I was driving home (1993 Nissan 240sx, Auto, HICAS, ABS), after a few minutes of driving, the temp needle just started climbing, almost got to H before I pulled over and shut the engine off and let it cool for 5-10 mins.
I remember when I started it, the O/D light flashed a few times, I thought that was weird, but didn’t give it a second though because it drove fine at the time.
I opened the hood, I could hear the coolant under the radiator cap, it sounded HOT, so I waited a while, then I started the car again, temp was about halfway on the gauge. The car drove fine, didn’t seem to have a significant and noticeable loss in power (I obviously didn’t floor it at a sensitive time like that)…what could be wrong?
My guess is that the water pump is working intermittently, I’ve owned this car for a week and put a good 200km behind the wheel, never had a temperature problem. It does seem to take a while to warm up, and the heater air still doesn’t feel too warm even after 10 minutes of driving…after a while though, it seems to be moderately warm.
Anyways, I did a few searches, and people are saying to burp the cooling system. (I have to look further into it cuz I dont know how exactly to do it safely). Also, the intermittently working water pump could also be a candidate. Any thoughts?
How much are thermostats (I think they should be 10 bucks-ish…but thats just a guess)? And are they easy to replace yourself? I am not mechanically inclined, but I am a car enthusiast so I’m willing to work hard to learn how to do basic maintenance myself. Also, how much would a used or new waterpump run me, and where do you suggest I purchase these parts?
first, check coolant level in coolant reservoir and the rad itself, just make sure the system is cool, cuz its under pressure, before u open the rad cap. if its low, u should pressure test the system to find out where the leak is coming from. if its ok, when was the last time the engine coolant was flushed and replaced? ur suppose to do it like every 2-3 yrs. so if its more then that, then change the fluid, and since ur there, change the thermostat…it cuz be sticky and making hard to open…cuzing no circulation of coolant, thus overheating the engine.
I had the same problem in my 1991, it would overheat, the gurgling noises and no heat from the heater core. And yes…it turned out to be the thermostat. You can locate the thermostat by following the lower rad hose to the engine, the hose will be clamped to a housing fastened to the block by 3 bolts which I believe are 8mm. Remove the rad hose (be prepared as coolant will obviously come pissing out like Sea Biscuit) then remove the housing. With some emery cloth or sand paper (not too abrasive) clean both mating surfaces so that they are both bare metal. You can use some silicone gasket maker to secure said gasket to either the housing or the block for the installation of the new thermostat so that you don’t have to fidget with the gasket to keep it aligned. Be sure you don’t over tourque the bolts as the are small and will strip threads easily. Once this is complete it is now time to “burp” the cooling system. First things first top up the rad itself, then there will be a very small bolt where the upper rad hose meets up with the intake manifold, there should also be a small yellow sticker with red writing that says “never open hot”. So take this bolt out and then continue to add the coolant/water mixture to the rad untill it pisses a STEADY stream of coolant out of this hole. Quickly reinstall the bolt from whence it came while the coolant is coming out. Once this is complete start the car with the rad cap off and let it idle for a bit, keeping an eye on both the coolant level and the temp gauge. The level in the rad should go up and down, possibly some bubbles may come out. Once in a while stick your finger (and do be careful, cause it might be hot) in the open rad to see if it’s getting hot. If it is then put the rad cap on while continuing to run the vehicle. Again, keep a close eye on the temp gauge. start blasting your heat in the car. When the thermostat opens you will get heat galore inside the car, another way to verify this is to feel the lower rad hose to see if it’s getting hot (and be friggin careful sticking your hands down there!!!), if it is hot then your thermostat has opened successfully opened, if the car begins to overheat and that hose is still cold then continue to “burp” the system all over again. At this stage if further bleeding is required it is to be done with the small bolt on the intake manifold by the upper rad hose. Use caution as the system will now be under pressure and the trick is to un-thread it just enough to see bubbles coming out around the base of it. This must be repeated until the bubbles turn to a steady flow of liquid (hopefully you don’t have to preform that part, the initial bleed usually does the trick) Once you’ve bled the system out , both hoses are hot and you have heat continue to run the car with the rad cap sealed for 10-15 minutes to ensure that it does not overheat. Once this is confirmed road test the vehicle and then you should be good to go.
Oh, and 9 times outta 10when the water pump starts to go it has a weep hole on the top of it that will start to dribble coolant out to let you know it’s on it’s way out. Hope that helps you out, best of luck!
Thank you very much, that was EXACTLY the kind of detailed response with thorough instructions I was after. Once I’m temporarily free from university rapage (Biophysics ftl), I’ll give it a shot.
btw the “pissing coolant like seabiscuit” thing…LMAO
