Why is my new radiator still leaking?

champeny · champeny's Garage

Just had my radiator and water pump, thermostat and housing replaced this week.

Then it started leaking out of the cap almost everytime I turned off the engine after driving for awhile. So I replaced the cap. It is still persisiting.

It leaks so much that the warning "Check coolant level" comes on. I refill to the mark, but it keeps leaking.

I was told that when pressure reaches 13lbs, the cap opens up to releave pressure.

What can be causing the excess in pressure?

94-325i · 04-18-2003, 06:55 PM

Did you bleed it?

champeny · champeny's Garage

Yes. The mechanic bled it.
Is there something I am missing?
Thanks

94-325i · 04-19-2003, 07:08 AM

it is imposible that you replaced the cap but it is still leaking. Take a look to all cooling hoses. Here is the link that may help you out.
http://www.logun.org/radflush.htm

sayah · 04-20-2003, 04:53 PM

I think you might have answered your own question. You said it "leaks out of the cap" . Check for other leaks in other parts of the cooling system if replacing the cap does not help.

Why did you need to replace the parts you said in the first place? Is this just part of a continuing problem?

supertack · supertack's Garage

I've got the same problem. I noticed a splattering of dried coolant down the side (drivers) of the radiator. I need to refill periodically because of the check control warning as well. I actually brought this topic up on a different thread, but didn't get much of a response. Hope someone gives ya some idea, cause I definitely have an eye on.

94-325i · 04-21-2003, 07:34 AM

Your radiator has broken neck (there is a hose connect from top of radiator to thermal stat housing). Hope this help.

Quote:

Originally posted by supertack
I've got the same problem. I noticed a splattering of dried coolant down the side (drivers) of the radiator. I need to refill periodically because of the check control warning as well. I actually brought this topic up on a different thread, but didn't get much of a response. Hope someone gives ya some idea, cause I definitely have an eye on.

supertack · supertack's Garage

So which part actually needs replacing, 94-325i? Would it be the hose, or the tank? If the neck is broken, is that an isolated part? Here, what number is the part that your refering to?

Thanks

supertack · supertack's Garage

Lookin at this diagram, the refill tank (#15) is on the passenger side of my car, yet the splattering of coolant that Im talkin about is on the drivers side. Now the hose (#19), should follow suite & be on the passenger side as well, yet like I stated, that's not where I'm seeing an appearent leak. what other part could cause this drivers side splattering?

94-325i · 04-22-2003, 07:27 AM

see picture. Hope this help.

supertack · supertack's Garage

Naw, that's not where Im seeing the dried & splattered coolant. It's on the other side of the radiator.

champeny · champeny's Garage

In my case, I was driving on the highway when the radiator blew at the neck where the hose connects. These originally had plastic necks - now they have metal necks because this was a common problem I understand.

Supertrack you may want to keep an eye out for this, or even consider replacing the radiator before it blows.

Mine followed with a blown waterpump. Ultimately, I replaced the radiator, waterpump, thermostat and housing, and cap.

It has not leaked in a couple of days, and I hope it was just air pockets or something.

George325 · 04-22-2003, 06:40 PM

I blew the upper neck of my radiator last weekend and got a new one from Hendrick BMW. It also has a plastic neck. Should the new ones have a metal neck? It had a production date of 10/2000. My 94 325is has 100K and this looks to be the origional radiator. I also changed all the hoses and waterpump (easy with the good access).
thanks

champeny · champeny's Garage

Aftermarket radiators come in both plastic and metal for our year(s) bmw. I think Pelican Parts stocks both. I am told that later models come from the factory with metal necks.

supertack · supertack's Garage

CHAMPENY, what does the metal necked part cost in comparison to the plastic one?

champeny · champeny's Garage

Generally the price difference is minimal. Varys by brand. I have seen $150 up to over $200 depending where you buy. The problem is finding someone who has them available. I was forced in to another crummy plastic one.

Jared at Pelican Parts · 04-23-2003, 04:45 PM

As far as i am aware, I thought the necks on the radiators were an integral part that could not be replaced., Am I incorrect in thinking this?

champeny · champeny's Garage

Yes - Unfortunately, you have to replace the whole radiator. Some might tell you that you can fabricate a part, but you're asking for trouble.

Anyway - I am still getting the warning light that tells me to check coolant level. Even though I cannot find any leaks now.

Mathew Neal · 09-16-2003, 02:41 PM

Did you ever find the leak- I searched and found this thread very useful-
She yelled at me that "the coolant light came on" while I was still sleeping i said "it will be OK" and went back to sleep.

I hope we still have a BMW when she gets home.

curious to know where leaks are common?

champeny · champeny's Garage

I believe the original leak was caused by either air pockets in the system or an overfilled radiator. The radiator cap has an automatic overflow valve that opens when the pressure gets too high. In any case, there are no leaks now.

I still get the warning message, "check coolent level" telling me that the level is low, however my level has always been fine, and the car never overheats. My suspiscion is that the coolent level sensor is malfunctioning or was perhaps damaged during the installation of the radiator.

Hope things work out for you.