I have noted of late that my engine seems to be running quite hot. I dont know for sure because the thermostat is still in the same position. (which I read somewhere that it isnt that accurate.) The good news is obviously with that, this means my engine isnt overheating yet. However when I run with the aircon on, the temperature gauge does move upwards a notch or 2. Now, without the temperature gauge hitting H yet, I feel the car is overheating as steam (made from coolant) comes out from the passenger side headlight which is where the coolant spare bottle is. After filling it full and that happening again, I noted that the spare bottle got empty and coolant level low after another incident of 'steaming' This has happened late last year and I brought the car in to Joe (Dontex). He did a pressure test and found no leaks, he said my old radiator cap isnt keeping pressure and that my fan gears does not lock (doesnt go faster when hot), so we replaced both items. The theory was that when the cap couldnt keep the pressure in the tank, the overflow went back into the spare bottle at high pressure forcing out the spare coolant. (which explained the leak and steam) Now that those faulty items were placed, I would have thought that the problem should be fixed. However, what happened today is that I noted coolant leaking under the car (again only from the passenger headlight side), after driving back from work. When the engine is cooler, I opened the radiator cap and noted a slightly lower coolant level and that my spare bottle is still full. I have intention of bringing the car back to Joe for a look see again. However, I would like to get some ideas on what else to check for. (hence this post). In regards to the engine, I have a lightened underdrive pulley, and adjustable cam gears. The cam gears are hydraulic and meant as direct replacement for stock ones which make noise and leaks. At the install of these parts, I discussed with Joe and asked joe to up the cam gear's timing slightly. My question is that would this have contributed to the heating issue? For those who may require the information. I am running an NA auto with an aftermarket oil cooler up front. Radiator is stock. Any ideas what may cause the heating issue or what else to check?
First thing to check is air in the system. Jack front of car up, put heater on full heat. Loosen air bleed scw on top of radiator, run ebgine till at normal temp. If there is air in the syerme upi will see it bubbling around the air blled screw. if no air then water will seep out
Also remember that the stock temp gauge is notoriously unreliable, hitting the H doesnt mean you are over heating it means you have already overheated! the gauge can read normal and still be on the hot side of happy. Best to check the temp with (insert personal preference of data scanning software here) or get an accurate aftermarket gauge
the underdrive pully wont help as it slows the water pump down im sure that you can get overdrive pully for water pump and this may help have you flushed your radiator
Thanks for the info guys. I had a talk with Joe and he says it's most likely that the lack of an overdrive pulley for the water pump that is causing my Z to run warmer (which started or happened mostly after the underdrive pulley install). Anyway, made an order for it from Cazracing this morning, hopefully get it all installed and running (and solve my issue) by next week. Thanks again!
The car isnt overheating yet but running hotter then normal. And it was only found to be doing that after the install of the pulley and the new cam gears (which were done at the same time), which was why I mentioned that the timing was upped a little as well. I suspect the increased timing may well have some impact on the heat as well, but I am not too sure. However, after the posts here as well as talking to the mechanic, the lack of an overdrive pulley (hence making the water pump run slower) is likely to be the cause of the increased heat buildup. Mind you though, the car never had the higher heat (ie leaking coolant from spare bottle after a drive on a hot day) issues prior. We can only guess and I am hoping that the overdrive water pump pulley will help resolve that problem. Otherwise as you have said, it could well be a bigger issue, but of course no one hopes that is the case.
my point is changing to an underdrive pulley should have NO effect on temperatures IF your cooling system is working properly. and if it does that means your cooling system is barely coping to start with. (my guess is your 20year old radiator ) I tested this for a few weeks on my car (traffic /hot days) changing from stock to alloy . (and not looking at the stock guage .I have power FC ). Same temperatures .absolutely no change You will be surprised at the difference 56mm alloy radiator makes .
