1998 SL500 stalling problem - 70k miles

[davesurti]

when my car is in park, and I tap the throttle, the engine rpm will dip below 500, and the oil pressure will reach near zero, and sometimes the battery and/or bas-asr lamp will flash.. most of the time the engine does not stall.. however, a similar situation occured while i was driving

one time when coming to a complete stop, the rpms dipped below 500 and the car stalled

another time, when i was creeping in traffic, the rpms dipped again and the car stalled

any idea of what could be wrong? maf or camshaft sensor of some sort? is the timing off?

[Carlos Serrano]

It is possible that the EGR valve is stuck open, the symptoms are very similar to your description.

[davesurti]

Originally Posted by Carlos Serrano

It is possible that the EGR valve is stuck open, the symptoms are very similar to your description.

im taking my car to the shop soon... after browsing through the forums, i came up with this list:

• Start with new plugs, wires, cap and rotor
o 1996-1998 V8 do not have cap/rotor or spark plug wires
o Coils have wires to the spark plugs
Might need new spark plugs

• Fuel Pump Relay

• Crankshaft Sensor

• Check the fuses on top of the relay (red) behind the battery, there should be 2 ten amp fuses, pull and see if one or both are blown, it has been known to happen after jump starting the car

• Mass airflow sensor

• Bleed the brakes

• Idle valve - can sometimes stick especially if the car has been sitting for some time.


• EGR Valve

what do you think carlos?

[Carlos Serrano]

The BAS-ASR lamps will come on when there is low voltage, they will come on and stay on at start-up if your battery is weak until your alternator raise the voltage then they will go off. Do you have a good battery?
The ignition wires will cause rough idle when getting old without check engine light, how old are they?
Crankshaft positioner sensor will leave you stranded at a stop when the engine is warm and the car won't re-start till it cools down if you are lucky.
How about the fuel filter? When was it change last?
An EGR valve that remains open will cause the engine to idle rough, die at idle, and loose power at full throttle smoothness. the valve usually fails to close due to dirt or damage in the valve seat area.
Check for vacuum leaks, the hoses will crack and leak with less miles than that.The cannister purge vacuum hose have the tendency of coming off at the valve, also the MAS sensor gaskets become crushed on the bottom side with age and they allow air to come in below the sensor.

[davesurti]

Originally Posted by Carlos Serrano

The BAS-ASR lamps will come on when there is low voltage, they will come on and stay on at start-up if your battery is weak until your alternator raise the voltage then they will go off. Do you have a good battery?
The ignition wires will cause rough idle when getting old without check engine light, how old are they?
Crankshaft positioner sensor will leave you stranded at a stop when the engine is warm and the car won't re-start till it cools down if you are lucky.
How about the fuel filter? When was it change last?
An EGR valve that remains open will cause the engine to idle rough, die at idle, and loose power at full throttle smoothness. the valve usually fails to close due to dirt or damage in the valve seat area.
Check for vacuum leaks, the hoses will crack and leak with less miles than that.The cannister purge vacuum hose have the tendency of coming off at the valve, also the MAS sensor gaskets become crushed on the bottom side with age and they allow air to come in below the sensor.

the bas-asr lamps only flash when the car is about to or does stall.. the battery is acutally brand new...i will have the rest of the things you spoke of checked out by the shop.. thanks for the help.. i will keep you updated

i acutally drove it around last night and today and the problem has not come up again... another problem i did not mention is that the door locks opening by themselves and not being able to lock them without restarting the car.. might be a vacuum leak as well, according to other posts

[tecqboy]

Vacuum for the door locks comes from a seperate vacuum pump and is not related to engine vacuum. So, your door lock problem is not likely to be related to your other issues.