EricCR

If you need instructions on how to remove each panel, glovebox, etc. just let me know and I can take some pictures. This is roughly where everything is located. Hope it makes some sense. Blue arrows indicate cool air, red = hot and yellow = warm or ambient. The green arrows are meant to indicate that each sensor communicates with the HVAC panel. The sensors themselves are located exactly where the text is. I forgot to label the white "T" in the center of the heater core. It's the vent where the vacuum hose from the "Tc" connects.

The way it works in our R50s is simpler: A hose connects the cabin air sensor to the main duct behind the stereo. As you activate the HVAC and air moves through the duct, it creates low pressure on the hose and it draws air in. Funnily, for all this to work Nissan had to leave an open vent behind the stereo so you have some cooling there Anyway, long story short, the AC is still doing its random hot air shenanigans after cleaning the cabin air temp sensor. I took almost everything apart short of removing the evaporator and the heater core. I was still able to see the AC in action and what exactly happens when I get those seconds of warm air. In short, it's the blend door actuator which is letting some air pass through the heater core (it opens for a few seconds, then the sensors probably detect the temp increase and the actuator closes the door again). That happens even with the temp set to 60 and air directed just to the front vents, which in theory and according to the service manuals, should never cause the blend door to open. My hunch is that the HVAC control panel itself is bad since it should be taking the readings from the cabin air sensor, the intake sensor, the sun load sensor and the temperature you set to signal the actuators how to move. So I'm going to get a used one off eBay to try it out. I doubt any of the temp sensors are bad cause they are simply miniature MAFs which heat up and then measure air passing through, but that's still a possibility. My worst-case-scenario plan would be to disconnect the blend door actuator. I don't use the heater anyway. If you suffer from not-so-cold air, you might have a similar issue with the AC being fine but air warming up because it mixes with air from the heater core. I'm sorry I didn't take other pictures besides that one above, but let me try to make a diagram of everything back there.

Ok, I removed the lower dash panel under the steering wheel and no wonder why my AC is acting up: Interestingly, in my E39 there is a little electric fan that pulls cabin air through the sensor. In this Pathy it's vacuum driven and there is a hose that goes all the way to the blower behind the stereo. The hose is as dirty as the sensor is. Next thing is finding the intake air temp sensor and also cleaning it up.

140k miles on mine (a 2003 auto) and it honestly feels like a new car. I also bought it recently but you can tell when a car has been properly maintained and when it still has a ton of life in it. Transmission shifts very smoothly, engine pulls hard, no strange noises or major leaks and minimal rust. I did put loctite on the power valve screws (they were all there) but other than that, I'm sure this thing could last another 150k or more. Parts scarcity may be a bigger issue in fact.

Yup. I downloaded the factory repair/maintenance manual and it's the only place where that minuscule grille is referenced. Thanks for confirming it. I will take that lower dash panel off and see if the sensor is dirty. There is also an air intake temp sensor (for the AC, not the engine) behind the glovebox. I will see if that one is easy to reach and clean. I spent a few hours last night reading and the automatic HVAC takes the readings from the internal temp sensor, the intake temp sensor, the sun load sensor and the desired temperature to calculate how to adjust the internal blend door. It's a fairly complicated system. What the AC shop told me now makes some sense. According to the service manual, as soon as the system reaches the desired temp, an actuator moves the blend door to allow some air to pass through the heater core so the air warms gradually and temp doesn't drop further. Since I can get both cold and hot air I don't think my door actuators are bad, but probably the HVAC panel itself, which houses the logic board and is supposed to take all those readings and make adjustments, might be acting up and it's opening the blend door too much, exposing the heater core for a few seconds and then it quickly figures that the temp is increasing a lot and goes back to closing it.

So I took the car to have the AC system checked and everything was OK. It's charged, there are no leaks and there should be no apparent reason why it randomly blows warm air. At the shop they mentioned that a faulty heater core might be the culprit but I can't see how that could be related. I have found two things in the past weeks too: I normally set recirculation mode and leave it like that. As with any car, air resistance causes fans to be louder in that mode, but for the few seconds that I feel warm air, I also hear as if the recirculation flaps open and let outside air in (maybe blend door actuator?). If I set the AC temperature to 60 F (lowest setting) then there's no more warm air. This is my workaround for now but I do want to get to the bottom of this. The above leads me to think that the HVAC has problems measuring cabin temp and adjusting itself. I cleaned the sensor under the windshield and I'm considering buying a used HVAC panel to test it out (they're relatively cheap anyway).

