Blindaviator

I just finished with replacing the water valve and was able to take the bleeder cap off while it was running without it pushing water out... The water valve was in pretty bad shape so that was part of the issue... Now I will see over the next day or two if that solved the problem or not...

Ok I just tried what you suggested and only got about half way done before I had an issue. I started it up and let it idle with the cap off. The water was staying steady inside the radiator and the temp was almost to operating temp. I decided to take the bleeder cap off in the back to let it push out some coolant so I would know it was full. The instant I removed the bleeder cap the coolant rushed out of the radiator like a fountain. I bet I lost 1/4 of a gallon in a second. The moment I put the cap back on it stopped and the water level stayed steady. I put the radiator cap back on and then removed the bleeder cap and nothing came out of it. I know it is clear of obstructions as I used a suction hose to get a little coolant out of it earlier. I have never seen something like this before. It makes me think there is a blockage in the system somewhere. Could the water valve being stuck closed cause it to do this?

I have a drive way that is on a slight incline that I use to fill the radiator. The bleeder plug at the back is close to the same height as the cap. When I take the bleeder plug off it will "burp" out a little coolant. I will park it there again tomorrow and jack it up a little and try what you suggest and see if that helps.

I just rented the chemical test and used it on the cooling system... The chemical stayed blue so no hydrocarbons in the coolant... The only guess I have left is the water valve thermostat needing to be changed... When I changed the main thermostat it did have quite a bit of corrosion on it... Doesn't look like it has ever been changed in ~215k miles so I am betting the water valve hasn't been either... Changing the thermostat and radiator stopped it from pushing water out into the overflow... It still loses water but at a much slower rate...

The first thing I tried on the trip back was Bars-Leak Liquid Copper which I have used before, with success, at sealing leaky and fully blown head gaskets... It made not a single iota of difference... Between that and the pressure remaining good in the cooling system for many hours after turning the engine off tells me it is highly unlikely to be a head gasket... Normally if it is a head gasket (even a small leak) it will rapidly lose pressure in the cooling system as it bleeds down... There is no bubbling of the coolant, no white smoke out the rear and no water / oil mixing... None of the normal signs of a leaky or blown head gasket are present... If it was high pressure from the cylinder pushing into the system you could see bubbling or foaming of the coolant while it was running with the radiator cap off... I have been meaning to do a chemical test on the cooling system to check for un-burnt hydrocarbons in the system but haven't managed to get the test yet... Will prolly grab one tomorrow to make the determination for or against...

The only water hose I can't really see is the one for the water valve... If that one was leaking it would be running inside the engine or down the back side and dripping on the ground... Put the stock cap back on and it still has a small amount of water loss... The only conclusion I can come to is the water inside is boiling into steam and being released through the cap as I drive.... It might or might not be the water valve thermostat causing it... But at this point I don't need to spend more money on a *possible* fix... I am about 99.5% sure it is not a head gasket as there are no other signs or symptoms of it... Also noticed a wet spot under the center of the engine a few nights ago... After jacking it up and looking with a light it seems to be oil coming from between the rear of the engine and the transmission... Rear main seal is really all it can be... So it will be traded in soon for something else... I need something more reliable...

Ok so I had a longer trip today with outside temps around 80... After I stopped at my destination I popped the hood and checked for water. I didn't see any coolant but I did hear the cap releasing what sounded like air... After it cooled down I checked the water and it was down slightly so I refilled... On my 30 minute journey back I used the A/C to really test the system... Again when I reached home I heard the cap slightly releasing air... I just now checked it again and it was down slightly again... I replaced the nissan cap a few days ago with one from Vatozone thinking that could be one of the issues... I tried putting the original Nissan cap back on and it feels much tighter and the spring seems stronger... Will try leaving it on and see if the same happens... The Vatozone one could be the wrong pressure or just generally crappy...

Ok so the low water situation *MAY* have been still some trapped air in the system. After filling and bleeding the system again last night I had taken the vehicle on the exact same run as previously and the water level is still full this morning. This afternoon I will be taking the truck on a little longer run which will tell me if the problem is truly solved or not.

