RB26powered74zcar Posted July 24, 2002 Share Posted July 24, 2002 I have a Motorsport Auto 4 row rad. in like new cond. and its not keeping my water temp below 195-212, sometimes as much as 215 with air cond on. Would changing out to an ALUM rad. solve this issue, considering of course everythings in good working cond. I want to not have to worry about overheating ever, even at idle with air on in 100 deg. weather. What would be the best fix for this problem? Thankz Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted July 24, 2002 Share Posted July 24, 2002 I had one of those radiators in my 240z with a turbo engine, and it did not keep my car any cooler than a 3 row. A good electric fan would probably help, especially if you can use it as a pusher and put in on the AC condenser. I like the stock Nissan turbo radiator, and I think it does a pretty good job of keeping an engine cool. Quote Link to comment Share on other sites More sharing options...
Guest Frank280z Posted July 24, 2002 Share Posted July 24, 2002 Check your thermostat? I changed up to a 185 and this helped. Had a 165 and had overheating problems. Timing could be a factor also. Quote Link to comment Share on other sites More sharing options...
timh Posted July 24, 2002 Share Posted July 24, 2002 Even an nice aluminum radiator isn't enough with A/C and your timing being off. I just learned that lesson last week. Installed a Howe aluminum radiator (have a nice camaro radiator for sale!) and still ran up around 210-215 with the air on. Finally invested in a "dial-advance" timing light (cheap lights are a waste) and up'ed my initial up to 15°. That's gotten me to about 195° at 75mph in 95° Oklahoma heat. I'll probably go a few more degrees advance to see what it does. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted July 24, 2002 Share Posted July 24, 2002 Lets asume you have the engine running right for now. What type of fan are you running? If it's the factory clutch type then I would first make sure that is turning the fan fast enough to cool your car. I had one once that didn't cool the car enough during idle but, worked fine on the highway. You'll just have to try and compare the way the fan spins when it's cool vs. how anther one does and take a guess about it. If it spins very easily then it might be bad. I know it's kinda hard to tell but, it could be a proublem. The clutches are not that expensive at AutoZone or something but, at Nissan they are rather costly. Also you might have the air conditioning system checked to make sure that it has enough freon. If it doesn't then it could be heating up your condenser to much and nothing you do will help to solve the proublem. The hot air coming off the condenser would be simply to much for the system to handle. I have a stock 3 row turbo radiator and my car does fine in all temps here in Dallas. I do have an oil cooler off a turbo automatic on my 5 spped car. This helps the oil stay a little cooler during extended highway runs. I once heard that the oil can help the water but, the water can't do a thing for the oil. This is all inreference to cooling ofcourse. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted July 24, 2002 Share Posted July 24, 2002 I think it is important that we use the proper terminology when describing these kinds of problems. When a car overheats, the temperature gauge continues to climb into the red zone and coolant will eventually spew out of the catch tank, and in extreme cases, cause engine damage. Running hot is water temperature that is higher than what you normally see under similiar conditions, but does not cause any coolant to spew or engine damage. Running hot may be an indication that the cooling system is degrading which may eventually lead to overheating. 215 degrees is far from overheating and in my opinion is not even considered running hot. But if that is higher than you normally have seen in the past then it might be prudent to take some basic maintenance measures first before going to extra fans or larger heat exchanger (radiator). Check timing, make sure you do not have too high a concentration of antifreeze because glycol is not as efficient of heat conductor as water is, but you need glycol to protect against corrosion, and protect against freezing. Make sure your radiator is clean and your thermostat is new, functioning properly and is not clogged. Make sure your radiator is clean and not pluged with bugs and leaves. If engine driven fan, make sure the clutch is working properly and the shroud is in good condition and seals against the core. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted July 25, 2002 Share Posted July 25, 2002 I may be wrong, but a factor that is often overlooked in many cars is getting the air out of the system. Case-in-point: I had just installed a new radiator in my wife's minivan last week, taking out the old blown radiator, and the sucker still overheated! I finally burped the system and voila, no more overheating problems. Davy Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 25, 2002 Share Posted July 25, 2002 Ditto DavyZ. My Z overheated every time I cranked it up (so much so the engine had to be shut down). Once I "burped" it, or got the air pocket out, it runs steady at 180. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 25, 2002 Share Posted July 25, 2002 Burp the radiator? What do you do throw the radiator over your shoulder and pat the bottom tank? Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 25, 2002 Share Posted July 25, 2002 Well, in my case the air (or steam pocket or whatever it is called) was not allowing the water to flow throughout the cooling system. Looking into an filler that I installed between the radiator and the block, it was obvious no flow was taking place by watching the fluid in the filler neck. At first I thought I had accidentally installed a reverse flow water pump on the engine and it was not pushing the fluid through the block. But after I opened the other cap which was higher in elevation, the hot air escaped, the engine actually did make a burping sound, and that was it. I closed the cap that burped the motor (many newer engines actually have a small threaded plug at a high point in the cooling system that is removed just for this purpose if you ever flush your system), started the engine up, and immediately I could see the fluid flowing quite rapidly through the tube from the radiator back to the block, and it's never overheated since. Quote Link to comment Share on other sites More sharing options...
