Shuddery engine

jordanfaf

I have a 2006 mini cooper S
when sitting at idle the car begins to shudder a fair but. It dosnt happen all the time but regularly enough.
I am aware that I have a stuck timing chain tensioner however I feel it may be the sparkplugs causing the shuddering. The previous owner changed them in 2013 (about 25k kilometers ago) and I'm wondering we ther to change them again or put the problem down to the chain tensioner

cletus

Regardless of the shudder, the plugs are probably due a change. Out of curiosity, when was the oil, oil filter and air filter last done

Prenderb

Could be ignition coils. Have you noticed power down aswell?

Foxhole Norman

Shuddering at idle is usually ignition coils alright, could be an air leak too, do you hear any whistling when accelerating or would it be too hard to discern with the Super/Turbo charger?

Irishcrx

The spark plugs shouldn't need changing that soon but it's always good to be ahead of schedule with them. Do you hear any ticking coming from the engine? Could be a plug has come loose.

To check the coils, start the engine , open the bonnet and locate the coils, disconnect the electrical connections one by one and see if it makes a differance to the idle. It should start to idle rough when you disconnect one of them , if you find one that makes no apparent differance , then the coil is shot. To confirm this you can swap the coils over and see if the fault follows the coil, if it does you you've confirmed a new coil is needed.

Generally - but not always the following are the main causes of idle/coughing/hunting issues in engines.

* Coil packs , spark plugs , leads
* MAF sensor
* CAM sensor
* Lambda sensor
* Timing out of allingment
* Vacuum leak in piping

Start with the easy items and work your way up. If you have an OBD2 scanner , plug it into the ECU and see if there is a fault code present.

i57dwun4yb1pt8

^^^ also dirty throttle body ^^^^

kkelly77

Irishcrx wrote: »

The spark plugs shouldn't need changing that soon but it's always good to be ahead of schedule with them. Do you hear any ticking coming from the engine? Could be a plug has come loose.

To check the coils, start the engine , open the bonnet and locate the coils, disconnect the electrical connections one by one and see if it makes a differance to the idle. It should start to idle rough when you disconnect one of them , if you find one that makes no apparent differance , then the coil is shot. To confirm this you can swap the coils over and see if the fault follows the coil, if it does you you've confirmed a new coil is needed.

Generally - but not always the following are the main causes of idle/coughing/hunting issues in engines.

* Coil packs , spark plugs , leads
* MAF sensor
* CAM sensor
* Lambda sensor
* Timing out of allingment
* Vacuum leak in piping

Start with the easy items and work your way up. If you have an OBD2 scanner , plug it into the ECU and see if there is a fault code present.

Sorry to hijack, but would a blocked EGR valve also cause this issue?

Squatman

kkelly77 wrote: »

Sorry to hijack, but would a blocked EGR valve also cause this issue?

possibly, but not really, the bloked EGR valve should choke up the engine and reduce power. it will reduce the rate at which the engine revs up too....


OP if you rev it slightly does the shuddering go?

jordanfaf

Squatman wrote: »

possibly, but not really, the bloked EGR valve should choke up the engine and reduce power. it will reduce the rate at which the engine revs up too....


OP if you rev it slightly does the shuddering go?

It goes when I tap the accelerator but returns at idle generally. I'm booked in for a service on Tuesday with my mechanic. He's gonna check my chain whule it's in too. he thinks the shuddering is sparkplugs or a coil pack or something.