Bleeding The Air Out Of Coolant System - VQ40DE Nissan Frontier Xterra and Suzuki Equator

This video explains how to install an air bleeder port/screw, how to bleed the air on a coolant system, and an overview of coolant parts under the hood. This information can be applied to most vehicles but is directed towards Nissan Frontier and Xterra and along with the Suzuki Equator that has the VQ40DE. This process of bleeding does not need to have extra tools like a venturi vacuum or compressor.
Here are the three top reasons you know you have air in the system.
1. No heat when stopped.
2. A sound of water movement near the riders dash when vehicle moves forward or stops.
3. Overheats.
www.z1offroad....

[@ELEVOPR]

I never saw this video did know you had it posted. I will soon be doing this same upgrade I picked it up from Z1 in October 2023 but since it is a vacation truck and on an island I can't get to it as of yet. But Soon I will be on vacation and get to it. I will also upgrade the Rear Hose assembly that runs behind the engine by the firewall, That long hose also has the same issue where it breaks at the T-part because of the heat making the plastic T brittle. This is the Part Number for those that want to upgrade that part also "Dorman 626-598 Engine Heater Hose Assembly" Once again thanks for sharing.

[@autoxadvice4159]

You aren't wrong about the right side couldn't pipe. I have a video for that as well 😅

[@Doesntmatteratall]

Nissan really got the cooling system right with the HR engines but all the DE style cooking systems are a pain in the butt. Great video, just bought an 07 Xterra and will be doing this with some other cooking upgrades

[@autoxadvice4159]

Thanks for the positive feedback. Good luck getting yours sorted.

[@craigcardoni5007]

Just found you on the frontier subreddit. I'm getting my 2019 frontier today so I'm subscribing to your channel. Thanks for all the helpful info. 👍

[@autoxadvice4159]

Thx for stopping by. The 2019 will serve you will. These are great great trucks not too many quirks, Judy haven't changed much since 2005. Enjoy your new ride.

[@shawnwaldrop3702]

The 2nd gen Frontier didn’t have a bleeder valve. Because it’s a closed system. The main symptom of “air” in the system is when your heater blows cold air at idle. That’s what the reservoir is for. If you’re having this issue, fill the reservoir ONLY. Run the truck normally. When you get to a stopping place, let the engine cool down. Open the reservoir cap and fill, if necessary. Always use the BLUE stuff if you don’t use official Nissan coolant. No need to burp, bleed, beg borrow or steal. Your fluids are low. Top them off. If you’re having other issues, more coolant or having air in the system is the least of your worries. Start checking for leaks, or a bad thermostat.

[@autoxadvice4159]

All correct. I have another video explaining all of what you just said. Using the air bleeder valve after you do a complete drain helps to get the air out quicker that is all. I didn't really explain that in this video. All the other stuff you said is spot on.

[@shawnwaldrop3702]

@@autoxadvice4159 sorry if you thought I might have been hating on your video. You have some great info here. And a reminder you give - that it’s not always a simple fix. Appreciate the detail 👍

[@autoxadvice4159]

No problem. To be honest there are very very few people that understand this closed system for the vq40de. It's not so much that's it's a closed system it's that Nissan's miss labeled or miss positioned the reservoir on these trucks. If they would have made it so the full/low markings were higher then owners when filling would fill between the lines (like normal filling procedures) and this would never be a problem with low coolant, no heat or gurgling. My other video has gotten 99% "you fixed mine" rate in the comments.

[@8683roy]

When my engine is cold & I first start the engine the coolant drops significantly in the jug and then goes back up as it warms up. That’s why I wonder if it should be checked when first started cold like some others have suggested. You should take a look at your level when it’s cold, start it, & then see what your level says. You may be surprised what you see.

[@bryandoherty9399]

This is also happening on my 2022 Frontier that is the VQ38DD, I'm going to try bleeding the coolant system or "burp" as I have seen on forums, and the VQ38 uses the same style pressurized system. I figure it is worth a shot

[@autoxadvice4159]

Hey thanks for stopping by and commenting. The 2nd and 3rd gen Frontier has a closed coolant system and it burps itself as long as you have enough coolant in the system and none is leaking. I am not sure if the 3.8 reservoir has had any changes but on the 4.0. I have concluded that the markings are too low you need to fill the coolant to the fill line or 1in over. A lot of people have thanked me as it has fixed their issue. Burping only needs to happen after a drain and fill and that's only because you want to have as much air out of the system before driving and closing everything up. Check out my other vid of fixing no heat or gurgling.

