Issue

C

CryptoWhale

Member
Following on from my last thread where I had the expansion tank replaced for a lovely sum of £250 as it was leaking.


First day temp gauge jumped up and down from the center to 3/4 of the way.

Coolant low light has been coming on every so often, mainly while the heater is on.

I've had to top the coolant up by about 2 litres since getting it back from the garage.

This morning driving to work the temp gauge shot up to the red but and beeped, fans kicked in and then went straight back to the middle.

Have I been unlucky and bought an absolute dog of a car or are constant issues the norm on these Z4s? I've spent an absolute fortune since buying it in January.

And it now looks like I'm going to be paying out even more money to fix this issue. Just hoping it's not the water pump
 
I would send it back to the garage that did the work on the expansion tank and tell them you believe there is a possible air lock since the replacement and get them to see if they can find out what's wrong, after all you spent quite a lot of money just to have your expansion tank replaced,
Saying that these are not new vehicles and at this age you can expect things to go wrong, expansion tank is a very common failure along with a few others to boot. Sorry to hear you are disillusioned with your relatively new purchase and that the charm of Z4 ownership is wearing thin.
 
Supporting the airlock theory there

Deffo get it back to the garage for them to resolve
 
Thanks for the reassurance guys. I'm hoping that's all it is.

How easy is it to sort myself if it is an airlock? Is it just a matter of bleeding the system using the ignition on / heater low and gas pedal for 10 seconds?

I'm reluctant to take it back to the garage if it is due to their incompetence and to let them work on it again, along with the fact I'm working all week so they will be closed by the time I can get it there. :thumbsdown:
 
Where you based?

What engine size is it?

It’s not difficult to do but I would be taking back to the place that did it- you paid your hard earned cash!!
 
Sounds like an airlock in it from what you describe, when you bleed it you need the heater set to max hot and have the car as high as you can get it at the front so the filler is at max height above the heater matrix. with cap off to begin with run the engine up to normal operating temp and watch the air escaping at the filler hole. Once you see only a small amount of air escaping (bubbles) put the cap on and open the bleed screw and watch for air (bubbles) escaping, once only coolant leaks from it then shut the bleed screw. All air should have been expelled so test drive it and monitor the guage.
I have a vaccum bleeder which works well but you need a compressor to use it, after draining the system the vaccum bleeder is connected via the filler and with compressor running it sucks all the air out of the system, the rubber coolant pipes are seen to collapse on themselves as the vaccum increases. You then by shutting the valve on the tool monitor the guage on the tool to see if the vaccum holds, if it dosn't then you have a leak somewhere in the system. If it holds then you can then use the tool to suck the replacement coolant mix into the system used it on a Z3 with similar issues to you and it got rid of air trapped in the heater matrix ok. Once system is refilled run the engine up to temp and use the bleed screw to expell any air left in the system. Goy very little air out after using the vaccum filler on the Z3.
 
[ref]CryptoWhale[/ref], not sure if you've said before, but whereabouts are you?
I'd advocate going back to the garage, but if you're not confident they'll sort it and you don't want to yourself, then maybe another member close by would help out.
I would, but doubt you're near to me?
 
Cryptowhale, Don't lose heart mate. I presume your car is a 3.0Si vintage 2007'ish and on 100k miles'ish. It's just knocking on a bit and it's been around the block. Most issues on E85/86 are age/wear related and some have been maintained better than others or had stuff replaced previously. Everybody seems to go through a rough patch or two with these cars but then you get it straight and sorted and have a good 'purple patch' and all is then right with the world :D
 
When things stop going wrong with mine I think I'll probably get bored and sell it.

EML came on the other day which might fill some with dread, but I thought "Ooo, I wonder what that could be!" (split intake boot) and skipped off to get the laptop and spanners out again.

My point being, if you are even slightly interested in doing this kind of thing yourself, I'd say have a go at bleeding it. Learn a little more and gain confidence each time something goes wrong and eventually you can wave goodbye to those pesky labour charges.

If not, you paid the garage for the job so take it back to them to finish it properly :thumbsup:
 
I've got the 3.0si N52 engine. In what order do I remove the cap and bleed screw and put back on as there seems to be conflicting info? Am i correct in thinking the procedure is the following;

Remove cap and bleed screw
Top coolant up
Put cap and bleed screw back on ( this is what I have read - All though I would have thought bleed screw needs to be off still)
Initiate bleed procedure (ignition 2, full heat, first fan setting, accelerator for 10 sec).

