Lumpy running diagnosed

[tug]

Dead easy mate, my indie didnt even charge me, it took the mechanic less than 5 minutes. Im sure it will cure it for you. If you could have heard mine on start up, it sounded like a machine gun!

Sounds perfect now.

 

[Barny]

Thanks Tug, shows how good these forums are, i will wait and see what there price is first, if its reasonble i will let them do it as there a performance garage and they do a lot of performance cars, did you find you got better torque at low revs as well as i assume it affects the timing

 

[tug]

Along with the tensioner replacement i also recently swapped out the coil packs, everything at very low cost. The zed now feels positive and very smooth through the torque range.

A big difference was felt after the packs change, but it now feels complete and very much like a new motor.

Im sure with a new tensioner you will be out of trouble and in a fantastic motor.

 

[Barny]

Well just got the car back, it was a stretched timing chain and also the the Vacuum pump was leaking so that had to be replaced also, the oil had emulsified and had seeped into a few crevises, they found a broken engine mounting and had to completly flush out all the system, all the oil was changed and all relevant gaskets and bolts replaced as per BMW specifications, with labour a total of £1200, really pissed of but it is all sorted now, has any one got a spare rope

 

[Derry]

My idle issue was from my air flow regulator. If the car doesn't breathe right it doesn't run right.

Might not be....but worth a check!

 

[Derry]

Sorry only read the first page....glad she is sorted

 

[tug]

A lot more than was thought, sorry for you mate. Hows it running? if it feels and drives how you wanted it to then perhaps money well spent?

Glad you got to the bottom of it though.

Cheers tug.

 

[Ewazix]

Well just got the car back, it was a stretched timing chain and also the the Vacuum pump was leaking so that had to be replaced also, the oil had emulsified and had seeped into a few crevises, they found a broken engine mounting and had to completly flush out all the system, all the oil was changed and all relevant gaskets and bolts replaced as per BMW specifications, with labour a total of £1200, really pissed of but it is all sorted now, has any one got a spare rope

Feel for you mate that hurts

TBH I didn't think it was wise to duck changing the chain if the tensioner had gone west, unfortunately a baggy chain sets up waves at certain speeds and can impose some really high forces - your bill would seem cheap compared to a snapped chain wrecking an engine! Still all sorted with upgraded parts now and you can confidently enjoy the car again

 

[Barny]

Just been out for a spin, engines great no noises but there is now a slight vibration through the gear stick and at 3000 rpm in third theres a strange noise like a loose exhaust sound, wonder if its because they put a new engine mount on, going back tomorrow for them to have a quick check

 

[Barny]

Turned out to be a loose exhaust heat shield, all done now

 

[walker1c]

Bike chains always stretch as well, obviously not as strong as a car one but still.

In pedal cycle chains at least, "stretching" is actually wear in the link pins and the surfaces that bear on them. You'd have to have really massive thighs to stretch the links themselves. It's quite common, probably because bike chains are made as light as possible and are susceptible to poor lubrication and abrasive dust.

But it's surprising to see this in a car chain at 27k miles.

 

[gannet]

Bike chains always stretch as well, obviously not as strong as a car one but still.

In pedal cycle chains at least, "stretching" is actually wear in the link pins and the surfaces that bear on them. You'd have to have really massive thighs to stretch the links themselves. It's quite common, probably because bike chains are made as light as possible and are susceptible to poor lubrication and abrasive dust.

and don't forget the cogs wear along with the chain, making it costly when you have to replace the chain every 6 months

I've tried more expensive chains but found they didn't last appreciably longer than the cheaper versions so ended up being a waste of money..

slight thread highjack though

OP - glad you're running sweetly again

 

[Ewazix]

It's a fault with the timing chain tensioner that allows slack running, the slack causes excess wear in the chain. It must a bit of a BMW thing as I had the same fault on my Cooper S.

 

[tug]

Turned out to be a loose exhaust heat shield, all done now

glad for you mate.

 

[Barny]

Well its been about a month since the work was done and guess what, the lumpy start up is back,excatly the same as before, been back to the garage and they says theres nothing wrong with it, no codes on the diagnostic, one day it drives like a new car, the next its got this annoying noise now and again, feels like ive spent £1200 on nothing, any ideas on what i can say to the garage, they have had it back but cant find anything wrong with it, is this common on the Z4 or is it me being paronide, just feels like the timings out and its a sort of pinking noise now and again, going for a spin now will let you know the outcome

 

[tug]

What fuel are you using mate? reason for asking is mine runs like sh*te on normal unleaded/supermarket crap :thumbsdown:

Now all i fill up with is Shell V Power Nitro and the zed seems to love it, smooth as silk

Although having said that it might not be a fuel problem :idunno:

 

[Barny]

Yeah im going to try that Tug, was talking to the mechanic and he said he had 3 BMW,s in all for that same thing, bad petrol, also put some Wynns injector cleaner in today and noticed the difference straight away, although it might not last

 

[tug]

Hope it is that mate, for you, high octane all the way.

 

[GaryT]

Its completely weird how some cars are sensitive to octane rating and others aren't, whereas mine runs on everything just the same, i could probably take a pi55 in the tank and it would run great :lol:

 

[tug]

Its completely weird how some cars are sensitive to octane rating and others aren't, whereas mine runs on everything just the same, i could probably take a pi55 in the tank and it would run great :lol: