Cooling question?
 

I hate starting a cooling thread but I cant seem to find answers so here goes!


Currently i have 199,xxx miles and thus far:

~130,xxx waterpump & thermostat were replaced
~191,xxx expansion tank, all hoses (except heater valve to core) auto trans thermostat, fan clutch, radiator and aux fan were replaced. ( not 100% sure what happened but car was on its way to overheating on freeway in stand still ( i think ac was on and aux fan died and fan clutch was too old just my thought) but it was almost in red when i saw it so i blasted the heat and parked it immediately on shoulder. After like 1hr it was cooler and with the heat blasting it did not move past the 12 o'clock position since that time 2yrs ago)

now i've noticed if i drive and park. i come back to a coolant puddle ( i had noticed that i was topping off coolant more frequently lately but no puddle) However now i have a puddle i re-bleed the system i jacked up the drive side and it helped lots of air came out. but what i wanted to find out is should i feel the flow of coolant in the hoses? if i drive hard the radiatior is hot if i let it sit its barely warm....not to mention the lower hose is barely warm and i can even pinch it closed and i dont see the coolant overflow when the ET is open!!!! (i thought if it was pumping and i blocked off the lower hose i would see it build up and over flow but nothing) but if i let the car sit idling the coolant slowly rises and overflows on its own. And when i shut it off it kinda burps i can do the same to the top hose i can pinch it off and i dont feel pressure or a fluid flow but the car DOES NOT over heat. its at 12 all the time but its puking coolant from the expansion cap from what i think its just plain over pressurized system.. and i dont believe its a faulty cap bc the top hose gets really expanded like its much larger from built up pressure ( mainly air).

but if i raise rpm to 2-3K i can see the little stream in the ET like everyone describes when doing a bleed procedure..... Im planning on replacing the water pump and thermostat but wanted to hear peoples thoughts on the topic! http://www.xoutpost.com/images/smilies/dunno.gif

can someone with a 3.0 verify if you feel pressure/flow of coolant at idle from upper or lower hose?

i have a 2003 3.0 x5

Need to find that leak first. My 3.0 starts to pressurize the cooling system as soon as the temp needle is at 10 o'clock. Once the leak is corrected, I'd look to a mis-behaving thermostat. I've had an OEM replacement go bad a year after it was installed.

2002 X5 3.0 289,600 miles
2004 325i 120,000 miles

well the logic is that the components have plenty of age on them thus its time to change them any way that being said I stated that the coolant is coming from the cap on the ET. if you look it states on it that it holds pressure until a certain amount and once that limit is reached it will let the excess out. thus my point about my system

i dont feel coolant flow i have 4 other suvs and cars and all of them once the engine is at the proper temp you can grab either lower or upper hose and give a squeeze and feel the flowing coolant but on my x5 i dont. thus it defies logic in the sense that my x5 should be overheating but its not and i drove the shit out of it so i know it was hot but nothing wont go past the 12 oclock but the lower hose remains cool to the touch which i have never felt on any car the the lower hose is always warm to hot but of course not as hot as the upper....

i hope this makes sense now


PS: the car was under warranty till 100K so it had 2 thermostats perior and one pump i think one around 50K and the next was near 90-100K but it failed around the 130K ( only went above the blue if i was stopped no codes )

im leaning to a malfunctioning thermostat also but since the majority of the cooling system is new i rather throw a new pump and thermostat in their also but while im looking at thiings i was just trying to see if any one had a similar situation and who knows it might be some thing else then those 2 things.

oh the leak is coming from the cap but only after hard driving but what concerns me is the deformation of the upper hose it looks like it expands about half inch more and ive never seen it like that so i know there is excessive pressure build up

Don't forget over pressure in the cooling system is one sign of a failing/failed head gasket. A combustion gas test (measures combustion products in the coolant) is a cheap way to check that.

I thought by now every person on the planet knows that temp gauge dial at 12 clock position means nothing and the real temp is accessed through OBD. Temp at 12 clock position could be anywhere form 75 C to 115 C. It's well known that BMW buffered the temp gauge on many BMW models.
As somebody else suggested, do head gasket failure test and watch temp through OBD as I mentioned, then go from there.