole world of difference.
It is now getting towards needing this treatment again.

[BX]

I have pointed this out numerous times. EOBD code readers are only designed to read fault codes mandated by eobd legislation which is mainly concerned with emissions. This legislation did not apply to diesels until 2004. However on Bosch equipped HDI cars a basic obd tool can give a wealth of information on vehicles built as early as 2001. I haven't tried xantia or early 406 cars so I cannot say if they can be read. On Siemens equipped vehicles these scanners do not work on vehicles built before 2004. The most valuable information is obtained by reading live data. If your C5 has Bosch injection most scanners will give you good information.
In contrast a faulty crankshaft sensor on a 2007 Transit will not be shown to an EOBD scanner. It will however be revealed to a Ford specific scanner. This is ok as regards regulations. If the sensor is faulty the engine will not run and no emissions are produced.
It is nothing to do with the French being a law unto themselves. This information is mainly from experience and some from manufacturers manuals.

[lexi]

My 02 plate HDI has a VDO ( siemens?) tank pump. Does that mean it does not have Bosch injection? The IP Pump is Bosch I think.
Or do you refer to the ECU being Bosch?