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 #)


If you are going to DIY, this is a pretty involved job but doable.


- 4% water content in brake fluid, so brake fluid flush -> but what would be causing this?


Do this yourself and save the money.


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).


My 1991 was pretty much the same after I changed the radiator. I used a cheaper brand instead of the better quality Behr. Temps fine at highway speeds, but in warm weather combined with hills, the temp would be over 100 and then the aux fans would kick in and bring it down.

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.

This is about what I got.



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.

This sounds like engine mounts but I would think the mechanics would have seen it. Easier to do than a water pump.


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)

I found this to be either weak battery or weak charging system. Check the voltage regulator (attached to alternator) and replace if well worn.