[Len_Beach]

Hi Guys,

I had my coolant flushed last week and I'm now on a 200 mile drive of mostly motorways so I thought I'd call up the secret menu and see what effect the flush had on temperatures.

Prior to the flush I recall temperatures getting to 91-92 degrees and settling around 89.

This morning, the temperature in motorway speed traffic got as high as 95 and settled around 92-93 degrees.

In stop start queuing the temperature was as high as 98 fluctuating between 95 & 98.

Is this normal?

The coolant was Comma G48 which is BMW spec.

[oli3]

That's normal. Coolant temp should sit in the 90-100 C. The thermostat open at 88 C.

Having a lower temperature is not a good thing, the engine has been designed to operate at it's most effective and efficient in the 90-100 degrees as fas as I know.

Comma G48 is a good coolant, I used it in my E46, haven't flushed the E92 yet.

[E60525d]

Originally Posted by Len_Beach

Hi Guys,

I had my coolant flushed last week and I'm now on a 200 mile drive of mostly motorways so I thought I'd call up the secret menu and see what effect the flush had on temperatures.

Prior to the flush I recall temperatures getting to 91-92 degrees and settling around 89.

This morning, the temperature in motorway speed traffic got as high as 95 and settled around 92-93 degrees.

In stop start queuing the temperature was as high as 98 fluctuating between 95 & 98.

Is this normal?

The coolant was Comma G48 which is BMW spec.

What was the condition of the old coolant?

[Len_Beach]

Originally Posted by E60525d

What was the condition of the old coolant?

I'm not sure Buddy. My mechanic made the swap and didn't comment on the old coolant.

After a little more stop start driving during which time the temperature peaked at 100, got back to motorway speeds and the temperature was steady at 92-93 occasionally hitting 94.

[E60525d]

Ah ok, I presume it has been bled properly? There is a BMW process to bleed the system after a coolant change.

I may change mine too. I will be changing the oil in the gearbox soon so it makes sense to drain the coolant whilst the undersheet is off.

[Len_Beach]

Originally Posted by E60525d

Ah ok, I presume it has been bled properly? There is a BMW process to bleed the system after a coolant change.

I may change mine too. I will be changing the oil in the gearbox soon so it makes sense to drain the coolant whilst the undersheet is off.

I had a looked yesterday and topped up with half a litre.

I found two processes for bleeding the system, one was in relation to an electric water pump which ISTA suggested the N57 has however I couldn't get it to work. The other was a manual process, open the bleed screw, remove expansion tank cap, idle for 5 minutes, replace cap, rev to 3k a number of times then idle for a further 5 minutes.

I didn't add any further coolant after this although I've driven from Leeds to Swindon this morning so I'll check the level when I get back to the hotel tonight as that should have pushed through any air bubbles.

It's well worth changing the coolant if you're doing the box. If you haven't already, change the diff oil as well as that made a massive difference on mine.

[MAN15H]

My 335i normally sits at about 110 and when I push it the gauge hits 120 or just over.

[E60525d]

Originally Posted by Len_Beach

I had a looked yesterday and topped up with half a litre.

I found two processes for bleeding the system, one was in relation to an electric water pump which ISTA suggested the N57 has however I couldn't get it to work. The other was a manual process, open the bleed screw, remove expansion tank cap, idle for 5 minutes, replace cap, rev to 3k a number of times then idle for a further 5 minutes.

I didn't add any further coolant after this although I've driven from Leeds to Swindon this morning so I'll check the level when I get back to the hotel tonight as that should have pushed through any air bubbles.

It's well worth changing the coolant if you're doing the box. If you haven't already, change the diff oil as well as that made a massive difference on mine.

I presume this is the procedure you tried that didnt work -

But anyhow, the method you tried should of bled it anyway so I dont think you have air. Might be worth monitioring the temps for the next few days.

Yeah I have a few jobs planned all under the car, gearbox oil, diff oil, coolant flush, CDV delete and fuel filter.

[oli3]

Originally Posted by MAN15H

My 335i normally sits at about 110 and when I push it the gauge hits 120 or just over.

Are you sure that is the coolant temp and not the oil temp? Sounds like the oil temp if you're talking about the gauge on the cluster.

