1997 328 rad plugged?

[guymandude]

1997 328

Last weekend at autocross lower rad hose poped off. The hose clamps were a little loose.
I fillled it with water and drove it home.

I just went to drain it and barely anything was coming out. The overflow stayed full. I used some compressed air to blow some more through. Only about a gallon came out.
After i stopped with the compressed air liquid would come back into the reservoir to about the top of the level sensor.

I filled it and tried to bleed the air. I used the mothod seen here. https://youtu.be/nSTCBsuPr1I
I had no water coming from the breather hole when squeezing the hoses just air. The lower hose feels like there is nothing in it. The heater was blowing cold.

I have a new thermostat, water pump, overflow, upper lower hoses and the hose to the overflow. The rad is unknown.

I am planning on replacing the rad but i am wondering if there is another place where there may be a blockage that i should be considering replacing at the same time.


Any help is appreciated

[bluptgm3]

I think you lost more coolant than you realized.
Shouldn't be any blockages, other than a possibly a stuck-closed thermostat, but should not affect the cold fill and bleed.
The process outlined should work, there are those that claim the fill and bleed should be done with engine off.

I dill a 1/8th inch hole thru the 'up arrow' in the thermostat to facilitate the bleed.


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[guymandude]

More background.

I swapped this engine into the car one year ago. That is when i replaced the cooling parts but i kept the old rad to keep cost down. When i originally drained and filled it. It was normal. A steady stream from the drain plug and then a trickle until i removed the expansion tank cap then a steady flow untill the rad was drained.


This flow is like having the cap on but i actually have it off. That is what makes me think it is plugged.

When i filled it with water at autocross i drove it home 300km without a problem and i had hot air.

when i got home and parked the car overnight the overflow would go down. When i opened the cap it would release a vacuum and the water would start to fill the overflow again up to the level it should be. I was not loosing coolant.

[pbonsalb]

Could be partially clogged if a previous owner dumped sealant in it. Check the radiator date. I would not trust a plastic tank past 10 years.

Probably you did not bleed the cooling system properly or the head gasket is leaking.

[66 6]

I've seen 300k radiators that were still in perfect condition (inside). Unless someone dumped some stop leak in there, clogging is not your issue.

[Eric93se]

Your head is going to be damaged, your overflow tank if original is probably bad as well. There should be a plastic tube inside on the right, runs top to bottom.

[Cobra1956]

When the car is running do you have heat? If you don't then your system is filled with air. If the cap is old it will suck in air rather than fluid from the reservoir. Out of curiosity when you drained the radiator what color was the coolant? Did see an M3 at the track this year that had coolant that looked like gravy and the system was clogged.

[guymandude]

The coolant was water and it didn't seem to have any debris in it. I have a new radiator and a new cap that should be here Saturday. I will see on Sunday if there is any change.

If not i will be checking for head gasket leak with a hydrocarbon tester.

I doubt the head is damaged as it did not overheat. And i drove it home 300+ km without overpressurising the cooling system or overheating.

[Cobra1956]

Is the system still together? If so do you have heat? If you have the radiator out hook it up to a vacuum cleaner and see what kind of suction you get at the other end.

[guymandude]

New rad is in now. I have heat again. Im still not getting coolant squirting out the vent hole when i squeez the hoses so i probably need to burp the system some more.

The old rad was crumbling at the upper rad hose. Half the plastic came off with the hose.

[Cobra1956]

It take some time to get the last bit of air out of the system. It helps if you elevate the font of the car an inch or two but it is not necessary. The way the hose is routed for filling is forcing the water in so the more you get in there, the more resistance you get. It is still filling but it takes longer. If you are using just water is should be distilled and you should use something like Water Wetter that lubricates the pump and inhibit corrosion as that iron will rust like crazy. I use Evans Waterless coolant as it does away with ost of the issues and has a higher boiling point although a bit of a pain to convert.