Is my top radiator hose supposed to collapse?
 

I just noticed that my top radiator hose was collapsed on itself after it had been sitting for a while.

I haven't noticed this before but that doesn't mean it hasn't been doing this for a while.

I don't notice any obvious cracking or other damage to the hose.

Could it just be time to change a weakening hose or is there potentially something more serious going on?

I will say that I also think that I have been smelling coolant lately from within the cabin.

My windshield will also be fogged up from the inside occasionally at startup but I don't know if this has more to do with cooler weather or not.

My first car was a 1987 Chevy Cavalier that did something similar and it turned out to be the heater core.....

My coolant level appears to be fine but I did notice what seems to be a crack in the seam where to two halves of the reservoir tank come together.

The coolant level is right below that.

It's time for a new radiator (expansion tank) cap.

Oh... Is this why radiators collapse on themselves? The tops and bottoms of the radiators themselves always seem to be collapsed like they are imploding on themselves. It has intrigued me.

Yep, bad radiator cap...

mine does this too (upper rad hose collapses after sitting)

not the cap, I have new 1. I think its normal (but dont know why...)

Try the cap first as indicated.

If there is a coolant leak, the hose should not collapse as air replaces the missing coolant.

If you remove the cap, does the hose expand back to normal?

The hose collapses because the pressure inside the cooling system is less than the atmospheric pressure. On a cold engine, the internal and atmospheric pressures should be about equal.

In addition, if the cap is bad, it tends to let some coolant out (worn spring/seals). So when the car cools down, the cooling system has less coolant to go with, so a vacuum develops and the hoses collapse.

Leaky heater core. I have been putting this off for a while now. Sun valley MB recyclers will pull a good used one, charged me $50 I believe, beats $300 new.

Step 1:remove steering wheel, dash & climate control
Step 2: Remove heater core.
Step 3: Installation is the reverse of removal.

Alternative: Flush & dry cooling system, replace PEG/H20 coolant w/ Propylene glycol, no water. Drill hole in pressure cap. Running the coolant loop at ambient pressure will minimize the leakage rate, Propylene Glycol boils at 1 atm, ~375F, specific heat is a little lower than water. May run a little warmer than w/ PEG/H20.

Cost about $30 / gallon for the coolant, I think.

Replace the radiator cap if it's not recent. Monitor the coolant level, make sure it's correct (at the seam on the plastic tank when cool). If the hose keeps on getting flattened (either partially or totally), try releasing the vacuum periodically. It may eventually work itself out. If not, don't lose sleep over it. My cars have been doing this for years with zero ill effects. Don't go trying to find a problem when there isn't one...

:euro:

I would not recommend a used heater core. It's a PITA job to change. Do it with a new one and rest easy for 10+ years.

You forgot to mention that Step 1 has about 80 sub-steps. Have fun.

hahaha right now i'd bypass it and revisit come november...

Removing the steering wheel is unnecessary.

It may not be "necessary", but if offers more room to work, and takes all of a whopping five minutes. I pull the steerinf wheel when I do this job. Just watch out for the cruise control stalk when removing & installing the dash.

:nuke:

For those with the tools an patience to pull a steering wheel seized on the shaft.