'93 520 M50 Auto. Power loss

[ed5000]

Hello,

This is my first post and I have a problem with my car. It's a '93 520 Touring automatic ( Not the fastest thing in the world, but it's not too bad either) My problem is when my car has been running for approx 30-40 minutes in stop/start city traffic from cold it gets a serious loss of power. (it's dangerously slow at taking off) The power delivery is very funny all through the rev range, sometimes it sticks at certain revs etc. This does not happen when driving on motorways etc. It also does not happen when the heater is on but having the heater on all the time is not ideal! This would suggest to me that is tempeture related (The car is not overheating and has recently had a new rad, water pump and thermostat). Sorry if this is a bit long winded but any help would be much appreciated. Thanks.

[632 Regal]

where does the temp guage sit when warm?

[ed5000]

It always stays at the halfway point on the gauge. I've checked under the bonnet when this happens and there are no signs of overheating at all. I had to fit the new thermostat as it would reach the quarter way mark (not hot enough)whilst on the motorway. I had the water pump changed at the same time as I've heard the plastic impeller breaks up over time. Until this power loss happens the car runs great. It has 115000 miles on the clock with a full BMW service history

[Jose]

Sounds like the auto-tranny is getting too hot on citty traffic. Do you know if your transmission oil filter has been changed recently ? It could be a restricted transmission liquid flow from the auto - tranny to the radiator resulting in too much heat being generated in your tranny resulting in malfunction.

[ed5000]

Sounds like the auto-tranny is getting too hot on citty traffic. Do you know if your transmission oil filter has been changed recently ? It could be a restricted transmission liquid flow from the auto - tranny to the radiator resulting in too much heat being generated in your tranny resulting in malfunction.

Hi Jose. Could this be the auto box? Would the box be affected by turning the heater on as this usually stops the problem from happening? I have noticed the button for sport/winter/economy gets warm after a while.

[632 Regal]

I agree, you should get the correct fluid for the trans and do a filter change before you go any further, could be old fluid pissing the valve body off, that would explain it not takin off in 1st gear and sticking in gears. Could be the wrong fluid too.

[ed5000]

The car is due to go in for a service on Friday so I will get them to change the oil and filter for the gearbox while it's there. What type of oil is this by the way? Sorry if these questions sound a bit stupid but it's my first auto box so its all a bit new to me. Thanks for your replys so far by the way.