318 won't go past 15 mph
 

ok well my 318 won't go past 15 mph and i have no clue what could be the problem, it goes onto second gear but it doesn't seem to have enough power to go past 15. im just wondering if anyone could help me figure out the problem

plugged cat?

Is this RPM or speed based? Do you have a manual or auto box??

Sounds like it's in "limp mode".

wth is that.. i dont know much about cars.. this is my first car so i need like major help

I just looked in the owners manual and couldn't find anything on limp mode. I know other e36's have it, not sure if the ti does or not. Is your car an automatic? Automatics have a transmission computer and if there's a malfunction it can cause the car to go into whats called "limp mode". This mode protects the vehicle from further damage by restricting power allowing the driver to safely limp the car off of the highway. Again, I'm not sure if the ti is equipped with such a feature, just something that popped into my head. Are there any lights illuminated on your instrument cluster?

my car is automatic or semi-auto.. only the check engine light its on but it was on before it got messed up, but what you say makes sence bcz it got messed up as i was driving but lets say it is limp mode how do i get it off

you'd have to figure out what's wrong with it and fix it, it might be whatever problem had your check engine light on got worse over time or a completely different problem popped up, scan the codes, it will at least point you in the general direction

you ppl seem to know alot, well how do i check codes??

You'll need to buy an OBD-II scanner to read the codes. Link or the port is on the driver's side under the steering wheel; where the foot-light is at basically. Or you can buy a peake tool which is specially made for the BMW's to read codes. It'll run at least $70 for a used one up to like $150 for a GOOD one. Depending on how detailed you want it.

What year is your car? If it's '96 or newer you'll need to buy, rent, borrow an OBDII scantool or take your car to a shop to have the codes read. If it's a '95, it's OBDI and you can get the codes by using the "stomp" trick. Turn the key to position two and immediately stomp the gas pedal completely to the floor 5 times rapidly. Then watch the check engine light, it will begin to blink in a series of flashes, pausing between each number. Count the flashes and record the 4 digit code on a piece of paper. Then search for that particular code. There might be more than one code stored.

its 98, ok i think ill buy the tool so i can have it for any future purposes, i remember my friend put some type of cheap gas line cleanin treatment, could that be the problem,you know fuel not burning right causing power loss or the limp mode?

If you have AutoZone close to you, step by they do FREE scan.