Cooling System Issues

[VaTechZHP]

Car has been throwing an intermittent low coolant light, but the car hasn't budged at all from center (I know its not very accurate) over the past few weeks.

I topped it off with some coolant, only to then realize it had dumped out while I was at work one day.

Today, I actually spent some time messing around with the car and figured I'd take a look at the cooling system to see what was going on.

The car was warm from just driving and when I took the top off, I didn't see much in the expansion tank, so I added some to the high level (even thought that indication is cold)

While letting the car adjust and kick out any air that might be in the system, the expansion tank seemed to be "volcanoing" out a bunch of coolant/water mix.

I let this go on for some time and didn't see any change. The coolant would overflow out of the top and what would seem like pulsating with a lot of hissing like there seemed to be a lot of pressure in the system while the car was hot and running.

I have since turned the car off to let it cool down for while and then will recheck the level to see where it settled and then see what happens tomorrow.

Any suggestions on things to check? The entire system was replace last summer, but it might look like the upper radiator hose is weeping a bit which I'm planning to replace shortly.

Here is a video of what the car was doing. Click the image and it might work? I've never tried to post a vid before!

http://i43.photobucket.com/albums/e388/andrewelmore/th_VIDEO0073_zps842cae91.jpg (http://i43.photobucket.com/albums/e388/andrewelmore/VIDEO0073_zps842cae91.mp4)

Thanks!

[kayger12]

It's a pressurized system, so I would expect it to do that with the cap removed. Don't see any issue with it.

I would imagine you either have a crack in your expansion tank or a bad hose at the connection to the tank.

What brand exp tank did you have installed when you did the overhaul?

[VaTechZHP]

That is my guess. I'm going to start with the hose since its easier. They were an off brand (cheaped out for some reason...) but I think I'm going to replace them with some oem parts and see how that works out, unless I can get some cool looking silicon hoses!!! (likely not going to go that route...)

Thanks!

[Avetiso]

It's a pressurized system, so I would expect it to do that with the cap removed. Don't see any issue with it.

I would imagine you either have a crack in your expansion tank or a bad hose at the connection to the tank.

What brand exp tank did you have installed when you did the overhaul?
+1

[VaTechZHP]

Well I just ordered a new upper OEM hose from ECS tuning along with a couple of other things for a few other cars of mine. I drove the car into work today to see what would happen and the needle was bouncing around a lot between the lower hash mark and the middle, and I had no heat the entire way in (about 20mins)

Seems I'll be parking this car for a little until the new parts come in, swap those over, bleed the system, and hope for the best!

[alexandre]

Bleed the system - there's an air pocket somewhere.

[Dave_B]

Yep, no heat = air in the system.

Turn the heat in the car set to 91, on the lowest fan setting. That causes the coolant to circulate the heater core where most likely the air pocket is trapped.

May take a time or 2 to do this. Took me 4 "bleeds" to be mine just right.

[aurelius]

And bleed air thru plastic screw on upper hose.

Depending on where you're seeing coolant residue on the upper hose, the bleeder screw could also be the leak source when the coolant is at normal running temp. Be sure the o-ring is still there and count the number of turns it takes to to remove the screw so that you do not over-tighten when replacing.

For more on how to avoid breaking the head off that screw, CLICK HERE (http://www.bimmerfest.com/forums/showthread.php?t=520253).

[VaTechZHP]

Thanks Aurelius,

I'll take another look and see if I can figure out where its leaking from. So far, the car seems to have fixed itself. Heat is fully functioning again, and coolant light has been off for some time now. I do have a replacement upper hose that should be at home to put in if I notice any additional leaks.

Thanks again everyone for the help!

The car has been running great and looks much better now that it has been washed!

[Dave1027]

It's a pressurized system, so I would expect it to do that with the cap removed...

Why can't you have the cap off while running the engine? I know you can't if it's hot because of expansion. But should be ok when cold.

I have been trying to learn this cooling system lately. It is looking like I received my zhp with the coolant over filled. I had some coolant leak out and I refilled. So if I understand correctly, the the top of the float stick should be at the rim when cold? Exactly what does the bleeder cap do? I would think it would be a bad idea to crack open the bleeder when the coolant is hot. I tried that and pressure began to escape. I would assume the system would not work correctly that way so I opened it again when cold to equalize the pressure.

[kayger12]

Why can't you have the cap off while running the engine? I know you can't if it's hot because of expansion. But should be ok when cold.

I have been trying to learn this cooling system lately. It is looking like I received my zhp with the coolant over filled. I had some coolant leak out and I refilled. So if I understand correctly, the the top of the float stick should be at the rim when cold? Exactly what does the bleeder cap do? I would think it would be a bad idea to crack open the bleeder when the coolant is hot. I tried that and pressure began to escape. I would assume the system would not work correctly that way so I opened it again when cold to equalize the pressure.

