300E with a couple of problems..

[ChrisS]

I've recently bought my first Mercedes, a 1988 300E, and would appreciate some advice re. the following:

1. There's a worrying sound from the auto box. When I engage P or N there is a noticable 'ching' sound, rather like the ringing of a bell. The box seems to shift alright and the noise wasn't there when I first drove the car. I'm no expert when it comes to automatic transmission - any suggestions?

2. A previous owner has run a supplementary power wire from a terminal in the fuse box to the fuel pump, presumably to bypass a failed fuel pump relay. I'm keen to get rid of this bodge but don't know which relay is which and the workshop manual doesn't say. Can somebody tell me which is the fuel pump relay?

Thanks in advance.

 

[Rog_E]

The fuel pump relay is the left hand (from drivers seat) relay behind the battery and plastic cover, the OVP relay is to its left and front but should be under it's own cover.

The 'ching' sound could be anything from a damaged engine/gearbox mount, propshaft coupling/bolt or torque converter mounting.

With care (chock the car!) get some one to engage gear whilst you try to isolate the sound from outside. Observing the engine with the bonnet open can help with the engine mount diagnosis!

Good luck!

 

[ChrisS]

Thanks for the advice - I'll try to pinpoint the source of the noise this weekend. I'm still not sure which is the fuel pump relay though - there are four under the cover behind the fuse box. Viewed from the drivers seat there are two metal cased relays to the right, a black plastic cased one in the centre and a similar one on the left. Presumably it's the left hand one?

 

[ChrisS]

Oh dear - please excuse my ignorance! I've been looking in the wrong place, have now located the fuel pump relay behind the battery as Rog-E said.. Thanks again.