[@senadgalijasevic8568]

This issue can be noticable in summer as well. With less coolant in the engine your cooling fan will run more often because coolant gets hotter since it circulates through the engine a lot more.

[@autoxadvice4159]

You are correct. You can hear gurgling and fans will run more in the summer. However, in the summer this is less noticiable to the driver as cooling is based on the AC system as the heat is based on the coolant. As soon as the coolant isn't transferring heat in the interior there is a instant awareness something is wrong with heat.

[@8683roy]

Seams to me when the coolant level is low enough to affect the heater operation...then the air in the system makes the level in the jug act funny. Now that I got the level up high enough & it's stabilized...the level is way more consistent as to where its supposed to be when I check it cold & not running. I only have 40,000 miles on my truck & I'm very confident I'm not leaking or going through any coolant at all but it does seam like the level has gone down a little over time & I'm wondering if thats a characteristic of this closed system. I mean the tank gets pressurized & there is a relief port @ the cap so I could see how some steam would get released at times. If steam gets released then some coolant is going with it. So my question to you is: Do you know if this system is supposed to lose any coolant over time or do you ever have to top off your reservoir? If so, about how often? Thanks.

[@autoxadvice4159]

I have also noticed that the level is not always in the same place every time I check it when it's cold. Its because the pressurization and depressurization of this closed system. Unlike an open coolant system where the overflow tank is pretty much at the same level if there is no leak. Think of it like a drinking straw. If you suck up water out of a glass through the straw you can then hold your finger over the top and hold the level till you take off your finger, same with blowing into the straw. As stated in the video I think because how we all are trained to fill to between the full and low lines that doing so in this closed coolant system there is actually a coolant reservoir labeling flaw. The height of the lines should be about 1.5 higher to accommodate to fill between the lines. There are are about three spots that are notorious for coolant loss and you can spot them easy. Both the inlet and outlets to the heater core (they have plastic fittings that crack and leak coolant). The leak will be white/blue crusts. Then there is a small hose that connects the bottom of the reservoir tank to the heater core line. This bottom hose can crack and leak as well and you can see white/blue crusts around the connection. Working on a new video today about these leak spots :). Hope this helps.

[@tbag-2224]

No footage of actually using the bleeder to bleed the air? Does it seem to do the trick? It doesn't appear to the highest point in the system

[@autoxadvice4159]

Sorry that ended up not getting into the video. However, you don't miss much. You fill up the radiator and as the radiator fluid comes up to the top it should come out at the bleeder screw. Then you keep filling it up to till the it over flows just a bit out of the screw. once at the top close the screw and then run the truck. I think it does help get the air out of the back side however, I found that I had to keep adding coolant over four or five trips. My coolant level cold stays just below the full line now and that seems to be the ticket. I think these trucks are harder to bleed than the open system because it take such a long time to get all the air through the system and back to the reservoir tank. One last point is that the bleeder screw should be the same level as the top of the radiator so that there is no need to lift the front of the truck if you using the bleed screw.

[@tbag-2224]

@@autoxadvice4159 thanks!

[@autoxadvice4159]

@@tbag-2224 Thanks for stopping by and watching the video.

[@autoxadvice4159]

FYI - The Nissan Frontier/Xterra did have a bleeder port on the 2005-2009 models but was removed on the later years. Other than that I have not found any other design changes on the coolant system.

[@stevenr8080]

Where can I get that part with the bleeder valve. I was only able to find dorman # 626-610. But has no bleeder valve. Thanks and great video!

[@autoxadvice4159]

Here you go. www.z1offroad.com/z1-products/z1-motorsports/z1-58-aluminum-coolant-bleeder-port-p-19840.html

[@8683roy]

Do you know if the coolant is supposed to be checked while the engine is running? The owners manual only says to check it when it’s cold but I’ve read other guys said you’re supposed to check it when it’s running.

