(1989 CRX Si)

Doesn't blow hot air when fully warmed up (barely bearable when car is at a stop; freezing while driving on the highway). Hot/cold valve opens. Did a full coolant flush. No leaks/clogs in heater core.

When I had the heater core inlet hose off, started the car and turned the fan on, no coolant would be forced out of the engine (some drained but none after that). This makes think it's the water pump but it doesn't overheat.

Ideas?

 

Bump

I'm thinking water pump or thermostat.

 

Change your thermostat first, it's $10 fix. You can also check if there's coolant seeping from the water pump, that's usually the indicator that it's gone bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote"> You can also check if there's coolant seeping from the water pump, that's usually the indicator that it's gone bad.</TD></TR></TABLE>
Wouldn't the engine overheat if it's the water pump? The gauge sits where most Honda's do and never gets to halfway.

 

Typically if you have the seepage the pump is bad, but still capable of moving coolant. This seepage overtime will leak enough coolant that there becomes air pockets in the system, there is actually a bleeder on some motors to bleed the system as you add coolant.

Just about the only way a bad pump would cause an overheating issue is if the shaft snapped or it locked up which would probably throw the belt keeping the car from running.

With the heater valve open and the engine at operating temps, are both of the heater hoses warm. It could be the valve arm is moving but it's not opening internally.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Trakhor &raquo;</TD></TR><TR><TD CLASS="quote">Typically if you have the seepage the pump is bad, but still capable of moving coolant. This seepage overtime will leak enough coolant that there becomes air pockets in the system, there is actually a bleeder on some motors to bleed the system as you add coolant.

Just about the only way a bad pump would cause an overheating issue is if the shaft snapped or it locked up which would probably throw the belt keeping the car from running.

With the heater valve open and the engine at operating temps, are both of the heater hoses warm. It could be the valve arm is moving but it's not opening internally. </TD></TR></TABLE>

x2, good info ^^

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Trakhor &raquo;</TD></TR><TR><TD CLASS="quote">It could be the valve arm is moving but it's not opening internally. </TD></TR></TABLE>
Never thought about that. I'll check it out. THanks

But shouldn't coolant have been forced out the engine while running (out the port that leads to heater core inlet hose)?


Modified by WhiteOnRice at 8:27 PM 11/29/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WhiteOnRice &raquo;</TD></TR><TR><TD CLASS="quote">
Never thought about that. I'll check it out. THanks

But shouldn't coolant have been forced out the engine while running (out the port that leads to heater core inlet hose)?


Modified by WhiteOnRice at 8:27 PM 11/29/2007</TD></TR></TABLE>

How are you sure you removed the proper hose? did you remove both hoses?

Lets say for a sec the valve is broken internally and the hose you removed is the return, then no coolant would flow. That is why I ask did you do both hoses.

I'm not questioning your ablility or knowledge, but what means did you use to determine the heater core was not clogged?

 

When you removed the hosing you probably leaked out a bunch of coolant. Then you ran the car and nothing came out. Ya, that's normal cause you drained the system to that level. Your pump was likely just spinning air.

 

its under the heater core, behind the stereo center consol. stick your head in from the passenger footwell and look up under the heater core. youll see a white plastic lever and probably the cables that are loose. reach up to the front of the heater control and rotate the temp **** to see the cables. it should be obvious how to put it back together.

common problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Trakhor &raquo;</TD></TR><TR><TD CLASS="quote">How are you sure you removed the proper hose? did you remove both hoses?

Lets say for a sec the valve is broken internally and the hose you removed is the return, then no coolant would flow. That is why I ask did you do both hoses.

I'm not questioning your ablility or knowledge, but what means did you use to determine the heater core was not clogged?</TD></TR></TABLE>
I'm sure it was the inlet. I removed both hoses and water flowed through perfect both ways so the valve is fine.

I'm going to check the what dacrxkid4rm253 said. It's obvious how to tighten those cables? (the temp **** has tension 2/3 of the rotation from cold to hot).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WhiteOnRice &raquo;</TD></TR><TR><TD CLASS="quote">
I'm sure it was the inlet. I removed both hoses and water flowed through perfect both ways so the valve is fine.

I'm going to check the what dacrxkid4rm253 said. It's obvious how to tighten those cables? (the temp **** has tension 2/3 of the rotation from cold to hot). </TD></TR></TABLE>

That is a good thought, I had forgot about that. Also check for debris like a pen or something from blocking the door. Iirc, there is a "clamp" that holds the cable in place, you can loosen this and slide the housing of the cable away from the end of the cable that attaches to the blend door. I hope that isn't confusing. It's hard to describe.