What can it be? Please help, urgent now.

[Rob]

Howzit Guys,

Well now my cooling problem is a more seriouse issue. :(

Here's the problem:

When I start her up, she takes the normal 5 - 10 minutes to get to operating temp. Also she takes around 5 minutes when driving to get warm. Now while I'm driving at around 60 or higher, my temp remind half way. Any slower or even if I idle the car for 1 minute, she will get hot and if I don't start moving or if I don't turn it off, she will overheat. :(

Here's what I've checked:

Thermostat:

I let the engine warm up, once it got to normal temp, I felt the hose going to the radiator and it was hot to the touch, no cool spots at all. This is telling me that the T-Stat is indeed working fine?

Coolant Level:

I have made sure it is at the COOL mark, however I still get the *Bing* "Coolant Level" on my dash for some reason?

Clutch Fan:

Okay, I'm not a 100% sure this fan is working 100%, if I start the engine, fan come on straight away. When I shut the engine off, the fan turns off one or two seconds later, well, stops spinning. But I'm not sure it's blowing enough air though to the radiator? Anyway to test this?

I'm really at a loss with the problem. No idea what's causing this. See if I drive the car it's perfect. If I stop and idle for less then a minute, temp gauge goes past half way. :(

Anyone know how I can find out what the problem is here?

Any help would be greatly appericated.

Thanks a lot guys!

[mamilapon]

Did you put a hose through the fins of your radiator and washed it nicely? Is the fan clutch working?Water pump? Any leaks from under the water pump. Strange noise from the water pump. Get yourself a mechanics stetoscope and check noise from water pump.

[Rob]

Well I thought putting a hose to the rad, spryaing it with water will have the same effect as driving the car fast enough to get air to the rad, to cool the system down. So no, I didn't do that as I know that will cool the system down. And it's not the dirty, I checked and it's pretty clean.

Well if the hose's are getting hot, the pump is working. And if the pump had failed, the car would overheat while driving as well. Checked for leaks, can't see any.

[genphreak]

Well I thought putting a hose to the rad, spryaing it with water will have the same effect as driving the car fast enough to get air to the rad, to cool the system down. So no, I didn't do that as I know that will cool the system down. And it's not the dirty, I checked and it's pretty clean.

Well if the hose's are getting hot, the pump is working. And if the pump had failed, the car would overheat while driving as well. Checked for leaks, can't see any.Is the thermo fan working at both speeds? Jumpering the thermal switch on the Right side of the radiator will bring it on so you can test it, if this works but they don't come on as they should, the switch might be dead.

What is the ambient temp you are driving at Rob? If it is 30 plus, the thermos might be needed. The AC will bring them on, does it make any difference?

Try not to overheat the car at all, each time you risk breaking your headgasket's ancient seal on these long motors.

[ElSupremo]

Have you made sure the system is bled properly? The hoses can get warm/hot but still not be bled completely.
My initial thought is your H2O pump is going bad. It can pump at low rpms but is cavitating at higher ones. Air in the system could cause this too, though.

[Rob]

Genphreak

Ambient temp is normaly between 18 - 25c.

See this is the issue, I don't think the fan is working correctly at the right speeds it should do. How exacly do I test the fan and it's switches? You see if the engine is hot I cannot hear the fan with hoot closed, is this right? My A/C tank is empty, so I need to re fill it before I can test that out. Could you please explain how I test this fan and switch?

ElSupremo: How do I test your theroy?

Thanks a lot for the help guys!

[DaveVoorhis]

Okay, I'm not a 100% sure this fan is working 100%, if I start the engine, fan come on straight away. When I shut the engine off, the fan turns off one or two seconds later, well, stops spinning. But I'm not sure it's blowing enough air though to the radiator? Anyway to test this?

Once the engine's warmed up and idling, gently push a rolled-up newspaper against the spinning fan. Don't try to block the fan -- you're just trying to provide a teeny bit of resistance. If the fan stops, the clutch is bad.

BTW, the coolant low warning is probably a result of a corroded connector to the sensor. It's on the bottom of the coolant tank. Pull off the connector and clean the sensor and connector contacts.

[Rob]

Oh, okay that sounds like an easier way to test that fan. I will try that. And if it doesn't stop, fan/clutch is ok?

