HPower Surge

[36SlaMMed]

When Im driving regular or even flooring my c36, at about 4000 rpm i feel a surge of power and stick to my seat. But before that, it feels like the car wants to go but it cant, right when the 3500-4000 rpm range is reached it releases all of which it was holding back. This a description of what it feels like. Is this a problem?
If so whats the solution.

Thanks

[jnolte]

I just think the computer is getting confused wether u want to go into WOT and the tranny dosent know if it wants to dowm shift or not. I get this on my 36 and 43.

[moebiusgold]

Hmm, my 36 doesn't really get going till 5K. I think this is how they all are. JIrwin, comment?

[J Irwan]

Originally posted by 36SlaMMed
When Im driving regular or even flooring my c36, at about 4000 rpm i feel a surge of power and stick to my seat. But before that, it feels like the car wants to go but it cant, right when the 3500-4000 rpm range is reached it releases all of which it was holding back. This a description of what it feels like. Is this a problem?
If so whats the solution.

Thanks

I think your MAF is acting up
it could be on and off randomly

which explain the engine hestitant..

unless you have turbo you should not experience any lag below 4000rpm (just like 996 TwinTurbo which has lag under 3000rpm).

Also if you look at the powerband of C36 and C43, they're should have a lot more power even at idle. and the peak torque available early.
Meaning the acceleration is smooth vs E36 M3... as the peak power available at higher rpm.

The E36 M characteristic is every gear you shift you feel the car faster.
As on C36 and C43 you feel the urge from the low rpm, and as the you through the gear the acceleration is pretty constant


A healthy C36 should bevery snappy even stock. (vs. E36M3 matic, S4 matic - B5 chassis, forgive me for comparing with auto since it is only fair to compare)
With the mod that I have now , my C36 can lit the rear 255 rubber very easy without doing a brake stand.

I would try to replace the MAF first.

To tell you the truth the MAF on BMW is not as sensitive on Benz

Bt the way what is the mileage..????


Regardz,

[36SlaMMed]

42000

Is MAF the Mass Air Sensor??

thx

[J Irwan]

Originally posted by 36SlaMMed
42000

Is MAF the Mass Air Sensor??

thx

yes.

also do you currently or has been using K&N drop in filter (or other comparable aftermarket drop in filter).

Edit: forgot to ask what year of C36 is this.
Since the powerloss can be a result of a lot of thing, but my first gut feeling is MAF . And they do go out a lot time in many cases.
Other possible cause: bad-ignition coil, bad coil end, bad wiring harness, bad throttle body (expensive part since it is an integrated unit with the electronic control module), bad plugs.

Regardz,

[36SlaMMed]

The thing is my MAF has just been recently replaced, and my plugs are new also. First i Had a KN cone filter, but decided to put the original box back in.


95 black/black 43000M
4mm pads in front ( was a 1mm but too low, now too high)
I think 1mm in back
Momo Extreme 18/8.5 all around


Just had the rubber between the tranny and differential replaced, because when the mechanic unbolted the bolts there was no more rubber just strings left. Should have seen the look on his face...

[J Irwan]

Did you still use K&N cone filter after the new MAF/MAS put in, then change to original airbox or you changed to original box then put it new MAF/MAS...?



Also the problem with 1995 is known as I mentioned above.


I would bring your car to the dealer so that they can diagnose the car..

(edit: typo )

Regardz,

[36SlaMMed]

I Changed the sensor first then put the box back in later.


How much do those diagnostics cost at the dealers thses days

thx

[J Irwan]

Originally posted by 36SlaMMed
I Changed the sensor first then put the box back in later.


How much do those diagnostics cost at the dealers thses days

thx

IT could have too late.

The problem with K&N drop in filter or other aftermarket filters is when they (if you buy brand new) or you re-oiled the filter element too much.

The oil will get to the sensor wire and make the sensor unresponsive.

So since you replaced the Sensor first then switched to OEM airbox, there is possibility that your new sensor already contaminated..

I am not saying that this is the problem, but if the sensor is a possibility. The sensor is really sensitive.


Regardz,

[moebiusgold]

I second that. Those things are very touchy. They only go downhill from new. They don't like dirt or cleaning either. I've read them with a scanner, & with the engine running, and you should see the differences sometimes. Almost allways less after touching them. Very unrobust part in my mind and expensive

[jnolte]

Originally posted by moebiusgold
I second that. Those things are very touchy. They only go downhill from new. They don't like dirt or cleaning either. I've read them with a scanner, & with the engine running, and you should see the differences sometimes. Almost allways less after touching them. Very unrobust part in my mind and expensive

MB problay made them like this to make more $$. Just like the wonderful sealed "matinence free" tranny, BS!!! Or how bout the biodegratable Wire harness??? All big MB flaws!!!

[pnsji]

In M104 motor engine, a lot of things could go wrong that make the perfomance of your car "weaker".

You should try to inspect the engine, look for leaks. Try to look around:
- exhaust manifold
- front of timing chain cover, where the serpentine/fan belt are
- intake manifold area, and also where 1 of the vacum lines connect to the intake manifold
- underneath valve cover
- look around the head

Your car is from 1995, have you changed any gasket? timing chain cover gasket? valve cover gasket? head gasket?

In general the rubber gaskets after getting very hot and high preasure oil, they are no longer function as the original. Hence any leaks will lower the compression and lose HP in certain RPM.

The other thing that I learn about M104 motor, they have solenoid magnet to control the positioning on the intake cam. Depending on the driving behavior, they will adjust to the correct one. This could go wrong as well. However, if this go wrong, the check engine light will go on.

If you want to have your car running in tip top condition, having the dealer diagnosed your car is probably the best bet. They know what to do.