New M45 owner, first issue...cooling system...

[nuQ]

Picked up my 2003 M45 with 111K from CT and drove it back to PA a few days ago. It was a quick purchase so I did not have the luxury of test drives or having a mechanic look it over, but it's in very good condition, and I will clean and perform the necessary maintenance to my standards.

When I picked it up the owner went over the car with me, and made a point to show me the coolant level which I thought was a little odd, but we moved on. On the drive home I noticed the A/C would seem to blow warm, then kick back on to cold periodically. The transmission seemed to hunt around for gears sometimes and a little lag when the pedal was crushed, but I know that's par for the Infiniti course with some transmissions. But, made it home with no issues, and the car seemed to run very well.....noticeably faster than my old Q, which is great.

Anyway, tonight I drove about 5 miles to the notary, and then stopped in a drive thru. While waiting, I noticed the temp gauge heading north, and almost to the top. I pulled into a parking spot and turned it off, but didn't see any steam or noises (thankfully). After about 10 minutes I started home and the temp gauge went back to mid level (normal), but started heading north again when I was almost home. Parked it in the garage and let it sit for about an hour (again, no steam or gurgling). I took off the engine covers and saw no leaking coolent anywhere, or oil, or any leaks,,,engine looked totally dry. I started it up and put the HVAC to hot, and instantly blew hot air into the cabin. The temp gauge stayed right in the middle of normal for the 10 minutes it was idling, but when I looked again into the engine, I could see that the engine fan was not turning at all. I could hear the clicking like it should turn on (I assume the fan turns on by thermostat instead of constantly running..?), but nothing. When I was inside and could hear the clicking, I also noticed that the A/C would go warm and the RPM's would jump, then settle back down.

Any ideas where I should begin the troubleshooting tomorrow morning? As some know here, I have been a longtime Q45 owner, but the M is all new to me, and definitely want to start out on the right foot with repairs and maintenance. Your responses and help would be greatly appreciated, especially since my wife was not thrilled with this purchase, so hopefully this repair can be made quickly and quietly!! Thanks!!!

[asoomal]

If it's easy, remove the connectors for the fans and connect it to a battery with a fuse and see if they run.

[Double E]

The basics first (including the test suggested above).

What's the coolant color & level look like? Not just in the resevoir, but in the radiator too. Was the level low or too high in the resevoir when the seller pointed it out?

One of the fans in the car actually runs on hydraulic fluid and there's a cap to check that fluid level, just behind the radiator. Be sure to look at the house routing for leaks on that assembly.

I'm not sold on the hesitation & hunting being a transmission issue but I don;t know either. My first M went to 137K miles and with regular fluid changes it was still strong as hell.

[nuQ]

Ok-----I really hate "flying blind" as I have no manual to fall back on, so I apologize in advance for asking a ton of questions. The car is going in Tuesday for it's state inspection, and my mechanic is great with basics (or if I tell him exactly what to look for), but would love to diagnose and hopefully fix before that.

Now,,, 1. the fluid levels look fine in the radiator, and halfway between min-max in the overflow. When the seller pointed out the fluid, he opened the overflow tank and had me smell the cap. He stated that it was recently changed and a "clear" fluid was used. I know he had been taking the car to an Infiniti dealer for service (near West Haven CT), so I'm a little concerned why this wasn't addressed...he had it in the dealership for an oil change, leather repair, and possibly to top off the coolant the day I picked it up...

2. The hydraulic fluid level definitely seems low,,near the bottom of the dipstick when cold. This is from the smaller reservoir to the right side of the radiator looking from the front of the engine. When I asked about this in Autozone, they never heard of a separate reservoir for the fan, but then one of the employees came forward that used to work at a Mercedes dealership and said they used the same set up for a few years too. What type of fluid should be used to fill this up??

3. I'm having a tough time finding where the electrical plug is for the fan itself? Also, is there more than one fan? I'm only seeing the main one. Also, which relay would be the one for the fan?

Thanks again for helping take care of this. I don't want to drive the car at all until this is resolved,,,and it sucks having to see it sit!!

[nuQ]

Ok-----I really hate "flying blind" as I have no manual to fall back on, so I apologize in advance for asking a ton of questions. The car is going in Tuesday for it's state inspection, and my mechanic is great with basics (or if I tell him exactly what to look for), but would love to diagnose and hopefully fix before that.

Now,,, 1. the fluid levels look fine in the radiator, and halfway between min-max in the overflow. When the seller pointed out the fluid, he opened the overflow tank and had me smell the cap. He stated that it was recently changed and a "clear" fluid was used. I know he had been taking the car to an Infiniti dealer for service (near West Haven CT), so I'm a little concerned why this wasn't addressed...he had it in the dealership for an oil change, leather repair, and possibly to top off the coolant the day I picked it up...

2. The hydraulic fluid level definitely seems low,,near the bottom of the dipstick when cold. This is from the smaller reservoir to the right side of the radiator looking from the front of the engine. When I asked about this in Autozone, they never heard of a separate reservoir for the fan, but then one of the employees came forward that used to work at a Mercedes dealership and said they used the same set up for a few years too. What type of fluid should be used to fill this up??

