markman34 Posted March 2, 2007 Share Posted March 2, 2007 Hi everyone, I'm suffering a car with no heat. I'm certain that my heater core is clogged up and I'm wondering if there is a recommended chemical for cleaning. I have already done a cooling system flush with a prestone flushing product but the heater core is still providing very little heat. (low flow) I plan to by-pass the core so that I can blow out any crap in there and am wondering if there is a recommended product to do so. Of course, I don't want to use anything that will harm the core. I'd rather change the engine than replace the core! Any help is greatly appreciated. Thanks! Link to comment Share on other sites More sharing options...
nipper Posted March 2, 2007 Share Posted March 2, 2007 Too much chemical can hurt things. I think your at the point of chainging the core. nipper Link to comment Share on other sites More sharing options...
Frank B Posted March 2, 2007 Share Posted March 2, 2007 try flushing your heater core. Go to the hardware store and buy a garden hose repair end, the female kind that will screw onto your garden hose, a short pice of heater hose, like 12 inches, then you clamp the heater hose onto the repair end. or you could cut the end of a garden hose off and use that. Remove both hoses from the heater core and clamp the hose you just made onto the outlet pipe, to back flush, the one that goes to your intake manifold IIRC. I like to turn the water hose on, crimp the hose in my hand to stop the flow, then hook it all up. It's tricky but you don't want all that pressure going into the heater core. If you have a helper, just hook it up, crimp the hose, have them turn the water on, then slowly release the crimp to slowly increase the water pressure. You will see all kinds of crap come out of it! After the water runs clear, hook the hose to the other pipe and do it again. Reinstall everything and enjoy. If water doesn't flow though it, flushing won't help and you need to replace it. If it's in real poor condition, corroded, you may burst a hole in it and soak the carpet, but I have never had that happen, yet. You MAY get lucky and get the same results simply by reversing the hoses on your heater core. It doesn't matter which way coolant flows through it, but reversing the flow can break up the deposits. If it works, flush your coolant out after you've run it that way for a while to get that crap out of the system. Good luck. Link to comment Share on other sites More sharing options...
Frank B Posted March 2, 2007 Share Posted March 2, 2007 Also, are you sure the thermostat isn't stuck open? Is the guage reading the proper temps? If it's so cold outside that the engine isn't getting up to temp, try sliding a piece of thick cardboard down in front of the radiator. I've had to do that on cold days(1 degree or less), remember the wind chill factor while driving at 60 + MPH too! But never cover the entire rad. Just 3/4 of it. I like to cut a diamond out of the cardboard in the middle. Link to comment Share on other sites More sharing options...
markman34 Posted March 3, 2007 Author Share Posted March 3, 2007 thanks for the replies. I knew the "free beer" thing would work! I have added the cardboard in front of the rad . This is normal for me when the temp gets to -20 C The engine/rad temp seems to be great and I have heat in the heater core too. But, when I turn on the heater fan, it will first blow very hot and then cools down. This makes me think that I have poor flow through the core. (the things I learned in plumbing school:lol:) More air flow through the core brings the temp down. I have the hardware to do the core flush but was thinking that a caustic flush may help break down any scale that may be clogging everything up. We Canadians need our heaters to work and this one just isn't cutting it. Thanks again! Marko Link to comment Share on other sites More sharing options...
Frank B Posted March 3, 2007 Share Posted March 3, 2007 Try it without the chemicals first. If you can't get water to flow through it, you can't get the flushing agent though it either. You can try less caustic stuff first like a 1lb box of baking soda disolved in water in your cooling system, or a bottle of vineger. Either one you'll have to remove all the anti-freeze anyway and that's not a good idea this time of year. I'm telling you man, try the garden hose thingy flush first, I've had some locked up cores flush out that way. Remember, your household water pressure is 60 lbs +, sometimes higher than 100 PSI!! Your cooling system vents at 13lbs.....Just remember to krimp the hose in your hand, then gradually open it up to slowly increase the pressure through the core. Link to comment Share on other sites More sharing options...
DaveT Posted March 3, 2007 Share Posted March 3, 2007 This is normal for me when the temp gets to -20 C After checking the flow - you would benefit from adding a switch & solenoid to disable the fresh air intake - it is open except when OFF or A/C Max is selected. Link to comment Share on other sites More sharing options...
nipper Posted March 3, 2007 Share Posted March 3, 2007 Wheres the beer? nipper Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted March 3, 2007 Share Posted March 3, 2007 Well... I was ´bout to Ask that, but then I saw: thanks for the replies. I knew the "free beer" thing would work!... Marko: I think that you don´t need to invite Beer, Just A Li´l Patience... People here are Soo kind, and there are Always one of us to Bring Help Also, I think I have The Solution -I Believe- to your Subie´s Problem: Check EXTERNALLY the Core, I mean I´m Almost Sure that Between the Fan that Blows and the core, with time, dust and Road dirts got there and Clogged in some way the Flow... So I suggest to check that... That was the problem in one Subie EA82 I´ve Repaired... Good Luck! - JesZeK Link to comment Share on other sites More sharing options...
