heater control valve for 16V engine

[911tracker85]

I suspect I need to replace the heater control valve on an 87 944S 16V, or I have some major vacuum issue that is not effecting the engine running. common symptom, always HOT. I have already checked the flappy control in the footwell.

but so far I cannot find it down under the intake where the WSM says it should be.

the 16V has a very different intake and occupies a lot of the space where all the docs I have read say it should be.

looked in WSM, read Clarks garage writeup, PET.

anyone know where it is located?


searched threads but cannot find.

[asoduk]

Next to the oil filter

[ernie9944]

Originally Posted by 911tracker85

I suspect I need to replace the heater control valve on an 87 944S 16V, or I have some major vacuum issue that is not effecting the engine running. common symptom, always HOT. I have already checked the flappy control in the footwell.

but so far I cannot find it down under the intake where the WSM says it should be.

the 16V has a very different intake and occupies a lot of the space where all the docs I have read say it should be.

looked in WSM, read Clarks garage writeup, PET.

anyone know where it is located?


searched threads but cannot find.

This is the location of the HCV on my 968 not 100% sure but should be the same on your S both car being 16 v motor,like --asoduk-- mention on top of the oil filter,btw very hard to get at due to it's location.Let us know if you found it.

[Gawernator]

That looks even worse than the NA haha, suddenly I feel better

[mhariush]

What are the symptoms again? I have an 87 S and the engine is running hot. New water pump and new thermostat. Replaced coolant and bled it for a long time to get out any air bubbles. Still goes hot. Hot when idling. Cools down when driving. But gets hot sometimes when driving as well. Haven't figured out exactly when it goes hot and not.

Could it be my HCV too?

Originally Posted by 911tracker85

I suspect I need to replace the heater control valve on an 87 944S 16V, or I have some major vacuum issue that is not effecting the engine running. common symptom, always HOT. I have already checked the flappy control in the footwell.

but so far I cannot find it down under the intake where the WSM says it should be.

the 16V has a very different intake and occupies a lot of the space where all the docs I have read say it should be.

looked in WSM, read Clarks garage writeup, PET.

anyone know where it is located?


searched threads but cannot find.

[Gawernator]

I would see if your fans are working.

[mhariush]

Fans run, hear them when i turn the car off. Pretty sure they run when i idle too, but will try and double check that.

When exactly should they go on?

Originally Posted by Gawernator

I would see if your fans are working.

[Gawernator]

They go on at a set temperature designated by your thermo fan switch, it should match the thermostat. I am replacing mine because I had the same issue where idling the temperature would get too high because the fans weren't running. Driving it would be nice and cool. I still am not sure if I just had too high of a temperature switch or if it was faulty.

[ernie9944]

You can refer to Clark's Garage Home Page for trouble shooting your car overheating issues,once on site enter "Garage Shop Manual " then scroll down to "Cooling System" could very well be a thermostat or thermo fan switch issue.Btw when was your water pump last replace?

[mhariush]

Got it. I'll probably get a new temp switch then. Getting the one that will kick in at thw lowest temp sounds good then . I'm in LA so gets pretty hot during the summer

[mhariush]

Hi ernie
I'll look over that again. Have new pump and thernostat, as noted in a couple of posts up. Have about 5k miles on them.

Thanks

[Gawernator]

Try to get the one that matches your thermostat. You don't want the fans running before the thermostat opens or your fans will be constantly running and worked to death

[mhariush]

That makes sense. Thanks

[ernie9944]

Originally Posted by Gawernator

That looks even worse than the NA haha, suddenly I feel better

You should,removing the one on an NA is just like receiving a bouquet of roses from your love one versus aon the head doing it on a 16V.

[ernie9944]

Originally Posted by mhariush

Hi ernie
I'll look over that again.( Have new pump and thernostat), as noted in a couple of posts up. Have about 5k miles on them.

Thanks

Sorry should have read your post more carefully.

[mhariush]

No worries ernie, appreciate the help regardles

[djnolan]

If you drive the car on the open road or highway without stopping for 5 or 10 miles, what does the temp gauge read?

It should read at or below the first mark (about 1/3)

If it is above this you could have a coolant leak, bad thermostat, clogged radiator, air in the system, blocked radiator air flow, bad water pump impeller, and a few other things.

It would not be caused by the fans or the heater valve (unless leaking), though.

[mhariush]

It doesn't go tht cold, usually stays around the mid mark. I'm thinking I didn't get the thermostat seated properly in the water pump when I installed it.

[Gawernator]

Yeah it's not the fans if you are that hot on open road driving. Even when my fans weren't working right I was still at the 1/3 mark on the highway

[djnolan]

there are a million possibilitie, so

Is it overheating enough to cause coolant loss thru the overflow tube? if not maybe the temp gauge is not accurate, or the sender is not good, or the radiator is mildly clogged, or the tstat is bad...