This is an oddball one which I'd like an opinion on.
My motor is a Grande Punto 1.3 Mjet 75bhp. It drives very very well except for two annoying issues which might be linked. Car is 2007, has 51000 miles on it and a full history.
Firstly, in a high gear at low revs, it shudders a bit around the 1300rpm mark. It feels like a misfire or like its going to stall. But if you go below 1300, its ok. It's most noticeable in 4th and especially 5th, but somethings you can feel it momentarily if pulling away. MAF and EGR were disconnected and made no difference. There's no stored fault codes and all of the live data looks spot on. So I don't think this is electronic, it's more like drivetrain.
Secondly, driving along at around 40mph, the ride is very choppy. The wheel rims are all true and. balanced. Shocks and ball joints are all ok. I replaced the tyres with 4 brand new ones which improved matters slightly. Ride at higher speeds are ok.
Someone I know commented that there could be a DMF issue, but my car doesn't have one. Could these be caused by a faulty drive shaft or worse, a wonky diff? When either fault occurs, it seems like its coming from the passenger side.
Best way to check the inner tripod joints will be to remove shaft and strip down And check those needle rollers I've had plenty of vehicles give shuttle shake acceleration Trouble is its not always noticeable in a inner joint unless its shagged out with loads of play
Years ago, Ford used to state in their vehicle handbooks that the vehicle should not be driven below 1500 RPM in any gear. It was good advice and should apply to all vehicles in my opinion. Puts far to much stress on engine and transmission.
Used to change alot of 5th gears on Vauxhalls, almost always due to customer driving too high a gear at too low a speed. My sister found out the hard way that 5th gear, 40 MPH, 1100 RPM = expensive.