1993 300CE (w124) - questions

[optimizer]

Hi there,

I'm hoping to get some suggestions about what repairs to make and what a reasonable charge to do it would be.

I went to an MB shop to get a check done of my vehicle, and here are some of their recommendations:

MB recommended fixes:
- Water pump leaking (but fluid levels look fine): 3 hrs labour + water pump (and how do I know exactly which water pump to buy from the parts store? I have the MB part #)
- Left lower control arm ball joint shows some play: 3 hrs labour + control arm (mine is a single piece apparently)
- Rear differential vent cap is seized
- 4% water content in brake fluid, so brake fluid flush -> but what would be causing this?
- Valve cover appears to be leaking ($600 parts + labour) -> is this worth fixing, another MB shop says it's 'sweating a little' and not worth fixing.

Other issues I've noted:
1) Engine runs warms (around 100 to 105) in stop and go traffic, in warm weather. It runs normal (85) when there is better airflow to the engine (e.g. going 50+ km/h). The thermostat, fan clutch and radiator have been replaced within the last year (thermostat for this same issue, fan clutch because the old one was a bit worn and the radiator for a different issue). The aux cooling fans come on as they're supposed to (around 107 I think).

2) There is some play in the steering when driving straight on the highway. The car will sometimes sway left or right very slightly even if there's no apparent changes in the road surface (a couple newer cars I have track straight on the same roads)

3) Fuel consumption from cold starts in winter seems to be very high. In winter, I could do about 300 to 350 miles per tank, while in summer I normally get 400 miles.

4) Cold starts in winter weather are weak

5) Engine sort of sounds like a diesel when I am idling in drive gear (sound goes away when I'm in park, or as soon as I engage the throttle). When I say this, I mean there's a rattling sound from the engine bay (sounds like somewhere up front). Idle is smooth otherwise.

6) Coolant light "glows" in warm weather when engine is running warm. That is, the light is not on, it just glows very faintly... I can only usually see it glowing at night time, not during the day. However, the light bulb itself works correctly (e.g. when I turn on the ignition, it will light up correctly)

7) If there is a passenger sitting in the back left (or any other load), then I hear a noise from the wheel well every time I go over a fairly large bump in the road. Doesn't look like there's any rubbing, and mechanics couldn't replicate the issue enough to be able to find the problem. It sounds like a low-pitched squeak.

I'm probably making the car sound like it runs terribly, but it generally runs very well overall! I'd like to ensure it's always in great shape and appreciate all the help I've gotten from this forum!

Thanks!

1993 300CE (w124)