I'm going to look at that connecter either tonight when I get home, or the weekend. Will test fan as soon as I get home. So I must wait until temp needel is half way, correct?

Many thanks!

[Mitch90535im]

Is the 525 subject to the same clogged "pisser" line that I experienced with my m30? In my case I detached the line from where it attaches to the radiator, blew compressed air into it to eliminate the clog (I could then hear and see bubbling in the coolant fill tank, and that solved the problem. This was after I bled 20-30 times, replaced a perfectly good fan clutch, thermostat, tested the aux fan switch, and had a new waterpump in hand ready to replace. I believe it was Winfred who suggested I check the "pisser" line.

[Rob]

No, the 525i's don't have that line going to the Rad tank. Wish it was that simple. :(

Thanks for the help anyway. Appericated!

[genphreak]

No, the 525i's don't have that line going to the Rad tank. Wish it was that simple. :( Thanks for the help anyway. Appericated!Yes the overflow tank is on the side on a 525. Some people use a pencil with the fan, its not a terribly reliable test and risky so I think the paper sounds the best approach to get a rough idea. The clutches do need to be changed, I renewed mine as it had never been done, but the old one was just fine anyway. Make sure you bled the car properly, ie by doing it first when cold and not running; just by letting the fluid through the bleeder until it spits only clear coolant. That's how it is on the M30 with the overflow tank above the motor- so check the reccommended procedure for your motor is- a lot of peeps on here are confused about bleeding, best to go by the Bently Rob.

[Rob]

Hi there,

Okay, will do the test later tonight. I'm not sure I am 100% up to bleeding the car. You see, my consern is the engine running while I'm bleeding it. She will just overheat while I'm doing it. I am far too worried about the headgasket going and stopped using the car until problem is fixed. I've read many bleeding guides. And the say turn heating controls up and fan on. However that fan doesn't really make a difference. What do you suggest I do?

[Rob]

Okay, decided. Here's my plan of attack on this lovely car this weekend.

1. Test fan and clutch
2. Drain whole cooling system.
3. Go buy new coolant. At the moment it's just water in the system, no Coolant at all.
4. Re fill cooling system with 50 water 50 coolant.
5. Bleeed system,
6. Clean Coolant Sensor.
7. Hope and pray that the Head Gasket is still in tacked.

Does this sound like a good plan of attack on this problem?

If the H.G is blowen, I might as well look at a new car. :(

[632 Regal]

test the auxillary fans in front of the radiator by turning the AC on, the fans should come right on. you can see them through the front grill. If not track the problem, if they do then the thermo switch or relay could be bad, one step at a time.

REPLACE your clutch right away, if it was good it shouldnt heat up, since it cools down at speed im guessing the radiator isnt clogged. Im not one for sticking my arm into spinning things myself but whatever floats your boat. Much easier than replacing a headgasket.

[Rob]

Jeff, my A/C needs refilling. So that fan doesn't come on. :(

[632 Regal]

it should run when it gets hot though.
Jeff, my A/C needs refilling. So that fan doesn't come on. :(
use distilled water when you change the coolant.

[Rob]

Oh okay. Now if that fan isn't working....would this definitely cause the problem, or only make the car run a little hot when engine compartment gets hot? Or will it overheat?

I'm pretty sure it isn't working. Anyway I can jumper it so thus testing fan and switch?

Thanks a lot for the help, Jeff. Apperceiate it!

[Alexlind123]

The main fan should provide "viscous resistance" when turning it with the engine off.

[Javier]

the sensor connector in the radiator. It's a three pole connector, jump the pins in pairs, one pair selection does nothing and will do no harm to jump them, the other two jumping possibilities turn on low speed and high speed.

You need the water inside the radiator to be hot to turn on the auxiliary fan (I mean, if pump is not pumping, or tstat is not opening, water in radiator is cool no mater the engine is overheated, and fan will not turn on). You can also test the temperature sensor with a boiling water pan and a cooking thermometer, below is a picture of the sensor internals. you can hook a continuity tester to the pins and wait for water to reach 91 and 99 degrees C to close the contacts (you will not reach 99 if above sea level so will have to switch to boiling oil instead). If failed, replace the sensor.

Fan clutch need to work to have things running normal. It will avoid over stressing the auxiliary fan and engine temperature. (as you see, fan engages only when things are turning hot (91-99).