Thanks. Coolant as in freon, aye? The weird thing is that other than that, it's ice cold 99% of the times. I'll still go and have it tested regardless. Just knowing that it's not normal in these cars is reason enough. I'm still learning a lot from this Pathy. I took the intake manifold apart and all 6 butterfly valves along with their respective screws were still there, so I'm way less concerned about the car now. I loctited all the screws anyway (they were not loose but didn't take much force to unscrew them either). I'm going to make a routine of checking them every 50k miles or so. I also have an oil leak which sounds like a PITA to repair so I'm still deciding if it's worth fixing. Other than that and a rattling rear hatch, the car is perfect so I'm very happy with it. With the lockdown I haven't been able to really use it other than for short trips and such. It's a shame.

Hey folks, My 2003 sometimes does this weird thing of blowing warm air for a second or two when the AC is on (it's the digital HVAC). I don't know if it's a rudimentary way of keeping the right temperature but this is the only car I've seen in which is so noticeable. Since the car is relatively new to me, perhaps it's a non issue? Otherwise the AC blows cold and doesn't seem to be getting warmer over time. Is that something I should go and have it checked?

Got it. Thanks a lot to all. I'll confirm the source of the leak with a picture tomorrow with good light, but it does look like it's not something for the amateur DIYer (me). I'm comfortable changing oil, brakes and such, but between the lack of proper tools and time, I leave major repairs to others. As for the rattle, mine is sitting at 130k miles so maybe it will last for a bit. It takes me a very long while to put 100k in any car so I think I should be fine. I use Royal Purple in all my cars and have had good experiences with K&N oil filters.

This worries me. I haven't added any additives (although I admit I did buy a can but still hoping not to use it), but my Pathy rattles for like 1 second (at most) on cold startups and I've been blaming it on a slightly loose timing chain. Both my E39 and a 70's Corolla I own do rattle a bit when cold with no issues whatsoever and I've owned both for 15 and 20 years. Any way of identifying lifters from chain noise?

Thanks guys! I do have an update. When I went to pick the car up, we put the car on the lift and my indie showed me the place from where the oil is coming from. Almost exactly above that oily screw (dead center on the pic above) there is a vent or a port and after cleaning everything up and driving it for a bit, that's the only place that leaks a drop or two. The rest of the engine/transmission is completely dry, including the valve covers and the oil cooler area that you guys mentioned. He reiterated that in order to get to the actual leak behind that port/vent thing, he would need to either take the whole motor out or the whole transmission. After what I saw I believe him, unless there is a simpler way we both ignore. Not sure if all that makes sense. I'll get under the car tomorrow to take a better pic. Stupid me didn't do it when the car was on the lift.

Got it, I'll look around that area. Ugh, if it happen to be the VCs then it's the exact same ****** situation I've had with my E39. I've replaced that gasket countless times and after a few months the same leak appears, near the firewall. I'm sure that valve cover (plastic) is cracked or chipped but I'm still in denial.

You are correct, that's a 2003 VQ with an auto and AWD. Sorry I didn't mention it up there. You mean if I have plastic VCs they could need replacing, so they warp or develop cracks? Or were you referring just to the gaskets? I'll check the other stuff meanwhile. Thanks.

Hi folks, My new-to-me pathy has been trouble free for the past few months but now I noticed a few drops of engine oil on the floor. It's really not a lot and it only leaks when the oil is hot. I got under the car and at first glance it appears the leak is coming from the oil pan gasket. The thing is, I took it to my indie and he says the oil is actually coming from somewhere above the oil pan, and it would require either taking the engine out or the whole transmission to pinpoint the leak (both of course $$$). He's a great indie but he mostly sees my E39 and BMWs in general, so maybe not being familiar with the pathy he's thinking about tackling this the hard way. I'm hoping he's not right, or is he? Here is a pic I took of the oil pan (it's not the greatest photo but I can take more from other angles): Any common leaky spots up there? How much of a PITA would it be to properly fix the leak?

Thanks, guys. I'm going to order 16576-5W900 and see how it goes. I'll report back if that's the duct without the extra port (probably only needed for an extra sensor in the QX4?)

