Overheating?! Not Again!!!

[///Sniper535]

Car over heats only when i'm stopped at an incline... Why is this?

New water pump, fan and clutch, replaced all belts, no coolant loss, coolant is fairly new. What gives?

[Dr. evil]

thermostat??

don't really know your cooling system but anytime my needle goes past half way i have some air in the system.

[mamilapon]

Did you replace your stat man? If not do it and bleed it properly. Other than that give your radiator a good clean inside and out

[Sam-Son]

This is kinda a dumb question but will a high performance water pump do a better job of keeping the car cool and keep it from over heating in higher temps?

[filip00]

Car over heats only when i'm stopped at an incline... Why is this?

New water pump, fan and clutch, replaced all belts, no coolant loss, coolant is fairly new. What gives?

like the others said, thermostate, or the system isn't bled properly.

what you do is first replace the thermostate...and then fill it with coolant.

run the car until it get's warm, turn the heating fully on, and then on the cooler under the bonnet, you have a little screw near the big cap where you pour the coolant in. you unscrew it gently until air starts flying out. when all the air is gone, and it starts to lose water thru that screw, then simply screw it back in and it's done.

check if the coolant level is in place, if not, pour some more and you're done.

[bsell]

Car over heats only when i'm stopped at an incline... Why is this?

New water pump, fan and clutch, replaced all belts, no coolant loss, coolant is fairly new. What gives?

Nobody asked so I will...nose up the hill or down?

If nose up then the 'air bubble' should be in the front of the engine, possibly starving the water pump for liquid to move around. Which means no coolant flow in the engine...

If it overheats with the nose down, well then I don't really know. Could it be that your new pump was set up wrong from the factory causing low output for a given shaft speed?

Either way, making several bleeding attempts sounds to be in order. I just had my radiator blow out and get replaced. The shop bled the system with the heater valves shut I think as after driving it and using the heater a little, I had to add two cups of coolant to get the level back to the cold minimum.

If you are sure the system is airless, then you have to look at parts failure.:(

Brian

[///Sniper535]

No air in the system. Car overheats on at angle facing down or up. The first time it happened it was facing up. The second time if was facing up. I tried the bleed screw last night and just coolant came out. The only thing i haven't changed would be the thermostat...

[DaveVoorhis]

Any chance fluid has leaked out of the fan clutch? Though your symptoms do sound like air trapped in the cooling system, the fan clutch contains a hydraulic fluid; it will just freewheel if the fluid is absent.

[filip00]

okay, try the fan clutch. when your car is hot, turn the engine off. try to move the fan clutch with your hand, if it moves rather easily. it's broken.

[///Sniper535]

i bought a new fan clutch like a month ago.

[DaveVoorhis]

i bought a new fan clutch like a month ago.
So? I once bought a new master cylinder for a Ford truck that leaked fluid out as quick as it was poured in. When I returned it, the parts jobber said, "Oh yeah, we've had a whole crate of those do that." I went through two aftermarket clutch slaves in six months on an E28, before I bought one from BMW and it lasted. Sometimes new parts suck.

[Jehu]

Are you sure the Coolant /Water mix is at 50/50? I just had mine overheat last night after five hours of hard highway driving (http://www.google.com/maps?f=d&hl=en&geocode=&saddr=28+james+st+milford,nh&daddr=560+University+Ave,+Norwood,+MA+02062,+USA+t o:1236+bay+rd+amherst,ma+to:714+east+new+lenox+rd+ pittsfield,ma+to:42.233602,-73.046722+to:17+winthrop+st+millers+falls,ma+to:28 +james+st+milford,nh&mrcr=3,4&mrsp=4&sz=10&mra=dpe&sll=42.3352,-73.039856&sspn=0.482197,0.840454&ie=UTF8&ll=42.265114,-72.372437&spn=1.930875,3.361816&z=8&om=1)and after i let it sit for about 40 Minutes and added a half gallon of H2O i was able to drive it home another 70 miles home with no temp rise. I bypassed my Heater Core last week and didn't refill the system with a 50/50 mix , just used all Anti Freeze.... big error in judgment .

[///Sniper535]

I had my car on ramps nose up and let it run for sometime and no overheating. Fan clutch seems to be in perfect working condition.Definately no air in the system. If this happens again ill look into a new thermostat.