[@autoxadvice4159]

Check coolant level when cold. If you open the coolant caps you will get spraying hot liquid and steam on you. The system is under pressure. Plus it could be at a different level when it's hot. Also only check at the reservoir not the radiator, when you look into the radiator it will look empty. And also only full at the reservoir.

[@8683roy]

Ok. I understand it has to be cold when you check it but my big question now is should the engine be running or should it be shut off?

[@autoxadvice4159]

It's not going to matter too much at that point as your thermostat will be closed and the coolant will not move all that much. I usually check the level on the reservoir and make sure it's full or 1in above the full line.

[@jkddaddy]

Great videos. Will be following your tips. Do you have a recommendation on coolant? I don’t know what antifreeze was in my truck and realized late that mixing is not advised. I’m anxious to do a flush. And uh how is antifreeze supposed to be disposed?

[@autoxadvice4159]

Thanks for stopping by and watching. I did my flush with Nissan blue OEM 100k mile antifreeze. However, other manufacturers make blue 100k mile antifreeze that should work just fine. I just recommend getting a 100k mileage antifreeze. I'm one that doesn't recommend mixing antifreeze. This goes back to the days of dexcool used in GM vehicles. It caused problems and destroyed engines with mixing. My local community has a recycling process so it's pretty easy.

[@georgepower7115]

I tried to do that with engine cold on my 2020 frontier. But as soon as I start it coolant starts coming out of radiator and I’m not able to get the air out of the system, because of that my heater only works on max heat. Any ideas on how can I burp it? Thanks!

[@autoxadvice4159]

Check out my "coolant fix 5 min" video. It will give you tips on fixing the no heat issue. In your case you may have to do the fill method more than once. This video was more for burping the system after a coolant drain and refill.

[@daveyboysmith4575]

Very informative. I do have a question. One day I unscrewed the cap, don’t know why. A little anti freeze came out then I quickly closed it. Is that an issue? I have noticed any heat loss. Thanks.

[@autoxadvice4159]

The radiator cannot be 100% full (though close) because there is over flow tube back to the tank. That tube should be open and not blocked so that air coolant can expand into the tank. I think you should be ok as long as your tank coolant level is close to full or no more than 1in above full.

[@vicpnut1]

Does the oil catch can help,make any difference? I saw on an Xterra page how a lot of people were adding them so I amazoned one up…that was awhile ago and havent installed it ,so am wondering what the benefits are …well I u derstand it helps filter oil out of vacuum pcv etc..but in the real world of a more or,less babied 180,000 mi 06 Xterra s s it really helpful, or more of a safety catch in case other issues in system are failing .?.?

[@autoxadvice4159]

A bit of back story here. The crankcase becomes pressurized and to revive that pressure a pcv valve is used. When pressure is released air, oil, and moisture is expelled. In the old days that was released openly outside the engine and onto the ground. Nowadays it's ported back into the crankcase to be returned. It's not a lot over a short period so the engine doesn't have a problem returning it. However, the oil coats the intake and gets everything nasty. The other downside is that your engine is a little less inefficient and burning oil is bad for the O2 sensors (again not enough to hurt anything over a short period). With a catch can it collects all that contamination and stores it into a can. The cans benefits are minimum but if you like to keep your truck running optimum it's really not a bad approach. The low cost to have one isn't really a factor. Just basically keeping your components that more clean.

[@vicpnut1]

@@autoxadvice4159 great , thanks 🤙🏼

[@autoxadvice4159]

Not a problem. If you subscribed i have an upcoming video about the catch can and ironically my catch can setup caused a check engine light (not the can itself but one of the hoses split allowing too much air into the intake).

[@vicpnut1]

@@autoxadvice4159 seems these Nissans are pretty finicky. Coupla yrs back I had a new exhaust from and including The catalytic converter and back put in, but it was aftermarket so now I’m plagued with 420 and 430 codes anywhere from 20 miles to 300 miles they pop up… I can be clearing the codes up to twice or more a day, or sometimes I won’t see it for over a full tank of gas🤷🏼‍♂️…The mechanic that did the work knew it might be an issue( I was informed via Xterra forums to only use OEM parts so I relayed that info to the mechanic.) and he thought he had a cure by putting spaces in the new O2 sensors. It had always worked for him in his 40 yrs as a master mechanic….That didn’t turn out to be the case lol….I pass emissions with flying colors and he did a ton of work for about half the cost of the parts alone (if I were to buy em ) …so I live with the codes, though they still make me nervous as those were the codes I was getting when it completely died due to cats clogging …anyways yeah I’ll sub .