[AWSAWS]

Originally Posted by oli3

Are you sure that is the coolant temp and not the oil temp? Sounds like the oil temp if you're talking about the gauge on the cluster.

It'll be the oil.

My oil sits 110 to 120

My water normally maxes about 98-100. It's often at 90.

[Len_Beach]

Originally Posted by E60525d

I presume this is the procedure you tried that didnt work -

But anyhow, the method you tried should of bled it anyway so I dont think you have air. Might be worth monitioring the temps for the next few days.

Yeah I have a few jobs planned all under the car, gearbox oil, diff oil, coolant flush, CDV delete and fuel filter.

Yeah that's the one. I tried it 5 or 6 times with no luck. ISTA states that this is the correct procedure as well.

Interestingly I read another users post regarding a thermostat change on an N57 and it states to follow the procedure for belt driven water pumps to bleed the system.

Good to hear the coolant reservoir cap isn't going to blow off with the temperatures!

It's interesting that new coolant is around 5 degrees hotter than before.

[E60525d]

Originally Posted by Len_Beach

I had a looked yesterday and topped up with half a litre.

I found two processes for bleeding the system, one was in relation to an electric water pump which ISTA suggested the N57 has however I couldn't get it to work. The other was a manual process, open the bleed screw, remove expansion tank cap, idle for 5 minutes, replace cap, rev to 3k a number of times then idle for a further 5 minutes.

I didn't add any further coolant after this although I've driven from Leeds to Swindon this morning so I'll check the level when I get back to the hotel tonight as that should have pushed through any air bubbles.

It's well worth changing the coolant if you're doing the box. If you haven't already, change the diff oil as well as that made a massive difference on mine.

FYI, out of interest I tried the bleed procedure today I also couldn't get it to work. Looks like it is not for the N57 engine.

[ChawenHalo]

Originally Posted by Len_Beach

Yeah that's the one. I tried it 5 or 6 times with no luck. ISTA states that this is the correct procedure as well.

Interestingly I read another users post regarding a thermostat change on an N57 and it states to follow the procedure for belt driven water pumps to bleed the system.

Good to hear the coolant reservoir cap isn't going to blow off with the temperatures!

It's interesting that new coolant is around 5 degrees hotter than before.

Probably more efficient heat soak... I would not worry too much so long as your calorstat is funtioning its fine at those temps. These are pretty sturdy blocks and if your car gets anywear near critical temps there are a myriad of sensors that will tell the car to tell you to reduce speed etc.

I've suffured serious (to my mind) overheating problem on an old 2.8 due to a thermostat being stuck closed until pressure just pushed it open (admitidly on the old cast iron block) and the car has never ill suffured from it long term. Frankly it did not seem to even vaguely give a sh)t and that was many mile ago...

[MAN15H]

Originally Posted by AWSAWS

It'll be the oil.

My oil sits 110 to 120

My water normally maxes about 98-100. It's often at 90.

Sorry guys I misread the OPs initial post, that is indeed my oil temp.

Still glad to see its the same for some others as I thought it was running a little high at 120.

[AWSAWS]

Just want to note I had jb4 mobile logging turned on the other day travelling home from work. Oil was at 100, water got to 105 which was the highest I'd ever seen. It was a bit concerning. This was crawling along in solid traffic with the car still warming up which is why the oil was still cooler than the water.
Anyway as soon as I got to dual carriageway speeds the water temp dropped like a stone to 87. Thanks to all the airflow over the radiator. Great to see. Glad my water pump is still working. Outside temp was 19C.

[KashE90]

Originally Posted by oli3

That's normal. Coolant temp should sit in the 90-100 C. The thermostat open at 88 C.

Having a lower temperature is not a good thing, the engine has been designed to operate at it's most effective and efficient in the 90-100 degrees as fas as I know.

Comma G48 is a good coolant, I used it in my E46, haven't flushed the E92 yet.

I have a question for you. I have a 2009 328ix with the N52. My coolant temp will hold at 90-96 degrees Celsius but when stopped in traffic will jump to 110c. Should I be worried? Before my coolant flush the cars temp were about 10 degrees cooler. Used OEM BMW coolant as well. I’m at 129k miles on the car and I keep up with all of the maintenance for it, at it’s regular intervals.