Gloyale Posted March 3, 2007 Share Posted March 3, 2007 The fresh air intake can be defeated by simply disconnecting and capping the Vaccuum line that goes to the vent door. if you bend the glovebox sides in a bit it will swing open further so you can see into the dash. The Vac hose is easy to spot back there. it is hard plastic line until about a foot before the air intake box. pull off the rubber part and cap the plastic line, or just put a clothes pin on the rubber to clamp it, whatever. With no vaccuum to the door it will stay closed and recirculate cabin air. I vote for the garden hose flushing, and an inspection of the core to see if there are leaves/debris piled up on it. It's easy if you don't have AC, the box between fan and core comes right out. That said You should think about the condition of your water pump. OEM pumps had a heavy cast piece for an impeller, but aftermarkets often use a stamped peice of steel. These stamped impellers are prone to rusting away if the car has been run on just water(unlikely in Canada I suppose) They rust away and you have just a bare nub spinning inside the water pump. So the flow through the whole engine would be very low. If your top radiator hose gets very hot, but the bottom one is totally cold, this may be the case. If you have a new(ish) pump and have always had good Antifreeze mix in it this is probably not the problem. But I did once have excactly the same simptoms in a Nissan Maxima and the water pump was the problem. Link to comment Share on other sites More sharing options...
markman34 Posted March 4, 2007 Author Share Posted March 4, 2007 SO here's the update, I have cleaned the HC with a strong vinegar solution. We had a really warm day so I have added a flush tee and flushed the entire cooling system with the garden hose. Adding the flush tee helps with burping the system too! Added a new 60/40 mix of coolant. Good for -50 ish I'd bet. (I'll measure tonight) And......... Holy COW! it's freakin' hot in there! Success Thanks for the tips everyone. Next, I'd like to investigate the core to see if there's a buildup of debris in there and am wondering if I can get in there to see it without pulling the dash. I plan to check the damper door to see if it's functioning properly too. Any more tips? I love these cars! Now I'm off to get some booze for the honkey game tonight! Cheers All! Link to comment Share on other sites More sharing options...
Gloyale Posted March 4, 2007 Share Posted March 4, 2007 SO here's the update, I have cleaned the HC with a strong vinegar solution. We had a really warm day so I have added a flush tee and flushed the entire cooling system with the garden hose. Adding the flush tee helps with burping the system too! Added a new 60/40 mix of coolant. Good for -50 ish I'd bet. (I'll measure tonight) And......... Holy COW! it's freakin' hot in there! Success Thanks for the tips everyone. Next, I'd like to investigate the core to see if there's a buildup of debris in there and am wondering if I can get in there to see it without pulling the dash. I plan to check the damper door to see if it's functioning properly too. Any more tips? I love these cars! Now I'm off to get some booze for the honkey game tonight! Cheers All! Awesome, glad it worked. You can inspect the flapper function by checking the cable that is clipped to the side of the heater box on Drivers side . It is pretty easy to see without removing anthing. Look to see that the cable housing is clipped in tight and that it is moving the lever it's connected to when you move the Temp. selector. The core itself can be seen by removing the lower plastic cover on Pass side. You can see that the ducting is in 3 sections from right to left: Blower, Evap Core box(AC) or just an empty box, then the heater core/distribution box. If you have AC/ you have to disconnect the refrigerant lines in eng comp to remove the evap core. If you DON"T have AC you are lucky. There are metal bands clipped around both ends of the box, and 2 or 3 10mm bolts holding it to firewall. It remnoves easy asnd the heater core and flap are visible right there. Note however the core cannot be removed without removing the whole distribution box. But you can clean the leaves out of it. Last thing, plug that fresh air intake vaccuum line. it can be accessed easily by simply tilting the glovebox down. Reconnect in summer. It makes a huge difference. I have spent alot of time driving soobs in sub zero weather Link to comment Share on other sites More sharing options...
markman34 Posted March 4, 2007 Author Share Posted March 4, 2007 I have the cabin air recirculation. Is that about the same as plugging the vacuum line? With the dog in the car, If I'm not bringing fresh air in to the car, the windows fog up pretty good. I usually leave the air recirc thing shut off. I'll get in to the heater ducting tomorrow and see if the core is plugged. It's all working great since the flush but i'm curious to see what's going on in there. I'll let you know if anything interesting turns up! Link to comment Share on other sites More sharing options...
Gloyale Posted March 4, 2007 Share Posted March 4, 2007 I have the cabin air recirculation. Is that about the same as plugging the vacuum line? never mind then. Lucky Canuck. QUOTE=markman34]With the dog in the car, If I'm not bringing fresh air in to the car, the windows fog up pretty good. I can relate to that. 3 dogs Link to comment Share on other sites More sharing options...
Skip Posted March 4, 2007 Share Posted March 4, 2007 "Now I'm off to get some booze for the honkey game tonight" Whoo dem honkeys playin'?? Link to comment Share on other sites More sharing options...
psylosyfer Posted March 18, 2007 Share Posted March 18, 2007 disconnecting the hoses under the hood and opening up the garden hose while holding against the cores OUTLET tube,full blast, worked great for me! After new 195 thermostat did nada. Link to comment Share on other sites More sharing options...
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