No heat and overheating

[blkspruce]

Hi all.

My 95 525i was recently in an accident and the impact caused the radiator brackets on top to break. There is coolant leaking from somewhere not diagnosed yet. My wife drove it to the store and there was no heat and it began to overheat and blow steam from the valve.

I cannot locate the leak now, only a puddle in the garage. Please help me with where to begin.

Thank you

[colo525i]

I'd start by looking at the radiator, it has plastic connections that could have broken in that impact. The radiator core itself may have been damaged and need replaced. Don't drive the car until you figure out the cooling system problem and replace/bleed the coolant, as the 525 is susceptible to ruining the headgasket if overheated.

[blkspruce]

How am I to tell if the core is bad?

[filip00]

i'd check the thermostate, the visco clutch, and surely replace the radiator and hoses.

how is the car overheating? only when running idle, and goes back to normal when driving, or the temp just keeps rising?

[blkspruce]

When driving and idle, keeps going up

[Chris'91'525i]

How am I to tell if the core is bad?

I'd fill the radiator with water as much as possible, then start motor and set the heater to full heat with fan on. Raise the RPM's and contine to add water till it's topped up with water.
Bleed it, and put the Rad. cap back on.
Wait for Temp. and pressure to bulid up. And you should be able to locate obvious leaks.
If you saw a puddle under the car, it should show up again if you do the above.

[TC535i]

No heat, overheats at idle? Sounds like an improper bleed, air pocket in the heater core.

Bleed, bleed, bleed again. Search about bleeding the system. Do it parked on a hill if that helps, so that the "bleed screw" is the highest point in the system.

[blkspruce]

No luck. I just tried bleeding and car ran for about 20 minutes and the temp guage was getting high again. I shut it off before it hit red. I pinched the hoses when the guage hit mid way and they are not expanding and filling with coolant. I tried to bleed from screw and no pressure.

What else please.

[filip00]

thermostate then. change it.

[blkspruce]

Not thermostat, I replaced it and although it did not over heat there is no heat in the car. I cannot bleed it for there is no pressure in the hoses. What am I missing?

[DaveVoorhis]

Accidents can cause damage in strange places. I think a close visual inspection of everything would be a good idea.

Then fill and bleed the rad as follows: Open the bleed screw, and fill the rad to the brim. Squeeze the rad hoses to eject air. Wait for the level to stop dropping, and be patient. When the level has stopped dropping, fill it again. Repeat until the level no longer drops. Turn the heater fan to full and the heat controls to full hot. Then start the engine and quickly blip it up to 3500 RPM a couple of times and stop it -- don't run for more than 30 seconds. The coolant level will have dropped. Fill it to the "cold" mark. Run and blip again to make sure, and top up if necessary. Repeat until the level no longer drops. It should now be bled. Close the bleed screw.

Run the car and make sure it doesn't overheat. If it does, I'd suspect hidden damage to the rad core, or the water pump rotor has shattered, or a hose is pinched, etc.

[Ross]

Driving a car that you know is leaking coolant is a very bad idea.
These engines don't tolerate overheating well at all, once in the red is often enough stress to blow a head gasket. This sounds like what happened to you.
I suspect ignoring the warning is going to be costly.

[scott 4991]

The car will overheat if the fan clutch is not working. There is a test that my mechanic showed me - a simple one. Start the car with the hood open JUST A LITTLE in the back. Stand by the drivers door, in front of it where the hood it open. You should feel air rushing out from under the hood. If not, the clutch is bad. I ran across ovrheating, as we all have, a few times, and this simple test showed me my clutch was bad. If you feel just a little air, it's not working - you will know if it's working if the clutch is good.

sc

[filip00]

The car will overheat if the fan clutch is not working. There is a test that my mechanic showed me - a simple one. Start the car with the hood open JUST A LITTLE in the back. Stand by the drivers door, in front of it where the hood it open. You should feel air rushing out from under the hood. If not, the clutch is bad. I ran across ovrheating, as we all have, a few times, and this simple test showed me my clutch was bad. If you feel just a little air, it's not working - you will know if it's working if the clutch is good.

sc


there are more tests to see if your fan clutch is good....plus, it doesn't matter if his fan clutch is working or not, when the hoses after the thermostate aren't hot! it means the thermostate is closed! doesn't make much sense...

when the car is hot, turn it off, and try to feel the water pump, see if it's okay. check for some unusual sounds when the engine is running on cold...might be that the water pump isn't working?