M57 overheats unless revved
Discussion
Hi,
Hoping that someone might be able to shed some light on what could be causing my overheating issue.
535D E61 overheats in both slow moving traffic and on idle. Temperatures will exceed 100 degrees.
@ 80mph, it'll sit between 95-97 degrees as opposed to the 88-92 degrees that it should be sat at.
Radiator has been changed.
Thermostat changed.
Waterpump changed.
EGR + Cooler deleted.
If I cruise between 70-80mph on the motorway, the temps stick to around 95 degrees which is hotter than what it should be. If I then either ACCELERATE heavily (past 3.5-4k rpm) she'll drop temp very quickly to 88-90 degrees momentarily. Similarly, if I downshift to slow down, and the engine downshifts past 3.5k rpm, she'll also cool down immediately.
So what is stopping the cooling system when not at high rpms? Someone please make it make sense!
The video below is after I had a short journey. Temps quickly hit 100 degrees as I pootled around town, and then I discovered that If I rev the nuts off the engine, it'll cool down. How strange!
https://www.youtube.com/shorts/-hHLykVZRvE
Hoping that someone might be able to shed some light on what could be causing my overheating issue.
535D E61 overheats in both slow moving traffic and on idle. Temperatures will exceed 100 degrees.
@ 80mph, it'll sit between 95-97 degrees as opposed to the 88-92 degrees that it should be sat at.
Radiator has been changed.
Thermostat changed.
Waterpump changed.
EGR + Cooler deleted.
If I cruise between 70-80mph on the motorway, the temps stick to around 95 degrees which is hotter than what it should be. If I then either ACCELERATE heavily (past 3.5-4k rpm) she'll drop temp very quickly to 88-90 degrees momentarily. Similarly, if I downshift to slow down, and the engine downshifts past 3.5k rpm, she'll also cool down immediately.
So what is stopping the cooling system when not at high rpms? Someone please make it make sense!
The video below is after I had a short journey. Temps quickly hit 100 degrees as I pootled around town, and then I discovered that If I rev the nuts off the engine, it'll cool down. How strange!
https://www.youtube.com/shorts/-hHLykVZRvE
It's odd behaviour for the gauge to respond so quickly to the engine speed. As said above that could be an electrical fault rather than a temperature issue. I would start by checking all the earth connections between the engine and the body.
On the mechanical side the problem could be air in the coolant. The pump has to be revved to drive enough coolant up to the sensor for full contact. You don't mention anything about loss of coolant so if there is air in the system it could be due to a blown head gasket.
On the mechanical side the problem could be air in the coolant. The pump has to be revved to drive enough coolant up to the sensor for full contact. You don't mention anything about loss of coolant so if there is air in the system it could be due to a blown head gasket.
Locknut said:
It's odd behaviour for the gauge to respond so quickly to the engine speed. As said above that could be an electrical fault rather than a temperature issue. I would start by checking all the earth connections between the engine and the body.
On the mechanical side the problem could be air in the coolant. The pump has to be revved to drive enough coolant up to the sensor for full contact. You don't mention anything about loss of coolant so if there is air in the system it could be due to a blown head gasket.
Hi, On the mechanical side the problem could be air in the coolant. The pump has to be revved to drive enough coolant up to the sensor for full contact. You don't mention anything about loss of coolant so if there is air in the system it could be due to a blown head gasket.
Apologies. I actually missed that vital piece of information out! So prior to the water pump being done, it was going through a lot of coolant but only normally when I would drive it around town..I could sit for 3 hours on a motorway journey and it wouldn't drink a sip of coolant, but around town it would soon say "Coolant low". I assume this was because on the motorways I could pretty much keep the temp at around 95, whereas in town it would regularly hit 110-115degrees.
Since the water pumps been done however, I've only driven it on a 280mile journey and then parked it back up so no idea if I still have the same issue.
I'm going to check the aux pump as a poster above mentioned, and see if I can bleed the air out of the system again to rule that out.
Headgasket seems very unlikely on the M57 engines, so I'm reluctant to go down that path until I have a solid diagnosis. Nothing in the oil cap to suggest so either.
In response to some of the other posters, yes the electric fan is working and kicks in when temps get high.
Car was revved at my industrial unit, so no neighbours were offended!
Regards
It sounds like a head gasket, cracked head etc. These are all the hallmarks of a petrol BMW HGF, unusual on an M57 but not impossible.
