engine and drivetrain Cooling issues

[AdamJ]

Well I'm trying to get a car back on the road after it being neglected for a while.

I've fixed the oil leaks, now it's on to the cooling system.

I can drive the car for 5 or 10 minutes and then the temp starts to go way up. I took out the thermostat and tested it in a pot of water. It opens up and closes like it should. (I think it was around 75 or 80C).

After shutting the car off after heating up however, the hose to the thermostat on the engine side is very hot, while the hose to the radiator is moderately warm. Similarly, the top of the radiator is very hot to the touch while the bottom of the radiator is only slightly warm.

I get it. Coolant isn't flowing through the radiator and it points back to the thermostat. Could it be something else? Is my water pump kaput?

[eurotrash]

clogged radiator..? Maybe pull it and run water through it in reverse of the flow.. see what comes out.

[Napes]

I think you may be right when you say "coolant isn't flowing through the radiator" but the problem may not be the thermostat, because you say you tested it and it appears to open and close as it should.

It sounds like your radiator needs to be taken to a radiator shop and have them rod it out. They'll remove the top and bottom tanks and clean the water passages so you get the req'd flow of water thru it.

Generally, once the thermostat is open, the hose leading into the top of the rad. will be hot while the hose coming out of the bottom right side should be noticably cooler.

Bob Napier

[AdamJ]

I guess if I'm going to go through the expense of getting the radiator repaired, it might make sense just to upgrade to a 320i radiator. Last time I looked they were something like 120 bucks.

Just as a final check before I replace the rad. I'd like to rule out other possibilities. Would a water pump failure be evident from coolant leaking out a weephole in the pump? Do these have a weephole? In my experience I've seen water pumps fail and there isn't much evidence. I'm not sure how that works, the impeller is spinning and the vanes are still intact, so how does it exactly "fail". sorry for the digression. . .

[BDB]

adam.

i have a racetep 320i radiator i am selling for $100 shipped. i just had it cleaned out by a local radiator shop about a month or two ago. i decided to stay with the stock size. if you're interested, i can send you pics this weekend (sunday afternoon PST). im heading on a flight right now.

thanks,

bob

[GoFaSSter]

I have not looked at the water pumps on our cars, but on others I have worked on had WP problems. The impellers were actually corroded and not moving fluid causing overheating. Some would move, but not enough to keep cool. This only happened on two cars I had bought and I knew they had not been well maintained.

[AdamJ]

Bob

I would definitely be interested in the Rad. When you get around to it I'd like to see the pictures. Thanks

[BDB]

Adam,

Sure thing. I fly back on Sunday so ill send you pics. Can you email me so I can send you back the pics to your email?

[kbmb02]

I can drive the car for 5 or 10 minutes and then the temp starts to go way up.

That's warming-up quickly. Before replacing parts, you might consider testing for combustion gases in the coolant (the testers are readily available). If the test is positive, it's indicative of a failing head gasket. -KB

[cyclopticgaze]

Hey, Adam. Glad to hear you're back hammering on the 02. Mine's creeping along slowly.

I'm just chiming in to say that if you keep the rad you've got and need a radiator shop, that old guy in Woodstock was good to me. Leak tested two of mine on the spot for no charge. And replacing the water pump might be a good idea anyway. They don't cost much and it's an easy job if you're already got the rad out. After plugging coolant leaks and replacing the t-stat, I still had problems like you're describing. Then I pulled the water pump and found this:

Best of luck!

[c.d.iesel]

NO!

just have your original 02 radiator recored

by any radiator shop - it's not rocket sciece,

the standard replacement core that all radiator shops

order for the dimentions of the 02 radiator is

a big improvement over the original core.

no need for 320i rad, electric aux fans

and if your thermostat is 20+ years old?

replace it with a NEW one . It's just a cooling system.

Treat it to new parts every 20 years.

and any time you open the system like removing a hose, the thermostat, you need to throughly re-bleed the system.

Heater on HOT, front of car jacked up high,

feeling all hoses untill even temp flow and full heat.

after the car cools off for a few hours, then top to the correct level

cold which is about 1 to 1.5" below the filler cap.

You should see a raised bump on the front wall of filler neck

for FULL cold

air pockets will also give you the HOT/cold pockets that you feel in the

hoses!

and the photo above is what comes from never changing coolent,

nasty water, prolonged periods of not running

Think what the inside of the hoses and heater core look like! YIKES!!

[yeewiz]

+1 it's the radiator

replace the waterpump while you're in there. remember, the car's been neglected. spend the $$ to get your cooling system healthy. it's only the system that keeps your motor from burning up ;-)

[AdamJ]

Brett: Yeah I bought a bike so the '02 has been on the back burner for a while. I just realized that I'd like to drive this thing before the snow hits.

I had the front covers off to re-seal the engine and the water pump "looked" good. I brushed off a little corrosion but nothing major. Yours looks like it came off the Titanic.

C.D.: You were right. System only needed to be "burped". I jacked it up, opened up the heater valve and had a bunch of air bubbles come out. Granted, the radiator isn't in optimal shape. I'll probably have the local rad shop go through it.

There must be a name for the phenomenon that occurs sometimes at work in the middle of the day when there is nothing to do, the portal to the internets is open and you find yourself somewhat obsessing about your latest car hobby . . Next time I'll stop and think more about it first. Ha ha.

[-=Charley]

If you're filling the coolant up correctly, there shouldn't be much question of the water pump working correctly.

leave the cap off the rad and let the car heat up and thermostat open. Is coolant gushing out of the there once the car heats up? That would be bad. If not, you should see some coolant start to move into the radiator. If you don't see some good flow, it may be your pump. If your pumps good, but rad is plugged, you'd have popped hoses or bubbles by now. I think it just has air trapped somewhere

If you suspect your rad is plugged, you want to check temp from side to side (horizontally) not top to bottom. If it's working correctly, it should be hot on top and cooler at bottom.

edit: oops, just read your last post