[@clevc112]

When I try to fill my radiator it just over fills the reservoir.

[@autoxadvice4159]

If you are doing a drain and fill then you can fill from the radiator while running truck to temp, but watch out it can overflow when the thermostat opens. If you are just wanting to add coolant you should fill at the reservoir not the radiator. This is because opening the radiator adds air to the system and that air has to migrate to the reservoir. This is a closed coolant system which means the reservoir needs to have the spring cap on it to purge any steam and air when it gets to temp. Drive it around, let it cool, add coolant and repeat till the level stays at "full" or 1 in above the "full" mark.

[@Frdzed]

VQ40DE coolant temp reads 221F after around 30 mins of driving here in sunny florida ambient temperatures are around 94F today, is the engine running too hot? Electric fan is triggered into high speed mode once temp reaches 221F hence why I notice it.

[@autoxadvice4159]

That appears to be a bit high. As the thermostat at around 195. Your temp gauge should read just below the middle. When has your coolant been changed and the thermostat. Also make sure your current level is at the full mark or 1in above full.

[@Frdzed]

@@autoxadvice4159 coolant was changed and flushed and bled a few times recently when the rear heater hoses were replaced due to them being brittle over age. Today I drove around with the AC off and just highest heat setting didn’t make much of a difference perhaps 208-215F range. But as soon as heater turned off and driving it goes back to 221F regardless of AC being on or off.

[@autoxadvice4159]

Check to make sure the cap that has the spring is on the reservoir and the other plain cap is on the radiator. Also, was the thermostat ever changed? And if yes was it a Nissan OEM thermostat.

[@Frdzed]

@@autoxadvice4159 I’ve checked the caps and I’ll probably start with the easiest item the thermostat and I’ll be buying a genuine unit oem. Thanks. I checked the viscous fan and it feels pretty stiff when hot and slightly loser when engine is cold. I assume that’s ok. As I initially perhaps that the viscous fan wasn’t adequately cooling the engine thus causing temps to increase. But temps remain a steady 221F with the electric fan on high speed which activates at said temperature above.

[@autoxadvice4159]

Maybe you can clutch not working right. If you do get a new thermostat, make sure you test it before you put it in (even oem).

[@tedstriker754]

You never used your bleeder valve. I was waiting to see how to use it but that never happened. I guess with your temp normal you must have figured it wasn't needed.

[@autoxadvice4159]

I did but probably should have shown it better. When filling up the coolant leave it open and the air will escape. Then let it run and warm up and you can squeeze the upper house to get more and more air to escape. Eventually it needs to be closed when the thermostat opens. When the valve is closed you can burp the rest of the way if needed. In this coolant system you don't need to get all the air out. As the air will move to the reservoir and will escape. However, you must have enough coolant to allow the air to travel. That is why I recommend keeping the coolant level to full or 1in above.

[@tedstriker754]

Thanks, replacing the radiator on a 2010 Xterra@@autoxadvice4159

[@sefofatai6618]

I could use some help with my 2008 Frontier 4.0L. I put a used engine in it and runs ok. But the top radiator hose gets hot but the bottom hose stays cool. Heater blows cold. I replaced water pump, timing chain tensioner and thermostat. I jacked the front of truck up and loosen heater hose til I see coolant coming out as I filled it. Still the same problem. Could I still have air in the system or do I have another issue ?

[@autoxadvice4159]

This system is self air purging. Make sure the spring cap is on reservoir and not on the radiator. Make sure the coolant is up to the full level and no more than 1in over it. What's odd in your statement is that the bottom hose is cool? What about your temp gauge is if indicating overheating or not heating up?

[@sefofatai6618]

@@autoxadvice4159 temp gauge after running for approximately 20 minutes moves slightly above mid mark. but I know its running hotter because when I opened the oil cap to top off oil. I can see small amount of smoke burning. What do suggest I do next? thank you for replying.

