I own a daily-driver 525 TDS (1996 E39, 2.5 liter diesel engine M51D25 with 143hp), stock... and it really is a POS money sucker! It does have lots of electrical problems like:
- termometer is incorrect, always displays negative outside temperatures (even in the summer, with 35ºC);
- the displays seem have erratic behaviours and parts of it get blacked out (more common on the radio display);
- most plastics are definitely bad quality ones, as they break easily (window switch frames, e.g.);
- electronic modules tend to fail (my rear door's power locks and windows, as well as trunk lid, all recently failed);
- headlight housing is extremely fragile and can break when you change bulbs (have to be extremely careful);
Their gasoline engines seem to be quite reliable, but the diesel ones are the worst:
- Diesel pump failed at 140.000km's (2.000€'s for a new one) - it seems to be a recurrent failure;
- Plumbing tends to blow, for no apparent reason;
- Threw up a rod, at around 200.000km's;
For the record, the car had it's maintenance on schedule, at a BMW dealer. Even the dealer acknowledged the existence of problems with the E39, and the M51D25 engine in particular. Don't know if other models have these issues too.
I'm trying to get rid of it anytime soon - my dream is to set it on fire and see it burn and the crushed on a press. Fortunately, I can't
. Guess it's time to get the cooler Renault Mégane
