Juddery Diesel

maxgreenwood · Post by **maxgreenwood** » Mon Jan 07, 2008 10:13 pm

My engine (1.7TD) sometimes judders between 1-2000 rpm, apart from the other day after i'd hammered round some country lanes for an hour and it was nice and smooth, and now a couple of days later seems intermittently juddery again.

Does anyone have any experience of this?

Also I'm thinking my steering is heavier than it should be, and curiously lighter when car is cold. What does this point to? I've read on here about reconditioning the FDV.

Many thanks for any words of wisdom.

cavmad · Post by **cavmad** » Wed Jan 09, 2008 7:34 pm

Heavy steering does indicate the fdv/lhm issues afaIk. Regarding the juddering have you run low on fuel recently and have you checked or replaced the fuel filter? Just wondered if the problem was related to fuel.

jeremy · Post by **jeremy** » Wed Jan 09, 2008 7:50 pm

Have you checked the fuel filter recently? - If the filter is choked it will restrict the flow which will probably first show yp when the system is stressed - ie under acceleration.

Otherwise the most usual cause of poor running is air leaks. If you have a Bosch pump this will include the leakoff pipes - with a Roto-diesel they're irrelevant to poor running - they just leak and smell.

Is the LHM pump belt tight - which means really tight?

Otherwise the heavy steering is probably due to a worn pump. LHM will be thicker cold - enabling the pump to seal better? The steering takes a large volume of high pressure LHM.

maxgreenwood · Post by **maxgreenwood** » Wed Jan 09, 2008 8:52 pm

thanks guys i'll check the fuel filter it runs fine when the turbo kicks in above 2000rpm. don't know if its a bosch or roto yet. I can imagine it might be when put your foot down the lurch forward throws the fuel back somewhere down the line - as if pressure on the fuel is not enough. Doesn't matter how full the tank is.

The pump is a bit weepy so could be that re the steering. will try to check the fdv filters, i gather there are a couple which are easy to get to in situ?

the pump belt seems tight about 5mm play in belt. i think this is right?

its a bit wet and cold this time of year so getting under\into the car outdoors is so much less appealing!

jeremy · Post by **jeremy** » Wed Jan 09, 2008 10:37 pm

If it runs correctly under full boost its unlikely to be the fuel filter. My own DTR Turbo Estate isn't sensitive to fuel level but I never run it for long with the warning light light on as I do wonder if I might have trouble on a steep incline and don't want to find out!

FDV filters don't generally block and are not easy to check. They often rupture - (I wonder if this is due to excessive revving of cold engines?? - so not a problem on diesels)

Where is the pump leaking from? - air can cause problems if it gets in to the LHM - and the only place it can get in is the hose from the reservoir to the pump - usually without any external sign as the pipe is under suction - so lets air in without letting LHM out. If its manky - for diagnostic purposes you can substitute a section of clean garden hose. The ends MUST be good - and well tightened with good clips. The original Citroen ones should not be re-used as its unlikely that they will tighten sufficiently to seal again.

Is the LHM fresh and green?

To expel air do Citroebics - raise and lower the car fully a number of times.

maxgreenwood · Post by **maxgreenwood** » Fri Jan 11, 2008 12:38 am

i'll have a look at the hose from the res to the pump. Its the garage i last had the car in for changing a strut return pipe, they told me the pump was a bit weepy, something he'd seen before, nothing too much to worry about, not sure exactly where the leak is coming from, could it be the housing itself?

re the juddering between 1-2000rpm, it happens in all gears and gets into the same rhythm regardless of speed. Could it be something between the engine main drive shaft and the wheels driveshafts? (I don't generally knw that much about cars - not sure how its all connected) i say this as its the weight of the car lurching as if the drive force to the wheels is engaged then not in a continual cycle as if something is loose and coming away from its housing or something. couldn't be the cambelt could it? It was changed 9000 miles ago.

Way2go · Post by **Way2go** » Fri Jan 11, 2008 1:24 am

maxgreenwood wrote:Could it be something between the engine main drive shaft and the wheels driveshafts?

Could be your UV joint(s) possibly but this would normally be flagged as a fail or advisory in the MOT test. Did you have a recent MOT?

maxgreenwood · Post by **maxgreenwood** » Fri Jan 11, 2008 10:34 am

it was MOt'd in April last year. I was going to change over registration when this is up in April to Irish and when you do that you can actually wait until the anniversary of its first registration to get it NCT'd (Irish equivalent of MOT) over here so i was going to do that but i'm aware i could be missing finding things that need sorting in that extra year.

I might get it checked by Noel Dolphin over here he seems to be the citroen man in Dublin.

i reckon its something to do with the transmission of power to the wheels. better be safe than sorry.

maxgreenwood · Post by **maxgreenwood** » Fri Jan 11, 2008 10:42 am

(it was first registred in April 91 so theoretically I could get a year's motoring without MOT)

cavmad · Post by **cavmad** » Fri Jan 11, 2008 3:51 pm

Long shot I know but from the symptoms could it be an engine mounting bush on the way out? Have you tried slamming it into other gears (e.g from 3rd to 4th) quickly and releasing the clutch as quick as possible to see if problem continues?

cavmad · Post by **cavmad** » Fri Jan 11, 2008 3:51 pm

Long shot I know but from the symptoms could it be an engine mounting bush on the way out? Have you tried slamming it into other gears (e.g from 3rd to 4th) quickly and releasing the clutch as quick as possible to see if problem continues?

cavmad · Post by **cavmad** » Fri Jan 11, 2008 3:51 pm

Long shot I know but from the symptoms could it be an engine mounting bush on the way out? Have you tried slamming it into other gears (e.g from 3rd to 4th) quickly and releasing the clutch as quick as possible to see if problem continues?

cavmad · Post by **cavmad** » Fri Jan 11, 2008 3:51 pm

Long shot I know but from the symptoms could it be an engine mounting bush on the way out? Have you tried slamming it into other gears (e.g from 3rd to 4th) quickly and releasing the clutch as quick as possible to see if problem continues?