3. I'm having a tough time finding where the electrical plug is for the fan itself? Also, is there more than one fan? I'm only seeing the main one. Also, which relay would be the one for the fan?

Thanks again for helping take care of this. I don't want to drive the car at all until this is resolved,,,and it sucks having to see it sit!!

[asoomal]

Most of the time, the hydraulic fluid for the fan is usually just plain old ATF.

Is it red? It'll sometimes say it on the dipstick or the cap.

[nuQ]

It definitely is reddish in color,,,can't see it written anywhere on the reservoir or dipstick. I can add ATF fluid to it, but hopefully someone else will write in and confirm. I'll be checking all day today and tomorrow on here, as I'm working on my cars this weekend. Thanks!

[nuQ]

Ok----a whole day of all things Infiniti! Completely detailed the exterior of my Q45 that's for sale, then finished up with the M45. Let it idle in the driveway to get it up to operating temps, and both radiator hoses were hot.

The temp on the dash stayed solid at halfway, but when I turned on the A/C, it really did not blow cold. I could hear a clicking in the engine,,,like the A/C switching on, or the fan trying to engage?? But the fan is not turning on. I did check the hydraulic fluid in the reservoir and it was absolutely empty. The dipstick read nothing, and even when I put a small piece of paper in to check the fluid color,,nothing. I believe it was reddish when I checked it quick the other day. I can't imagine an empty reservoir is doing any good, but, would this keep the fan from working?

Also, does anyone know exactly what fluid should be used in the reservoir?

[asoomal]

As per AllData

"INSTALLATION
Install in the reverse order of removal.

Apply Genuine Nissan Power Steering Fluid II (the cooling fan fluid) or equivalent to the O-ring of the cooling fan fluid hose (on the feed side). Then insert the O-ring to the water pump so that it does not come out of the attachment groove.

For bleeding the air from the cooling system, refer to "REFILLING ENGINE COOLANT".
See: Coolant\Service and Repair

For bleeding the air from the cooling fan fluid, refer to "COOLING FAN INSTALLATION".
See: Radiator Cooling Fan\Service and Repair

INSPECTION AFTER INSTALLATION
After installing water pump, check for leaks of the engine coolant using radiator cap tester. Refer to "LEAK CHECK".
See: Coolant\Testing and Inspection

Start the engine. Visually check that there is no leaks of the engine coolant and cooling fan fluid."

Just Dexron ATF.


FIll up the reservoir and see how it runs.

[nuQ]

Thanks, I will refill it tomorrow and see what happens. Being that it is completely empty, I can't imagine that it's helping anything. Keeping my fingers crossed that this will solve the problem. I'll keep you updated.

[nuQ]

Thank you, thank you, THANK YOU!! I got a quart of Mobil1 synth trans fluid today, and slowly filled up the reservoir, turned on the M and heard a "creaky" sound coming from the engine, and went out to see the beautiful sight of the fan spinning! It was making a little bit of a noise, which I think was just from non-use. I kept shutting off the car and rechecking the level, and by the end, I used almost the full quart to get the level where it was holding steady. I'm thinking the previous owner was not aware of the hydraulic reservoir, and it didn't look like any fluid had been added in a long time (the top of the reservoir was completely dry and no old stains). Also, the A/C began blowing ice cold, too.

So, again, the NICO site proves to be so incredibly valuable to those of us interested in maintaining their cars correctly, and as economically as possible. I can only imagine what most mechanics would attempt to fix first, before heading to the hydraulic line as the reason for the non functioning fan.... I know it has happened many times, from what I've read.

So relieved this first fix was nothing major! Thanks again all for your input!!!

[nuQ]

PS---the "creaky" noise went away after a few minutes, and everything sounds fine now....

[Double E]

That system is supposed to be sealed, meaning that the liquid went somewhere before you bought it. Keep an eye on the level going forward & look for a leak.

[nuQ]

I was thinking the same thing. It looked pretty obvious that it had been a long time (if ever) since any fluid was added through the reservoir, as there was no sign of drips or wipes. There is also no sign of leaks under the reservoir, or anywhere around where the upper hoses attach. The car is going in for state inspection in the next day, so I will have then look when they are under the car. With the bottom cover under the engine, I'm sure many leaks can be disguised by that...

[Double E]

true. The lower panel is a PIA for routine oil changes.

You're doing your own changes?

[nuQ]

I typically take my cars to my mechanic and bring the oil and the filter. I'm going to have him do the oil (this time) and probably the rear diff, and plugs. The fan is still working fine today, but I did notice when I started the car, that there was a drip under where the radiator hose connects into the water pump. Unfortunately it is in a hard spot to reach with my finger, as I wanted to see if it was coolant or hydraulic fluid. I stuck a piece of paper towel in the spot with the drip to see the color, but it came out black and I couldn't tell. Then the drip just stopped, so I'm not sure. I wanted to do a full flush of the coolant anyway, so maybe I'll just have them put in a new thermostat, and hopefully a new gasket will solve the leak, since it looks like it's coming from that area.

Just weird since it was dripping pretty steady, but then just stopped. I'll definitely keep an eye on it moving forward.

Do most here just take off the bottom cover??