My comment was specific to his video where the coolant was splattering out all over his motor.

You can certainly have the exp tank cap off with the engine running. I've filled and bled that way in the past.

As for your ZHP, overfilling the coolant is common with the e46 cooling system and can certainly cause problems.

The bleeder cap allows air to escape at the highest point in the cooling system.

Whether hot or cold, you need to depressurize the system to bleed it, so if you leave the exp cap on and crack the bleeder screw when the coolant is hot, you will definitely vent pressure (and coolant) through the bleeder.

[aurelius]

There's a pictogram on a tab next to the ET cap which shows how to fill such that the float is within a certain range relative to the rim on the tank.

Or there should be, but it's detachable and may be AWOL, especially if your tank has been replaced. You can buy a new one.

Topping off and reading the float level should be done when coolant is stone cold.

[Dave1027]

Follow up question.

I've been checking the coolant every morning an noticed something odd. I think it might be normal.

When I open the cap the float rod is low, like a hair below the top of the neck. So I crack open the bleeder, air starts sucking in (indicating a vacuum has built up) and the float begins to rise.

What I think has happened is when I last drove the car the coolant heated up, it expanded the coolant and air in the system. The cap release some air and then closed off. The system cooled down then built up a vacuum.

So with all that said, what is the correct coolant level?

[danewilson77]

http://www.youtube.com/watch?v=noMikl7gOT4

[Dave1027]

Well OK. That youtube makes it simple. I won't open the bleeder any more. Going by that youtube method means my coolant is slightly low.

[WOLFN8TR]

Figured I would post here rather than starting a New Thread.

I just replaced my entire Cooling system except the radiator. New Hoses, Tstat, Exspansion Tank, Water Pump (Stewart), Pulleys, Belts, Auto Trans Tstat, Temp Sensors.

I did the Mechanical Fan swap to Electric Fan a month ago so my Electric Fan is New. Was working perfect before the cooling system overhaul now it will not come on. I bled the air out of the system properly. My fan used to come on at 185 degrees, I watched it climb to 198 degrees before I shut the car off and NO Fan?

It was late lastnight so I said screw it, will look at it tomorrow.
Anyone have this issue after doing their cooling system?
Could the new lower radiator sensor be bad even thou its reading the coolant temp?

Thanks....


Gary

[kayger12]

Is the sensor OEM or aftermarket?

Check/double check electrical connectors and fuses.

[WOLFN8TR]

Thanks for the response. I do believe its FAE, will go check.

Can someone verify what temp your Electric Cooling fan turns on at? Apparently our cars operate from 89-96 Celcius (192-205).

Before doing my cooling system it would turn on at 186 degrees or 86 Celsius. Today I let it idle and made sure all the air was out of the system. Turned the AC on and the fan does come on. Turned the Heat on and I have heat. The fan finally came on at 198 degrees or 92 Celsius. Seems to be fine but the fan comes on when the engine temp is higher than before. Could this be a difference in the Temp Sensor brand?

--------------------------------------------------------------------------------------------



OBDII Functions

Once you've selected what you want to monitor, you can only cycle through the options that are in that subsection. For example, if you select 7.0, engine coolant temperature, you can only cycle through other 7.x displays until you turn the ignition off and repeat these steps...

Instructions to access the hidden OBC functions:
1. Hold Trip Reset while turning ignition key to on position
2. OBC should show "Test"
3. Use Trip Reset to select function 19.0 that unlocks all the features
3. Wait for display to show "Off"
4. Depress Trip Reset for 1/4 second and release it
5. With no delay press Trip Reset several times to select one of the following functions

BMW E46 On-Board Computer (OBC) Hidden Codes

SubSection
Number Example Description

7. Temperature and Speed
7.0 021+Coolant/Engine temperature (21C)
7.1 130Ambient/Outside temperature - chg met 5 pts. 125/130/135



EDIT: FAE made in Italy
http://www.ecstuning.com/BMW-E46-330Ci-M54_3.0L/Engine/Cooling/Temperature_Sensor/

http://img.tapatalk.com/d/13/06/06/yvuma3e9.jpg

[WOLFN8TR]

When ordering your Cooling system parts DO NOT cheap out. I thought this drain plug for the Radiator was OEM but its MTC. I had a slow drip and had to put the old OEM plug back in.

Look at the oring diameter.
Look at the thread difference.
The top is bent on the MTC plug.

8945

8946


Gary

[billyjack]

Wow, thanks for the pictures of the drain plugs. Good example of shoddy aftermarket engineering. I'll buy some cheap parts for some cars but I always compare them to the old part I'm replacing to see if I can spot any differences or defects.