High water temperature issue

[escarolo]

Hi all!

This weekend I really enjoyed my CSL but connecting the A.C. the temperature gauge exceeded 3/4 and almost reached the red zone, even driving into highway, 100-110 kms/h, 35º C outside.

Any idea?

Best regards

[NZ_M3]

I would check the thermostate first - it might be stuck closed or half way open causing the temperature to rise when there's more load on the engine - i.e. the aircon pump going.

Failing that it might be the water pump.

Another thing to check is to see if your fan is engaging - the fan clutch might be worn out and not coming on.

[shimmy]

Hi all!

This weekend I really enjoyed my CSL but connecting the A.C. the temperature gauge exceeded 3/4 and almost reached the red zone, even driving into highway, 100-110 kms/h, 35º C outside.

Any idea?

Best regards

my occassional heat issue is on track only, at 100% throttle and on very hot days ONLY so not totally like yours. The minute i come off the throttle it will be back to norm within one or two bends

let us know if you solve it"

[escarolo]

I will change thermostat and fan clutch.

Thanks!!!

[shane@mbtech]

I will change thermostat and fan clutch.

Thanks!!!


Dont do fan clutch, if its getting hot when moving its not the viscous fan

If however its getting hot when standing, then cools as soon as you drive, I would suggest the viscous fan coupling. :thumbs:

Easiest, cheapest thing is stat as suggested.

[escarolo]

Dont do fan clutch, if its getting hot when moving its not the viscous fan

If however its getting hot when standing, then cools as soon as you drive, I would suggest the viscous fan coupling. :thumbs:

Easiest, cheapest thing is stat as suggested.


Fan clutch price is not so high, so I prefer to change it. The car has 80.000 kms, so sooner or later I will have to change it.

What about water pump? Should I change it or wait until it fails?

[shimmy]

Fan clutch price is not so high, so I prefer to change it. The car has 80.000 kms, so sooner or later I will have to change it.

What about water pump? Should I change it or wait until it fails?


i changed water pump first even tough £400 as if it fails it could be the end of the engine

[_Nathan_]

Shim - have you considered the lower temp stat, might help keep things under control while you work out what is going on?

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=11531417215

[shimmy]

Shim - have you considered the lower temp stat, might help keep things under control while you work out what is going on?

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=11531417215


its a possible option :thumbs:

[shane@mbtech]

Shim - have you considered the lower temp stat, might help keep things under control while you work out what is going on?

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=11531417215


Is this the tropical stat the gorilla talked about?

Its worth a punt for the price Shimmy

[_Nathan_]

Think so, that is the one I have in mine anyway.

[shimmy]

But it does not increase the cooling it just makes it start earlier

on the odd occassion mine gets hot it's heat soaked at full throttle on. Boiling day

not gonna make any difference except make it start half a lap later!

[_Nathan_]

Wasn't saying it is a complete fix, just to help you keep it under control until you find the root cause :)

It isn't going to make things worse either way!

[escarolo]

Also, the Motorsport T-stat will turn on the SES light.

I ordered SACHS fan clutch yesterday, let´s see what happens.

Best Regards

[_Nathan_]

SES light?

[Curly]

But it does not increase the cooling it just makes it start earlier

on the odd occassion mine gets hot it's heat soaked at full throttle on. Boiling day

not gonna make any difference except make it start half a lap later!

Had one on the rust bucket didn't seem to make any diffence

[escarolo]

SES light?

Yes, this one

http://i31.tinypic.com/1z1v9zp.jpg

[_Nathan_]

I haven't got that I don't think?

[glendog74]

I haven't got that I don't think?

I'm sure you have - unless you junked the original dash?

From the owner's manual: 'Engine' light - Exhaust emission values have deteriorated.

[_Nathan_]

I meant I don't have it on!

[cantfind1]

Think you guys should try one of these, those lower temp ones are useless they don t provide any more flow just open earlier, I have one of these modified ones in my car and can honestly say it works! Plus no engine light!

http://www.ca-automotive.co.uk/single_prod-cHJvZF9pZD0xNjcz.html

[cantfind1]

Shimmy, its prob your rad blocked internally, it happens, I know you have alrady replaced all the other bits of the cooling system.

You could always go for one of these.

http://www.ca-automotive.co.uk/single_prod-cHJvZF9pZD0yNzE5JmNhcl9tYWtlPWJtdyZjYXJfdHlwZT1lND ZtJmNhdF9pZD03JmNvbXBfaWQ9MTM2.html

It s what I will be sticking in mine when it needs replacing.