[@sefofatai6618]

@@autoxadvice4159 also I can feel top hose is getting extremely hot along with heater hoses but heater still blows cool along with lower hose. after running approximately 20 mins. the lower hose should be almost as warm as the top? should I pull out the new thermostat from Carquest and test it in boiling water? the radiator looks clean inside and seems like its been replaced. I'm burnt out

[@autoxadvice4159]

I always recommend OEM thermostat. Plus before putting and thermostat in test it to make sure it opens and closes as required. Also make sure the hole with the jiggly is on top.

[@georgepower7115]

@@autoxadvice4159 similar to me. My 2020 was on an incline (front down) cold engine. And myself for some reason wanted to check the coolant level, I started it and noticed coolant coming out of the radiator 3 seconds after I did. After that my heater didn’t work 100% as before. I know it has air in system. The other day engine cold and on a incline (this time front up) I started it to add more coolant and same thing, it came out again 2 seconds after I did. Any help on how can I bleed it. I heard it’s self air purging but at this point I’m lost. Thank you!

[@kristiansmith3977]

So I have a problem if anyone can help I have a 2012 Nissan Frontier sv in the overflow tank keeps spewing coolant out in I’ve changed radiator and thermostat nothing is helping.it only has 60,000 miles on it.

[@kristiansmith3977]

I’ve also never have seen smoke or anything different in the oil I’ve taken it to a mechanic they said it was the Radiator but hasent fixed.

[@autoxadvice4159]

A couple things here to try. Make sure that you did not mix up the radiator cap and the reservoir cap. The caps are the same size. Make sure the cap with the spring is on the reservoir and the one just with the rubber seal is on the radiator. If you have the caps on the right containers then I'd possibly replace the reservoir cap as it may not be functioning correctly. Last make sure that the fluid is about 1 in above the add line for the correct heat flow through the system.

[@kristiansmith3977]

@@autoxadvice4159 so yeah there on right the thing is that every time is it take about 15 min to overheat when I take it on a drive but it only hits half every time In dosent go higher than that but when I come to a stop the overflow happens than the gauge goes to normal

[@kristiansmith3977]

@@autoxadvice4159 in the ac I have problem with to takes a while for it to kick in than the heat is bad so I’m guessing I have air in the system

[@autoxadvice4159]

@@kristiansmith3977 Is the truck over heating and the gouge on the dash indicates this? If so then you have more of an issue which could be a stuck thermostat, plugged radiator, or the water pump may not be operating.

[@rajorab5055]

What do you use to keep your engine bay so clean?

[@autoxadvice4159]

Nothing. But then again since Covid started my truck hasn't been driven all that much. I have in the past used my air compressor to blow the loose dirt off and then used simple green and a rag. I probably should take it to car wash and do some light degreasing but that's for another day. 😂

[@NeverEnoughPyro40]

All you need is some Castrol super clean and your garden hose! Mix the super clean with water in a spray bottle 70% super clean and 30% water, Spray your entire engine everything and let it sit for about 10 minutes, Now take your garden hose and spray it all off! When you’re all done start your engine let it heat up then shut close your hood and turn the engine off and let it dry completely, Then if you would like you can take a can of tire foam and spray your entire engine bay for a shine! Make sure that your engine is cold and in the shade when you do this and try not to get any super clean on your paint but if you do just spray it off with water because it will strip the wax, Also when you first start your engine you may get a little belt squeak but do not worry it will go away when it dries! If your engine is really greasy and dirty you can use super clean full strength and repeat the process as many times as needed to remove all the grease! I have done this on my frontier and there is nothing that cannot get wet under the hood, Also do not use a pressure washer! If you reply with your email address I can send you pictures of my vehicles that I have done this too and I have never had an issue! Also unlike a lot of KZbinrs who pretend to be mechanics I am an actual Mechanic with over 23 years in a shop and I have owned my own shop for the last 6! Good luck and have fun

[@chicagoreviews7656]

Part number

[@autoxadvice4159]

Which part number do you need? The Z1 off-road part?

[@jimdodge5766]

Bottom line crappy design

[@autoxadvice4159]

It's not so much of a crappy coolant design as a lot of cars/trucks have a closed system. I think Nissan full labels needed about two inches higher on the reservoir. This way you would fill to mid marks like everyone has been taught to do with most fluid checks. When this system is working it will bake you out.