The upper radiator hose is collapsing as the car cools

Hi Joe,

Thank you so much for your response. I’m on cap #3. The second one I got was only rated at 16 PSI and the required PSI for this Saturn is 18... The radiator hose collapsed with both of those new caps.

I replaced the top hose you called out in the diagram, and it didn’t remedy the radiator hose collapse issue.

Also, the hose collapses with the radiator cap off, or so was told by the initial mechanic I took it to before trying to work out the issue myself. He performed that diagnostic test, not me personally.

I’m still at a loss and don’t want to start throwing money at new parts randomly. Thank you again for any insights you can offer.

Hi Joe,

It looks like the upper radiator hose is not collapsing upon cooling down with the radiator cap off. Is it possible that we’ve gone through several new caps that are all defective? That strains the odds a bit doesn’t it? Or no?

Joe, the hose returns to normal shape when loosening the radiator cap upon cooling down, and you can hear a rush of air. I think somehow, I’ve gotten a couple bad aftermarket caps.

It looks like I can get a 13psi, but I’m concerned about overheating as the car runs a little hot as it is. I’ve tried both 16 and 18 PSI, but they were AC Delco aftermarket. I’m going to get an OEM cap and see if that works. The original was an 18 PSI.

My buddy repeated the test with the cap off last night and the coolant overflow bubbled over badly when he stepped away for a few minutes... Is there any chance air was introduced into the cooling system? I hope that didn’t cause another headache.

Thanks again for all your insights.

Will do, Joe. Just to clarify, the fluid wasn’t bubbling, it straight up boiled over due to running the car too long without the cap to perform that radiator hose test you recommended. We did a block test for exhaust in the radiator fluid and that was clean, though we haven’t conducted all the tests the link you provided outlines to detect a bad head gasket. Will keep you posted as we go through the steps. Really appreciate all your input.

Joe, the OEM cap made no difference. I’ve gone through 3 GM AC Delco caps and one of another brands. The upper radiator hose continues to collapse upon cool down and when I remove the cap, the hose relaxes and takes its original shape. The hose is the original hose, and the car has around 120,000 miles on it.

Your messages and what I’ve read along with this test points to the cap, but all of these caps can’t be bad. I’m still at a complete loss and I’m not sure what to do next. And as I mentioned, the block test for exhaust gasses in the fluid was negative.

The hose is pretty soft in general. Sort of spongy but not from deterioration. I’m reluctant to put something on there that isn’t factory to artificially keep it from collapsing. I don’t know how hard or inflexible that upper hose was from the factory, but maybe I should check one out and compare.

Thanks for checking with the site owner. Will be curious about his thoughts and recommendations.

I’m going to check that out asap. I am also planning on replacing the valve cover gaskets as there is a bit of oil in the tubes and some smoke upon start up sometimes, so I think they’re worn out. Sound reasons?

Joe, the update is that the car runs much better after new plugs, wires, and valve cover gaskets. The molded vacuum tube that runs over the valve cover snapped as I was removing it, heat has made it brittle, so I repaired that with a piece of brass tubing and covered it in shrink tube. Since replacing the upper radiator hose, it has not collapsed upon cool down so I’m wondering if it was a combination of a completely worn-out original hose (which had become spongy) and a possible air leak. I drove it extensively yesterday and put it through its paces and the only odd thing is that when I parked it, the idle wouldn’t come down from 2k. I turned the motor off and restarted it and it idled normally so I’m wondering if there is a small leak in on of the emissions vacuum hoses. It did not happen today, but I’ll keep testing. Overall, I think we may have patched up the rough spots in this car for now... If these repairs hold over the next week of testing, I’ll take care of some of the lesser issues, air conditioning, and cosmetics.

Thanks for your help and suggestions along the way.

Hi Joe,

The engine idle seems to be normal now. Another issue has cropped up since doing the radiator flush, changing out the thermostat, and putting some fuel injector cleaner in one tank of gas. There is a white smoke that comes out of the exhaust - rather heavy at times, and not at all other times. It’s intermittent, so I’m wondering if it could be a bad ECTS. The car isn’t overheating, the coolant level isn’t dropping, nor is it creamy from oil contamination, and the oil isn’t contaminated either. The upper radiator hose hasn’t collapsed since it’s replacement either. The white exhaust doesn’t smell sweet like coolant, and the engine runs great since I replaced the plugs, wires, and valve cover gasket.

Any idea what would cause this intermittent white smoke? It smells bland - like regular exhaust, but maybe a little harder. Not sure if that makes sense. The main thing is it doesn’t smell like coolant or oil. I appreciate your thoughts.

Los Angeles... It’s been humid, but I think the volume of it intermittently is more than condensation. It’s irregular, sometimes none, sometimes a lot. It absolutely does not smell like coolant or oil. Any chance it’s the fuel injector cleaner I put in the gas from the last full tank? Thank you again so much for your insights.