How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt, Mechanical Engineer
Category: BMW
Satisfied Customers: 23082
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your BMW Question Here...
Matt is online now

My 1999 BMW 323i has started to judder when stationary. it

Customer Question

My 1999 BMW 323i has started to judder when stationary. it was intermitant at first happening maybe once a week. Today it has become more regular and when in drive is now also making a knocking noise.

I have recently had the gear box sump replaced as well as a the coolant reservoir and this has begun since the work was carried out.

Can you please advise what this could be.
Submitted: 5 years ago.
Category: BMW
Expert:  Matt replied 5 years ago.

is this the automatic gearbox or the manual?
Customer: replied 5 years ago.

it is an automatic gear box

Expert:  Matt replied 5 years ago.
Hello David

I'd suspect that the gearbox may be low on oil so check its level with the gearbox warm and just after you've moved the selector through all the positions leaving it for a few seconds in each one and then back to park.

You can top up the box through the dipstick tube if required and make sure you use the correct oil for your car as the fluids are not all the same. Some manufacturers recommended a change of the type of fluid - Speak to the local dealer and parts dept - they will advise you on the updated fluid to use..

If that’s all OK then check all the electrical connections of the gearbox, remove each connector in turn and spray with contact cleaner. Check that the wiring to the gearbox is in good condition with no chafing or frayed wire

Customer: replied 5 years ago.

Shoud have mentioned the gear box oil was changed when the gear box sump was replaced. have not had any warning lights appear that would normally come on when oil low or there is an issue with the gear box.

Expert:  Matt replied 5 years ago.
Hello David

if the knocking is only when you pull away or accelerate then its possibly a faulty propshaft joint or it could be a faulty / worn mounting - check the tightness of the engine and gearbox mounts and their condition - this is best done by using a jack to take the weight of the engine off the mounts and seeing if any cracks or splits open up in the rubber.Also check the tightness of the mounts bolts