Javier

[joshua43214]

The engine fan has a viscouse clutch in it, this allows the fan to rotate with the engine at all times, but not run at engine speed unless it becomes hot enough to engage. This is mostly done so you wont waste energy running a fan that is not needed.

When the fan engages, it will turn with the engine with no slipage. When you rev the engine, it will instantly speed up, and instantly slow down on decel. when you stop the engine, it will instantly stop. The fan should engage at just about the 1/2 gauge point and will cycle on and off with the thermostat. T-stat opens,blast of hot air heats the fan clutch and it engages. T-stat closes, clutch cools off and disengages.

Any of the above methods will work for testing the clutch, but if you rev the engine with the fan clutch engaged, you will have no doubt it working since you get a loud roaring blast of hot air that will make you feel faint on a very hot day.

The aux fan should also come on at higher temp, I think about 2/3 gauge. It will come on and will remain on until the engine as back to normal temperature.

If the coolant level is good and you still get the low coolant warning, the sensor is most likely bad, they fail very commonly, and are cheap. just replace it if it is suspect.

Another sign of a bad fan clutch is it being dirty. The oil will leak out of the clutch and coat the fins and then collect dust. The clutch should be the color of a normal dusty old part. if it has the black color that parts get when they have old oil combined with dirt, it is bad.

[Rob]

Thanks a lot for that, Javier. A lot of help there.

Can you tell me, when testing the fan clutch, it's spinning the fan itself, not the actualy clutch right? Also where about is the clutch?

Once again, thanks a lot!

[Rob]

Just read your post now Josh, again a lot of helpfull stuff. Thank you so much guys!

[632 Regal]

The clutch is the part that screws onto the waterpump, the plactic fan unbolts and will go on the new clutch.

Telltale sign if it works or not, it will sound like a schoolbus taking off from lights if its hot for about 10-30 seconds until the front of the clutch cools back down from air flow.

Im still betting heavy on a bad clutch. The aux fans help but cant do the whole job.

[Rob]

Thanks, Jeff. Will check when I get home.

Thanks a lot guys, apperciate it. Going home now, so will check thread in the morning.

Thanks all!

[Rob]

Okay, tested the switch for the aux fan. It's dead. I jumpered the connections and the fan spun right up. So switch is obviously dead. Will replace it.

I also don't think it's the fan clutch anymore. That fan spins pretty fast and I fan feel the air from the fan when above it. So do you think a leak somewhere in the system would cause this?

I'm running out of ideas here, guys. I'm going to bleed the system this weekend. There is no coolant in the system, just water. This may be the problem?

**** I really need to get this fixed. :(

[632 Regal]

does it sound like a schoolbus when taking off from lights?

Okay, tested the switch for the aux fan. It's dead. I jumpered the connections and the fan spun right up. So switch is obviously dead. Will replace it.

I also don't think it's the fan clutch anymore. That fan spins pretty fast and I fan feel the air from the fan when above it. So do you think a leak somewhere in the system would cause this?

I'm running out of ideas here, guys. I'm going to bleed the system this weekend. There is no coolant in the system, just water. This may be the problem?

**** I really need to get this fixed. :(

[Rob]

We don't really have school busses in this area. So I wouldn't know. It just sounds like my car pulling off. Like a deap sound. Jeff, what has that got to do with the cooling? Engine problem? Could be H.G?

Again, I want to thank you for your support and help, Jeff. I really do appericate it!

[LAXman2205]

Yea, I kept getting those warning for about a week or two a few months back and checked most everything. I was at a stoplight the day before I really was going to get it checked out and the temp went from the middle all the way to the red in about 2 seconds and coolant level and temp came on. I had my hand on the key to turn it off but the needle suddenly jumped back to normal.......Went to the nearest parking lot and found that coolant was oozing out of the top plug on the radiator. I started it up and coolant was coming out pretty fast. So yea id get that checked out lol....

[Rob]

Get what checked out? The H.G?

As I've said before. If there is enough air getting to the rad, she'll keep cool at half way.

Thanks.

[632 Regal]

you should hear the fan when you take off when its hot... dont know how to discribe it differently.

[Rob]

Can't say I can hear that fan at all while in the car. Only fan I can hear is the Aux fan. But I've jumpered that.