Another E46 cooling system failure diagnosis

[Zound]

Hi Guys,

I'll try keep it short.

1.Orange Coolant level warning on instrument cluster. Goes away after about a minute. Returned again after about 20mins and then again went away after a couple mins. I decided that since it was intermittent, that it didn't need immediate attention.
2. Coolant was filled correctly prior to Roadtrip.
3. After about 2 hours into trip, temp gauge jumps into the red. I immediately switch off engine and coast to safe location.
4. Checked coolant, all of it was gone. No visible leak or rupture points.
5. Acquired some water to try fill up system to get it to a garage.
6. Filled over 6 litres of water into the cooling system.
7. Started engine, put heater to max and fan speed to low and attempted to bleed the system.
8. Bleeding seems impossible since the expansion chamber starts violently bubbling the water out of the cap exit.
9. Tried bleeding system for hours, but with no success. Thought it might be thermostat since the far side radiator hose remained cold and evidently was not receiving any flow.
10. Called insurance, got flatbed tow truck, car now at home.

I have removed water pump, which seems to be in good condition and has a metal impeller (interesting). I have removed thermostat which also seems to be in good condition (wahler brand) - I'm not sure whether this unit can be tested with the hot water method. The hoses don't seem to be leaking and neither does the radiator.

This leads me to believe it can only be the expansion tank?

Read codes this morning and got 1)7D Activation electric fan and 2)7B Activation map cooling

Do these symptoms all point to a certain component?

Thanks in advance

 

[Gizmo]

Fault 1. Check that the fan is working. Fault 2. Replace thermostat.
Check the oil cap for milkyness.

---

How does the back of the water pump pulley look?

 

[GPGrobler]

From the symptoms you describe, it sounds like a head gasket failure to me. :sorry:

 

[Gizmo]

I decided that since it was intermittent, that it didn't need immediate attention.

The error of your ways.

 

[Maljan]

If the oil is not milky, a pressure test might reveal a leak. Those suckers are not always easy to spot.

 

[GPGrobler]

I really hope the oil is not milky, about the leak, that is so true. I also just had water vanishing from my car's cooling system.

No milky oil, no bubbling of the water when the car was idling, no water under the car, but after I replaced the radiator and hoses the water stopped vanishing.

 

[akajee]

I think the head gasket is gone because you water/coolant "dissappeared".

Check this out, I think this is an excellent Video to determine the extent of the problem if you have all the tools, but at minimum, you will be able to determine if the head has a problem be it cracked or the gasket.

7B Activation map cooling is DEFINATELY the thermostat. I had the same code on my 325 but mines did not overheat.

BTW, for the electric fan, you can activate it using the software so that you can actually see if it works.
I would also check the Viscus - check if there is a "gel" with dust stuck to the front, if there is, then that will also need replacement.

Link

---

This was the error I got for the Thermostat.

 

[Zound]

Thanks for the responses Gents, It's much appreciated.

So fearing the worst, my dad and I started doing tests for HG failure.
First: Compression Test. Interestingly, all cylinders came back with readings between 10.2 and 10.5 bar. The reason that is interesting is if any of you recall, my 5th cylinder ate the DISA pin which resulted in a compression drop to 8.5 bar. This cylinder now returns 10.5 on the compression test which makes me think the heat cycling of the car has helped straighten the possibly bent valves from the prior incident?

Second: Having watched the informative video provided by akajee, I decided to do a leak down test. I have confirmed that the thermostat is working by applying 12V across its terminals. So I cleaned up all the components and hoses and reassembled the cooling system. I continued to apply 12V to the thermostat and fill the system with water to ensure capacity is reached. Then one by one brought each cylinder to TDC and applied approx 6 bar of compressed air via my compressor and a diy pressure rig. If the HG was blown, I'd expect that through one of the 6 cylinders, the air would push through and be visible in bubbles/movement in the coolant and the top of the expansion tank. After testing each cylinder, not one provided even minuscule visible movement/bubbles in the coolant.

Third: Reassembled everything and tried to look for leaks under pressure and bleeding. Once again, set heater to 32C and blower speed to minimum. This time, no violent expulsion of water. I fill it to the top and put the cap on, hoping that any hairline crack or pressure induced leaks will be revealed. Monitored all engine operating stats via OBD and it seems the thermostat is perfectly functional, opening at approx 93C and causing the radiator outlet temp to start rising as the water starts flowing through the radiator. After 20 plus minutes of idling the car, could not identify any visible leaks. Also the car did not overheat and all cooling components seemed to be fully operational.

The only issue that arises is the small amount of vapour being expelled by the exhaust.This has been a problem with the car ever since I bought it, and is a tell tale sign of HG failure, a warped head or cracked block etc. The car only expels small visible traces of water vapour under idle conditions and has never been visible under load or applied RPM.

