Problem with Heater

[mashk]

Hi,

I'm having a problem with the heater in my car. When I turn it on in the morning, it can take a long time to actually start heating and when it does start heating sometimes the heat will go off. If it starts heating at all. As you can imaging it's a problem with all this cold weather and all my windows been frozen up.

The thing is, the heater does *work*, it's very intermittent when it does work though. Anybody have any ideas? I don't want to take it to a garage without a rough idea of what it could be.

Thanks

[oldcodger]

Hi,

It could be a few things which are diy-able.

Have you checked the coolant levels ? -sounds obvious, but happens !

The main thermostat, quicky checked by observing the dashboard temp gauge , after 20 mins has it got up to the middllsh position and holds there ok, meaning the stat is probably ok.

Have you got manual dial heater control or digital ? with either the controls might be damaged/ not operating correctly.

Finally it could be the heater matrix blocking up,  if you search the Corolla forum there as several posts about that and some methods of flushing it out.

 

[Billyboy81]

Try changing the cabin\pollen filter. 

[flash22]

Poor air flow would be my first thought, check the cabin filter if its standard A/C (if it has it) do the controls have any resistance to them when turned as the back of the controls can break and/or the cables seize

[mashk]

Many Thanks for the replies gents. Tried the cabin filter, even tried running the engine without the filter. Didn't really make a difference. Also checked the coolant levels, they were low to non existent. So I've topped them up. Ran the engine for a while with the heater on and it didn't really make a difference. Temperatures on the dashboard are fine, in that it stays in the mid position and I've never seen it veer towards the overheat. Going to have a look at the heater matrix. 

[oldcodger]

1 hour ago, mashk said:

checked the coolant levels, they were low to non existent. So I've topped them up. Ran the engine for a while with the heater on and it didn't really make a difference. Temperatures on the dashboard are fine, in that it stays in the mid position and I've never seen it veer towards the overheat. Going to have a look at the heater matrix. 

Hi,

You want to first check that you do not have a bad air lock in your heater due to the low water level.

Often, once refilled ,just running it for a day or so will naturally clear the air lock.

Before messing with the matrix think I would want to know why the coolant was so low  ?  thats not normal !

Its a fair chance you have a leak somewhere, using a torch and mirror, engine off,  have a good look around the thermostat housing, hose connections, water pump housing and radiator for signs of leaks , either obvious liquid or more often dried whitish, pinkish or brownish dried deposits.

Though you can see part of the radiator, you might have  to unclip the cooling fans and 2 bolts to allow a clear view of the front of the radiator, it was only by doing that I found the leak on mine.

Also unscew the engine Oil filler cap and see if inside the cap or the camcover is nice and clean or covered in a whitish creamy sludge ?

 

[mashk]

I've been driving the car for a couple of days now and the heater has been working a treat.

 

However, I topped the reservoir up to full on Saturday and the level was down to 1/4 above the low marker on Monday. So i topped it up again and I've just checked it now and it's at the same level. i'm guessing I've got a leak somewhere. i've had a look and nothing seems obvious. Best way to find a leak? The hoses look okay to me, so i'm guessing it could be the radiator? what am i looking at to replace it in a garage?

 

thanks 

[Stivino]

If it is sitting steadily between the high and low level, just leave it.  It's normal for it to fluctuate a bit between those marks depending on temperature.

[furtula]

1 hour ago, mashk said:

Best way to find a leak? The hoses look okay to me, so i'm guessing it could be the radiator? what am i looking at to replace it in a garage?

Get a big piece of cardboard, put it under the car, the leak will leave obvious stains in the morning.

If you have the plastic shield under the engine, then try to put 2-3 smaller pieces in.

 

If that does not work, then look around the obvious places, for example water pump, have you ever changed it? Usually they tend to loose a bit of fluid before dying, look for oxidation around it, like salt, then look around the hoses near the radiator. 

Also, does the car smoke? Maybe it's burning some oil, take the oil cap, is there "mayonaise" on the of the cap?

 

Also, as said above, always either compare hot, or cold, the levels fluctuate, so you cant measure cold, and then compare to what you measured when hot and vice versa.

[oldcodger]

You don't mention doing any of the checks I suggested, partic the oil filler cap c, so assume you are not a big diyer, so the best thing to do is take it to a garage and they can do a Pressure test on the cooling system and then they will be able to quote you for whatever repair is needed, could be a simple hose or something more expensive.

If its lost 3/4 of the contents of the reservoir  over the weekend then you have a fair old leak, however it might only be leaking when the car is running and the system is under pressure.

[mashk]

1 hour ago, oldcodger said:

You don't mention doing any of the checks I suggested, partic the oil filler cap c, so assume you are not a big diyer, so the best thing to do is take it to a garage and they can do a Pressure test on the cooling system and then they will be able to quote you for whatever repair is needed, could be a simple hose or something more expensive.

If its lost 3/4 of the contents of the reservoir  over the weekend then you have a fair old leak, however it might only be leaking when the car is running and the system is under pressure.

sorry oldcodger, i did check the oil cap, no white residue so i'm assuming my head gasket is fine. i can't see anything on the floor after the car has been parked up and i drive away. i was hoping it was fluctuating levels or something. anyhow i'll see if i reservoir depletes anymore if it does i guess its almost definitely a leak.  

 

appreciate the help gents 

[rafletcher]

6 hours ago, mashk said:

I've been driving the car for a couple of days now and the heater has been working a treat.

 

However, I topped the reservoir up to full on Saturday and the level was down to 1/4 above the low marker on Monday. So i topped it up again and I've just checked it now and it's at the same level. i'm guessing I've got a leak somewhere. i've had a look and nothing seems obvious. Best way to find a leak? The hoses look okay to me, so i'm guessing it could be the radiator? what am i looking at to replace it in a garage?

 

thanks 

First things first, take it to an independent and get them to do a pressure test on the cooling system. That'll show if there are any actual leaks. And don't overfill the reservoir, that can lead to siphoning over the overflow when the engine is hot.