SMARTLY Posted November 15, 2015 Report Share Posted November 15, 2015 So is your pressure cap on the radiator or the expansion bottle.Why should there be bubbles in the radiator - thought that was head gasket time? Have you white smoke coming out the exhaust? Did ypou jack up the front when you were trying to bleed it. Quote Link to comment Share on other sites More sharing options...
Rich Posted November 15, 2015 Author Report Share Posted November 15, 2015 On ours it's the radiator. Looking at the diesel engine in the Hayes manual it's on the expansion tank. There must be 2 types of radiator caps for the petrol engines. I thought maybe I'd let the coolant get too low and it's sucked the expansion tank dry pulling in air. I'm still not 100% sure it's losing coolant when the car isn't being used, I need to keep an eye on it again but based on the last 5 days it's not. No I didn't jack the car up to bleed it, there's no mention of doing that in the manual and I don't have a Honda one to check. I was really hoping to sort this myself but I need to take it somewhere now, I don't have the tools to check the pressure or check the head gasket. The trouble is if it's diagnosed as the head gasket we're stuffed as can't sell it like that and want to replace it next year anyway. Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted November 15, 2015 Report Share Posted November 15, 2015 I'd get the checks done, hopefully for peace of mind Quote Link to comment Share on other sites More sharing options...
NickT Posted November 15, 2015 Report Share Posted November 15, 2015 Don't forget to set the interior temperature to fully hot to ensure that the air is bled from the interior matrix. If your windscreen then gets misty, you can then narrow it down to the heater matrix. I personally would pressure test it first and not run the car with the cap off. If you're in a diy mood, get a spare radiator cap, still a hole in it and stick a tyre valve in it then use a foot pump/ air line to pressure it. Did you set your interior temperature to full as part of your tests or not? Running without a cap will not pressurise the system. Quote Link to comment Share on other sites More sharing options...
NickT Posted November 15, 2015 Report Share Posted November 15, 2015 Why don't you look at the inside of the engine compartment and find the hoses that go to the heater matrix. Remove them and connect them together. This will isolate the matrix from the system. If it still goes down then you can narrow it down to the matrix or engine area. I think you mentioned fogging of the interior. This is a sign of a slow leak at the matrix. I had this with my old astra mk3. Fortunately you could change this one from under the dash. I don't think my back would survive these days. . As I read the posts, it sounds like you're going around in circles. Is your car "fogging up" still or not? Have you bypassed the matrix or not? Have you run the car with the interior temp set to maximum temperature? Have you noted if there is a sweet sickly smell at the exhaust pipe (symptom of burnt coolant) All quick and easy tests to do Rich, I'm just trying to help you save money. You seem to be focused on the cap for some reason. If the above doesn't resolve, then perform a pressure test to a rating of the original cap pressure and/ or have the coolant "sniff" tested. Quote Link to comment Share on other sites More sharing options...
Rich Posted November 15, 2015 Author Report Share Posted November 15, 2015 Yes I know it won't pressurise the system without the cap but the coolant in the expansion tank rising and dropping dramatically is a sign of air in the system. I ran it without the cap to bleed it and yes I had the interior temperature set to high. The car only seems to fog when it rains, not when it's dry outside but that happens in all cars to some degree. No I've not bypassed the matrix yet, I still need to find some pipe to connect the hoses with. There is no heat coming into the car at all now so couldn't do that. There is the usual smoke in the morning when the car is cold and warming up but I've not noticed any steam. I haven't sniffed the exhaust though so will see if I can smell it. I've just checked the level now and it's back to just above minimum again. But with how much air was coming out and abit always overflows from the radiator neck that's not a surprise. I'll top it up again and go for a drive and then check the level afterwards and again in the morning. If I can find some pipe I'll bypass the matrix first before taking it anywhere. Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted November 15, 2015 Report Share Posted November 15, 2015 Is copper pipe for plumbing / heating about the right size? Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 15, 2015 Report Share Posted November 15, 2015 The stat will only open if its sat in water , if there is an airlock around it it will never open , at least not in time to prevent damage Is there a bleed screw anywhere ? Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 15, 2015 Report Share Posted November 15, 2015 Quote Link to comment Share on other sites More sharing options...
