Hello all, hope someone can help with this. 1998 C280. New transmission just put in. Drove car for 2 weeks. Then it would not start. Sometimes it sdoes and sometimes it doesn't. Last time had this problem replaced battery and start relay I believe. Insert key, turn and you hear click click click sometimes the car will start and sometimes it does not. When it does start it starts with plenty of turning power. Car runs beautiful otherwise. Any help would be appreciated. Vin: WDBHA29GOWF684757

I can only suggest starting with the obvious, if the transmission was replaced I think most technicians might disconnect the power supply. Check your battery connections!

battery connections checked good voltage and when car does start good cranking power.

On the outside of the vehicle, in the area beneath the drivers foot-well there is an electrical connection for the starter motor. This is the start motors main connection to the battery. It is possible that this connection may be causing an intermittent restriction in current flow due to corrosion. Disconnect your cars battery on the ground cable side, remove all the wires at this foot-well connecter block. Wire brush the terminals so they are clean and bright afterward reconnect the wires to the terminal block. (You may find that a 1/4” drive ratchet may be best for this repair).

SPECIAL NOTE: Do not over tighten wire connections! I mention this because I believe everybody wishes to avoid unwanted down time waiting for new parts.

Reconnect your battery ground cable then recode your radio.

the click click click noise you hear is probably the starter motor not engaging properly, (if the battery is connected properly and fully charged) the clicking is common in the UK, we normally hit the starter with a screw driver handle and "hey presto" it engages, it does mean that sometime soon you may need to replace it!!

MB service bulletin on that problem! Starter/ring gear interference problem.

MB offer a special non-metalic lubricant for the starter ring gear!

MB work instructions info is AF15.30-P-6405A.

A little dab on each & every tooth of the ring gear is required.

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A new transmission was just installed in car about 3 weeks ago. Terminals are good and clean. Started was removed and greased also. The problem is still there.

Sometimes when you turn the key nothing, sometimes humming from middle of firewall, and then sometimes clicking. At first I thought the clicking was the starter since when you here that on an american car it is either the starter or solenoid. But then why no sound sometimes.

Some one mentioned a neutral safety switch...no idea what they were talking about since they did not elaborate. Still have problem if you gents have any other ideas I can look at. Thank you.

Hi Dan

Please refer to my previous post regarding the connection at the X4 connector block, this is the main power feed for the starter motor. Exposed to the elements over time this connection has a tendency to develop corrosion which causes an intermittent starting problem. Disconnect the cable, clean the ring terminal with a wire brush and then reattach the cable, be mindful not to over tighten the nut. You may want to also double check your chassis to engine ground cable, it may be loose.

It is possible that your problem lies in another area (electrical plate on the valve body, the K40 relay, or the ignition switch) so before we head down one of those paths lets be wise and address the more common issues.

I would tend to listen to M.B. DOC. He seems to have a little experience...

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Cannot argue with experience, good luck!

Car was towed again to new mercedes mech. He called last night and said that the new starter that was installed shorted out the wiring to the control module and fried it.

Any one tell me if that makes sense. Guess he said, when they removed motor mount to get starter out they must of shorted the wires. I have no idea..I am totally lost. Do not even want to think what the new cost will be.