BAlford Posted July 26, 2002 Share Posted July 26, 2002 My car was running 220 degrees or so, I tried several things here is what worked. I put two heater cores under the front finders ahead of the tires. http://www.waskomtexas.com/zcar/re_car/engine_cooling.html Not much math just results. It now runs under 190 degrees. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted July 31, 2002 Author Share Posted July 31, 2002 Well, going back to basics solved the problem. I didn't think the fan clutch would be no good after a short few thousand miles. I guess aprox 400 - 4-- turbo'd rwhp is heck on a simple fan clutch..... Anyway, things are under control with the cooling situation. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
denny411 Posted July 31, 2002 Share Posted July 31, 2002 The worst cooling system I`ve ever had to "BURP" was on an MR2. With the radiator in front and the engine in the rear it is very easy to get air pockets. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 31, 2002 Share Posted July 31, 2002 Its a common misconception that aluminum radiators cool better than steel/brass. Given equal fin count and core size an aluminum radiator will not cool as well as a steel or brass radiator. Racers use aluminum radiators because they are lighter, not because they cool better. BTW... If the engine we're talking about is an L6, 215 degrees is fine. The L6 likes (most power, most efficient) to run 200 to 210 degrees coolant temp. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 31, 2002 Share Posted July 31, 2002 Yeah many of the cores as Pete says are furnace brazed and usually the end tanks are tigged on. IMHO the brazing is superior to your average brass solder joint. Just an opinion of course. Regards, Lone Quote Link to comment Share on other sites More sharing options...
BAlford Posted August 1, 2002 Share Posted August 1, 2002 Why beat your head on a wall? Here is what will fix the problem. http://www.waskomtexas.com/zcar/re_car/engine_cooling.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 1, 2002 Share Posted August 1, 2002 Balford: good resource. Get the hot air from out of the engine bay. Nate's V8 Z (Nezzie 76) has the hood held open about 2 inches by pins to let the hot air out. He has a stock z radiator with an electric fan which cools better than expected. Datsun engineers had good reason when they upped the dispalcement on 280 Zs to offer those plastic functional louvers on the hood to exhaust the heat from under the engine bay. You cannot see it on the Tomahawk Zs except from the passenger compartment but with the hood closed there is a sizeable opening at the rear of the hood and cowl to exhaust air from the engine Bay .Designer Rory Bateman told me that this was done in anticipation of V8 motors that needed to have no restriction in hot air exiting from engine bay since the Z design was already deficient in allowing hot air to escape from the engine bay.My 2 cents or alot of hot air. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted August 1, 2002 Share Posted August 1, 2002 An alumnium radiator can be made to have a larger opening flue inside which will give better cooling even the radiator is same size. 4 row with same size opening will not be anymore effiecient. It'll just hold more water. Also, running tapped water with the proper rust prevent additive will give your car a better heat transfer. Car Craft had a excellent article awhile back. It should be an helpful to find it. Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 1, 2002 Share Posted August 1, 2002 John, all, One of the AL radiator brands claims that it's not the material's thermal conductivity (i.e., copper/brass are better than AL), but the conduction between the better AL radiator fins and tubes. Some of the AL radiators have the fins and tubes adhered and/or welded together, making the radiators actually cool better than copper/brass radiators. Quote Link to comment Share on other sites More sharing options...
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