Five-8

Hi All

Have completed TB/WP & top end refresh, and am now troubleshooting/checking.

I replaced the HCV last year, which cured a problem with heat always entering the cabin, now i am wondering if it is the culprit for the no heat condition.
Car currently is just filled with distilled water(while checking for leaks)surely this isn't the problem.
Also wondering if the thermostat might be stuck, it sat out for nearly 3 months and i neglected to check it before putting it back in(doh)
Temp guage reads just as it used to, ac fan comes on like it is supposed to,air is working like it used to...rad hoses seem to have an appropriate temp difference.


Is it possible something else is at play here?Vacuum related?

Thanks for any insight

Cheers,

kmascotto

did you plug the vacuum port back in? is the valve moving?

hacker-pschorr

Years ago i had an Audi that had no heat after a coolant flush. It ended up being an air bubble not allowing coolant to fully flow through the heater core.

The valve should default to open (full heat), but anything is possible.

Randy V

The hot water valve to the heater core defaults to the open position in the event of vacuum control loss, so unless the valve is stuck closed it's probably not that.

davek9

Yes what Randy says ^^^, so when you start the car and the HVAC controls are set to Cold and or Off, you should see the lever "close". and open once the engine is not running.

My vote is for an Air bubble, did you bring the car up to temp and then let it sit over night or till cold?
Doing this usually requires a "topping off".

Dave

Five-8

Yes sorry fellas i forgot that you can see the HCV actually opening closing.So after checking, my HCV lever is moving when heat/air are requested...and also defaults if i unplug the vacuum.
So this suggests it is not the HCV.
So a bubble perhaps?
Any other possibilities come to mind?

Thanks Fellas!

Five-8

Today is the first day i have brought it up to temp, and have not moved it...so perhaps i should let it sit, after topping it off.

Thanks

Bertrand Daoust

Run the car for a while (with the system to full heat).
It often takes a bit of time to get all the air out.

Had the same little problem two weeks ago after the TB/WP job.
Everything's good now.
Good luck.

hacker-pschorr

Is the radiator cap off? If not, that is the problem.

Take the cap off, start the engine, make sure the heat is on high with the fan off.

Once some heat is starting to build up in the engine, I start squeezing the upper radiator hose.
One of two things should happen:

1. Fluid level drops, that's all the bubbles leaving. Top off and wait for #2:
2. It starts to boil over - put the cap on....all bubbles should be out.

At this point you should have some heat.

Five-8

I have the cap off and have let the engine run with it off, i have massaged the hoses, and topped up.Only thing i haven't done is run it to boiling point and run the heater without the fan,have had the fan going each time i have tried it.

Will give this a go...thank you sir!

Cheers,

j.kenzie@sbcglobal.net

On mine, I got a "low coolant" warning a week or so after a full coolant flush. Then after topping off, I got heat, not until then. I have heard of loosening the coolant temp sensor as a air bleeding point, but I have not done this myself.
Dave

Five-8

Fellas,

All is well. Since the consensus was an air bubble, i went ahead and drained out the distilled water, and then filled her up with 50/50 Zerex/distilled water.Once the car had fully heated, topped her up, drove to the end of the driveway and back...soon had heat and plenty of it.
Clearly, trapped air was the culprit, as you guys suggested.

Many Thanks!