Thanks. Yeah, I figured there wasn't much life in it with these cracks: I'm going to order the duct from Amazon. Especially considering that the part is already scarce.

So, I *think* 16576-5W900 (same as 16576-5W90A) is the part I need. The difference between it and 16576-4W00A is that 4W00A has an extra port with a metal plug right next to the resonator opening, while in 5W900 it is sealed. This is just for reference in case someone finds this thread in the future.

Well, I'm an idiot and I just found 2 different parts on Amazon (weirdly they don't show up if I search directly in Amazon, only if I go through Google first). Anyone knows the difference between 16576-5W900 and 16576-4W00A? They look identical to me. https://www.amazon.com/Well-16576-5W90A-16576-5W900-Pathfinder-Production/dp/B07M6S9B9S/ https://www.amazon.com/Well-Intake-Resonator-Infiniti-Pathfinder/dp/B07BFJHKKG/

Hi! So I've been busy doing lots of minor stuff to my new-to-me 2003 pathy and yesterday while checking the spark plugs I noticed that the intake boot/duct has some superficial cracks, mostly where it connects to the throttle body and also around the resonator box. I took it off and checked the cracks with a flashlight and I'm pretty sure they don't go through yet. - I come from the 90's BMW world so brittle plastics/rubber to me mean doom. Should I consider that Nissan used better materials and the duct will last a long time in that state? - I found a thread from 2017 and it was already difficult to source that part for under $200. It looks like it's only sold along with the resonator, clamps, etc. Do you know if someone still sells just the duct?

Hey folks, So I pulled the trigger (told you I was being serious! ?). I bought the Pathy in the first set of photos I posted above. She's a USDM 2003 SE with 130k miles, throttle-by-wire (thought those started after 2004), A/T, with the only options being the tall roof rack and the Bose stereo (more on that below). What won me over was how mint it was considering the mileage, especially the interior. It pulls hard, exhaust pipe is clean as a whistle and I don't see or feel any indications of power valve failure (but that's TBD once I take the intake apart). It's evident that one of the previous owners was a smoker, probably back when it was in the US (it has been here since 2012). There is a brown stain just above the driver's seat and it smells, not a lot by now, but definitely noticeable. I went to pick it up yesterday and since then I've been polishing all glass, headlights and cleaning the interior. There was this nasty brownish crud everywhere. Next weekend I'll tackle the power valves and report back. If there's something missing I'll do a compression test afterwards. Wish me luck! It is the one that I thought was grinding when switching from 4L to 2H but you were all right, I was just being too slow to shift. Heck, even the manual says that. I have a few new questions though: The driver's side window auto up works, but just after it closes it goes down like 1/3rd of the way. I can still close it by pulling the switch a second time. I suppose it "thinks" there is something in the way. I think I read somewhere that there is a way to reset it by accessing the motor, aye? The tach is just a bit jerky, most noticeable between idle and, say, 2k rpm. 2 other R50s I test drove also had a similar quirk. Is it normal? Were USDM 2003 R50s affected by the Takata recall? I don't want the airbag to kill me. Is the "seal" trim between the fender flares and the fender supposed to be yellow-ish? I guess not, it looks bad. Here she is receiving some much needed love: Headlights before polishing: Clock fixed! Resoldering did the trick: This is probably not as easy to fix, but I'm giving it a try (it turns on and sounds fine but after a minute or 2, the screen goes dark and I lose most controls): Wasn't fun pulling the ashtray out and finding this: Much better!: Obligatory strut tower photos:

Hey pal @mjotrainbrain, Can you merge this post with this other one?: Sorry, the first time I got here I went straight into the FAQ section and when I was ready to post I didn't go back to the main forum (Sorry for the headache. I'm that clumsy). @01Pathmaker: Thanks man! I already pulled the trigger. Going to reply on the other thread I created.

When that happens it's one of 3 things (or a combination of them): a very worn key, a very worn lock mechanism or it's simply stuck. We have a Sentra at home and I just replaced all 3 locks (doors and trunk) because a similar thing happened.

