[woggledog]

as per:



Can ran fine between manchester and London at the weekend, and generally runs okay. However, because of some other issues (overfueling on 1 cylinder) I had INPA plugged in for my journey to work

The car has done 195000 (it's a feb 2007 m47TU2 engine) on it's original water pump

Coolant levels are fine, oil is fine (had TWO oil services in the last 2 months)

I'm guessing the impeller in the pump is shot, and it's not pushing the coolant around. Replacement ones are £30 off eBay, so a simple repair (unless I get giddy and take the front of the car off :-) )

It cooled off to 113C when moving but in traffic it got high as 117C at one point

[DriverLDN]

I had a similar problem this weekend. I was driving and I received an amber warning telling me to slow down due to engine overheating, then a minute later I received a red warning advising to pull over. Most folk have said it appears to be the Waterpump and Thermostat which needs changing.

[woggledog]

Just squeezed the top hose to the radiator with the engine warm and running. As soft as you like. New water pump ordered

[Aragorn30d]

if the temperature was really at 115c, i'd have imagined the coolant hose would have been rock hard. The system pressure rises with temperature.

If the pump doesnt fix it, it might just be a faulty coolant sensor?

[Jules59]

My E91 330D LCI ran hot (103C) - changed the single thermostat myself - now temp is rock steady at 90C. water pump was not the problem.

[woggledog]

Originally Posted by Jules59

My E91 330D LCI ran hot (103C) - changed the single thermostat myself - now temp is rock steady at 90C. water pump was not the problem.

Was this the EGR thermostat or the Engine (underneath the manifold) thermostat?

[AWSAWS]

I take it, it's high for a diesel as my modded 335i often runs 110 to 120C.

[woggledog]

Originally Posted by Aragorn30d

if the temperature was really at 115c, i'd have imagined the coolant hose would have been rock hard. The system pressure rises with temperature.

If the pump doesnt fix it, it might just be a faulty coolant sensor?

I drove home last night, around 8 miles in stock start traffic. Car was fine, but the thing that occurred to me is that BOTH engine and coolant temp are around the same temperature.

Does this mean BOTH temp senders are gone or that it is the water pump?

[woggledog]

Looks like my INPA is duff. Invoked the hidden menu and on my stop / start drive home Friday night, got to a max 76c and even dropped occasionally when coasting in high gear:



New EGR and coolant thermostats ordered and will be replaced this week.

[Millerin]

Originally Posted by AWSAWS

I take it, it's high for a diesel as my modded 335i often runs 110 to 120C.

Same with my tuned 335i. I heard N54 run hot anyway

[Soul_Glo]

+1 check the BC Hidden Menu for Coolant Temp as above.
Otherwise the temp is high even if the engine runs hot and needs to be addressed be it water pump or thermostat.

[Stoatmaster]

Guys,

Is this not because BMW run a variable coolant temp system?

As I understand it, when in ECO (Cruise mode), the water temp will be allowed to increase to approx 108c. This is to deliver better emissions. When under load (Sport), the base temperature will decrease for power and reliability reasons. (Think its 90c)

I would certainly explain why BMW did not fit a coolant temp gauge, as people would be bringing it back to the dealer constantly as the readings were all over the shop. I remember reading about this on here, so I will see if I can find the resource. Unsure if it is engine specific.

EDIT - Found it, although this was referring to the N52, unsure if it applies across the range.

Well, there are technically 4 temperature maps, but in most cases the engine should be running on Eco mode, so this right.

The four modes are as follows (there is a PDF online that I am referencing here):
• 112°C ECO mode (economy)
• 105°C Normal mode
• 95°C High mode
• 80°C High + mapped thermostat mode

[N88888_dawg]

Originally Posted by Millerin

Same with my tuned 335i. I heard N54 run hot anyway

n54 runs high oil temp
not coolant