Engine fan at 100c

Biggman83 · Post by **Biggman83** » Mon Jan 29, 2024 7:24 pm

Hey everyone,

I’m new here, I’ve just joined to ask a few questions. I’m about to embark on an overdue self service for my E89 28i 2014. Life got in the way and I’m reluctant to spend the £££ with BMW getting them to service it.

I’ve noticed recently that the oil temp is rising to just below 100c and the cooling fan is kicking in. I’d say the engine is currently running about 30 - 40c hotter than normal.

I don’t get any warning lights, and my fluid levels for both coolant and engine oil are fine. Both fluids are old, so I’m hoping that by replacing them and the oil filter, the Issue will fix itself.

Should I be aware of anything else potentially being the route of of the issue. I’ve seen various messages about fan sensors, but I’d imagine that the fan would run constantly even at low temps or not at all if that was an issue.

Any helps or suggestions would be greatly appreciated and thank you in advance.

Matt

Smartbear · Post by **Smartbear** » Mon Jan 29, 2024 8:05 pm

Biggman83 wrote: ↑Mon Jan 29, 2024 7:24 pm Hey everyone,

I’m new here, I’ve just joined to ask a few questions. I’m about to embark on an overdue self service for my E89 28i 2014. Life got in the way and I’m reluctant to spend the £££ with BMW getting them to service it.

I’ve noticed recently that the oil temp is rising to just below 100c and the cooling fan is kicking in. I’d say the engine is currently running about 30 - 40c hotter than normal.

I don’t get any warning lights, and my fluid levels for both coolant and engine oil are fine. Both fluids are old, so I’m hoping that by replacing them and the oil filter, the Issue will fix itself.

Should I be aware of anything else potentially being the route of of the issue. I’ve seen various messages about fan sensors, but I’d imagine that the fan would run constantly even at low temps or not at all if that was an issue.

Any helps or suggestions would be greatly appreciated and thank you in advance.

Matt

That temp sounds pretty normal, think my 20i used to sit around there.
Rob

matsmith749 · Post by **matsmith749** » Mon Jan 29, 2024 9:20 pm

110-120 degrees c is the normal operating temperature of the engine oil - midway on the guage.

A few problems from your comment - if you thing 100 degrees is 3-40 degrees too hot, then you normally see about 60 degrees oil temp right?

That would be mental, way too cold for the normal running temperature. Fan coming on at 100 is also bad.

So yeh, you have something wrong (or your numbers are a mile off).

Get it code scanned & go from there.

Biggman83 · Post by **Biggman83** » Mon Jan 29, 2024 10:16 pm

Thanks for the comments. It’s one of those things you don’t take any notice of until something changes, so apologies if my figures are off. I had read somewhere that 100c is fine but with the fan running fast, I can hear it over the engine noise if I’m sitting in traffic I’ve started to pay attention to the gauges more.

Pondrew · Post by **Pondrew** » Mon Jan 29, 2024 10:18 pm

matsmith749 wrote: ↑Mon Jan 29, 2024 9:20 pm Fan coming on at 100 is also bad.

That's the oil temp, though, not the water temp. Without a decent scanner there is no way of telling what the water temp is.

I have found in both my (N20) E89s that the oil temp usually sits around the 80-90 c mark, unless it is being driven fairly hard, then it can go up to 100c ish. If it was 60 it wouldn't register on the gauge as that don't move until past 70.

Not sure what water temp the fan switch cuts in at, but presume it is around 115c, as the thermostat doesn't open until 108

matsmith749 · Post by **matsmith749** » Tue Jan 30, 2024 10:50 am

Pondrew wrote: ↑Mon Jan 29, 2024 10:18 pm
matsmith749 wrote: ↑Mon Jan 29, 2024 9:20 pm Fan coming on at 100 is also bad.
That's the oil temp, though, not the water temp. Without a decent scanner there is no way of telling what the water temp is.

Yes - the OP quoted the oil temp as being a concern, hence my reponse regards the oil temp.

Biggman83 · Post by **Biggman83** » Fri Feb 16, 2024 3:13 pm

I've been in the process of some trial and error fixes. Oil and coolant are both at Max levels but I've bought some new coolant to top up with. I'm thinking maybe its a faulty thermostat sensor on the radiator fan. Is this a common issue at all?

Smartbear · Post by **Smartbear** » Fri Feb 16, 2024 5:25 pm

Biggman83 wrote: ↑Fri Feb 16, 2024 3:13 pm I've been in the process of some trial and error fixes. Oil and coolant are both at Max levels but I've bought some new coolant to top up with. I'm thinking maybe its a faulty thermostat sensor on the radiator fan. Is this a common issue at all?

Scan the car with a code reader, that should show any problem areas.
Rob

Biggman83 · Post by **Biggman83** » Fri Feb 16, 2024 5:29 pm

Scan the car with a code reader, that should show any problem areas.
Rob

I need to get hold of one to use. That'll have to wait until pay day i think.

enuff_zed · Post by **enuff_zed** » Fri Feb 16, 2024 5:41 pm

Biggman83 wrote: ↑Fri Feb 16, 2024 5:29 pm
Scan the car with a code reader, that should show any problem areas.
Rob
I need to get hold of one to use. That'll have to wait until pay day i think.

If you say where you are there's a chance you may find a forum member near you who will read the codes for you.

Z4-forum.com

Z4-forum.com