[shimmy]

Think you guys should try one of these, those lower temp ones are useless they don t provide any more flow just open earlier, I have one of these modified ones in my car and can honestly say it works! Plus no engine light!

http://www.ca-automotive.co.uk/single_prod-cHJvZF9pZD0xNjcz.html


I almost nicked it today!

[cantfind1]

Haha, oh well in that case you don t need to buy one just go and take yours out and take a look at mine and modify yours the same way. Basically cut the slit and snip the spring, not too much though get it exactly like mine.

If mine s missing I will find you!!:thumbs:

[shimmy]

If mine s missing I will find you!!:thumbs:


finding me will be easy, getting it back may not be ;)

[The Gorilla]

Hi,

The S54 water pump, pumps at a
given flow rate.

The amount of water flow will be dictated by
the smallest restriction in any given flow path.

The Thermostat when open is not the smallest
restriction in the flow path.

The Thermostat housing is prior to the
crossflow water ways that cool the head
and the block on the flow path.

All the CA Stat can do is increase the volume of flow
from the Thermostat location to the cylinder head,
about 150mm, where the water will then again flow at
the same rate as any thermostat.

The flow rate can only be altered by increasing the
flow rate of the water pump which the CA Stat does
and can not do.

The 55 degree Stat was designed so that the stat does not
fluctuate in opening where the ambient air temp at say 70
mph is 60 degrees and the static air temp is say 85+.
Even brief stat closeuers can cause differring expansion
rates bewteen the S54 Alloy head and steel block, whereby
a more steady rise and fall in heat sink temps is preferred.

Regards,

The Gorilla.

[cantfind1]

Hi,

The S54 water pump, pumps at a
given flow rate.

The amount of water flow will be dictated by
the smallest restriction in any given flow path.

The Thermostat when open is not the smallest
restriction in the flow path.

The Thermostat housing is prior to the
crossflow water ways that cool the head
and the block on the flow path.

All the CA Stat can do is increase the volume of flow
from the Thermostat location to the cylinder head,
about 150mm, where the water will then again flow at
the same rate as any thermostat.

The flow rate can only be altered by increasing the
flow rate of the water pump which the CA Stat does
and can not do.

The 55 degree Stat was designed so that the stat does not
fluctuate in opening where the ambient air temp at say 70
mph is 60 degrees and the static air temp is say 85+.
Even brief stat closeuers can cause differring expansion
rates bewteen the S54 Alloy head and steel block, whereby
a more steady rise and fall in heat sink temps is preferred.

Regards,

The Gorilla.


That´s all very well and good mate, but the modified thermostat works, its a proven product. Theory sometimes doesn´t work in practice.

[The Gorilla]

Hi,

Cantfind1,

I always want to learn.

So please explain how if
a water pumps flow rate is 'x'
how the water flow is increased
without the smallest restriction
in the flow path being increased
and the pumps volume being increased ?

The CA Stat can no more increase
the water flow than any other stat.

Its not theory either I'm afraid.

Regards,

The Gorilla.

[shimmy]

I'm missing something here

if the stat opens it increases flow, that is what it is there for

if the CA stat let's water pass when stat closed surely that is increasing flow prior to the stat opening as a minimum unless the pump somehow changes flow when stat triggered.

Surley the stat must be the most restrictive part of the system otherwise it does no good at all and has no affect when opened.

[shane@mbtech]

I'm missing something here

if the stat opens it increases flow, that is what it is there for

if the CA stat let's water pass when stat closed surely that is increasing flow prior to the stat opening as a minimum unless the pump somehow changes flow when stat triggered.

Surley the stat must be the most restrictive part of the system otherwise it does no good at all and has no affect when opened.

The gorilla is saying that thermostat is not the smallest part in the loop so by removing it, it will not increase flow so to speak.


The CA stat in my eyes will just make the engine run slightly cooler, much the same as the 55* stat does, different ways but much the same outcome.
The CA stat is open all the time slightly, making it run cooler, whereas the 55* stat opens earlier in order to let it run cooler.
Except in my view the CA stat cannot maintain a constant temp like either the standard stat or the 55*stat does.
I personally would opt for the 55* stat as I think it would be safest.


The function of the stat is

1. To bring the engine up to optimum operating temperature as quickly as possible and
2. To maintain the engine at optimum operating temperature thereafter.