@enuff_zed - I'm in Sheffield buddy so quite a bit away but cheers :thumbsup:

@patriot66 - Bang on, all though its touching 113k - Don't get me wrong the car is great fun but it's been more problematic than most of my previous cars some of which where a lot older and higher mileage than this. It's my first BMW I did not expect to be having a different issue crop up every other week, just disappointing because the financial cost of running the car is really taking away the fun now :thumbsdown:
 
CryptoWhale said:
Am i correct in thinking the procedure is the following
Click to expand...
17 00 039 Venting cooling system and checking for leaks (N52)

Warning!
Danger of scalding!
Open sealing cap only after engine has cooled down.
Wear protective gloves and goggles.

Important!
Follow instructions for working on cooling system.

Electric coolant pump!
Observe special venting procedure after replacing engine or heating cooler.

Only when refilling!
Use only recommended coolant.
Observe mixture ratio.
Perform filling operation slowly.

Adjust coolant level to MAX.

Maximum cold fill level:
Top edge of coolant expansion tank is level with marking (2).

Important!
The following venting procedure is necessary e.g. when a part is replaced in the cooling system or when the cooling system is refilled.

Only when venting!
Open cap (1) on coolant expansion tank.
Open vent screw (2).

Important!
Fill coolant expansion tank up to lower edge of filler neck with recommended coolant.

Pour in coolant slowly.

Close vent screw (2) when bubble-free coolant emerges

Close cap on expansion tank.

Do not open the coolant expansion tank cap during the venting procedure.


Connect battery charger.
Switch on ignition.
Set heater to maximum temperature, activate ”Automatic” button, then reduce fan to lowest setting.
Press accelerator pedal for 10 seconds to floor. Engine must not be started.
The venting procedure is started when the accelerator pedal is pressed and takes approx. 12 minutes.
Check cooling system for leaks.
If the venting procedure has to be carried out several times, allow DME to drop completely (ignition key removed for approx. 3 minutes), then repeat from Point 3.

Checking coolant level: Important!
Check coolant level at a maximum coolant temperature of 30 °C.

If ambient temperature is above 30 °C, allow engine to cool down at least to ambient temperature.


Open cap carefully.

Fluid level is OK when top edge of coolant expansion tank lies between both markings (1 and 2) on float needle.

Minimum cold fill level:

Top edge of coolant expansion tank is level with marking (1).
Maximum cold fill level:

Top edge of coolant expansion tank is level with marking (2).
If necessary, top up coolant.

Close cap on expansion tank.
 
When I replaced the oil filter housing gaskets I ran coolant flush through a few times using the method, then rinsed, then filled. Don't be surprised if you need to run it a few times.
 
It's a shame you have been having issues with your car because the 3 litre N52 is a great engine!

I've got one in my E90 330i daily that has done 115K and it still drives really well.

This should have been sorted by the garage that replaced the expansion tank, but if they aren't familiar with BMWs fitted with electric water pumps they might not have done the electronic bleed procedure.

You really want to use a good BMW Indy garage - it can save you so much pain!

I've got two near me run by ex-Sytner guys and they are brilliant, but if you gave an indication of your whereabouts I'm sure someone on here could give you some suggestions. :thumbsup:
 
Scooba_Steve said:
CryptoWhale said:
Am i correct in thinking the procedure is the following
Click to expand...
17 00 039 Venting cooling system and checking for leaks (N52)

Warning!
Danger of scalding!
Open sealing cap only after engine has cooled down.
Wear protective gloves and goggles.

Important!
Follow instructions for working on cooling system.

Electric coolant pump!
Observe special venting procedure after replacing engine or heating cooler.

Only when refilling!
Use only recommended coolant.
Observe mixture ratio.
Perform filling operation slowly.

Adjust coolant level to MAX.

Maximum cold fill level:
Top edge of coolant expansion tank is level with marking (2).

Important!
The following venting procedure is necessary e.g. when a part is replaced in the cooling system or when the cooling system is refilled.

Only when venting!
Open cap (1) on coolant expansion tank.
Open vent screw (2).

