washed the engine bay a bit sat....now heat blows cold?
 

make any sense?
sat after work, i decided to try and clean up the engine a little bit and change my valve cover gaskets.
so i sprayed a little simple green and then water to try and get some of grime and grease off.
then i hit it with a little compressed air. changed valve cover gaskets.
then monday was taking my son to school and noticed that cold air was blowing.
why would this happen?
prior to wash and gaskets, the heat worked as it should.??

Re: washed the engine bay a bit sat....now heat blows cold?
 

It could just be a coincidence. Do you have a valve that lets heated water through the heater core?

Re: washed the engine bay a bit sat....now heat blows cold?
 

That's usually sign of a bad head gasket or air in the system.

Re: washed the engine bay a bit sat....now heat blows cold?
 

thanks for reply.
not sure if i have the valve your talking about tho

funny thing was later on the same day i posted this....
i drove to work, and put the heat on and it was warm. then later turned cool again.

why would this happen. either be cold, no heat. or sometimes throw hot air?

Re: washed the engine bay a bit sat....now heat blows cold?
 

a bad head gasket??
would this have been something that was going bad?
would this have happend in my cleaning of engine and changing valve cover gaskets??

how do i check and how hard if its gone bad?

thanks again for any help and advice

Re: washed the engine bay a bit sat....now heat blows cold?
 

no coolant leaks?or low
do all the other heater controls work right?
maybe you knocked off the vac feed for the controls?
the valve ,i've had it for rear heaters in burbs with a dual heat/ac core unit(keeps the heat from going threw when the ac is on)
havn't seen it on reg front heat/ac's

Re: washed the engine bay a bit sat....now heat blows cold?
 

no leaks that ive noticed.
truck seems to run good. with no probs.
i know rad needs to be changed. just dont have the money now to do it.
sometimes a drop or 2 will come out. but its weird. couple drops, then runs dry... as in no leaks.

as far as if my controls work right.
thought i only had the one to control. from in cab. and they seem to work ok.

no much noise from the 2 lower settings but higher 2 sound and prove it works.

prior to me wetting things down and moving stuff around a bit for access to gaskets. i know it worked.

thanks for the help tho man.

Re: washed the engine bay a bit sat....now heat blows cold?
 

you prob won't/don't see it drippin while driving/hot
may wana warm it up from cold with the rad cap off to burp it
ok if the truck runs good prob not a vac leak

Re: washed the engine bay a bit sat....now heat blows cold?
 

Would a worn diverter affect the output of cold and hot? Hope you get it figured out?

Re: washed the engine bay a bit sat....now heat blows cold?
 

thanks for reply.
ill try and burp it before work today.
not really sure how air would have gotten in there tho??

i thought maybe thermostat was stuck....then again, i dont know much about the mechanics of things.

thanks for help guys.

BlackTopMotors....again, not sure what you mean diverter?>

Re: washed the engine bay a bit sat....now heat blows cold?
 

It is the large box under the dash that has a flap door inside to divert air flow to the A/C vents or to heater/defrost diverter box...

The door lets air from one source move to another...like closing and opening different vents in your home

The flappers/doors go bad and don't completely shut out cold air and or heat...especially in our year trucks...notorious for going bad...

It may not be this at all; just trying to help you trouble shoot

Re: washed the engine bay a bit sat....now heat blows cold?
 

if you have a leak the air will get in
the controls he said seem to work ok so i would rule out the black box
put a sheet of news paper under it after a drive,and maybe wipe the crossmember under the block......looking for green

like in my pic

Re: washed the engine bay a bit sat....now heat blows cold?
 

thanks for info and pics.
unfortunately i dont know what im looking at in the pic. sorry. im a dumb ass.
today came home at 7 am. was cold. turned on the defrost/heat. and it came out warm.
ill post a pic of where ive seen green from time to time. but its not always.
but its right from radiator. on the side.

Re: washed the engine bay a bit sat....now heat blows cold?
 

I dont know if anybody had suggested it but check the vacuum hose that goes through the firewall by the evaporater ( I think that is what its called )It controls the duct door inside of the cab. If it is not connected it will make the control doors for cool and hot air act all crazy and haywire. I have knock mine of on several trucks and hunted the same problem

Re: washed the engine bay a bit sat....now heat blows cold?
 

thanks.
gonna have to try and find what your talking about. good chance that could be it.
moving things around to get gaskets off, and pulling wires to better route them might have led to me knocking this thing off, or loose. now just gotta find it.

Re: washed the engine bay a bit sat....now heat blows cold?
 

Should be a plastic vacuum line and should run from the passengerside firewall to behind the carb and attach to the carb or the intake.