any expert on cooling system?

[moneytree]

Ok I have had this series of problems now all to do with the cooling system.

1.) Alternator Failure
2.) When alternator was replaced, workshop did a flush of cooling system
3.) car broke down, one of the hoses tore
Apparently, debris was moved in this flushing took place, exposing leaky areas that were previously coverd by debris and hence not leaking (workshops explanation)
4.) Hoses, Thermostat, Water Pump were replaced. All said to be LEAKING. I did not have any leaks before, could this truly be because of the flushing of debris exposing leaks??? Anyway I drove off with a huge bill and confirmation no more leaks in the system
5.) Fan operation screwed up, always ON, car very hot, gearbox malfunction. went to another shop again.
the heater valve seems to be clogged and not closing too. am driving with AC and heat parallel.
6.) Shop replaced radiator and thermostat again, saying thermostat was very dirty inside and radiator had a lot of debris, the cooling was not effective. Also the expansion tank was leaking, needed to be replaced.

7.) Today after driving long distance, find a puddle of coolant under the car...

the story goes on...like the song from celine dion...my heart will go on and on...

[Quicksilver]

These shops your going to;
Are they BMW shops or just
local mechanics

[moneytree]

Original BMW shop fixed the alternator

Then they fixed the Hoses, thermostat, waterpump after the breakdown

For the overheating and the last fix (Radiator and 2nd thermostat) I got fixed at an independent shop which was supposed to be an OK shop (cause I thought its a gearbox issue but thank god they said it may be a cooling thing only)

They also tested for leaks after replacing those parts and found none, 3rd confirmation in a month. 4 days later, its leaking/dripping again below the car.

now is at BMW original shop again because I try to claim warranty on fixing the leaking cooling system

this is all within 4 weeks...

[moneytree]

So the two repairs were done at BMW Original Shop and the other one at BMW specialist (only BMWs)

could it still be that the coolant gets too hot in this climate and expansion of hot liquid forces a leak whereas in cold temp testing cannot find it? but then again hoses etc are all brand new, how many more components can there be to replace?

I live in Malaysia and I believe it is a UK import may not be the hot weather version.

[supersteve]

if it's a 4.4 liter it sounds like the valley pan.

[WolfX5]

In my opinion this whole thing about debris magically "hiding" in various cracks and crevices only to suddenly materialize again after a coolant flush is BS. The whole purpose of a flush is to clean out any debris, but that has to be followed up with a pressure test to determine what is and isn't leaking. Other than the dreaded valley pan issue (8 cylinder only), if you've had your water pump, thermostat, hoses, radiator, expansion tank and water-cooled alternator you've done pretty much ALL that can be done for the cooling system. Bottom line, I'd start to suspect deficient (non-bmw) parts and crappy workmanship and I'd bitch like hell until the original BMW shop fixed the problems for good (at their expense).

Good luck!

[moneytree]

yes this debris explanation also sounds foul to me as it has been flushed two times now and like u said almost all parts have been replaced already...

what or where is this valley pan and what does it do, what is the problem with it? I have not seen it in the diagram

[moneytree]

ok one more question; if it is truly the valley pan:
they have fixed all hoses incl. the ones behind the engine. for this they had to remove parts of the engine cover to do so, and in the process could they have fixed the valley pan at little additional work?
I just want to make sure they dont charge me the labour twice if they should have found the leak on the original checkup/inspection for leaks.

also, would this leak not show up under pressure testing?

[fast4d]

no. they would have to remove the intake manifold off to do the valley pan/cover.

I don't think they replaced all the hose because there are a couple BEHIND and you would have to remove the intake and rear coolant log to get to them. remove the top engine cover and look down into the valley. if you see liquid then it's the valley pan. if you are parking on a hill the coolant to run down and drip. park it facing up hill. you'll see a puddle below the bell housing (in front of transmission)

the valley pan is a slow leak but it'll puddle underneath the intake "in the valley" until you are on an incline.

[moneytree]

it is a 4.4i

I will hear what the workshop has to say tomorrow.

would there be anything easy to replace and worthwhile when this valley pan is being fixed? this car has about 65k miles now. perhaps valve cover gasket? I did notice some oil around the engine housing near the bolts.