Andrew K Posted April 1, 2016 Share Posted April 1, 2016 Hi everyone Been having some machanical problems with my partners car and unsure what the problem my be! Right this is what is wrong, It doesn't lose water but it has overheated 4 times now with no warning, temperature gauge reads normal (in the middle) once warmed up and never goes above that, it is working as starts low when cold and then stays steady in the middle once warm, the heater in the car works fine once up to temperature. Last time she was driving it and it overheated she noticed some smoke out the back from the exhaust (not a lot) on normal driving, the car prior to this happening had been used mid afternoon for a while but then parked up for roughly 6 hours and then used for a journey, not sure if this is anything to do with what's happening with the overheating! Hopefully someone can shed some light on the problem and help me out as I'm stumped as to what is causing the overheating I know it's not much of a car but it was my old grand ads car which he past on to my partner, it's a Nissan Almera, Hatchback, 1996 GX 1.6 5dr Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 1, 2016 Share Posted April 1, 2016 I'm no expert, but here goes: You said it overheats: how do you know it's overheating if the temperature gauge reads normal? White smoke out the exhaust usually means water vapour: could be coolant, but more likely to be vapour from the air, and that's normal when the engine's cold. If the coolant level isn't dropping at all, then it can't really be coolant. There might be a head gasket leak letting small amounts of coolant into the cylinders, I suppose. The engine would probably smoke a lot with a barely-noticeable loss in coolant level. I think you can get a "sniff test" done to test for this. Quote Link to comment Share on other sites More sharing options...
Nic Posted April 1, 2016 Share Posted April 1, 2016 Possibly a worn radiator cap not holding the pressure in the system and allowing the coolant to boil at a lower temperature. Quote Link to comment Share on other sites More sharing options...
Andrew K Posted April 1, 2016 Author Share Posted April 1, 2016 I'm no expert, but here goes: You said it overheats: how do you know it's overheating if the temperature gauge reads normal? White smoke out the exhaust usually means water vapour: could be coolant, but more likely to be vapour from the air, and that's normal when the engine's cold. If the coolant level isn't dropping at all, then it can't really be coolant. There might be a head gasket leak letting small amounts of coolant into the cylinders, I suppose. The engine would probably smoke a lot with a barely-noticeable loss in coolant level. I think you can get a "sniff test" done to test for this. It happens without any warning and it explodes out the expansion tank, it split the rad hose one time but it was looking a bit worse for ware from old age but after having a new one on its done the same again recently. So it could be a slight head gasket leak you reckon, this was one of the things I thought it might be but not 100% sure so may pay to get a sniff test done!? Possibly a worn radiator cap not holding the pressure in the system and allowing the coolant to boil at a lower temperature. Would something as simple as that cause such a problem!? It is a OEM rad with the cap on which came with the rad, maybe it's a bit old and so doing what you mentioned? Quote Link to comment Share on other sites More sharing options...
Annabella Posted April 1, 2016 Share Posted April 1, 2016 Air lock or headgasket, water pump if it has one. Have any pipes collapsed in the heating system. Quote Link to comment Share on other sites More sharing options...
Andrew K Posted April 1, 2016 Author Share Posted April 1, 2016 Air lock or headgasket, water pump if it has one. Have any pipes collapsed in the heating system. Yeah hasn't had the water pump changed in a while, I haven't noticed any collapsed pipes in the heating system but take it you mean inside the car? Was wondering if a dodgy thermostat migh have something to do with it maybe. Quote Link to comment Share on other sites More sharing options...
Annabella Posted April 1, 2016 Share Posted April 1, 2016 Collapsed pipes from the inside of the pipes in the engine bay area. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 2, 2016 Share Posted April 2, 2016 It happens without any warning and it explodes out the expansion tank, it split the rad hose one time but it was looking a bit worse for ware from old age but after having a new one on its done the same again recently. So it could be a slight head gasket leak you reckon, this was one of the things I thought it might be but not 100% sure so may pay to get a sniff test done!? Coolant exploding out the expansion tank is sometimes caused by overheating, but not always. As Nic suggests, it can be caused by an old cap not holding pressure any more. The bit about the hose splitting is concerning though. If it was just a faulty rad cap, then the hose shouldn't be affected. It would just come spewing out around the rad cap. Those two together suggest overpressurising (although I'm trying to imagine what you mean by the hose being split. That would take immense pressure I would think). Is the hose rubbing against anything hot, thereby weakening it? The hose split needs more investigation, but I would start by: Changing the rad cap. They're pocket money to buy. Don't buy an uprated one, go OEM. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 2, 2016 Share Posted April 2, 2016 Get a sniffer test done on it. I use a dye type and back it up by a sniff with the Bosch 4 gas analyser. Quote Link to comment Share on other sites More sharing options...
Andrew K Posted April 3, 2016 Author Share Posted April 3, 2016 Coolant exploding out the expansion tank is sometimes caused by overheating, but not always. As Nic suggests, it can be caused by an old cap not holding pressure any more. The bit about the hose splitting is concerning though. If it was just a faulty rad cap, then the hose shouldn't be affected. It would just come spewing out around the rad cap. Those two together suggest overpressurising (although I'm trying to imagine what you mean by the hose being split. That would take immense pressure I would think). Is the hose rubbing against anything hot, thereby weakening it? The hose split needs more investigation, but I would start by: Changing the rad cap. They're pocket money to buy. Don't buy an uprated one, go OEM. I might try the cap and see what that does but like you say it's concerning its building that much pressure it's split the pipe! The pipe split were it joins to the radiator and also broke away some of the plastic on the radiator, the pipes not touching anything either. Over-pressuring would that likely be caused be the head gasket going or something else? Quote Link to comment Share on other sites More sharing options...
Andrew K Posted April 3, 2016 Author Share Posted April 3, 2016 Get a sniffer test done on it. I use a dye type and back it up by a sniff with the Bosch 4 gas analyser. Thanks Chris I think this will be the first thing to get done and try to get this sorted, the sniffer test with dye and the Bosch 4 gas analyser can be done at most garages I take it? Quote Link to comment Share on other sites More sharing options...
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