[priapus6879]

Hi guys. Proud to finally be an official member of the forums, as I recently acquired a 525i anthracite blue with 144k on it. All in all, it runs great, however a month into ownership, I had to replace the radiator, which busted a hairline right above the BEHR logo on the rectangular seam. Thanks to all of you with very helpful info and links, the process was a breeze of a DIY. I just completed the process late last night and am still bleeding the bit of air out of the system, started late today due to the rain we have been experiencing in the northeast. All aside, I'm uncertain if the previous owner ever replaced the thermostat. Could this be the reason why I'm experiencing spikes in the temp needle? The OBC reads between 105-110f whilst idling, and somewhere around 115 or so during non-strenuous operation. Which seems to be normal from what I have read between here and other sources. During the short bursts of operation, the needle shoots towards the red, but of course I pull over before it has a chance to approach the red. Of course, once I pull over, the needle resets until another random act of driving causes it to spike again, any help? Do I just need to keep bleeding to release the air? Or could this be something more sinister? Any advisement would be greatly appreciated. Thanks again for all the help!
:roundel:

 

[edjack]

Did the temp spike before replacing the rad? If not, you have air in the system. Before you do any more bleeding, consider replacing the water pump, t'stat, and hoses, unless you know they've been replaced within the last 40k.

Examine the fan clutch: when rotating the fan, there s/b resistance like it's moving in molasses. If free to rotate, it needs replacing.

It's very difficult to remove the air in the cooling system of the six. Try this procedure from the TIS. It assumes you have already topped up the system. You may have to do this 2-3 times. Some even jack up the front of the car by a foot or so.

TIS M54 Bleed Procedure.

To ensure the cooling system is properly vented, it is absolutely essential to follow the steps below:

1. Undo cap but do not remove from expansion tank. This prevent excessive discharge of coolant from the expansion tank.

2. Turn on ignition.

3. Set heating controller to max. temperature.

4. Set blower to low level. This opens the heating valves and sets the auxiliary water pump in operation.

5. Run engine and briefly press accelerator pedal three to four times (approx. 4500 to 5000 rpm) to flush engine cooling circuit.

6. In doing so, do not run engine for longer than approx. 30 seconds; otherwise coolant will heat up and expand.

7. If the coolant level in the expansion tank drops in the process, top up the expansion tank to the max. cold fill level.

8. Screw on cap tightly and allow engine to warm up until thermostat opens.

9. Check coolant level. Pay attention to differing expansion tank designs.

Transparent expansion tank:

Allow engine to cool down before checking coolant level. Coolant temperature must not exceed 30 deg C. If ambient temperature exceeds 30 deg C, allow engine to cool down at least to ambient temperature.

Check coolant level and if necessary top up coolant to max. cold fill level (see marking on expansion tank).

Note:

The tank mark indicates the fluid level at approx. 20 deg C. Use recommended coolant only.

Black expansion tank:

Allow engine to cool down before checking coolant level. Coolant temperature must not exceed 30 deg C. If ambient temperature exceeds 30 deg C, allow engine to cool down at least to ambient temperature.

Check coolant level and if necessary top up coolant to max. cold fill level (the ball on the float needle is on the same level as the top edge of the expansion tank).

Note:

The tank mark indicates the fluid level at approx. 20 deg C. Use recommended coolant only.
RA

 

[rdl]

... stuff deleted ...
All aside, I'm uncertain if the previous owner ever replaced the thermostat. Could this be the reason why I'm experiencing spikes in the temp needle? The OBC reads between 105-110f whilst idling, and somewhere around 115 or so during non-strenuous operation. Which seems to be normal from what I have read between here and other sources.
... stuff deleted ...

I think the temperatures you quote are not normal for the I6 engine in your car. Posts discussing typical temperatures under light load report ~95C for the I6 and lower by 10C or more under load while the V8s run hotter. For example, my 2001 530 M54 will run 95-96C during idling and steady highway driving. But the temp drops to mid 80s in 3 to 4 seconds under heavier load, e.g. near full throttle acceleration to pass on the highway or even stiff (but not jackrabbit) starts from a stoplight. I'm pretty sure that you have the M54 engine too, just 2.5 liters vs the 3.0 in the 530. So something is not right with your engine.

Edjack has given you good advice. Although to get the car back on the road & assuming no temp problems before replacing the rad I'd do the TIS bleeding before replacing parts. It's easy to do, less expensive and no harm done if it fails to correct the problem.

However, given 144k miles, unknown history & a failed radiator you should be planning for the cooling system overhaul sooner rather than later, as in ASAP. The collected wisdom in the forums is an interval of 80 to 100k miles, so you're probably well overdue.

