HELP WITH COOLING SYSTEM

[andyglym]

Been thinking about changing the coolant but it looks like it could be far more hassle than it's worth.
Good luck Stevo and Martin, hope you get the problems sorted.

Not changing it at the required intervals will just compound any internal corrosion issues mate, if any.

 

[Stevo7682]

Yeah Steve im afraid Andy is right these sorts of problem get created by not changing the coolant

 

[Bozzy]

I realise you're both right of course. It's just the thought of going through all the hassle you're having, when at present everything is fine and dandy.

Shame the coolant can't be changed in the same manner as brake fluid, to minimise air locks.

 

[Stevo7682]

I realise you're both right of course. It's just the thought of going through all the hassle you're having, when at present everything is fine and dandy.

Shame the coolant can't be changed in the same manner as brake fluid, to minimise air locks.

Lynne's zed not air locked had sat about with deteriorated coolant only driven short journey caused scale in cooling system trying to restore proper heating think im getting places though.

 

[Sean d]

I realise you're both right of course. It's just the thought of going through all the hassle you're having, when at present everything is fine and dandy.

Shame the coolant can't be changed in the same manner as brake fluid, to minimise air locks.

I need to do mine but keep putting off due to all the issues you see on this forum,

 

[mrscalex]

I was discussing with @Mnbrennan and he said this only seems to happen on M52s not M54s. Certainly I've not had this on an M54 (or M44) yet. What's different in an M52?

 

[Mazza]

I have just put in a new thermostat in mine 1.9 lt ( M44 I think?)and while doing it, flushed through the system. Also, I did blow the system through with an air line from a wet/dry hoover which did clear out a lot of standing water from the block. . I followed the instructions in the manual about raising the front end, having the heater on full and bleeding the system. It took ages as it does say slowly add new coolant, but went ok. I have since just topped up the expansion tank where it had dropped a bit but all seems ok and running at normal temp and heater etc all working.
While it was filling I did squeeze various pipes to move any air them.

 

[mid life crisis]

@TaffDaddy as discussed earlier

 

[g8jka]

My brother had all sorts of problems with the cooling system on his 2.8 E36. He was forever changing fluid, topping it up and bleeding it and in the end he changed the heater matrix and hasn't had a problem since. It may not be the problem with yours but worth looking into when you have the dash out. Hope you get it sorted soon.

 

[Mnbrennan]

My brother had all sorts of problems with the cooling system on his 2.8 E36. He was forever changing fluid, topping it up and bleeding it and in the end he changed the heater matrix and hasn't had a problem since. It may not be the problem with yours but worth looking into when you have the dash out. Hope you get it sorted soon.

Yes I suppose there is the theory that if the heater matrix is restricted, then air could be 'pooling' before the heater matrix as the rising water level when filling isn't pushing it through. Then when I get the revs up it pushes the air through and back around the system

Last night I did get the front end as high as I could, but doesn't seem to have helped.

I have now bought a pressure testing kit, as all of this has started (again) since I replaced the water pump. Air could be getting in somewhere. Hopefully this will help A) confirm that there are no leaks in the cooling system; and b) enable me to push the water round the system without the engine started.

 

[Mnbrennan]

Just a quick update on this.

I had been thinking about the 'pooling air' theory before the heater matrix.

On the drive home this evening I had again issues with overheating. The vents would go cold, the car would start to overheat and raising the revs to 5k would enable heat to come through the vents and the car would cool down to the normal level. This would repeat over and over. On coming into the estate the car would overheat.

My theory was that the restriction in the heater matrix wouldn't allow the air to be pushed through as the cooling system was filled with water. Only with increased revs and pressure from the water pump would enable the air to be pushed through, hence getting heat to the vents.

So this evening I raised the revs in the street (must have looked like a right hooligan) to get heat into the vents before switching the car off. The theory being that the heater matrix would now be full of water and the air past it, enabling it to be bled out. I went to bleed the system and only water came out. So I raised the front end and let it cool down.

I then popped off the top hose - full of air! So I filled with coolant through that hose and connected everything back together in the hope it would solve the problem....

I took it out for a drive, and immediately got constant heat through the vents rising with water temp (above 2k rpm again) and, most importantly, no overheating! I came back into the estate and again no overheating.

So whilst this appears to have solved the overheating issue (tomorrow will let me know better), I think I'll have to replace the heater matrix (which only appear to be available abroad!). The rest of the cooling system has been replaced (with good reason I would assume). That job can wait until I get the dash out to fit the extended leather.

