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Righto then, my car seems to want me to freeze to death.
E33 GLi galant, 1993 with 2 liter SOHC engine and manual transmission with some 300k kilometres 184k miles on it.
No A/C.The car refuses to give warm air, which is a bummer since it is winter here. I’ve bled the cooling system for who knows how many times, removed the heater core hoses and liquid seems to circulate there when I blow to either one of the hoses. At least it comes out from the other hose.
Radiator cap has been replaced, twice. Aftermarket part both times.
New thermostat didn’t improve anything. If something, made it worse. New one is set to open in 88 centigrade when the old one was 82.
With the old one there was a hint of warm-ish air every now and then.
Engine temp stays normal, no overheating or too cold and thermostat opens.Also, when I bleed the system with radiator cap off it does give warm-ish air, as soon as I slap the cap on and go for a drive it’s cold again. Also the hoses to the heater core don’t feel warm but every other hose does.
Why the liquid wouldn’t circulate in heater core when you close the system I have no idea.
Again, I’ve bled the system for ages and there is no air coming out anywhere, no matter how much and what hoses I squeeze while doing it.
Checked the hose connections from a service manual, everything goes where it’s supposed to.Worst case scenario I’m afraid of is blown head gasket. Oil and coolant aren’t mixing, there’s no bubbles appearing to radiator and spark plugs don’t look washed. Hard to say from exhaust since ambient temp is below freezing all the time and it’s always a bit white but it doesn’t smell sweet like it would if it burns coolant.
Second choice is that there is a very stubborn air pocket somewhere and I just can’t seem to get it out. I find it hard to believe but it is possible.
Or the system is blocked somewhere but still somehow manages to circulate the coolant in heater core occasionally when radiator cap is off.
So, if anyone has any ideas suggestions they are more welcome before I stab either myself or the car.
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First, Replace your radiator cap with an OE one from mitsubishi them selves. Asian vehicles are picky about what parts and brands you put on them. Second Bleed the cooling system out one more time, while making sure you have the thermastat in the car full on heat. Then raise the engine RPM to about 2k. untill the cooling fans come on. This video will really help you out:
and this one for cleaning/un-clogging a heater core:
These two video’s should help you. If you still have no heat, it might be that the heater core it’s self is bad and is in need of replacement.
Guess I’ll wobble to diamond desk tomorrow and get the OE radiator cap and try what it does.
I’ve been doing the bleeding about like that, RPM around 2 – 2,5k RPM until fan starts blowing, always on full heat. Shouldn’t matter though, no valves in water lines that go into the heater core. There’s a plastic flap that allows hot air from heater core andor outside air depending on the position heater knob.
I’ve checked that it closes the outside air supply completely when you turn heat all the way up.when you do the bleeding procedure.The heater fan needs
to be off.But the heat selector to the full hot position.Aaand it’s still a no go. Got the OEM-cap and was bleeding the system. Radiator fan came on multiple times during this process, RPM varied in range between 2 – 3,5k rpm. Few first times the fan kicked in the liquid surface lowered for some reason and I refilled the system but eventually it stopped lowering.
Squeezing the hoses while keeping rpm over 2k with cap off and once again the hoses going to heater core got warm and it did blow some warm air but as soon as I put the radiator cap on the hoses to core started cooling and no more warm air coming.
I doubt the core itself is faulty since it gets warm while the rad cap is off but guess it’s a possibility too.Thermostat is an odd shaped fellow and guess you could install it wrong way. One of the heater core hoses connect to thermostat housing and maybe it is possible to block it with the thermostat but still doesn’t make sense to me with the cap onoff thing. Need to check that out when the car cools down a bit.
Guess I wasn’t clear enough. No, I didn’t try to bleed the system cap on. It was off while bleeding, naturally.
The system was full to the top of radiator, there is liquid in the reservoir to the max level and no air coming from radiator and yet when I close the system water stops circulating in the heater core for reasons unknown to me.From what I’ve read, there’s only a few reasons for it. As you’ve stated, a stubborn air-pocket, an obstruction, or, and this is the only thing I think you may not have checked yet, the heater control valve. If they both (in and out of heater core) seem to be about the same amount of warm, you might wish to follow them further up to the control valve on the one line. That may not be functioning correctly. Should be fairly apparent if it’s hot before the valve, then lukewarm after.
At first glance it sounds like you have air in the system still. Sometimes they can be hard to get out. The biggest clue is the fact that the hoses are both cool or cold to the touch. If the heater core were clogged you would most likely have one that’s hot and the other cool or cold. I suppose it’s possible you have a restriction in one of those hoses OR a problem with flow through the system. Say your water pump isn’t doing so well. If that were the case then there would not be enough coolant flow through the system and you would also have trouble getting heat. I’d check the heater hoses and bleed the system out again. This time let the system sit with the engine off and the radiator cap off after you get the engine up to temperature. Sometimes this does the trick on difficult systems. If that doesn’t work you might consider removing the water pump to have a look at the impeller.
Well, will know more after the weekend. Managed to get a place where I can flush the system and put some water through it and hopefully get rid of any blockages that may be there.
From what I’ve gathered blockage is one option, pressure building up in the wrong place when system closed and not circulating in the core properly.
One of the hoses going to heater core is connected to a metal pipe that connects to lower radiator hose connection and it yet splits up into two more connections. Other connection goes to the heater core and other one is some sort of bypass.Guess trying to bleed the system some more doesn’t hurt, although I’ve spent more time bleeding this system already than any of my previous cars combined.
Not ready to remove the water pump just yet, it has less than 2k kilometres on it, was renewed with timing belt. With the old pump the heat issue was also there. Maybe not as bad as it’s now, but definitely was there.
As I can barely make out myself that explanation of the connections, I made a picture. All by myself with great skills on MS Paint.
Idea being maybe one of those hasn’t got sufficient flow through them when system closed.Also don’t forget to feel the hoses going into the heater core. They should both be hot or warm to the touch. If one is hot and the other cold or cool to the touch then perhaps you have an obstruction inside the heater core. Flushing may help but some can be more stubborn than others. Keep us posted.
Well, the flushing did something. There actually is warm air coming now. Not hot, but better.
Emptied system, used external water hose to flush the system. There were chunks of un-identified things coming from here and there. Mild mix of coolant in with STP coolant cleaner and let it warm up for 30 minutes as the instructions told me. Flush the system again when cooled down a bit, run some water through it to get the cleaner out and put in coolant, 50:50 wateranti-freeze.
Bleeding the system after this seemed to be a bit easier, the coolant seems to circulate much more freely in the system. But still a bit pain in the posterior. Even if it seemed that no air was coming out with the car running, it has few times burped out some air after stopping the engine and letting it cool down for a good while.
That seems to have stopped now finally and no air is appearing in the cooling system and the air coming inside is a lot warmer than it used to. But as I said, not hot yet. But at least now the car can be used even if it’s cold outside.At this point the hoses coming and going to the core seem to be equal-ish in temperature, as good as measurement I can give with feeling them with my hands. Definitely warm both hoses.
Still checking the systems coolant level frequently when it has cooled down after driving to see if there is air and maybe I can find the last missing heat.
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