SBpunk Posted June 25, 2017 Share Posted June 25, 2017 Is it possible for an overflow coolant bottle to cause a cooling system to get hot/boarder line overheat? I've been hunting down this cooling thing and noticed the level in the bottle never changes. Also when I first start it they coolant comes up through the fill tube (with the cap off) and even when I increase the RPM the coolant level in the neck doesn't go down. This is the first time working the coolant system in a long time and I thought once you start increasing RPMs its supposed to suck the coolant into the radiator. Possible the water pump is going the wrong way? Like I said might be a dumb question. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 25, 2017 Share Posted June 25, 2017 Radiator cap could be bad causing both issues. Link to comment Share on other sites More sharing options...
SBpunk Posted June 25, 2017 Author Share Posted June 25, 2017 Been through a few radiator caps. Was the first thing I tried and like the 5th and the 100th lol. Just put another on yesterday. Link to comment Share on other sites More sharing options...
Ωhm Posted June 25, 2017 Share Posted June 25, 2017 Hose from radiator to overflow bottle plugged? Link to comment Share on other sites More sharing options...
SBpunk Posted June 25, 2017 Author Share Posted June 25, 2017 Hose from radiator to overflow bottle plugged? Not sure to be honest. I'm guessing there's one at the bottom of the bottle? If there is any good tricks for unclogging it? Link to comment Share on other sites More sharing options...
Ωhm Posted June 25, 2017 Share Posted June 25, 2017 Air hose. Link to comment Share on other sites More sharing options...
Eagle Posted June 25, 2017 Share Posted June 25, 2017 ... I thought once you start increasing RPMs its supposed to suck the coolant into the radiator. Possible the water pump is going the wrong way? Like I said might be a dumb question. From where? From the overflow bottle? To suck it requires a vacuum -- you can't have a vacuum with the radiator cap off. And it doesn't suck coolant from the bottle into the radiator when you increase the RPM. The radiator is supposed to be full. Coolant expands when it gets hot, so as it heats up some coolant is forced out the filler neck and into the overflow bottle. After you shut the engine off, as the system cools off, the coolant contracts and pulls the overflow back from the catch bottle into the radiator. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 25, 2017 Share Posted June 25, 2017 To check the hose from the radiator to the coolant bottle, just pop it off at the radiator filler neck nipple and blow in it. It should bubble up in the never pressurized overflow tank. Also while it's off run a piece of wire through the nipple to the filler neck tube to make sure that's clear. I don't think there's anything wrong with your 91 open system. If the pump was running backwards you would definitely know it - overheating maximus. I only have to add a pint or so a year to keep the level between the tank marks. I also use a 14# pressure cap as it tends to run a bit cooler than the stock 12# cap. Link to comment Share on other sites More sharing options...
SBpunk Posted June 25, 2017 Author Share Posted June 25, 2017 Ok ran air through the line toward the overflow bottle. Nasty stuff came out. Had this probably not so brilliant idea to do it toward the radiator. Found a loose hose clamp (leaked) but now my coolant looks like the pic below. How possible is it the air pressure popped the head gasket? I haven't ran it much yet. About 10 miles and waiting on it to cool down a bit to check. Oil still looked fine but figured I'd ask the experts. Link to comment Share on other sites More sharing options...
Ωhm Posted June 25, 2017 Share Posted June 25, 2017 Head gasket should be alright. Radiator cap should have bled off any excess pressure. Two (2) different kinds of radiator caps out there. One for closed and one for open systems. Something to do with a moving poppet valve. Link to comment Share on other sites More sharing options...
SBpunk Posted June 25, 2017 Author Share Posted June 25, 2017 Sweet good to hear. Going to flush it again next weekend just to clear it out. The radiator cap popped off (pressure release one) and lower water pump hose started seeping out. I've got to get a new overflow bottle. Thing is pretty gross. Still not helping my overheat but I'm starting to think theres some other stuff internal wrong. Rebuilder might have screwed up somewhere. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted June 28, 2017 Share Posted June 28, 2017 How old is your radiator? Coolant in the tote looks nasty. Two (2) different kinds of radiator caps out there. One for closed and one for open systems. Something to do with a moving poppet valve. Huh? A closed system cap and open system cap can't really be mistaken. A closed system has a thick plastic cap, from a Jeep or a Volvo "pressure tank", they look nothing alike, and one won't fit the other. You need a regular 16# cap. Not a super cheap cap either. Stant was a good brand but have heard different lately, so maybe a dealer cap. There is a poppet valve on some thermostats, never heard of one on a cap. And get a solid cap, not one with a pressure lever. Link to comment Share on other sites More sharing options...
SBpunk Posted June 28, 2017 Author Share Posted June 28, 2017 How old is your radiator? Coolant in the tote looks nasty. Two (2) different kinds of radiator caps out there. One for closed and one for open systems. Something to do with a moving poppet valve. Huh? A closed system cap and open system cap can't really be mistaken. A closed system has a thick plastic cap, from a Jeep or a Volvo "pressure tank", they look nothing alike, and one won't fit the other. You need a regular 16# cap. Not a super cheap cap either. Stant was a good brand but have heard different lately, so maybe a dealer cap. There is a poppet valve on some thermostats, never heard of one on a cap. And get a solid cap, not one with a pressure lever. Tried two of the caps from the dealership. Both were leaking pretty good. The pressure release cap I had from AutoZone hasn't had an issue so far. I'm planning on ditching the CSF radiator and going back to a new mopar stock radiator since it worked great before they were swapped. I've read up on Naxja and a few other forums and noticed a trend with people in my situation. I'm also going to get a new overflow bottle and A/C system. My R12 is leaking anyway and only working when theres some higher RPMs. 134a it is Link to comment Share on other sites More sharing options...
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