Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: DD-Indeed on 22 July 2015, 18:06:55

Title: Heater issues with hot engine
Post by: DD-Indeed on 22 July 2015, 18:06:55
Hi !

I've been wondering for many years, that what could be problem, because, my V6 2.5 Omega heater acts very strangely and is annoying in the winter. What's happening, is that when I get going with cold engine in the morning, for example. After couple miles, the heater blows warm air nicely for some time. But, when the engine heats up to normal operational temperature, the heater starts to mess around. It blows COLD air only, unless I put the heat level to HI, then it will blow hot air. Any level between LOW - 27 C blows cold air.

Coolant fluid levels are normal.
Thermostat is working ok.
Heater Bypass Valve is working correctly and been replaced everytime, it has gone broke.
Been resetting the heater system, but it's not helping.
Waterpump is working ok.


Only thing come to my mind, is those Vacuum Lines, that goes to the multiram valves and behind the engine. Last time I changed the cambelt, I removed those and they might be in a wrong order, after I did put them back. Could that be the cause ?

Or could it be, that the electric assistant waterpump is broken ? The one, which is positioned in the hoses under the cooland tank. Those pumps are special features here in Scandinavia, they pump more warm water to the heater, since here is very cold winters sometimes and the engines own waterpump can't keep up with the needs of the heater.
Title: Re: Heater issues with hot engine
Post by: Andy B on 22 July 2015, 18:49:10
....
Or could it be, that the electric assistant waterpump is broken ? The one, which is positioned in the hoses under the cooland tank. Those pumps are special features here in Scandinavia, they pump more warm water to the heater, since here is very cold winters sometimes and the engines own waterpump can't keep up with the needs of the heater.

I'm sorry, but can't answer your question, but the additional pump isn't specific to Scandinavia, some cars here are fitted with them. I do know though that it's the same pump unit as fitted to the side of the main radiator as an extra pump to circulate coolant when very hot & the engine is switched off
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 22 July 2015, 20:05:36
....
Or could it be, that the electric assistant waterpump is broken ? The one, which is positioned in the hoses under the cooland tank. Those pumps are special features here in Scandinavia, they pump more warm water to the heater, since here is very cold winters sometimes and the engines own waterpump can't keep up with the needs of the heater.

I'm sorry, but can't answer your question, but the additional pump isn't specific to Scandinavia, some cars here are fitted with them. I do know though that it's the same pump unit as fitted to the side of the main radiator as an extra pump to circulate coolant when very hot & the engine is switched off

Yes, there is that another one near the radiator. At least that one is working.
Title: Re: Heater issues with hot engine
Post by: Andy B on 22 July 2015, 20:07:22
....
Yes, there is that another one near the radiator. At least that one is working.

You could use another known working one in place of the pump you think you're having problems with ...... I meant to put that in my other reply  :-[
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 22 July 2015, 20:09:50
....
Yes, there is that another one near the radiator. At least that one is working.

You could use another known working one in place of the pump you think you're having problems with ...... I meant to put that in my other reply  :-[

Yea, I could do that and test it out, if that solves the issue. If it doesn't solve the problem, then it's about those vacuum pipes.
Title: Re: Heater issues with hot engine
Post by: RobG on 22 July 2015, 21:18:07
http://www.omegaowners.com/forum/index.php?topic=90499.0
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 22 July 2015, 22:04:15
http://www.omegaowners.com/forum/index.php?topic=90499.0

Thanks! I'll check those.
Title: Re: Heater issues with hot engine
Post by: Entwood on 22 July 2015, 23:33:46
Try this .. disconnect the small vacuum pipe from the top of the HBV and then block the pipe with a small screw, leaving the HBV open to atmosphere. As "vac" turns heat off you should now get hot water flowing to the heater matrix all the time, so giving you warmth.

If it remains cold then you have proved the HBV is not passing hot water to the heater matrix. IF you get heat you have proved the HBV is working, you now need to find out why you have a "vac" when you don't want it !!