I may have spoken too soon... Just went outside after it cooled down over the last few hours and the water was low just like before... Guess I will see over the next few days if anything has changed... If not I will trade it in and buy something more reliable.... Beginning to regret my decision to buy a Pathfinder over a 4Runner... Avoided the 4 Runner because of all the reported problems with head gaskets only to find the Pathfinders may be the same... I am going back to older Chevrolets... I never had these kind of issues with a good Chevy V8...

Some background on the issues I was having for those that might have similar issues... I was having issues with unexplained water loss on a cross country trip (2100 miles). The only time I would see any water was when I exited the highway after a long ~75mph run and that was just a small amount pushed out of the overflow container. I didn't see any signs of a leak and no apparent coolant being pushed out of the overflow at highway speeds. After running about ~200 miles I would stop and let it cool. I would generally have to add about 16oz of coolant. The pressure seemed to stay good for several hours while cooling. The temp gauge never showed above normal temps. When I needed to use the heater it would feel hot most times but seemed to cool off when I exited the freeway. At highway speeds the temps would be so high it would burn my feet at times. After reaching my destination in Texas I looked into it better. Around town it would rarely push any coolant out of the overflow but the level in the radiator would still seem to drop slowly. I also had a bearing in the alternator going out even though I just replaced it a couple of months ago. So today I changed out the alternator, thermostat (main one in front) and the radiator. I had to run / drive and top off the coolant 3 times to get all the air out. I parked the vehicle on a slight incline (nose up) and would pull the bleeding plug off the line at the back of the engine, fill up the radiator and recap them all. Run / drive a few minutes and let cool. Rinse and repeat. Keep in mind to turn on your heater to high when bleeding. If the vehicle is at operating temp and the heater is blowing cold you have air in the heater core. Keep bleeding until the heater is good and hot and most of the air should be out. Check coolant levels over the next few days. I ran it on the highway at 75 for about 10 miles and returned home. No more coolant being pushed out and temps are stable. Dunno if it was the radiator or the thermostat but it seems to be solved.

Well I made the 2100 mile trip from northern California back to Texas. But along the way I started to have coolant loss issues. I had the truck about 2 months before the trip and probably put about 1500 miles on it with no issues. During the trip I made it all the way out the south end of Cali and just hit I-40 when I stopped for some rest. In the morning I checked fluids and the coolant way dry in the top of the radiator. I ended up adding almost 1/2 of a gallon between the radiator and over flow. I also stopped at a Vatozone and picked up a new Radiator cap just in case. During the rest of the trip I would stop about every 200 miles and let it cool down. I would have to end up topping it off but it was only about maybe 12-16 ounces each time. By the end of the trip I had just used the last of that gallon to top it off. So 1 gallon in 2100 miles of constant driving. I have seen no obvious signs of a leak other than some coolant would be pushed out of the over flow when I dropped off the highway to get fuel or food and that was only a very small amount. That in it's self should not happen in a normal running system unless the system has built up a lot of heat and you slow too quickly. Normally no leaks & coolant loss would mean a head gasket leak but I have seen none of the other classic signs of that. No foamy coolant, high pressures or rapid pressure loss when shut down. It would hold pressure for 3+ hours after being shut down which tells me there isn't a leak. I also dropped a bottle of the Bars Leak Liquid Copper when I first saw the low coolant. Normally if it was a leaky head gasket that stuff would temp seal it and stop the leak until you can replace the gaskets. It didn't make a difference. I finally figured out where the water pump weep hole is and as best I can tell I don't see any water coming out of it. I started to notice on the last leg of the trip a growling noise. It is the classic sound a bearing makes in the water pump or idler pulley when it starts to go out. I will be taking the belts off later today and start it without them to see if the noise continues. If so it will be time for a water pump. At no time during the trip did the water temp get much above 190 (I used my OBD2 scanner in live data mode to monitor it). Even when pulling up the steep mountains at 75mph. No overheating. No obvious leaks. So anyone have any suggestions on what to check to determine the problem?

