1990 535i Valve Tapping

[TheEndIsNear]

Hi all,

First of all I realize you all have covered this subject a few times but alas I have more questions. I just bought a 1990 525i with 247,000 miles. This car is amazing, runs strong. She does have a very loud valve tapping about half way down the cam. Now I realize this is common for this motor, what I am un clear on is a few other things and am curous if a valve adjustment will affect things. First of all the fuel milage is about 5mpg lower then it should be. Second, theres a small hesitation off the line at low RPMs but she takes right off after about 900RPM. Thirdly, theres a slight bit of dark smoke from the exhost when you get on it very hard also a little soot around the tailpipes almost like the timeing is off a bit. My last concern at this time is the transmission oil, instead of there being a red ATF as I'm used to theres a clear oil almost like a hydraulic oil, is this normal?

The Nube,
Josh

[jjdickm]

I have a 1990 525i as well and I do have that loud tapping noise and it didn't go away when I adjusted the valves. I also do have that hesitation off the line but its not really the strongest of bmw motors the m20 is really too small for this car it does pretty well and don't get me wrong its pretty quick but nothing compared to the 535i or 540 m5 and so on. is this an auto or manual if its manual it almost carmel color and if its auto it should be red dexron typeII ATF. if its clear change it. the soot in the exhaust is usually common in older car mine has a little when I shift real hard. hope that helps alittle you have a good car one thing I recomend to do is change all the fluids and change the timing belt. you don't really know when the last time they have been changed and this will give you a fresh start. the timing belt is crucial if that slips its allot of money to have someone rebuild it. my friend did that with his 325 m20 and it cost him 1800$

[632 Regal]

you may have a few very common issues going on, what about the plugs/wires/other ignition componants? ICV could be gummed up too.

Since the car is new to you what is documented as for replacement of common wear items such as belts/hoses/waterpump/fluid changes?

Best to replace all the items you cant track to prevent other serious and very costly problems down the road.