So I'm still no closer as to identifying what exactly has happened. Most importantly, why did the water exit/disappear and why could I not rebleed the system if it was simply a minor leak.

Going to give this a try today, provided I can get my hands on it, apparently Big Boys Toys Pretoria might have stock.

Rislone Head Gasket Fix

 

[Gizmo]

The thermostat on the M54 works like any normal thermostat, its only on the freeway over 100km/h when it receives voltage from the DME that closes it slightly raising the coolant temperature to give better fuel atomisation and thus saving fuel.

Bent valves don't straighten themselves, its more likely the valve seat has worn in way that is making a seal again. When the valve turns under normal operation you will lose the seal again.

 

[Zound]

Have any of you ever used a chemical sealant for Head Gasket repair, experiences?

 

[Gizmo]

I don't believe in the stuff, its like cholesterol for engines.

 

[Maljan]

Maybe as a get you home bush mechanic trick but I'm not convinced that it will
work. Or last for long even if it does work...

 

[Zound]

So got the Rislone Head Gasket Fix (Makro Centurion) and applied it this afternoon. Once again. Monitored all cooling system components and everything seems to be operating correctly.

Have left the car to cool over night and will test tomorrow morning. Naturally, I'll be carrying a couple 2litre bottles of water and a tow rope.

Have just learnt about the hidden instrument cluster function allowing you to see the coolant temperature. Quite cool!

 

[Gizmo]

Share cluster function please?

 

[Legacy]

Share cluster function please?

http://www.bimmerforums.com/forum/showthread.php?597288-E46-Easter-Eggs

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 function s

BMW E46 On-Board Computer (OBC) Hidden Codes
Example description
1 Car Engine and cluster data
1.0 46nnn Chassis nr/VIN serial number (last 5 digits)
1.1 4nnn K-number
1.2 690236 Cluster Part #
1.3 045210 Coding (04)/diagnosis (52)/bus index (10)
1.4 1200 Week (12)/year of manufacture (2000)
1.5 09_160 Hardware (09) and software # (16.0) of cluster
1.6 Not used
1.7 04__44 CAN-version (04) KI-revision index (44)
2 (test) Cluster System Test - Activates the gauge drivers,
indicators and LEDs to confirm function
3 SI Data
3.0 1098 Used fuel in liters since last SI (Service Inspection)
3.1 0231 Periodic inspection days; elapsed days (since last SI)
4 Momentary Consumption
4.0 0145+ Instant fuel consumption - 0145=14.5 liters/100km
4.1 0018 Instant fuel consumption - 0018=1.8 l/Hour
5 Distance Gone Consumption
5.0 082 Average mileage; 082=8.2 liters/100km
5.1 0536 Calc. km to refuel (momentary distance to go)
6 Fuel Level sensor inputs in liters
6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
6.2 0442+ Indicated value (44.2) and tank phase
7 Temperature and Speed
7.0 021+ Coolant/Engine temperature (2.1C)
7.1 130 Ambient/Outside temperature - chg met 5 pts. 125/130/135
7.2 + Engine speed / Current RPMs 1/min
7.3 + Vehicle speed / Current Speed in km/hour
8 Input value in HEX form
8.0 1d0+ System voltage ADC-Value Hex code
8.1 26C33C+ ADC Values HG left/HG right
8.2 0000 ADC Value brake degradation sensor (000=o.k.)
8.3 18C ADC Value outside temperature
9 Battery
9.0 140 Battery Voltage - 140 = UB 14.0v
9.1 242013+?
9.2 074_78+?
9.3 0011+?
10 Not used
11 Not used
12 Not used
13 GonG Gong Test
14 Not used
15 Status cluster I/O-ports (bit codes) 0=low; 1=high
1st-belt contact, seat belt fastened=0; 2) ignition lock contact, key inserted=0; 3) door contact, door open=0; 4) clock button pressed=0; 5) SI reset=0, for reset=0; 6) EGS transmission failure=0
Status Digital Outputs (bits) 0=inactive, 1=active
1) Gong output; 2) Brake warning lamp; 3) Low fuel warning lamp; 4) EGA lamp; 5) seat belt lamp; 6) manipulation dot
16 Not used
17 Not used
18 Not used
19 Lock Status; unlocks functions in range 3-18
19.0 L-On/L-Off Unlock: press button when "L-Off"
20 Not used
21 Software Reset; reset OBC settings
00 End of test

 

[Zound]

Okay, so took the car on its first drive (~40km) after the incident.

Journey was incident free. Temperature and coolant level behaved itself. Also, cant seem to see any trace of water vapour from the exhaust at idle any more. Exhaust tips are dry and Idle seems to be smoother and quieter too.

Will continue to monitor closely this week and if all remains fine, then I'll go get some anti freeze and mix some fresh new coolant for the system.