FWIW, I've found the TIS procedure Edjack quotes to be very effective in the 4 instances I've had to refill my cooling system. I've never had air left in the sytem & never had any temperature problems after a refill. I would add a recommendation that you confirm the auxillary water pump located on lower left side the the fan shroud is running during the bleed. It generates a considerable flow to assist sweeping air out ot the system. I learned this when I stupidly forgot to replace the bleed screw in the upper rad hose near the thermostat. I got a geyser 2 feet high with engine off but auxillary pump running. You should be able to hear a quiet hum or feel a slight vibration with finger on pump when it is running.

 

[champaign777]

I got a geyser 2 feet high with engine off but auxillary pump running.

this is what happened to me as well based on this DIY for M52 engine where it says left bleed screw open

http://forums.bimmerforums.com/forum/showthread.php?t=1423821

It appears to be wrong for M54 ! + my alternator was dead next 12H because of this geyser which failed on it lucky me it didn't burned

Here is the right procedure for M54/ M62 engines

http://tis.spaghetticoder.org/s/view.pl?1/01/34/82

 

[priapus6879]

I actually did the TIS procedure after the install due to, once again, finding helpful info from you guys in various posts. Thank you guys again for the information. Unfortunately I was not able to resolve the problem, though, today I noticed the lower rad hose is running virtually cold, upper from thermo is scalding hot. I have done the TIS procedure a few times now, with no resolution. My friend and his father are taking me over to the Bimmer dealer which is only miles from our respective houses. The car is in need of an oil change anyway, and before you call me crazy, the only reason I'm taking it to the dealer is b/c they know a few people in service and said they could get me the "friend" price of $39 for the oil change. At the same time they will do me a solid and be able to tell me what is wrong with it, so that I might tackle the remaining cancerous parts of the cooling system. Although I have hit a few speed bumps, I'm still not swayed from BMW. We had one in the family before and I can't wait 'til I can get her in tip top again, since you all know just as well there is nothing like a BMW. And hey, atleast while she's under their care, I'll get to see what the F07 is all about.

 

[MJB9]

this is what happened to me as well based on this DIY for M52 engine where it says left bleed screw open

http://forums.bimmerforums.com/forum/showthread.php?t=1423821

It appears to be wrong for M54 ! + my alternator was dead next 12H because of this geyser which failed on it lucky me it didn't burned

Here is the right procedure for M54/ M62 engines

http://tis.spaghetticoder.org/s/view.pl?1/01/34/82

In between step 6 and step 7, do you leave the car running, run out and check level (within 30 seconds), or turn off engine after stepping on accelerator three to four times?

My check coolant light came on for first time today. I didn't smell coolant, or have not seen any under car. When light came on, I was still about 5 miles from house, but immediately checked temp gauge. Dead center all the way home. I've owned car for about 8 months now and know very little history. It's a 2002 e39 525i and I just checked radiator. it's from 2007 and looks brand new.

I'll let cool and try bleed/fill tomorrow. Before I found this thread, I was just going to add coolant in reservoir and close it up.

Off course everything comes in threes. Other day was light issue, and today check coolant. While poking around, a coolant line has a leak. Jeesh! A/C is fine. Might even be condensation on the line.

Anyway, if someone can answer about step 6 and 7, that'd be great!

 

[rdl]

In between step 6 and step 7, do you leave the car running, run out and check level (within 30 seconds), or turn off engine after stepping on accelerator three to four times?

My check coolant light came on for first time today. I didn't smell coolant, or have not seen any under car. When light came on, I was still about 5 miles from house, but immediately checked temp gauge. Dead center all the way home. I've owned car for about 8 months now and know very little history. It's a 2002 e39 525i and I just checked radiator. it's from 2007 and looks brand new.

I'll let cool and try bleed/fill tomorrow. Before I found this thread, I was just going to add coolant in reservoir and close it up.

Off course everything comes in threes. Other day was light issue, and today check coolant. While poking around, a coolant line has a leak. Jeesh! A/C is fine. Might even be condensation on the line.

Anyway, if someone can answer about step 6 and 7, that'd be great!

When I've done my refills & bleeds I turned the engine off between steps 6 & 7. By the end of step 6, any air should be swept out the the block, heater core, etc. There isn't any point in keeping the engine running and it would continue to heat the coolant and cause it to expand. A heads up: even observing the 30 second guide I usually found the level down an inch or so the next morning. So don't panic until it's down again on the 2nd day.

Actually the few ounces difference in level won't affect engine cooling. The real point is to establish a reference level so that subsequent checks are able to identify a slow leak before it bursts and dumps the coolant system. On followup checks, I look at the level before starting the engine in the morning.

If you continue to experience slow coolant loss with no visible drips or leaks, you could try a UV test kit for ~$25. Add the dye to the coolant, drive for a few hours and then check with the UV lamp. I've had mini-leaks that I found only by the UV dye "flare." The leakage would turn to vapour from engine heat before it turned into a drip. It was tedious peering into all the obscure corners and so. But I was oh so relieved to find that I didn't have a failed headgasket!

 

[champaign777]

http://forums.bimmerforums.com/forum/showthread.php?t=1881201
This might help