Now I've done it... - PeachParts Mercedes-Benz Forum

duxthe1 · #1 10-01-2010, 01:04 AM

Most Mercedes engines are fine to wash but the 104 isn't one of them. Moisture gets down near the spark plugs and carbon tracks the outside of the ceramic insulator and shorts the plug. You should remove the 3 spark plugs under the coils and check for carbon tracking even though this isn't likely the ASR problem. If you find any carbon tracked plugs you should replace the connector on the coil also. An ASR issue after getting the engine wet

points to a throttle actuator problem. Whether it's the actuator, it's harness, or the connecting harness will have to be diagnosed. If you search "throttle actuator" here you will probably get more than you want to read.

Christine in FL · #2 10-01-2010, 01:27 AM

Quote:

Originally Posted by duxthe1

Most Mercedes engines are fine to wash but the 104 isn't one of them. Moisture gets down near the spark plugs and carbon tracks the outside of the ceramic insulator and shorts the plug. You should remove the 3 spark plugs under the coils and check for carbon tracking even though this isn't likely the ASR problem. If you find any carbon tracked plugs you should replace the connector on the coil also. An ASR issue after getting the engine wet

points to a throttle actuator problem. Whether it's the actuator, it's harness, or the connecting harness will have to be diagnosed. If you search "throttle actuator" here you will probably get more than you want to read.

I will, thank you.

Christine

nestorb98 · #3 10-01-2010, 02:23 AM

I've had a similar problem with my 91 300TE.

Turned out to be the distributor to coil wire. I got a couple of tips from Phil and a length of ignition wire. Now, periodically the tip near the coil carbonizes and it needs to be cut and re-crimped to the ign-wire.

I think that when the tips begin to get carbonized, the starter takes a longer time to start the engine and as a result the added pressure causes the weak point in your fuel supply to weep a bit.

Ferdman · #4 10-01-2010, 10:37 AM

Christine, as far as I know the fuel pump and fuel filter are located in front of the right rear wheel. It's odd that a gas leak would be in front of the left rear wheel.

amg280 · #5 10-01-2010, 01:21 PM

Quote:

Originally Posted by nestorb98

I've had a similar problem with my 91 300TE.

Turned out to be the distributor to coil wire. I got a couple of tips from Phil and a length of ignition wire. Now, periodically the tip near the coil carbonizes and it needs to be cut and re-crimped to the ign-wire.

I think that when the tips begin to get carbonized, the starter takes a longer time to start the engine and as a result the added pressure causes the weak point in your fuel supply to weep a bit.

Her engine doesnt have a distributor, it has coils instead.

amg280 · #6 10-01-2010, 01:23 PM

Quote:

Originally Posted by duxthe1

Most Mercedes engines are fine to wash but the 104 isn't one of them. Moisture gets down near the spark plugs and carbon tracks the outside of the ceramic insulator and shorts the plug. You should remove the 3 spark plugs under the coils and check for carbon tracking even though this isn't likely the ASR problem. If you find any carbon tracked plugs you should replace the connector on the coil also. An ASR issue after getting the engine wet

points to a throttle actuator problem. Whether it's the actuator, it's harness, or the connecting harness will have to be diagnosed. If you search "throttle actuator" here you will probably get more than you want to read.

I completely agree here. The M104 does NOT like water. I had so much water in my plug holes (yes i made the mistake of cleaning the engine), that the check engine light came on, it barely idles, and pop's and sputterd like a 60's american muscle car. It did not have anything to do with the ASR.