An internal combustion engine operates best at high temperature, with the coolant in the cooling system typically above 80°C - 85 °C (176°F - 185 °F). Wear on the moving parts is reduced and thermal efficiency is increased. Lower temperatures result in increased fuel consumption and reduced engine life. Higher temperatures result in overheating with the danger of premature combustion of the fuel air mixture, also know as detonation or knocking, and damage to engine components.

To ensure that the engine reaches optimum operating temperature as quickly as possible, the thermostat restricts the flow of water from the engine to the radiator to virtually zero (a small flow is required so that the thermostat experiences changes to the water temperature as the engine warms up) until the engine reaches optimum temperature. The thermostat then opens up to allow coolant to flow through the radiator to prevent the temperature rising higher.

Once at optimum temperature, the thermostat controls the flow of coolant to the radiator so that the engine continues to operate at optimum temperature. Under peak load conditions, such as labouring slowly up a steep hill whilst heavily laden on a hot day, the thermostat will be approaching fully open because the engine will be producing near to maximum power while the velocity of air flow across the radiator is low. (The velocity of air flow across the radiator has a major effect on its ability to dissipate heat.) Conversely, when cruising fast downhill on a motorway on a cold night on a light throttle, the thermostat will be nearly closed because the engine is producing little power, and the radiator is able to dissipate much more heat than then engine is producing. Allowing too much flow of coolant to the radiator would result in the engine being over cooled and operating at lower than optimum temperature. A side effect of this would be that the passenger compartment heater would not be able to put out enough heat to keep the passengers warm.

The thermostat is therefore constantly moving throughout its range, responding to changes in vehicle operating load, speed and external temperature, to keep the engine at its optimum operating temperature.

[Bounce]

Very good right up Lawsy.:thumbs:

[grumps]

Very good explanation ever thought of being a college lecturer! much better than when i was at college!.

[escarolo]

A

[magnust]

After almost two years, I have changed OEM stat, viscous fan clutch, water pump, temp sensor, coolant and cleaned water radiator...and the issue is not fixed. I'm getting crazy...:(

:banghead:

[cantfind1]

After almost two years, I have changed OEM stat, viscous fan clutch, water pump, temp sensor, coolant and cleaned water radiator...and the issue is not fixed. I'm getting crazy...:(

have you changed both temp sensors??

in this case you may have blocked water ways in the engine block somewhere..obviously something stopping the flow of fluid around...

[escarolo]

have you changed both temp sensors??

in this case you may have blocked water ways in the engine block somewhere..obviously something stopping the flow of fluid around...

I have changed the one that is in radiator hose, is there another one?

[The Gorilla]

Hi,

There is a Water Temp stat in the ''alloy'' water
pipe under the Throttle Bodies.

No 18 on the attached link-
http://bmwfans.info/parts/catalog/E46/Coupe/Europe/M3_CSL-S54/browse/engine/cooling_system_water_hoses/

Replace this Temp Stat as its cheap.

If you still have high water temp then-

Do you have an Old Thermostat ?

If you do, open the Stat and 'fix' it
so that's it permantley in the Open
Position.

You require this, as to just remove the stat
can cause water cavitation.

Run your car and see what the temps
do with Stat permantley open.

If car runs Ok, then purchase the Tropical / MS
55 deg stat, if not, then you need to test
flow.

Hope that helps,

Regards,

The Gorilla.

[escarolo]

Hi,

There is a Water Temp stat in the ''alloy'' water
pipe under the Throttle Bodies.

No 18 on the attached link-
http://bmwfans.info/parts/catalog/E46/Coupe/Europe/M3_CSL-S54/browse/engine/cooling_system_water_hoses/

Replace this Temp Stat as its cheap.

If you still have high water temp then-

Do you have an Old Thermostat ?

If you do, open the Stat and 'fix' it
so that's it permantley in the Open
Position.

You require this, as to just remove the stat
can cause water cavitation.

Run your car and see what the temps
do with Stat permantley open.

If car runs Ok, then purchase the Tropical / MS
55 deg stat, if not, then you need to test
flow.

Hope that helps,

Regards,

The Gorilla.

Thanks a lot, Gorilla.

I replaced the stat using the OEM one. I bought that sensor but finally i did not change it because i had to remove the air intake.

Tomorrow i am going to remove front bumper, clean the AC condenser and replace the sensor n 18.

Also, i have ordered Motul Mocool aditive

Let's see what happens...