Rich Posted November 15, 2015 Author Report Share Posted November 15, 2015 Copper pipe might be ok I'll have to measure it. I'll watch the video later but there is no bleed screw, same for the Accord and the Corolla I had. It was so much easier on our old 205, which had about 3 bleed screws! I topped the coolant up an hour ago to the max and ran the engine for a good 10 minutes on the drive first. The heating is roasting now!! No fogging on the windows and no coolant smell from the exhaust or vents - I think I can rule the matrix out? Drove the car for a good 5 minutes, including abit of dual carriageway and then pulled over. The bottom stat hose was still cold! The top one was very hot, so was the top matrix one and the bottom matrix hose was just warm/very warm. After another 5 minutes I pulled over again and the bottom rad hose was finally getting hot. When the hoses are squeezed they should be fairly firm but still squashy I think, if they're rock hard that means air is in them, have I got that right? The coolant in the expansion tank was well above the maximum mark again, I'm sure it should only slightly rise. I also noticed a small bit of coolant on the radiator neck that the cap fits on to, which weren't there before I drove off. Another thing concerning me is I've not seen the fan come on yet! I think there is still air in the system so I won't use the car until I've done another bleed. I also noticed the bottom of the rad was wet in the gaps I could see but that might have been where it overflowed earlier from the neck even though I had a rag around it. I'll try another bleed and then take it somewhere, I think I really need to get it tested. Quote Link to comment Share on other sites More sharing options...
NickT Posted November 15, 2015 Report Share Posted November 15, 2015 I'd just give it another bleed as it sounds like you've just had an air lock and then just monitor it Quote Link to comment Share on other sites More sharing options...
Rich Posted November 16, 2015 Author Report Share Posted November 16, 2015 I'd just give it another bleed as it sounds like you've just had an air lock and then just monitor it I'm going to do that Thursday morning, I can't be bothered with messing around in the dark after work! Hopefully another bleed will sort it but if it is air getting in while the car is being driven what else could it be apart from the head gasket? From what I have been reading up on Civic HG apparently the coolant and oil doesn't mix but there should be white smoke/overheating and neither is happening. This is the expansion tank, it's underneath the battery and tucked into the bumper a little, which makes it awkward to check the levels! I have marked the minimum and maximum levels in red, the yellow line is where the coolant was after driving the car last night and this morning once it had cooled down is the blue line. The radiator was full as well so there has to be air in there still. Hopefully a big burp will sort it out. It's the original cap and the Honda part number is for the 1.1/16psi cap. It's this one - http://www.amazon.com/Genuine-Honda-19045-PAA-A01-Radiator-Cap/dp/B00BFDFP60 http://www.ebay.co.uk/itm/HONDA-LAGREAT-RL1-CAP-COMP-RADIATOR-19045-PAA-A01-RADIATOR-CAP-/191547730122 Looks like that genuine one on ebay is also the wrong one as well, I've just looked at the other photos. The company I bought the new one from are asking for the part number for my cap (there isn't one on it) but it looks like some of the 1.4/1.6 Civic's were fitted with different radiators and caps. Quote Link to comment Share on other sites More sharing options...
Rich Posted November 16, 2015 Author Report Share Posted November 16, 2015 I've still got rad caps on the brain! Reading this from Eric the car guys website it sounds like it's the valve that helps draw coolant back into the system that could be faulty, so air will get back in. What I can't find is an answer as to whether coolant would leak from the cap if this valve was at fault? Believe it or not, your radiator cap is a key component of the cooling system. Other than keeping the coolant in the system, it serves some very important functions. For every pound of pressure listed on the cap, it raises the boiling point of the coolant 2º F. So if you have a 15-lb. cap, it raises the boiling point of the coolant mixture 30º F. This means that if you have a bad radiator cap, your cooling system won't be as efficient as it could be. The radiator cap serves another function, which is to control the flow of coolant during temperature changes in the cooling system. When the system is at operating temperature, the coolant expands, and it needs a place to go. A valve inside the radiator cap allows the heated coolant to exit the system into the overflow tank. When you shut the engine off and it begins to cool, another valve inside the radiator cap opens up to help draw that coolant back into the system. As the engine cools after you shut it off, the coolant inside the engine contracts and helps create a vacuum that draws the coolant from the overflow back into the system. If either one of these valves fail, it can cause issues with the cooling system. A bad radiator cap can cause air to enter the system, or it can release coolant too early, causing the overflow tank to overflow and boil over. Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted November 16, 2015 Report Share Posted November 16, 2015 Never knew all that, I just thought there was a spring that opened and closed so thinking about it when the spring moves it opens one hole and closes another. Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 16, 2015 Report Share Posted November 16, 2015 yep important things, if its allowing the tank to overflow there should be signs though Quote Link to comment Share on other sites More sharing options...