[filip00]

thermostate is the cheapest part of the whole cooling system, so just replace the damn thing.

btw, the coolant - water/antifreeze mixture is not important, as long as it's at least 20% antifreeze, 80% water, it's good. no need for the 50-50. it is important that you don't have more antifreeze, because water is a better heat isolant

[Jehu]

thermostate is the cheapest part of the whole cooling system, so just replace the damn thing.

btw, the coolant - water/antifreeze mixture is not important, as long as it's at least 20% antifreeze, 80% water, it's good. no need for the 50-50. it is important that you don't have more antifreeze, because water is a better heat isolant

Interesting and the gyst of my thrust was that I had more coolant than water which I hope was the one and only cause of My overheating. As i noted i did drive it after a cool off period after adding over a half gallon of water and again today got it hot and up on the highway and not a hair over Twelve O'Clock High so I assume that was the only thing. I started dreading it was the Thermostat while i was sitting in a dark and empty rest area in the way out wilderness of northwestern Massachusetts letting it cool. I hate spending money on long tows.. If I brought the car into a BMW dealership and asked them to flush and refill you think they'd do it 80/20 water to coolant?

[nbeckius]

thermostate is the cheapest part of the whole cooling system, so just replace the damn thing.

btw, the coolant - water/antifreeze mixture is not important, as long as it's at least 20% antifreeze, 80% water, it's good. no need for the 50-50. it is important that you don't have more antifreeze, because water is a better heat isolant

The antifreeze/water mix really depends on where you live. 50/50 is the recommended in many areas. Remember the water does the cooling, the antifreeze just does what it's name implies and has very poor cooling properties.

I've never heard of going more than 60% antifreeze in a system and if you live in an area where you never see below freezing temps you can not use it at all and go 100% water.

Distilled or purified water is best as it prevents corrosion. 75 cents per gallon at the market and it'll make the cooling system function better.

[Adnan]

Distilled or purified water is best as it prevents corrosion. 75 cents per gallon at the market and it'll make the cooling system function better.

Hi,

One reason to use coolant is that it usually contains lubricants for the water pump. Otherwise, I agree that water does the best job of cooling. If you do use just water, consider adding a wetting agent to it, such as Redline's Water Wetter. The change in surface tension offers a noticeable improvement in cooling.

Regards,
Adnan

[E34 530]

If you bought a Behr fan clutch, it could be bad. I bought one last year and it was bad right out of the box and they sent me another one which I think is going bad again.

[Chris'91'525i]

The antifreeze/water mix really depends on where you live. 50/50 is the recommended in many areas. Remember the water does the cooling, the antifreeze just does what it's name implies and has very poor cooling properties.
I've never heard of going more than 60% antifreeze in a system and if you live in an area where you never see below freezing temps you can not use it at all and go 100% water.
Distilled or purified water is best as it prevents corrosion. 75 cents per gallon at the market and it'll make the cooling system function better.

Theres a reason auto makers recommend a antifreeze/coolant mix.
Recommending 100% water is not good advice IMO.

Antifreeze/coolant besides the obvious it raises the boiling point of water, it does not evaporate like water does, it prevents rust and corrosion, and it lubes the moving parts in the cooling system.
Thats why you want to flush the system periodically, as the additives get depleted after a couple years.

[filip00]

Distilled or purified water is best as it prevents corrosion. 75 cents per gallon at the market and it'll make the cooling system function better.


it's so much easier to simply COOK the water at home, and have it distilled in a few minutes instead of buying it :D



2 Jehu - i don't know what mixture they'd give you in a bmw dealership, but i usually use the 80-20 and i'm satisfied with it. temperatures here are from -12 to +45 C and no problems whatsoever.

[DaveVoorhis]

it's so much easier to simply COOK the water at home, and have it distilled in a few minutes instead of buying it :D
Unless you're using a home distillation kit, boiling tap water will kill bacteria and drive off some chlorine, but it won't remove any of the minerals and most contaminants in the water. In fact, it will increase the concentration of these per unit of fluid.

[filip00]

Unless you're using a home distillation kit, boiling tap water will kill bacteria and drive off some chlorine, but it won't remove any of the minerals and most contaminants in the water. In fact, it will increase the concentration of these per unit of fluid.


i honestly didn't know that.....and no, i don't have a home destilation kit.... whoopsie :o

[ThoreauHD]

Yea, that white ring around your pot after you boil it is mineral sediment. That's what you're putting in the radiator. As far as the original poster, it's just the thermostat. I replaced mine just for giggles. Costs the same as a happy meal.