Weirdly enough, only the highest mileage car that I saw had a super clean tailpipe, but the engine bay was also strangely clean so I suspect the owner hid leaks and the dipstick was almost dry too. All in all, that car was suspicious in many ways. The only thing going for it was that it had a manual but I'm almost certain now that if I really want to wait for a manual, it will likely be a more basic car. I have an old BMW with stick shift, so that can still scratch my itch. The 80k miles pathy is mint but it's also lacking a few (to me) important things. I know that the stock headlights in R50s are not that great, so I would definitely want to retrofit fog lights. Missing cruise control is also not great, especially since the car will be used mostly on long trips. The driver's seat also has a torn bolster which needs to be reupholstered. In short, I still need to pour some additional money into it. Mechanically it is the safest bet, though, which I guess at the end of the day is the most important thing. It's a shame I can't see from which state the silver car was imported. It definitely saw snow from just looking at the engine bay and underbody, but it's also far from awful. Cars here do rust but it's the air humidity that gets them and it takes a fair bit longer than when exposed to road salt. I didn't look closely at the strut towers or under the wheel arches. Then today I found this in FB's marketplace, but it's a bit far from where I live. Still not sure if that dash on the passenger side is sun damaged or if it's just the photo. Price is right and has relatively low miles (120k). Also imported from the US but has been here since 2005:

Thank you! I'm a sucker for well-optioned used cars so even if I completely get you on the "less things to break" mindset, I'm still a masochist and will probably want those things anyway. Actually, the Bose stereo in one of the cars has a broken screen (it looks like alien gibberish). About the 4x4 indicator not going away, I actually felt the low range still engaged so it wasn't just the indicator. I've never owned any car with actual off road capabilities so I read several 4x4 forums last night and found that cars which go for long periods in 2WD mode only tend to get a "sticky" 4WD which fixes itself with use (and sometimes a fluid change helps). That took away some of my worries and coincides with what the owner said. I can go a test drive the grinding one again and try to be quicker with the lever. What strikes me as weird is that the other 2 autos didn't grind. This is the 130k miles '03, fairly loaded example (the bumper is now repainted). Maybe it was from someone who frequented these forums? VIN is: JN8DR09Y03W803820. This is the '04 with 80k miles:

Hi folks! First time posting here. Disclaimer: I'm a total newbie when it comes to R50's but I *think* I have done my homework and I'm 100% sure I'll buy one, so you will hear from me again. I'm about to buy a pathy and I definitely want the VQ engine. I'm a bit biased towards a manual car but I won't discard a nice example just because it's an auto. I won't use it frequently and mostly on gravel and maybe dirt roads but nothing extreme (some places around here are a bit remote but most roads are properly paved). I have a few questions about what I've seen and what concerns me around them: - Went to see a 2003 auto which grinds just a bit only when going *out* of low range (from 4L to 2H). The 4x4 cluster light also stayed on after switching back to 2H the very first time (it was fine in a couple more tries afterwards). The car has 130k miles. This is the 3rd auto R50 I test and the others didn't grind. It felt to me like the transmission was still spinning even in neutral and the owner says that the last time he used 4x4 was years ago. Is that something I should be worried about? Other than that, the car was imported from the US back in 2012 and there is a bit of rust, but mostly around clips, screws, nuts, etc. The body is healthy otherwise and it's a loaded SE, still rocking the original BOSE stereo. - Saw another automatic, a 2004 sold by the dealer here, so it's pretty barebones. Manual AC controls, no cruise, no fog lights (but weirdly has leather seats). The good thing is that it has 80k miles, almost smells like new still, the car is basically flawless. It's a bit more expensive than the others currently for sale, around $1k more. It will probably go for a couple of years without any major issues. I saw a couple more, one has too many miles and the other had a recent engine rebuild (it's manual so whatever killed it wasn't the power valves), so I discarded them. All 4 owners have told me their cars don't burn oil but 3 out of 4 had an almost dry dipstick. Nobody seems to know about the power valves, so maybe it wasn't as common as forums lead you to believe? The thing is, would you go for the better optioned car even with all the above quirks? Should I just sit and wait for the perfect manual to show up? Are manuals considerably more reliable? Manual+VQ combos are not as rare as in the US but they usually very basic. If some of these things have already been discussed to death, just point me in the right direction. PD: Stupid me posted this in the FAQ/pinned section first, so if a mod sees this, you can delete that one. I couldn't find the option. Sorry! Cheers, Eric