Rich Posted November 16, 2015 Author Report Share Posted November 16, 2015 Never knew all that, I just thought there was a spring that opened and closed so thinking about it when the spring moves it opens one hole and closes another. It's pretty clever for such a small part but really important for the cooling system, I thought it just kept the pressure in the radiator. yep important things, if its allowing the tank to overflow there should be signs though Yes that's what's puzzling me but looking at the tank and the parts diagram should it overflow back into the radiator, it looks like it does? http://www.lingshondaparts.com/honda_car_parts_selection_pfk.php?block_01=17S6A01&block_02=B__0510&block_03=15949 As I saw last night there is some dampness at the bottom of the radiator but when I bled it some overflowed so it might be from that. I really need to remove the bumper to inspect the bottom of it properly as you can't see much looking from the top. Quote Link to comment Share on other sites More sharing options...
Rich Posted November 20, 2015 Author Report Share Posted November 20, 2015 The level still hasn't gone down, the car hasn't been used apart from moving it on the driveway on Monday. If there was a leak in the system could an air lock stop it? I think I must've been dreaming about when it went down overnight but I was certain half the expansion tank went when the car wasn't used!! I didn't get the chance to bleed the system again yesterday (with it jacked up) as it was raining but it's supposed to be nice this afternoon. Last night I noticed someone had put a new genuine radiator cap on ebay that they had bought and didn't use so I made an offer and got it for just under £10 delivered so that will be here next week hopefully. I'm going to keep the other cap I bought as it fits the Accord, which also has a very slow coolant leak so I can at least try it on that and see if it stops. Quote Link to comment Share on other sites More sharing options...
Rich Posted November 29, 2015 Author Report Share Posted November 29, 2015 I tried bleeding the system on Thursday and had the engine running for 30 minutes. There were still bubbles coming out, quite large ones and the fans never kicked in. Also the bottom hose stayed cold the whole time. The level in the expansion tank was rising alot so there must be loads of air in there. I fitted the new cap and left it until today. The level had dropped to just under the maximum mark after it had cooled. Took the car out for a drive just now and it took 20 minutes for the stat to open so the bottom hose got hot. The heater was hot and no fogging and the temperature gauge was where it usually sits. The level in the expansion tank had risen very high again though. I think the only way to clear the air now is a drain and refill? Unless driving around might have dislodged some if I try again, cos when I bled it the other day the coolant wasn't circulating. If I just take it somewhere to pressure test it can it be done with this much air in it? Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 29, 2015 Report Share Posted November 29, 2015 headgasket ? yes they can pressure test it Quote Link to comment Share on other sites More sharing options...
Rich Posted November 29, 2015 Author Report Share Posted November 29, 2015 That's what I'm dreading, could air be getting in via the gasket making it impossible to bleed? I'll book it in then and get it checked over, I've done all I can. Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 29, 2015 Report Share Posted November 29, 2015 That's what I'm dreading, could air be getting in via the gasket making it impossible to bleed? I'll book it in then and get it checked over, I've done all I can. Not air but combustion gases Quote Link to comment Share on other sites More sharing options...
NickT Posted November 29, 2015 Report Share Posted November 29, 2015 Why don't you look at the inside of the engine compartment and find the hoses that go to the heater matrix. Remove them and connect them together. This will isolate the matrix from the system. If it still goes down then you can narrow it down to the matrix or engine area. I think you mentioned fogging of the interior. This is a sign of a slow leak at the matrix. I had this with my old astra mk3. Fortunately you could change this one from under the dash. I don't think my back would survive these days. . As I read the posts, it sounds like you're going around in circles. Is your car "fogging up" still or not? Have you bypassed the matrix or not? Have you run the car with the interior temp set to maximum temperature? Have you noted if there is a sweet sickly smell at the exhaust pipe (symptom of burnt coolant) All quick and easy tests to do Rich, I'm just trying to help you save money. You seem to be focused on the cap for some reason. If the above doesn't resolve, then perform a pressure test to a rating of the original cap pressure and/ or have the coolant "sniff" tested. Have you smelt the exhaust yet or had the "sniff" test at the expansion bottle yet? Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted November 29, 2015 Report Share Posted November 29, 2015 Is pump definitely working? Quote Link to comment Share on other sites More sharing options...
Rich Posted November 30, 2015 Author Report Share Posted November 30, 2015 I've smelt the exhaust but it seems fine to me not that I really know what I'm sniffing for! I'm hoping to get it booked in somewhere this week and get a proper diagnosis. I assume the pump is working but I'm sure that'll get checked as well. I'm just hoping it's not the head gasket, I don't know what I'll do then, just sell it off cheap and replace it. Quote Link to comment Share on other sites More sharing options...
liner33 Posted November 30, 2015 Report Share Posted November 30, 2015 LOL , the "sniff" test is where they try and detect carbon monoxide in the expansion test using test equipment ! Quote Link to comment Share on other sites More sharing options...
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