On my old blue 2.5 the cure was a replacement climate control panel as it had an intermittent fault, I had the same problem as you .. ok to start then useless.

On this one the problem was different.. the vac was permanent and was simply one of the small air valves stuck ... glove box out and replace the valve ...problem solved.

HTH :)
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 23 July 2015, 01:11:30

On this one the problem was different.. the vac was permanent and was simply one of the small air valves stuck ... glove box out and replace the valve ...problem solved.

HTH :)

Now that you did mention the glove box, I did notice once, that the inside-air recirculating flap is controlled also with Vac and it is also doing it's own stuff. Example, it closes the fresh air flow, when you swich from windscreen blow to windscreen-floof combo. What I am going to do, is to take the Vac hose off from the flap pump, plug the hose and jam the flap to a 50:50 position (50 % outside, fresh air and 50 % recirculating inside air) to make it work perfectly every time of the year and to be partially open in every ventilation position. There is so rarely the need to close the flap, so this kind of modification is good, some sort of an ''reverse engineering'' for that engineering mistake. :)



And also, I did have an issue, that in the winter, the side windows mist up very often. Reason to that was again, an engineering mistake: you weren't able to blow the air to the windscreen and to the side windows, at the same time.

Yes, there is those small vents in the dashboard, but they're useless. What I did, was this:

This is the side of the ventilation machine with the servos. Notice that blue wheel. That controls the four upper vent's open/close flap:
http://postimg.org/image/5byt1n4zt/ (http://postimg.org/image/5byt1n4zt/)

And here we have a control arm of it, that was missing in the previous picture:
http://postimg.org/image/w5ub9durt/ (http://postimg.org/image/w5ub9durt/)

And here, as you can see, I jammed the vent flap to fully open position, so now, whatever position I choose from the vent directions, it always blows air through those 4 upper vents. Like in a G-Astra:
http://postimg.org/image/g02k0heyx/ (http://postimg.org/image/g02k0heyx/)


No more misting windows. :)
Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 23 July 2015, 10:08:07
Another possibility is the sampling fan in the climate panel. This draws air into the little vent on the front of the panel over a thermistor. It commonly fails, which allows heat from the panel electronics to give an inaccurate temperature. Given that you get heating on the "hi" position, I would say the control of coolant to the heater matrix is OK.

Also - does the outside temperature sensor report a sensible reading?
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 23 July 2015, 13:22:20
Another possibility is the sampling fan in the climate panel. This draws air into the little vent on the front of the panel over a thermistor. It commonly fails, which allows heat from the panel electronics to give an inaccurate temperature. Given that you get heating on the "hi" position, I would say the control of coolant to the heater matrix is OK.

Also - does the outside temperature sensor report a sensible reading?

Yea, the outside temperature is correct, so it's ok.

I did once open the climate panel to change some bulbs, but didn't remember about testing that small fan. I'll open it again to check that.

The heater matrix is ok, if it leak, I would notice that and if it's channels are blocked, there wouldn't be coming any heat at all from it.

Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 23 July 2015, 15:02:23
The heater matrix is ok, if it leak, I would notice that and if it's channels are blocked, there wouldn't be coming any heat at all from it.

Yes, that makes me think it's inputs to the climate panel that are the problem. It thinks it's warmer than it really is.

The last picture in this guide shows the fan. I thought there was a guide to replacing it somewhere...

http://www.omegaowners.com/forum/index.php?topic=90571.0 (http://www.omegaowners.com/forum/index.php?topic=90571.0)
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 23 July 2015, 18:03:16
The heater matrix is ok, if it leak, I would notice that and if it's channels are blocked, there wouldn't be coming any heat at all from it.

Yes, that makes me think it's inputs to the climate panel that are the problem. It thinks it's warmer than it really is.

