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hi everyone have just joined & was wondering if any one can help my 110hp seems to have lost power and it feels like brake servo is not working for first couple of seconds when brakes are applied i have changed the maf sensor but no change someone said it could be a vacum problem or the map sensor would be gratfull of any help ray

is the engine managment light on ?

how long have you owned the car ? what car did you drive before it ?

Have had the car about 9 months had renault laguna company car before that.Engine managment light & also had message on display saying anti engine pollution sysyem defective but once i turned ignition off and then restarted the car no light or message

Hi ray & welcome to the site.

On the basis that a single fault is the most likely scenario, check all the vacuum pipes etc. Diesels have a vacuum pump to power the brake servo and the vacuum is also used to work 3 other actuators on a 110, which are controlled from the ecu, via electrical solenoid valves on the bulkhead.
They control, egr, turbo boost pressure and I can't remember what the other one does.
It's worth checking all the vacuum pipes for leaks / chaffing or oher damage first.

It's that doser/dozer thing, it's not necessarily there - mine aint got one

There's a lot of info over on the coupe club reference HDi issues
One of the guys is doing a lot of research at the mo

However he's isolated many issues down the vacuum system
If one part is leaking, then it affects the rest

Correct me if i'm wrong, but IIRC the valves have diaphrams in them, that can get damaged, and he recommends checking those

Absolutely right - here's the link

You'll have to join the coupe forum to read it, I think, but it's well worth the effort.

I think a fair bit of that doesn't apply to the 110 - no swirl valve, no reservoir, no inlet air heating, MAP sensor's in a different place, yadda yadda yadda...

He doesn't say what he was testing the vacuum with, vacuum gauges are cheap enough on ebay but not vacuum pumps which seem to double as brake bleeders

Thanks for the great input will check vacum system when it stops raining and see if it helps

Hi everyone tried to sort out my problems by changing vacuum pump,little solinoids & pipes still no change everything still exactly the same so tried something else where the vacuum pipe goes to the servo two pipes come of the bottom & go to the solinoids i put a spare piece of pipe on these in a loop so vacuum pump was only connected to servo & the brakes still were not working right if i hold my foot on the pedal it goes down after a few seconds so i wonder if the servo is the problem if anyone has any ideas i would be very gratefull as the mot is due shortly ray

That might actually be normal - viewtopic.php?f=1&t=4366&p=41826&hilit= ... ink#p41842

Not sure as still have lack of power & poor braking really need to try & sort this maybe only option to put in garage but depends when i can afford garage prices if anyone can help i would be very gratefull ray

I'de a leaking brake servo which caused similair problems. My dealer had never seen this before. Lack of power is especially at low revs (less dan 1800) and engine is producing a lot of black smoke at those low revs. If vacuum can leak away, the waste gate of the turbo stays open, lack of air into the engine is the result (no power and lots of black smoke).

took car to local garage today they said it may be low oil pressure as the oil pressure drives the vacuum pump but they have not done any test on vacuum system as far as i am aware suggested NEW ENGINE I think they are trying it on as car drives ok no smoke just poor acceleration and problem with brakes think i better find someone who can check the vacuum pressure for me ray

Sounds like complete rubbish to me - I'm sure the vac pump's driven by the camshaft.

Haynes wrote:...the vacuum pump can be checked with a vacuum gauge. Disconnect the pipe from the pump...connect gauge...start engine...after idling for 1 minute you should get about 500 mm Hg.

(which is about -670 mBar or -9.6 psi)