Lower Rad hose


Senior Member
hey guys, Quick question..... B18b in a 93 SI...I changed my thermostat cuz the temp was going over half way mark and was heating up....Now my question is that the lower rad hose connects to the thermostat, if the lower rad hose is not hot after a 1 hour drive does this mean my thermostat is faulty??? The upper rad hose is hot as a biatch...The temp is still going up, and i took all the air out of the system already!!!

thanks guys!!!!


Super Moderator
Replace your thermostat. It is fairly easy to do. I recomend an OEM honda one. I bought a murrays POS one, and the quality was just not there. They cost a little more, but well worth it.

Anyways, you just have to pull the hole, and with extensions, take the two bolts holding the thermostat housing on. If you cant get at the lower/rear bolt, you may find it easier to just unbolt the stater. Then, pry on the thermostat (not on the actual block) and then replace. Make sure you put it in the right way and you line up the two little notches on the gasket to the block (you will see when you do it). Then reinstall everything, then take the cap off the raditor, fill, turn the car on, and keep adding until the lower raditor hose turns hot.

On honda's a thermostat will normally open within 10-15 minutes of just sitting, and maybe a little less when just driving around. If it does not open, then it needs to be replaced.


Senior Member
i did that already..... I was wondering if the lower rad hose should get HOT....I drove for 1 hr on the highway and still nothing.....I changed the thermostat wit a cheapy one i got from canadian tire :( But the lower rad hose SHOULD GET HOT IF THE THERMOSTAT IS WORKING RIGHT!!!!!


Senior Member
My upper hose is always hotter then my lower hose. Is the right? Sorry for the thread jacking.


If the lower never gets hot, does that generally signify water pump?

Don't mean to thread jack but got the same problem with my engine i'm taking out.