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Discussion Starter #1
Hey all,

Okay so today I replaced my radiator cap and upper hose of the radiator as it wasnt the correct one and was pinching slightly.

I refilled the system, left the radiator cap off, and opened the bleed screw on the throttle body. I then started the car and watched the water shoot out through the bleed screw. I closed it and kept purging the system until the car was warmed up. I also opened the heater and turned on the heater blower and moved that back and forth a few times.

I took the car for a ride, and still the gauge would float a lot on hard turns. It would also go up a bit after sustained 4500+ rpms for about a block. Then would usually come back down to a where I could just see all of the top of the top mark on the gauge.

I got back and checked the top hose and actually felt a bit of pressure in it but if i wanted I could still pinch off the top hose. I opened the bleed screw while it was running and nothing came out. I opened the radiator cap and fluid started coming out of the bleed screw.

Yes, even after a 10 minute hard run at operating temp I can still open the radiator cap with no pressure behind it.

I cant figure this out. I cant figure out why the car is running a lil hot or why the gauge is floating a bit.

Am I supposed to be able to open the bleed screw with the radiator cap on while running and get nothing out until I rev the engine?

UGH IM l losing my patience :(

Jeff
'84 Spider
 

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But Mad North-Northwest
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Sounds like you need to pressure test the cooling system to figure out if you have a real problem. Any decent rad shop should be able to do it.
 

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Discussion Starter #3
It has a reemed and rodded out radiator that was checked for leaks, a new water pump, new thermostat and housing, new fan blade, new fan belt, new radiator cap, new upper hose.

Last time I took it in to my shop (a few weeks ago, they pressurized the system and it wasnt losing any pressure so they believe the HG is fine.

Blaaaaah
 

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:)I like it--vehicle repair through random yet complete parts replacement, I should have a new car by March 2010 at this rate.:p

Gauge reliability is not a strong suit for Alfas, never trust them, coolant temp with respect to a wavering needle should have NOTHING AT ALL to do with cornering...that said...get your temp gauge fixed. That ain't right.

Heater blower should stay off. You don't want to remove heat from the coolant for this process just want to circulate the fluid.

Did you bleed the cooling system at the WATER PUMP while filling? There is a 10mm hex head screw on the north side of the H2O pump that should be opened as you are filling the system. Once fluid escapes from that orifice, close it off and continue filling until rad seems full. With heater on (valve not blower), start car with rad cap off. Use a 14mm box end wrench to open the throttle body bleed screw and let out the air, --close it up when coolant is spouting--continue to top off rad until full then put on the rad cap. Go have a beverage while vehicle warms up. When vehicle is "warmed up" the thermostat should be open and you can tell if the upper hose is HOT--about 170 degrees hot or so;).
So, how do you reconcile a potential "liar" temp gauge into something that means something...trust your work (not some overpaid shop of dubious intentions/knowledge/skills) and your troubleshooting skills--go to Harbor Freight Tools and get you one of them cheapo laser thermometers. That's your truth. Pull over and use it when you suspect overheating.
 

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Discussion Starter #5
Thanks but that opens a few questions.

I didnt bleed at the water pump bc I didnt flush the fluid this time, it had full fluid so I didnt open that valve. Should I anyway???

Should it at any point start spouting fluid from the radiator? I never seem to pressurize. Even after a hard drive at op temp I can open the radiator cap and no pressure.

I was using one of those laser thermometers from my shop for a bit, but where the heck do I point it? haha

Thanks,
Jeff
 

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Discussion Starter #6
Oh and as to why I replaced everything - it needed it ha! I bought the car from a 77 year old man who bought it new. I dont think he replaced too much in the 107k miles of operation... It was the original waterpump, original radiator cap etc. These items flat out needed to be replaced.

Thanks,
Jeff
 

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But Mad North-Northwest
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The Milano doesn't have a bleed screw at the water pump, only at the thermostat body.
 

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Are you sure you have the right radiator cap? They are made for different lengths of filler necks. If you get a cap that is too short or a filler neck that is too long - was any work done on that item when the radiator was 'reamed & rodded'? - it'll not seal.

Aim the laser thermometer at the thermostat housing. Also at different areas of the radiator. When reading off the t-stat housing it should be close to the thermostat's rating. When reading off the radiator, it should be hottest along the top & cooler along the bottom and vary evenly in between. If there are hot or cool spots in the middle of tha radiator then go back to the radiator shop to 'discuss' those findings.
 

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Jeff,
Coolant shouldn't spurt from the rad without the cap, the cap is what allows the pressure to build up.

Try this: Assuming you have bled the system and its full of coolant--Start with motor cold, dump out the overflow tank, rinse well and partially fill with clean distilled H20. Go driving and make sure motor gets & stays at operating temp for a while. Afterwards, check the overflow tank for coolant mixed with the clean H2O. If it is, then I'd say your system is pressurizing fine and the rad cap works as it should.

As far as the thermometer I'd point it at the rad in vicinity of upper hose to see the coolant temp passing thru the t-stat then I'd point the thermometer at rad near lower hose. There should be a temp delta between the two.

Good luck
 

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I would not take it out for more test rides until you figure out why it is not building pressure when it heats up. If the cap was leaking you would see it spurting out there. If a hose or radiator was leaking you would also notice that. The ugly case is a blown head gasket where the coolant could be leaking into the oil or into the exhaust.

Check the oil is it milky?

Check the radiator fluid level - do you need to add fluid? and the overflow bottle - is it empty?
 

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Discussion Starter #13
I am sure I have the right rad-cap, I got it from centerline and they checked the number first and its correct.

I'm more worried about being able to take the cap off after a run without pressure.

Also, is this correct. I can open the bleed screw with the radiator cap on after a run and no fluid comes out there unless I rev it. If I open the rad cap, then fluid starts coming out of the bleed screw - is this correct?

The overflow is actually a bit too full now bc it is circulating into there.

OIl is not milky.

Thanks!
Jeff
 
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