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I gave that some thought a few weeks back and decided to do the math. Most people get an extra 3mpg with manual hubs. Without locking hubs: Averaging 17mpg @ 2100 miles = 123.5 gal 123.5 gal x $3.00 per gal (average) = $370.50 With locking hubs: Averaging 20mpg @ 2100 miles = 105 gal 105 gal x $3.00 per gal (average) = $315.00 The $3.00 per gal average is about the prices in most of California. About half the trip will be in Cali so that's what I based it off of. I know once I get out of Cali the prices drop precipitously... By the time I get to Flagstaff the prices will be closer to $2.00 per gal... Hubs cost about $170... The fuel savings would only be about $55.00 ... If the fuel savings was more I would certainly do it... If the CV's become an issue I have enough tools and jacks to remove them and continue my trip & repair them when I get to Dallas. Once I get back to Dallas and get settled I will certainly be putting manual hubs on. Over the long run the fuel savings will be huge not to mention the savings on wear and tear of the CV's...

I'm originally from the Dallas area. I came out here to northern Cali about 7 months ago to help a friend move and setup in an RV on some land. Got tired of the 20+ inches of rain each month and decided it was time to go back to Texas where the weather made some sense. Most likely will not be driving out this way again (at least not in a car). I drive 18-wheelers for a living so long drives are nothing new for me....

The belts look almost new and the idler pullies seemed ok when I changed the alternator. I spun them by hand and they didn't make noise or feel rough. I am assuming the 1st owner changed them at some point. CV's will need replacing at some point as the boots are starting to fail but they seem to be working fine right now. I will see about replacing them when I make it back to texas as I have limited funds to work with right now. I checked the front brakes by looking through the wheels and behind and they seem to have a good amount of material left. There was a little shudder in the front brakes when I first picked it up but that has since gone away. I believe the truck had sat for a short time as the 1st owner didn't want to replace the alternator. Probably developed some rust on the rotors which has since been cleared up. The E-Brake is good and strong, holds the vehicle in place well when I apply it. Brake pedal is firm and it stops straight at highway speeds. Wheel bearings seemed ok when I spun the tires by hand, no roughness or loose movements. I have limited funds until I get back to Texas. I will really check and replace a lot once I get back there. I appreciate all the suggestions of the stuff I forgot.

Well tomorrow I will be taking my R50 on a pretty long trip. Will be driving from FAR north California (almost on Oregon) back to Dallas. A trip of about 2100 miles. I've only had the truck for about 3 weeks and have done a lot of maintenance to it in preparation for the trip. So far I have done: - Replaced Alternator - Replaced most antifreeze when changing alternator - The power valve locktite maint. - changed oil and filter. Also put in some Marvel Mystery Oil during the change. - Changed transfer case fluid (it came out black) - Changed Trans fluid and filter (the magnet inside was pretty full) - Changed fuel filter (the fuel was dark brown from the old one) - Removed, cleaned and lubed the drivers side VVT solenoid. I still get the code occasionally but not as much as before. Only thing I still have left to do is the front and rear differential fluids. I am hoping the Marvel Mystery Oil will help to clean the VVT's more and prevent sticking / codes. Anything else I'm missing? Want to make sure I have a trouble free trip. Dam the fuel prices here in Cali are high. Local prices are hovering around 3.08 a gallon. Unfortunately almost half my trip will be in california. Once I get out of Cali the fuel prices drop considerably.

If you have to cut the hose end off just cut it back a little more and get a metal fuel line the same size from the local parts store and splice it in-between the line from the tank and a new piece of hose to the filter.

It is my understanding these trucks have cat's and resonator as well as a muffler (I haven't really checked that myself)... It could be that there is so much interference that the oil smoke doesn't make it out... I have seen others posting that they have unexplained oil loss and no idea where it goes so your not alone... I have had cars in the past that would only lose oil at highway speeds and leave no visible signs of it so it is possible... It would spread the oil across the bottom of the vehicle and any accumulations would be blown away before it could have enough to drip. Usually a sign of it would be an oil streak on the bottom of the vehicle... Basically I am just guessing here of course... I would personally pull a spark plug or two (several are quite easy to reach) and see what they look like.. That is the quickest way to tell if it is burning it...