Important!
Fill coolant expansion tank up to lower edge of filler neck with recommended coolant.

Pour in coolant slowly.

Close vent screw (2) when bubble-free coolant emerges

Close cap on expansion tank.

Do not open the coolant expansion tank cap during the venting procedure.


Connect battery charger.
Switch on ignition.
Set heater to maximum temperature, activate ”Automatic” button, then reduce fan to lowest setting.
Press accelerator pedal for 10 seconds to floor. Engine must not be started.
The venting procedure is started when the accelerator pedal is pressed and takes approx. 12 minutes.
Check cooling system for leaks.
If the venting procedure has to be carried out several times, allow DME to drop completely (ignition key removed for approx. 3 minutes), then repeat from Point 3.

Checking coolant level: Important!
Check coolant level at a maximum coolant temperature of 30 °C.

If ambient temperature is above 30 °C, allow engine to cool down at least to ambient temperature.


Open cap carefully.

Fluid level is OK when top edge of coolant expansion tank lies between both markings (1 and 2) on float needle.

Minimum cold fill level:

Top edge of coolant expansion tank is level with marking (1).
Maximum cold fill level:

Top edge of coolant expansion tank is level with marking (2).
If necessary, top up coolant.

Close cap on expansion tank.
Click to expand...

Cheers for this. Still confused though because if the bleed screw and the filler cap need to be put back on before initiating the bleed procedure... Where does the air go that's in the system?
 
CryptoWhale said:
Where does the air go that's in the system?
Click to expand...
Back into the expansion tank, so you top it up and if the level doesn't go down you're done.

If you have a vacuum kit that will do it in one go while also indicating any leaks.
 
I've done this process a few times now and I'm still getting the temp gauge jumping up and down going to the red and staying there for a minute or so before jumping back down to the center.

The low coolant light does not come on now when I have the heaters on though, unlike before.

When I do the bleed procedure, it sounds like the water pump is only working in intervals. Is this how it's supposed to work? Or is it supposed to be constant? I've seen videos on YouTube with the expansion cap off during bleed procedure and there is a constant flow of water into the expansion tank. Mine doesn't do this
 
CryptoWhale said:
I've done this process a few times now and I'm still getting the temp gauge jumping up and down going to the red and staying there for a minute or so before jumping back down to the center.

The low coolant light does not come on now when I have the heaters on though, unlike before.

When I do the bleed procedure, it sounds like the water pump is only working in intervals. Is this how it's supposed to work? Or is it supposed to be constant? I've seen videos on YouTube with the expansion cap off during bleed procedure and there is a constant flow of water into the expansion tank. Mine doesn't do this
Click to expand...

I'm not an expert on the N52 engine but the pump should work constantly

Would explain why you are getting warnings and fluctuations

Would that be a power supply issue to the water pump- assume you have checked connections/plug?
 
CryptoWhale said:
I've done this process a few times now and I'm still getting the temp gauge jumping up and down going to the red and staying there for a minute or so before jumping back down to the center.

The low coolant light does not come on now when I have the heaters on though, unlike before.

When I do the bleed procedure, it sounds like the water pump is only working in intervals. Is this how it's supposed to work? Or is it supposed to be constant? I've seen videos on YouTube with the expansion cap off during bleed procedure and there is a constant flow of water into the expansion tank. Mine doesn't do this
Click to expand...

What’s the mileage on your car? It sounds as though your electronic pump’s starting to expire, are you getting the radiator fan chiming in from a cold start? :?
Rob
 
Smartbear said:
CryptoWhale said:
I've done this process a few times now and I'm still getting the temp gauge jumping up and down going to the red and staying there for a minute or so before jumping back down to the center.

The low coolant light does not come on now when I have the heaters on though, unlike before.

When I do the bleed procedure, it sounds like the water pump is only working in intervals. Is this how it's supposed to work? Or is it supposed to be constant? I've seen videos on YouTube with the expansion cap off during bleed procedure and there is a constant flow of water into the expansion tank. Mine doesn't do this
Click to expand...

What’s the mileage on your car? It sounds as though your electronic pump’s starting to expire, are you getting the radiator fan chiming in from a cold start? :?
Rob
Click to expand...

Apologies I thought the pump had already been replaced!!
 
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