Engine Hesitant

[spookydave]

Hi Guys

i have noticed recently when i start the car ( 2.0 138 c5 x7 )

and i depress the throttle to set off it takes a bit to rev the car

also if i am driving along and release the throttle when i press it again the car is hesitant for a moment before picking up

almost like fuel starvation have replaced fuel filter and changed oil but it still does it 

any ideas please

 

 

 

[Randombloke]

Either the accelerator potentiometer is worn or the cable to it, if it is not mounted on the pedal itself, has become slack. You could measure the resistance across the pot whilst operating the throttle, and see if there is a dead spot. 

[coastline taxis]

change your fuel and air filters

[spookydave]

thanks guys 

will get new fuel and air filters this week 

will make sure i clean the fuel filter housing well because i believe they get a lot of gunk in them

[spookydave]

I have changed both filters and the car seems to be running better

But now another problem has reared its head

Both on starting and turning off the engine there is a metallic sounding noise also sometimes when ticking over and I give it a few revs when it returns to tick over sounds like something metal is catching

I wondered if this was the start of the death rattle of the dmf

Your thoughts would be much appreciated

By the way the car has just turned 80000 miles

Edited January 12, 2017 by spookydave

[paul.h]

You could look at the crank shaft pulley to see if the rubber insert is breaking up.

[spookydave]

thanks paul will check that 

would that cause vibration when ticking over as i have noticed that too

[Rookie2]

hi spookydave

 

Yes the crank pulley will cause the vibration, lots of it. it will/could, also lead to snapping of the timming belt and destruction of your engine.

[spookydave]

Thanks rookie2

Will get that changed as soon as I can then is it an easy job or a garage job

[Rookie2]

H Dave

 

If you are handy with the tools then there is no reason you cannot do it. I believe the crank pulley comes adrift from the cam belt pulley behind it, (careful not to let the cam belt pulley slide out, though the tension of the cam belt should stop that)

 

Just remember to torque the pulley nut/bolt up correctly but do NOT use the Cam Belt as a brake to aid tightening the crank pulley. Do not use heat on the new crank pulley nor strike it with a hammer etc.

 

cheers

Edited January 14, 2017 by Rookie2

[spookydave]

had a good look and feel of pulley and it seems to be fine

would the maf sensor cause rough idling or the egr valve

been to my local independent and he looked at pulley and couldnt see any problem

of course the car behaved while he had it and wouldnt make any of the noises

i will keep going and investigate further

what do you reckon with having a full diagnostics doing  

[Rookie2]

Hi Dave

 

Does no one who lives near you have a copy of the Lexia you could connect up to ? To be honest with you, Lexia from China is now so cheap it is silly not to have one. When I bought mine it cost me nearly 200, now you can get them for far less than a 100.

 

Anyway, what is the noise you are getting that concerns you Dave ? I ask because if it was to do with the timming then it would probably be continual, the crank pulley, I suppose, could make a noise when cold which disappears when it gets warm as the rubber insert softens.

 

Yep, the MAF could cause rough idling as could a bad injector, bad timming etc etc

 

If you suspect the DMF then consider getting it off and throwing it in the bin an replacing it with a solid flywheel conversion kit (sorry, I shouldn't really recommend that, but it is what I would do/ have done).

 

Despite all the manufacturers hype, family cars do not really need DMF, I'm an HGV C&E Driver (when I feel like it), DMF's were brought out for the heavy trucks to take the shock out of the gearbox when the truck pulled away with a large horse power capability. Next thing you know they start appearing in family runabouts and in my opinion are totally needless.

 

Apart from that, the conversion kits are cheaper than a new DMF even when you have to include the new solid flywheel, and certainly cheaper the next time you come to change the clutch as you never have to worry about the flywheel again.

 

Not sure if your motor has an access panel in the bell housing, if it has and you can see the flywheel through it, place a line across the flywheel from the starter ring teeth to the clutch plate. Hold the clutch still with a bar and using a screwdriver try turning the starter ring.

If my memmory serves me right, you are allowed a maximum of 19 to 21 mm radial movement.

 

If you can turn the starter ring any more than that whilst holding the clutch pressure plate still, then yes, the DMF is kaput.

[spookydave]

yes mate can get lexia done 

the noise is not continual sometimes just when ticking over

and sometimes when starting or turning the engine off there is no noise when depressing the clutch and the gear change is smooth and no juddering or slipping 

i will get a full check done and report back i think 

i too have a full hgv and psv licence and i agree with you small cars do not need the dmf at all 

[paul.h]

Some other things that might rattle are the exhaust and the exhaust metal heat shields if loose and worn engine mountings - just thinking of the last cheap things, hoping it is not going to cost a lot to sort out.

[spookydave]

my independent has looked and heard it and reckons its nothing serious 

the rough idling he says could be a lot of things including a sticky injector maf sensor and a few other things

going back to him next thursday for diagnostics but he says it might not show anything

[spookydave]

i ordered a can of maf egr and intake cleaner 

have sprayed it in as per the instructions now everything seems to be back to normal

still going to get car checked and diagnosed just for peace of mind

[spookydave]

have had car in today for a full diagnosis

it has come back with a fuel pressure sensor intermittant fault

my indy has ordered one and it will be going back to be fitted and cleared so i hope that will solve my problems

[spookydave]

well i am pleased to report all problems have for now been solved

new fuel rail pressure sensor fitted and all fault codes deleted ran test and no faults found

happy days for now

many thanks for all input