OverHeating Problem Please Help!!!!!

[robertv11]

Hello I have been trying to figure out the problem with my source of overheating..At first my 1993 q45 started to overheat when I was at a stand still but when I would accelerate it would go back down to the normal temp..So I thought it was theThermostat. so when I took it out and replaced it the problem got worse..So I put back the original one...The overheating has gotten worse whether I accelarate or not...It also gets worse when I have the AC on..It got to the point where steam was coming out of the hood..I located the source of the steam..It is the metal tubing between the Radiator and AC Condensor..Right at the very top most part where it forms an "L" before is goes downward...Is this common? Do I have to replace the condensor or radiator? Is there a way I can find out?Any and all help would be greatly appreciated.

Thank You....Robert

[Raxephon]

Welcome NICO

Any coolant loss? (Prior to the steam)

Does your clutch fan freewheel or is there some resistance if you spin it by hand when its cold?

The metal tube between the radiator and the condenser should be attached to the condenser and under pressure (a/c coolant), and doesn't flow into the radiator or the engine coolant system.

Have you had your radiator pressure tested?

How do your radiator caps look?

Don't forget to use the search button,(zerosearch), and to check out the Infiniti Online Mechanic section,(zeroforum?id=24), as well.

In case you don't have one, here's an FSM to help you out .

1994 Q45 FSM http://phatg20.net/modules.php...d=203

[elwesso]

If your overheating and the Tstat did not help, you need a new radiator. Bottom line.

[Raxephon]

If your overheating and the Tstat did not help, you need a new radiator. Bottom line.

Not always.

If you have a significant coolant loss and a perfectly good radiator, you will still overheat, regardless whether you have a thermostat or not.

Hence the, " Have you had your radiator pressure tested?", question.

[Jesda]

Make sure you use Nissan thermostats only! Theyre $2 cheaper anyway!

zerothread?id=109750

[BlackBirdVQ]

Check for any restriction of airflow to the radiator. Alot of times there will be debris on the radiator fins causing a restriction of air going accross the radiator. I would check between the radiator and condenser and infront of the condenser. Make sure the AC and viscous fans are working.

Once you do get the problem nailed down, make sure to flush the coolant out and keep an eye out on the coolant to make sure its not loosing it. If you start to loose coolant or overheat again- welcome to the head gasket club, I seem to be the only member of that club so far. 4.5K dollars later with my own labor I have rebuilt my motor and she runs like a beast from the east

[robertv11]

Wow..Thank You guys so much for the helpful advice..I have to say your q45's are to immaculate..It is inspiring:)I followed everyones advice and after further investigation I found out it was not the actual condensor tubing but the actual right side of the radiator that is leaking...I guess the leak was alot smaller before that would explain why it would cool down when I accelerated...So..How hard is it to remove the Radiator on a 1993 q45? For which Nissan Model Thermostat would I use? I am in Southern Ca..What is the average price for a Radiator for the Infinity??

Thank You Again,Robert

[elwesso]

A Nissan Tstat is $8, i just bought one from Joe today......

Radiators are like $200, but koyo makes OE replacement ones. You can call Joe at Infiniti of scottsdale and he'll hook you up.. Call him up at 1888-216-5328. Tell him that Wes sent you

I think theres a NICO sponsors that sells aftermarket replacement raditators for the Q...

Replacement is really easy.. just remove the trans cooler lines onthe sides, upper and lower radiator hoses. Then remove the fan shroud (2 screws on the top and bottom). you may find it easier to just remove the fan (I do), in which case thats 4 nuts on the pulley... Then youll remove that plastic piece that goes over the top of the radiator, remove the 2 bolts holding the brackets down... Then you can pul it out... Shouldnt take more than an hour, i did it last time in about 25 mins, but ive done it a few times

Heres an article....... zerothread?id=164371

[BlackBirdVQ]

I bought my OEM Radiator for 330 with taxes. It was supposed to be a aftermarket OEM repleacement radiator and once I pulled it out of the box it was a brand new Nissan radiator that would cost me bout 550 at Infiniti.

Remove the top plastic cover that spreads between the headlights- it has like 8 or so clips holding it down. Then get under the car and drain the radiator, remove the lower radiator hose which will be on the driver's side of the car, then remove the transmission cooler lines with a LONG screwdriver from the top. Sometimes the head of the clamp is pointing up or down so it depends, then use pliers to pop off the hoses. After that you will wanna remove the upper radiator hose on the passenger side of the motor, remove the bottom HALF of the radiator fan shroud- its just clipped in from the bottom of the car. With all the hoses and any wireing that might be attached to the radiator shroud removed, remove the 2 upper brackets that hold the radiator to the radiator support and then pull the radiator out through the top. Make sure NOT to loose the rubber snubbers that sit on the bottom of the radiator and guide the radiator into the brackets that hold it to the body of the car.

It would be a VERY wise idea to get some new radiator caps from a 300ZX Twin Turbo as they hold higher pressure and will increase the boiling point of the coolant due to higher cooling system pressures. Also get new upper and lower radiator hoses, and OEM thermostat if you haven't done so.

[Raxephon]

Not sure about where you are, but my local Nissan told me it was an Infiniti only item.

1989-1996 Q45 Thermostat: Part# 21200-60U01

Radiator Removal: http://q45.org/radiatorrr.html

Edit: Since Wes & Mike beat me to the radiator R&R, here are the part numbers for the hoses.

Radiator Hose Upper: 21501-60U10 (Right Bank)Radiator Hose Lower: 21503-60U10 (Left Bank)

Radiator Hose: 14055-60U70 (Left Bank, short one that connects to the thermostat cover)


Modified by anlasak at 8:40 PM 3/22/2006

[Jesda]

LOL! Alora thought that was my arm.

[Q45tech]

0.9 bar 13.25 psi OEM is the max safe value..............higher psi may just create leaks swell hoses and generally cause grief!

A properly maintained cooling system doesn't need any higher than 260F which is what a 50/50 mix will boil at 13.25 psi.

Remember the ecu starts freaking out when you exceed 225F coolant temperature having removed all the ignition timing it can.

[maxnix]

And why some of us run 75% Distilled water and 25% coolant with Water Wetter in the summer. Better thermal transfer capacity.

Although I know TexasOil and some others run brass ones, I still prefer aluminum to minimize electrolysis. You could always get a custom Griffin like Q45tech.
Modified by maxnix at 5:31 AM 3/23/2006

[gniknave]

You can get an aftermarket radiator with lifetime warranty for $170 (only that much because I no longer work there anymore) from 1-800-radiator. Ask Redman or Jesda if you're worried about quality...

EDIT: it might even be a free same day delivery to Fullerton. If you want the inside source, email me [email protected]