Ka24de-T overheating HELP

[peter32582]

I have a 1998 240sx base model w/Ka24de-T. I have a overheating issue and have tried everything that I know to fix it. So now I am calling on my fellow NICO members for help. The car starts fine and idles fine also. Once it reachs normal operating temp it stablizes during idle. But 5-10 mins into driving her the factory water temp gauge starts to rise to the H and stays there, but once in a long while the temp. drops down to middle like as if the thermostat is opening then as soon as it goes down it start to rise back to the H again?? It doesn't smoke from the exhaust or moisture, it doesn't overflow into he catch can either, doesn't smoke in the engine bay, no real signs of a tipical over heating issue. This just presented itself after I turboed the car. Replaced the waterpump and thermostat, think that that was the issue but to my luck nothing. Also ran Water Wetter and properly bleed the cooling system from the bleeder screw with the front of the car on jack stands to help aid the bleedng process. So now I'm stumped and need help.

SETUP:

Ka24de (stock)ARP head studsGARRET GT3071R turbo dual ball bearing (oil and water cooled)T28 Exhaust housingInternal WG (7psi)DeatschWerks 450cc side feed injectorsN62 (z32) MAFN62 MAF filter adaptorINJEN air filterMegan Bottom mount manifoldMegan Turbo elbowTurbo Dowpipe (3 inch)Tanabe Hyper Medallion G full exhaust system (3 inch)Custom Aluminum Intercooler pipingTreadstone Intercooler (30x12x3)HKS SSQV BOVFull Aluminum RadiatorWalboro 255lp intank fuel pumpCooling panelAll AN fitting (for oil and water lines)Oil filter Sandwich plateBattery relocated in the trunk (full Aluminum box)K&N oil filterNGK 4644 BKR7E spark plugs13 psi Stant rad. capNew waterpumpNew thermostatHayden 12 inch rad. fan X2 wired to a switch

[youngun21a]

Try it with out the thermostat..and see if it still overheats..

[bruinbear714]

When the dash gauge reads hot, is the thermostat open? Is the radiator hot?

S14 temp sensor. Make sure you have the proper temp sensor for your vehicle. An S13 one will read hot when the engine is actually cool.

[peter32582]

Try it with out the thermostat..and see if it still overheats..

I live in MN and running wthout a thermostat is not an opition, LOL. But i'll try t with out just for s***s and giggles, thanks for the reply.

[peter32582]

When the dash gauge reads hot, is the thermostat open? Is the radiator hot?

S14 temp sensor. Make sure you have the proper temp sensor for your vehicle. An S13 one will read hot when the engine is actually cool.

The Radiator is hot and I cant really tell if the thermostat is opening or not cause the engine gets so hot that the upper and lower hose is just collecting heat given off from the engine.

Also the temp sensor is a stock S14 that came with the car and yes it's the original motor the is in there also. I also thought for the longest time wondering f I should replace the temp sensor but if it's working why replace it. Thanks for your reply

[4cefed]

I live in MN and running wthout a thermostat is not an opition, LOL. But i'll try t with out just for s***s and giggles, thanks for the reply.

Um, don't remove the thermostat. Unless you have a mega-ginormous radiator with plenty of airflow to it, the car will overheat. With no restriction in the coolant system, the water won't spend enough time in the radiator to exchange heat. If you are going this route for diagnosis, take an old thermostat and remove the plunger, or use a large washer with a center opening close to that of a thermostat.