The last picture in this guide shows the fan. I thought there was a guide to replacing it somewhere...

http://www.omegaowners.com/forum/index.php?topic=90571.0 (http://www.omegaowners.com/forum/index.php?topic=90571.0)

Well, I hope, that the small fan is just jammed from dust and it starts working by just lubricating it. Because, I'm not gonna replace that small fan to new one. I know already, that it is going to cost too much, and when comparing to the condition of the car (rusty doors, 300 000 km on the clock, lot of sings of life), it would be just stupid to buy new one. :)
Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 23 July 2015, 23:34:42
You can replace it with a small computer fan that costs very little. I'm sure there's a guide on here, but maybe I'm mistaken. I think I've also got pictures of one somewhere.
Title: Re: Heater issues with hot engine
Post by: Marks DTM Calib on 24 July 2015, 10:51:48
Definitely a sampling fan fault, you can fit a small computer fan its place for very little money
Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 24 July 2015, 11:25:18
I think i was in the process of doing a guide at one point. I'll see if i have any pictures of the repair. :y
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 24 July 2015, 12:25:03
Thanks for the info, I'll check the fan and buy a computer fan for replacement. But, it would be good to have that guide, if there is one. :)
Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 24 July 2015, 12:49:22
From memory, you need a little 25mm fan, and 12v is available to supply it across the two outer pins of the original fan once you've removed it.
Title: Re: Heater issues with hot engine
Post by: Marks DTM Calib on 24 July 2015, 12:53:36
The outer pins give about 6V from memory which works well as the fan runs reliably at slow speed so is nice and quiet.  :y
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 25 July 2015, 15:40:38
Update!

The small fan in the panel works, so that can be counted out of the possible faults. Here's a video of it, turned the key to II-position and then off:

https://vid.me/C2BP (https://vid.me/C2BP)


And, I checked those VAC-lines on the engine bay. There was couple hoses, that were in wrong places. But, now they are in correct position, thanks to the images you have here, but I'm not yet gone for a drive, so I'll tell more later on, that did it affect anything. :)
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 25 July 2015, 17:52:09
Drove back to home with longer route than usually, to lift the engine temperature to normal. The fault still occured.

But, I noticed something. One servo was making a long sound, when I dropped the temperature from HI to 27īC and I did hear a very quiet sound of something moving. And I believe, that it was the flap, that controls the airflow direction between the two routes: going throught the heater matrix <---> passing it.

So, could it be, that it's not working propely and it moves fully from one side to another, when I adjust the temp between LO-27`C and HI ?
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 30 July 2015, 12:33:08
Anyone ? Is this common and/or repairable problem ? :)
Title: Re: Heater issues with hot engine
Post by: Kevin Wood on 30 July 2015, 12:38:26
What you report would be consistent with the climate panel thinking the car is hotter than it really is. I.e. there's a transition from full cooling to full heating between 27 and HI, and what you are hearing is the blending flap moving across its' full travel. Air direction between the floor, defrost and face vents also changes depending on whether the system is heating or cooling, so I think that aspect is normal.

You can see the temperature probe outputs in the live data using a tech 2. I appreciate you're a little far away, but if you can get it to someone with a Tech 2, that would shed some more light on the problem, I'm sure.
Title: Re: Heater issues with hot engine
Post by: DD-Indeed on 30 July 2015, 17:32:48
What you report would be consistent with the climate panel thinking the car is hotter than it really is. I.e. there's a transition from full cooling to full heating between 27 and HI, and what you are hearing is the blending flap moving across its' full travel. Air direction between the floor, defrost and face vents also changes depending on whether the system is heating or cooling, so I think that aspect is normal.

You can see the temperature probe outputs in the live data using a tech 2. I appreciate you're a little far away, but if you can get it to someone with a Tech 2, that would shed some more light on the problem, I'm sure.

Thank you for this! And yea, here is couple members on the Opel Club Finland, who has those readers, but even they are long away from where I am. But I'll try to get my hand on one of those readers.

And what can I do with that reader, does it show, if there is something wrong or can it do reprogramming in case, that there is issues with that panel's ecu ?