Air is getting in and when a load of it arrives at the water pump, the temp increases as coolant flow slows/stops. A good rev shifts the air pocket and the engine cools. A sniffer test of the coolant to detect exhaust gasses is the first step.
E61 with a temp gauge?
Air is getting in and when a load of it arrives at the water pump, the temp increases as coolant flow slows/stops. A good rev shifts the air pocket and the engine cools. A sniffer test of the coolant to detect exhaust gasses is the first step.
E61 with a temp gauge?
Panamax said:
keemaklan said:
Radiator has been changed.
Thermostat changed.
Waterpump changed.
EGR + Cooler deleted.
Who carried out this work and using parts bought from where?Thermostat changed.
Waterpump changed.
EGR + Cooler deleted.
Sounds to me like some of it hasn't been done right.
I-am-the-reverend said:
It sounds like a head gasket, cracked head etc. These are all the hallmarks of a petrol BMW HGF, unusual on an M57 but not impossible.
Air is getting in and when a load of it arrives at the water pump, the temp increases as coolant flow slows/stops. A good rev shifts the air pocket and the engine cools. A sniffer test of the coolant to detect exhaust gasses is the first step.
E61 with a temp gauge?
The temp gauge is within the secret menu which you can access by adding a load of random numbers in your VIN together, and then you go to Air is getting in and when a load of it arrives at the water pump, the temp increases as coolant flow slows/stops. A good rev shifts the air pocket and the engine cools. A sniffer test of the coolant to detect exhaust gasses is the first step.
E61 with a temp gauge?
Option 19, followed by your special code (related to your VIN) and then option 7. It then unlocks the stupid coolant temp. Its a 45 second faff every time you turn the car on.
Sniffer test of coolant to detect gases - Gotchya. Will find out if thats something my garage have access too.
keemaklan said:
If I cruise between 70-80mph on the motorway, the temps stick to around 95 degrees which is hotter than what it should be. If I then either ACCELERATE heavily (past 3.5-4k rpm) she'll drop temp very quickly to 88-90 degrees momentarily.
What you've described there might IMO be normal behaviour. Engine ticking over gently at a cruise, plenty of cool air passing the engine/radiator, thermostat closed. Hit the throttle, busy engine, lots more heat gets transferred into the coolant, thermostat opens and cool water from the radiator passes the temperature sensor, so gauge shows a drop.A quick click on the internet suggests BMW thermostats typically open at 88 degrees and a temperature range of 90 - 100 is normal. Might be worth you checking the bottom line on what's normal for your specific engine/car. I can't claim any personal knowledge of BMW diesels.
Where is the temperature sensor on your engine? Bear in mind it's often nowhere near the thermostat and there's no direct interaction between them. Just because the engine's at 95 degrees (which may be normal range) doesn't mean the coolant is at that temperature. The thermostat doesn't control engine temperature, it controls coolant temperature. Performance cars tend to have separate oil temperature and coolant temperature displays. The two can differ quite widely.
Water pump impeller knackered. The plastic vanes don't move enough water when idling.
My old Alfa 156 v6 did exactly this, cruise with revs up at a couple of thou and it was fine, sat idling and up the temp went.
But you've changed the water pump...
My old Alfa 156 v6 did exactly this, cruise with revs up at a couple of thou and it was fine, sat idling and up the temp went.
But you've changed the water pump...
Edited by Pepperpots on Monday 24th July 17:35
Do you know there's actually a problem? 100c is normal operating temp for the N57, so may not be that odd for an M57. Does yours actually go above 100? If you're not moving, so you're not getting passive cooling from the airflow, it seems pretty normal that the coolant temp would go up to a certain point until the car is triggered to do something about it, when it's not under strain it might well run hotter because it's more efficient to have thinner oil. If you're driving the car harder it might be responding to that and cooling the engine down for more power. The systems are pretty smart about how they manage the temperature.
Pepperpots said:
But you've changed the water pump...
This is the weird thing; and it's why I was questioning the parts & fitting a few posts back. Typically a BMW with wobbly cooling responds to treatment.I recall an unexpected overheating stop on M25 in my E39 where I undid the breather with a 50p piece and refilled the system from a bottle of my dear companion's sparkling water. Saw us through to the Mini dealer at Sevenoaks where I bought some proper BMW coolant...
Been there; done that.
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