I'll pop an update in tomorrow after a longer run to a course I'm on!

 

[t-tony]

Just a quick update on this.

I had been thinking about the 'pooling air' theory before the heater matrix.

On the drive home this evening I had again issues with overheating. The vents would go cold, the car would start to overheat and raising the revs to 5k would enable heat to come through the vents and the car would cool down to the normal level. This would repeat over and over. On coming into the estate the car would overheat.

My theory was that the restriction in the heater matrix wouldn't allow the air to be pushed through as the cooling system was filled with water. Only with increased revs and pressure from the water pump would enable the air to be pushed through, hence getting heat to the vents.

So this evening I raised the revs in the street (must have looked like a right hooligan) to get heat into the vents before switching the car off. The theory being that the heater matrix would now be full of water and the air past it, enabling it to be bled out. I went to bleed the system and only water came out. So I raised the front end and let it cool down.

I then popped off the top hose - full of air! So I filled with coolant through that hose and connected everything back together in the hope it would solve the problem....

I took it out for a drive, and immediately got constant heat through the vents rising with water temp (above 2k rpm again) and, most importantly, no overheating! I came back into the estate and again no overheating.

So whilst this appears to have solved the overheating issue (tomorrow will let me know better), I think I'll have to replace the heater matrix (which only appear to be available abroad!). The rest of the cooling system has been replaced (with good reason I would assume). That job can wait until I get the dash out to fit the extended leather.

I'll pop an update in tomorrow after a longer run to a course I'm on!

Hope that is the fix needed ......... for now Martin.

Tony.

 

[Stevo7682]

Just a quick update on this.

I had been thinking about the 'pooling air' theory before the heater matrix.

On the drive home this evening I had again issues with overheating. The vents would go cold, the car would start to overheat and raising the revs to 5k would enable heat to come through the vents and the car would cool down to the normal level. This would repeat over and over. On coming into the estate the car would overheat.

My theory was that the restriction in the heater matrix wouldn't allow the air to be pushed through as the cooling system was filled with water. Only with increased revs and pressure from the water pump would enable the air to be pushed through, hence getting heat to the vents.

So this evening I raised the revs in the street (must have looked like a right hooligan) to get heat into the vents before switching the car off. The theory being that the heater matrix would now be full of water and the air past it, enabling it to be bled out. I went to bleed the system and only water came out. So I raised the front end and let it cool down.

I then popped off the top hose - full of air! So I filled with coolant through that hose and connected everything back together in the hope it would solve the problem....

I took it out for a drive, and immediately got constant heat through the vents rising with water temp (above 2k rpm again) and, most importantly, no overheating! I came back into the estate and again no overheating.

So whilst this appears to have solved the overheating issue (tomorrow will let me know better), I think I'll have to replace the heater matrix (which only appear to be available abroad!). The rest of the cooling system has been replaced (with good reason I would assume). That job can wait until I get the dash out to fit the extended leather.

I'll pop an update in tomorrow after a longer run to a course I'm on!

Glad to see your getting somewhere hopefully if you've managed to purge a chunk of the airlock out it might sort itself .
You might well find level drops a bit as it cools and settles ..

 

[Mnbrennan]

Just a quick update

Over a 30 mile drive this morning it didn't overheat once, even in traffic, and I had a nice stream of constant warm air above 2k revs

 

[Stevo7682]

Just a quick update

Over a 30 mile drive this morning it didn't overheat once, even in traffic, and I had a nice stream of constant warm air above 2k revs

Great news Martin hope thats it sorted

 

[t-tony]

Just a quick update

Over a 30 mile drive this morning it didn't overheat once, even in traffic, and I had a nice stream of constant warm air above 2k revs

That's sounding promising mate. Fingers crossed

Tony.

 

[Antm72]

Great news and nice perseverance Hope it has resolved the issue

 

[Wilko58]

It seems I've now joined this illustrious gathering of Zeds that only throw out heat when being driven properly
I had the coolant changed over a year ago and don't think I had any issues with heating (didn't really need it) until this month. I also did the viscous fan delete around 9 months ago and never had any issues with overheating and still don't but can only get heat in when I raise the revs so it looks like I'll be trying the above solutions!
Where is the best place to flush the system from?
Cheers

 

[Mnbrennan]

Take the pipes off at the back of the engine bay and flush through there. I haven't got round to doing it yet!

 

[t-tony]

Best to "reverse" flush, so figure out which way the coolant normally travels, then flush in the opposite direction.

Tony.