Curious goings on with high mileage 130i - water pump?

[Somewhatfoolish]

I've had my water pump replaced two times now so I'm imagining this is going to be the third time, but just to investigate other explanations:-

Symptoms:

• Intermittent aggressive overheating alerts. Feels just like last couple of times water pump has failed but I don't drive it much, particularly with lockdown, so put off dealing with it for a bit

• Couple of weeks later, fuel pump goes.

• Replace fuel pump

• Continue to barely drive it but the overheating has gone. Put earlier alerts down to fuel pump starting to fail, either in actually causing overheating or dodgy electrical signals (garage told me when they replaced fuel pump various fuses went*).

• Do 80 miles in it the other day. Behaves perfectly.

• Do 150 miles in it today. In last 40 miles, it does the overheating thing twice, both while being driven robustly. But I usually drive it robustly.

NB during *all* of this there are no ODB codes at all. And for those unfamiliar with the model, it has no temperature gauge. You just get a yellow and red warning - and in the above scenario about 20 seconds between them! The alleged overheating lasts under a minute, during which it goes into limp home mode.

Is this going to be the water pump yet again or could it be something else? Tempted to try the air lock clearing procedure although I've not had a lot of luck triggering that in the past, despite it being pretty bloody simple.

*On typing this out I just realised I should probably check the fuse box, shouldn't I...

[b14]

Try and do the bleeding thing with the heater controls etc. But it sounds like the water pump failing again.

[mmm-five]

Had something similar on an Alfa, but it was just the thermostat.

[RUSSELLM]

Is the coolant temp sensor accurate ?

Alternatively, apart from the warning on the binnacle, what are the other visual symptoms of the overheat ?

Edited by RUSSELLM on Sunday 6th December 12:09

[Somewhatfoolish]

There are no other visual symptoms (nor does it smell hot or anything else, at least as far as I can tell) and irritatingly there is no temperature gauge so I can't see if it 'spikes' or if it's running warm all the time.

I only know it's in limp home mode because of a lack of power, and this lasts under a minute as it cools.

[JakeT]

Why don't you bring up the hidden menu when you drive? You can then see what the temperature is reading in the instrument cluster.


http://e90.wikifoundry.com/page/BC+hidden+menus

[Mr Tidy]

What you have described doesn't sound like a dying water pump, unless maybe you've got an intermittent issue with the electrical suplly to the pump.

I've had two water pumps die and both times they just stopped working completley. The first was in an E86 Z4 which does have a temperature gauge, but the 2nd was an E91 3 Series that doesn't, just the 2 warning lights you have in your 130i. And both times there was a fault code logged.

You say you've had 2 new ones already - do you know what brand? I had Pierburg ones fitted both times because that's what BMW used, I just got them somewhere cheaper! I was only wondering because my Z4 had managed 60K miles on the original but my next Z4 was still on the original when I sold it at 90K.

[Patrick Bateman]

What are the odds on two new water pumps being faulty?

That immediately makes me think to look elsewhere.

[g3org3y]

Patrick Bateman said:

What are the odds on two new water pumps being faulty?

That immediately makes me think to look elsewhere.

Agreed.

[VerySideways]

Water pump on my second 130i went at about 80k miles, water pump on my 330i (N52) went at about 65k miles.
Practically a consumable.

You say you've had the water pump replaced twice - when, and at what mileage(s)? And how long has it been (time/miles) since the last one?

[drdino]

Have you looked at the actual coolant temp (either via the secret menu or via obd) when you get the overheating message?