The upper radiator hose on my 1990 Accord EX swells up a lot (uniformily) as the car begins to get warm. The car temp levels off at the "normal" point and at the point that the thermostate opens the lower radiator hose becomes hot. The two electric fans come on and off as normal also. The heater works fine too. Do you believe it is a stuck thermostate - stuck halfway open, or the radiator is plugged - both of these causing a build up in pressure?? Could the radiator cap be the problem - not releaving pressure buildup correctly. Anybody have some ideas ??

Thanks.....

 

So the temperature gauge reads normal when it warms up... and the thermostat opens up which causes the lower hose to warm up...
All that sounds normal.

I'm thinking it's a weakened radiator hose. Get a new one before it bursts. Maybe that's a good excuse to get fresh anti-freeze & maybe a few other new hoses.

 

JimBlake, yes I plan to replace both the hoses, thermostate and coolant this Saturday. I hope you're right that it's just a weakened hose. Thanks for the reply...........

 

I'd agree that it's just time to replace the upper hose and maybe the lower hose if it has any swelling. Fairly common maint. item.
I've seen them swollen so big, it made me step away from the car for fear of bursting. LOL

 

I would advice that you replace ALL the cooling hoses,.(. bypass, radiator and heater,, )
if you call the dealer and ask for the cooling system hose kit. it will include all the hoses ,,( that is the way i get it )
this is they way i do it for my customers where car is soold and hoses get hard, swallen, etc etc

 

So today I replaced the upper and lower hoses, fluid and thermostate. The new hose (upper) one does not swell up like the old one. Test drive proved everything is working fine.

Deserthonda, you're right I should have replaced the other hoses. I did inspect them and they felt and looked ok. Next time I replace the fluid I will replace the other hose.

Thanks guys..................