Winter is coming fast over here and our 2002 S-10 take a long time to get warm inside. And the air temp out of the vents are barely 90°F. Temp on hoses going in to the heater are 160°F and going out is 150°F.

Could this be vacuum related? Reason I ask is that the vacuum hoses in engine room are really bad and need to be exchanged.

I guess the easiest way to find out is to change the hoses. I know there is a vent inside the heater that controls if the hot air is going in or not, is that one vacuum operated?

Appreciate any advice.

Thanks

 

The doors that control the temperature and distribution of the air are all vacuum-operated, so bad vacuum hoses can definitely cause problems. They're cheap and easy to replace, and you already know they're bad, so I would replace them as the first step.

 

Does it have or did it have Dexcool in the cooling system? If so, then your heater core may be partially plugged up. I would try and carefully disconnect both hoses going to the heater core and flushing it out with clean water. You can also GENTLY blow it out both directions with compressed air using a nozzle. Don't use full pressure though or you may be replacing it. I have 3 S10s and they have all done that.

 

You didn't say which kind of climate control you have - manual or ECC (auto temp). On my own ECC system, when the hoses and vacuum reservoir were rotten and leaking, all it would do is blow hot air out the vents - but mine also had a bad control module so anything is probably possible. But, as others have said, if you know they're leaking, you should definitely replace all of them - including (if it's a 4x4) to the vacuum switch on the firewall and the chamber under the battery - and definitely test the vacuum reservoir - mine was bad (leaking) so I had to make one out of a #2 tin can because I didn't want to pull the fender (new ones aren't available anyway). Back flushing the heater core is also a great idea!

 

Replacing the hoses is smart and easy and will let you direct the air through the proper vents but will not get the heater to heat it up better. Maybe a flushing like Crazy says is what you need.

 

Had my LIM done in 2014. Just had to back flush it for third time. I installed T's for the second one three years ago..
Run suppy hose into (usually) top htr hose, goes to water pump. Clamp between there and wp.
Discharge hose to hose going to manifold. DO NOT APPLY FULL HOUSE PRESSURE!
It's not mix of coolant ...it a*hole mechanics scraping paper into water jacket
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