Glad to see you got it... I have had some in the past I have only been able to get the same way... Really long ass extension, with a u-joint, going through the motor mount bracket, Etc... On those I will usually find where the stock battery wire is attached to the frame / engine and remove those for the next time I have to deal with the starter... Then it will usually have enough play to drop some and get that bolt.. Since I haven't done the starter on mine (yet) I will deal with it when it's time...

Learn something new every day...

Something else I was thinking about after my last reply... It is possible it is leaking out but only at highway speeds / under load & when you come to a stop the leak stops... One place to look (I just learned this yesterday) is the oil cooler... I didn't even know these trucks had one until I was doing some research... Apparently they are prone to leaking quite often... They have 2 O'rings that you can replace pretty easily and stop the leak (I will be doing this soon as I'm sure mine is likely leaking after 215k miles)... If the oil cooler is leaking it will likely not drip on the ground much as it's right beside the oil filter above the plastic brush guard... It would prolly only leak under higher pressures (highway speeds) where the oil would be blown to the rear of the vehicle by wind and not show on the ground when you stopped... Pictures with a how to I found over here: http://www.nissanforums.com/pathfinder/142468-2001-pathfinder-odd-oil-leak-pics.html

Yeah you are right on the R and Q... I was tired and not reading it correctly... But according to what I read the 123 is the service description and the E1 is load rating... Guess it depends upon the tire manufacturer as to which they use... I just went out and looked at the Firestones on mine and I saw the service description of 106T ... On the opposite side of the tire I saw E1 which is the load rating... Guess they don't always keep the load rating close to the tire metrics...

I have been researching tires a bit recently and found this bit of info if it helps: Load Range designates the tire's construction as it relates to its load carrying capacity and is represented by a letter. For example, "C" indicates the tire has a 6-ply load carrying capacity. The tire is not actually built with 6 plies, but contains one or two plies of equivalent strength. The Load Range also indicates the air pressure at which maximum load carrying capacity is achieved. SL (Standard Load) 4ply @36 psi XL (Extra Load) 4ply @42 psi C1 6ply @50 psi C2 6ply @35 psi D1 8ply @65 psi D2 8ply @50 psi E1 10ply @80 psi E2 10ply @65 psi F 12ply @95 psi G 14ply @110 psi I.E. -- LT265 /75 R16 123Q E1 OWL -- The E1 would tell you the load range & the 123Q is the service description. The R is the speed rating. The 105 you are thinking of is actually the service description I gleaned all this info from the Discount Tire website

If you pull the plugs refer to this chart to read them: https://www.ngksparkplugs.com/about-ngk/faqs/spark-plug-faqs/how-do-i-read-a-spark-plug You might also try a compression test while you have the plugs out. Although the compression will only tell you if there is an issue with rings. Compare the compression values with OEM tolerances. If one or more cylinders are too far outside the specs then you have to assume ring issues. If you have a laptop You could also pick up a cheap USB "Endoscope" or "Borescope" and look down into the cylinders for any visible issues.

In my experience with engines with significant oil loss it can really only be 2 options: 1) Leaking out. Either onto the ground or into the water. 2) Burning it. I would suggest pulling the spark plugs and see what they look like. If it is burning that much it should show on the plugs. As for the engine replacement if you are handy with tools you can do it yourself in a day or two. If you live in a larger metropolitan area you can likely find a good low mileage motor from a salvage yard with a short warranty for less than $1000. Try to make sure the one you get it from was salvaged because of an accident (preferably not a front end one). If you don't signs of damage on the vehicle then it was likely salvaged because of mechanical failure (which you don't really want to find out about the hard way after spending all the time installing it). Search over here and see what engines pop up in your area: http://car-part.com I personally would take a low mileage salvage yard motor over a rebuilt one. The re-builders usually don't care about the tolerances much when they rebuild one. They just get it somewhere close and leave it at that. The factory ones will have very good tolerances.