izzo Posted March 17, 2013 Report Share Posted March 17, 2013 Having cooling issues. Drive the car, water gets hot and boils/comes out over flow tube and fills it up then spills out. I've checked inside the floors for leaks, as well as outside. Can't find a single leak. I've checked the lower rad hose to make sure its not colapsing, and it has a spring in it to keep it from doing such I've heard the rad cap hold pressure before, but idk if its holding enough pressure.... Thermostat is new When the car is parked, I filled the rad back up and let it idle for 10-15 minutes. It didn't boil over, but also when I pulled the cap there was no presure I don't know whats going on here...... Need help & things to look for Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 Have you tested the T-stat? Even though its new, doesnt mean its good Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 I haven't tested it, but when the car was idling and warmed up it looked like the water was moving. Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 I haven't tested it, but when the car was idling and warmed up it looked like the water was moving. Moving or coming close to boil point? This will be one of these bizzare things I think, Just like the tranny to motor bolts Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Looked like it was moving. The water was hot to touch of course... But didn't seem to be boiling, no bubbles Quote Link to comment
racerx Posted March 17, 2013 Report Share Posted March 17, 2013 Wat does temp gauge indicate? Do you have reservoir tank? Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 Looked like it was moving. The water was hot to touch of course... But didn't seem to be boiling, no bubbles Only water or mix? Quote Link to comment
racerx Posted March 17, 2013 Report Share Posted March 17, 2013 How does upper hose feel, cold , hot, when car is up to temp Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 I ran out of mix so used water. But I was using fifty fifty Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 When drained was it all rusty looking(if you drained it) Quote Link to comment
datzenmike Posted March 17, 2013 Report Share Posted March 17, 2013 Where does temp gauge read when coolant spilling out? For $10 get a new thermostat and save yourself the stress of wondering and dicking around.. New is no guarantee it's good. If this was working and just recently changed, and now there's a problem, just think back to the last thing you did to it. If this does not solve the problem you have a spare to replace it when it does screw up or if you need a good one to test it again. At the least you've eliminated a possible cause. Compression leaking into the coolant will over pressurize and force coolant out. Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Yeah. Going to do compression test later . Mike. Temp gauge was non op. Just fixed that and letting her idle for a bit. Then taking for a test drive. Put new rad cap on also. Will replace thermostat. Is the symptoms I provided the sounds of a Shitty thermostat? Replaced it a year ago and sold car so Idk. Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 And fwiw. I had the cap off and let it idle plus jazzed the throttle didn't see any bubbles. Just seen water move around a little more Quote Link to comment
datzenmike Posted March 17, 2013 Report Share Posted March 17, 2013 Do you have a coolant bypass hose from the thermostat housing running down across the front of the timing cover to the lower rad hose???? Quote Link to comment
I'm BLUE Posted March 17, 2013 Report Share Posted March 17, 2013 I think Autozone rents coolant pressure testers with adapters last I checked ? (years ago maybe not now). A bad cap will cause some issues as well :) Thermostat's go bad all the time ,,, being bad out of the box is common now ( I won't touch certain brands , but trust none 100% until tested around town ). Compression test is good path if you think it's related , and make sure to stick some anti-seize on plug threads. If you want to spend some $$$ on a chemical coolant test ... to test for gases in your coolant system that's a good path to , but by the time you spent $$ on that you coulda replaced gaskets/thermostats lol. ( as we all know ) Make sure to check for a clogged/blocked radiator/block/passages. When I acquire a new L-series engine/car... I usually take all coolant hoses off , then take the thermostat out , un-screw the block drain and go at it with a pressure washer for 15-20 minutes. Made a HUGE difference on temp stability and warm up/cool-off in the last couple l-series engines I did it to ( cheap I know lol ). hmmmm good luck izzo. Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 I would do a stove top test on the t-stat, easy and quick, tells no lies 1 Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Dtp thanks man! Mike. The one off the thermostat housing is plugged with a bolt. I saw the water passage hooked up from the intake to the lower rad hose tho 1 Quote Link to comment
Guest 510kamikazifreak Posted March 17, 2013 Report Share Posted March 17, 2013 Mike. The one off the thermostat housing is plugged with a bolt. I saw the water passage hooked up from the intake to the lower rad hose tho That was datsuns, built in fail safe sorta Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Well. Took itfor a drive. It was three quarters or so way up temp gauge.... Hot as hell to the touch. Pulled the cap off at water shot out. Refilled and went home. Got three quarters way hot on way back. Quote Link to comment
datzenmike Posted March 17, 2013 Report Share Posted March 17, 2013 Dtp thanks man! Mike. The one off the thermostat housing is plugged with a bolt. I saw the water passage hooked up from the intake to the lower rad hose tho This needs to be connected or drill a 1/8" hole in the thermostat. The thermostat is outside the head. The block can get hot!!!! but the water around the thermostat is still cold. Engine boils over while temp gauge reads cold and thermostat is closed still. If there is a small hole or the bypass is hooked up hot water from the block will circulate past it and it will open in time instead of too late. Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Bah idk.. Where does the one off the thermostat go mike? i don't see a spot for it.... Slit my hand open tonight pretty good. done dicking with it for now, will get back to it tomorrow maybe & replace the thermo and do a compression test. If the compression test comes back good Then I'll see about removing the rad and taking it to the shop to get it tested. Wish I had a garden hose to flush the system out. Quote Link to comment
Xnke Posted March 17, 2013 Report Share Posted March 17, 2013 Also, is the heater line looped? This is a SEVERE No-No on the L6's, and should not be done on the L4's either. Drill a 1/8" hole in your thermostat and you don't need the external bypass line, besides the water pump can easily unseat and push open the thermostat anyway. It won't happen at idle, but cold rev an L and it'll unseat. We had a huge discussion on overheating over on HybridZ and put in about 12 hours of engine dyno time just studying the coolant paths and quirks. There is also an internal bypass line drilled into the engine block, to protect the water pump. It doesn't do much for warming the thermostat, though. Have you checked the radiator for blockages? The old Datsun copper core radiators can work really well even at 50% clogged up, then all the sudden you're over the tipping point and it overheats. Put your hand on the radiator while it's warming up and feel for cold spots in the core, that's a clog. Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Will do thanks man. To bad its auto and has trans lines hooked up. Easier to remove when manual. I'll feel around. I know the top is hot lol Quote Link to comment
izzo Posted March 17, 2013 Author Report Share Posted March 17, 2013 Well I was really hoping this wasn't the case. But, it is what it is. 1. 105 2. 40 3. 135 4. 130 Quote Link to comment
I'm BLUE Posted March 17, 2013 Report Share Posted March 17, 2013 Well...at least you know what's going on and caught it :) At least the machine shop will check for flatness for free (love that) Might as well do all your coolant hoses and blasts the passages/flush while there if ya can. Quote Link to comment
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