Rough running K Series? Check your timing!

[DMGRS]

Our beloved Rover 25 CVT has always run a little rough from cold - in particular it was a little 'bouncy' (for lack of a better term), feeling like it'd been filled with kangaroo juice along with quite a lot of hesitation at junctions.

Initially I put this down to the CVT gearbox - however the most I thought about it, the more I realised this would likely be something engine-related.
I checked all sensors; all OK apart from an out-of-spec pre-cat Lambda sensor. I replaced this which did help the rough idle and seemed to smooth things out a little, but it still wasn't quite right.

Taking a chance, I decided to remove the timing belt covers and was greeted with the scene in the first 2 pictures below - quite clearly a good deal away from being timed properly!

Picture 3 shows how the timing marks should align on the crankshaft pulley - the ridge on the oil pump should sit between the two dots.

Interestingly, the garage that'd charged the previous owner a rather large amount for the head gasket work carried out a couple of years ago had fitted a 5PK1145 auxiliary belt - this is far too short, and meant the tensioner was 'bottomed out' (making removal a real pain!)
We fitted the correct PQS101590 item and everything seems to work as it should with no lasting damage.

Needless to say, the car is a lot happier now - the 'bouncing' has completely gone, as has the hesitation when applying throttle.
If your K Series has similar issues, it may be worth checking your timing - it doesn't take long to do, and as usual the K Series is a joy to work on even with only relatively basic tools to hand.

[Matt_75]

A useful write up for any K Series owners with rough running!

Originally Posted by DMGRS

as usual the K Series is a joy to work on even with only relatively basic tools to hand.

I did my first head gasket and timing belt on our 1.4 Rover 25 a couple of months ago and, one or two slightly awkward bolts aside, it was indeed a pleasure to work on.