Leaking Coolant - BMW Forum

uclabruins1996 · 10-28-2004, 08:23 AM

Greeting everyone,
I have a 96 328I sedan. When looking straight down from engine bay, the coolant seems to be leaking between the radiator and engine. The coolant does seem to leak right after driving it. After driving the vehicle, then stopping it, I inspect under the vehicle for 5 minutes, I see do not see any coolant leaking. But after the vehicle cools down (I never hung around that long to check again), I see the puddle of coolant. Also, my onboard cpu is telling me to check the coolant (every 2 days).

Why does it leak after remaining stationary for a while, but there are no sign of coolant leak driving it?
Where should I check first? Any particular hoses? Common leaking area?

Thanks eveyone!!

97alpineM3 · 10-28-2004, 08:44 AM

A few good areas to check... Check all of your hoses.. as when they get old.. they get cracked... and that might be the problem... another is see if you can get a mirror of sort.. and check the water pump.. and around the water pump.. as it may be leaking from a bad seal.. there are also line running from the back left of your engine.. (looking forward)... check there... mainly.. check your lines...

Your post is rather confusing in that your not loosing fluid when the system is pressurized.. but you are loosing it when there is no pressure on the system.. Start the car.. let it warm up... check the hoses for leaks.. with the engine running... make sure its fully warmed up.. so that your thermostat opens and you are fully circulating the coolant... then once you have done that.. check the pump area... next shut it down... and then wait 5 mins or so.. and start looking at all of the areas you were previously looking at... then post what you find and we will work from there... or atleast help.

When your engine is running and warmed up... do you notice the fan wobbeling... and moving around... not in a perfect defined circle? If so.. then your pump is about to die... but that symptom is a very very unlikely happening...

Good Luck..

Les

dagoo98 · 10-28-2004, 08:59 AM

Quote:

Originally posted by uclabruins1996@Oct 28 2004, 07:23 AM
Greeting everyone,
I have a 96 328I sedan. When looking straight down from engine bay, the coolant seems to be leaking between the radiator and engine. The coolant does seem to leak right after driving it. After driving the vehicle, then stopping it, I inspect under the vehicle for 5 minutes, I see do not see any coolant leaking. But after the vehicle cools down (I never hung around that long to check again), I see the puddle of coolant. Also, my onboard cpu is telling me to check the coolant (every 2 days).

Why does it leak after remaining stationary for a while, but there are no sign of coolant leak driving it?
Where should I check first? Any particular hoses? Common leaking area?

Thanks eveyone!!

[snapback]220026[/snapback]

I am 99 percent sure that its your water pump. I have the same exact problem with my 2000 540/6 right now. My car is in the shop and is being repaired now. I'm not sure where the water pump is located on your car but mine is in the center of the engine behind the belts and pulleys. The exact location where my leak is coming from. When your water pump is going bad, it will never leak when you are driving but only after you have stopped and turned off the car.

NeverLeaned · 10-28-2004, 11:34 AM

If you have to fillup your coolant every 2 days then it should be a very leak to find. Grab a flashlight and mirror and stick your nose under the hood.

Good luck

///M3 FX · 10-28-2004, 02:42 PM

If its noting they said above do a compression test.

Brian325i · 10-28-2004, 03:22 PM

Man...now I have a coolant leak...the friggin radiator drain plug(cheap plastic) snapped as I was screwing it back in...now my whole coolant to water ratio is going to be off and I have to wait for the plug to come in.

ghead

uclabruins1996 · 10-29-2004, 05:46 PM

It's in the red circle.

http://img28.exs.cx/img28/7803/DSC00061copy.jpg

Click link for bigger picture.

So if you were to look straight down through the circle, the coolant will be on the ground. It is dripping about 1 drop every 20 seconds.

I also see some wet spot on the belt that is below the circle....
The fan is concentric, the revolution doesnt seem to be off.

The only thing I can think that is in the area is water pump, thermostat, thermostat housing.....

If it is the water pump, I will probably get the themostat and housing replace as well----to save on labor...

I may take the car to an independent BMW repair shop for them to do the compression test, to actually diagnose the problem. But I'm afraid they may try to sell me something that I dont need......E.g, you need a new radiator, engine gasket, etc..etc....

Thanks for your input guys!!!!!

Brian325i · 10-29-2004, 06:56 PM

Well I see that hose clamp right there....is it dry around where that hose clamp is? If that's not it then it's probably the thermo housing or the water pump. If possible try and reach up to find any wet spots.

steveo34 · 10-30-2004, 02:42 AM

Sounds like a cracked/leaky hose to me.

-Steveo

uclabruins1996 · 10-30-2004, 12:08 PM

Quote:

Originally posted by steveo34@Oct 30 2004, 01:42 AM
Sounds like a cracked/leaky hose to me.

-Steveo

[snapback]221108[/snapback]

The hoses are dry. After warming up the car, and inspecting the hose, I do not see any coolant leaking out of the hose.....

I've touch the hoses, and it's dry.

uclabruins1996 · 10-30-2004, 12:11 PM

Quote:

Originally posted by Brian325i@Oct 29 2004, 05:56 PM
Well I see that hose clamp right there....is it dry around where that hose clamp is? If that's not it then it's probably the thermo housing or the water pump. If possible try and reach up to find any wet spots.

[snapback]220914[/snapback]

It's dry around the hose and hose clamp.
Where is the thermo housing,thermostat, and water pump located on the care?
Is it possible to inspect it from the standing position.
I cant get under the car because there is not enough room to slide under the car.

Thanks

uclabruins1996 · 10-30-2004, 12:14 PM

Quote:

Originally posted by 97alpineM3@Oct 28 2004, 07:44 AM
A few good areas to check... Check all of your hoses.. as when they get old.. they get cracked... and that might be the problem... another is see if you can get a mirror of sort.. and check the water pump.. and around the water pump.. as it may be leaking from a bad seal.. there are also line running from the back left of your engine.. (looking forward)... check there... mainly.. check your lines...

Your post is rather confusing in that your not loosing fluid when the system is pressurized.. but you are loosing it when there is no pressure on the system.. Start the car.. let it warm up... check the hoses for leaks.. with the engine running... make sure its fully warmed up.. so that your thermostat opens and you are fully circulating the coolant... then once you have done that.. check the pump area... next shut it down... and then wait 5 mins or so.. and start looking at all of the areas you were previously looking at... then post what you find and we will work from there... or atleast help.

When your engine is running and warmed up... do you notice the fan wobbeling... and moving around... not in a perfect defined circle? If so.. then your pump is about to die... but that symptom is a very very unlikely happening...

Les

[snapback]220042[/snapback]

Les,

Is the waterpump, themostat, and thermostat housing accessible from the standing position (with hood open).
Moreover, where are the said parts located?

Thanks

Brian325i · 10-30-2004, 12:22 PM

The thermostat housing is what's connected to the hose...it should be a big black plastic thing. You unscrew it and the thermostat is inside of it. The water pump is connected to the fan right below the housing. Unfortunately you are going to have to take of the fan to get a good look at the water pump area....and it's a bitch to try and get off. Go buy a jack and jack stands if you plan on doing any other maintenance in the future because you'll need it. If you really can't find anything I suggest going to a auto shop and have them look at it. Yeah I know you're trying to save money but there comes a time where that's your only option.

97alpineM3 · 10-30-2004, 09:01 PM

Thermostat housing is directionly to the left of that large black hose.. its either all black plastic.. or its alluminum... inside of that is the thermostat it self....

For your water pump.. you see your fan... then the fan drive to a pulley.. then behind that towards the rear of the car of course.. is your water pump...

Good Luck..

Les