The hose pinching has nothing to do with it being secured, if it's pinching it's due to a blocked rad core.
One off the symptons of a faulty clutch fan is high temps out on the highway. Also the so called ruler test is a joke. It proves nothing. I once had a car overheating on the highway and it turned out being a rag behind the bumper blowing up across the radiator out on the highway. Every time i looked at the radiator it had droped down when i stoped. Was i pain to find it but maybe worth a look. Alot of Zed's run front mounts without heat problems so it more than likely not your problem. Try removing the seal on the plastic grills near the wipers to let more air thru the engine bay as a test. Other than that good luck.
go to auto barn and get yourself a flush for the radiator. it seems to me that there is shit clogging up your block or heads. run the cleaner for 1 or 2 days , ( READ INSTRUCTIONS ) then normal water, for 1 or 2 days, then put another cleaner in it for 1or 2 days , flush the system out . as your doing this make sure you are At operating temps, . the more you do it , the cleaner the system becomes . one bottle can only really do so much . when you are finished, flush the good water out again and again , keep flushing, a few times to get all the shit out of it .. At the start don't really worry about bleeding the system to much , as your going to dump it anyway . try do this a few times, to get it to the best you can .
How did you bypass the heater? If you have just looped a hose between the two pipes you are circulating water around and around without any cooling, you are effectively loosing about 25% of the engines cooling ability by taking potential flow through the rad and wasting it by looping it around. Make sure the hose or what ever you have blanking off the heater system does not flow any significant amount of water, a little is ok and this will help bleed the system, heaps is no good - bad for cooling efficiency. If the system does not have any leaks there is no way the lower hose can "pinch" or "kink" it should have about 10 PSI pressure in there - more than enough to stop it collapsing on itself :rofl:
Either blocking the heater outlets or looping them will have zero affect on cooling. Also, there does not need to be a leak for the lower hose to collapse, the water pump simply has to draw more than the rad core can flow. Yes, a properly operating cooling system will have 15-18psi block pressure and will not allow the hose to collapse, but this is not a properly operating cooling system. If it was not overheating before you changed the rad and hoses, change them back, it really is that straight forward.
Where did the 25% go ? Is there 25% less flowing through the radiator ? Watch this: http://www.youtube.com/watch?v=UYfmcfd_Ec0 Cut and pasted out of automotive cooling system 101.
The water pump can NOT create enough vacuum to collapse the lower hose if the system is under pressure - you would need a pressure differential across the radiator of over ~13PSI to do this. The rad would need to be seriously blocked to create this situation, not the case here given the info provided earlier. Even if the rad were blocked the ~13PSI differential would overcome the pump and blow the coolant back through the pump to try and equalise the pressure. If the system has no leaks it will build pressure as the water warms, when that hose is under pressure there is no way in hell the water pump will suck it closed/ blocked, even if it did this would cause more heat and more pressure and open the hose back up. Brisz I don't need to go look up crap I learnt 20 years ago to know if you have two systems running in parallel/ tandem from one pump and you reduce the resistance in one of those systems the one with the least resistance will take more flow. The pump can only shift a given amount, if you are wasting a lot of it running it around a circuit that does not provide any cooling you are wasting cooling efficiency end of story. Linking to vid on Youtube from some guys mucking around on a dyno at high RPM with a car that probably isn't up to full operating temp doesn't help this guy fix his car. You would think Nissan would get something as simple as a lower radiator hose right on the $100K top of the line car they built wouldn't you?. As I understand it the issue is happening at normal road speed - not high RPM, Also Nissan were smart enough to put the cold hose on the bottom of the system, gravity alone will give more pressure in the hose & help prevent collapse in comparison to systems with the cold hose at the top (stupid Americans). Also the radiator cap is located on the cold tank with a one way valve from the coolant tank, any negative pressure in that part of the system will result in coolant being drawn from the tank to equalise it to atmo pressure at least. I can assure you if there were a real issue with this problem on this car Nissan would have found and fixed it waaaay back in 1988 when they started pissing about with it. I've seen enough HEALTHY Z32s on dynos at high RPM to know cold hose collapse is NOT an issue regardless of internet rumour spread by people transferring factoids from brand to brand assuming a problem one car has will be a problem for all.
"the water pump can not create enough vacuum" You are right, it doesn't create any vacuum, or pressure for that matter. A water pump is a non-positive displacement pump, it's flow potential is governed by the sytem, the systems flow is not governed by the pump. A blocked rad core can cause a lower hose to collapse. The water pump does not "shift" any ammount of water. There is no waste, because there is no loss of convection, regardless of whether the heater outlets are plumbed or not.
It's a new rad, it's not overheating at high RPM it's over heating at normal road speeds, it runs to hot even at idle, new thermostat, good fan clutch etc etc etc etc etc. Even the crapiest of the cheap radiators and hoses work fine in normal road use. Good luck fixing it Anti I will leave you to the "experts".
You're kidding yourself aren't you? You want to start inserting bs remarks in your posts directed at me, you better bring a bigger stick than what you are wielding at the moment. I don't care what brand of rad it is, or how much it cost. A blocked rad will not flow sufficient coolant. Just because it is new, doesn't mean it works correctly as you well know.
The car has pretty much new everything in the cooling system, there is ONE thing that is different to most other Z32s on the road that are running fine. That one thing is the heater bypass, IF everything the OP has posted is true and correct then you can not rule that out as being the possible cause of the issue. All this talk of hoses collapsing etc - don't you think that might be just a little far fetched in comparison to a poorly executed "repair"? I did NOT post here for Brisz's opinion on my suggestion nor yours I posted here to help the Op fix his car. My post was directed at the OP - I do not care what your opinion is, nor do I care what Brisz's opinion is, I care for the OPs car being fixed, so far in the thread I see no fix. Let the OP try my suggestion, if he chooses to do so and it works then let that be proof that my stick is plenty big enough. Oh and by the way I have seen and fixed this problem three times already, once with one of my own cars about 12 years ago :zlove:
If you do not want an opinion on your suggestion, do not post it on a public forum. Do you not think posting a response to each others findings or claims promotes anything? Where does this 25% loss come from? How have you measured this loss? If I thought that this had merit, I would not have questioned it. Posting up bogus numbers to back a claim does not help any one. I have seen dozens and dozens of cars bypassed both ways, none having an effect on cooling. The reason I question the rad and hoses, they are new to the market of unknown quality. The issue was also not there before these were fitted.
