fyristus

So i've read tons of post on no heat issues but am unable to find my issue. I recently replaced everything over the summer to deal with the cooling system (radiatior, water pump, thermostat, radiator cap). I still kept getting air in the system because i could hear the swishing sound from inside the dash. Tried burping myself numerous times with no luck, it still blew bubbles out of the rad. I then brought it to a valvoline complete car center and they pressure tested the stystem and did a complete flush. Next day.. same issues. I then did a combustion test.. all clear. Now the winter is here and i need heat at idle. I havnt lost a drop of antifreeze in months.

What my car does it blow about a quart or so of antifreeze into the overflow tank and never takes it back into the radiator. So weekly i have been empting my overflow tank to the max level and it fills up my radiator to the top.. every time!! Why is this fluid not going back into the radiator?!?!?!

user name001

the best way to fill your cooling system is , when it is empty remove the coolant temp sensor COMPLETLEY, fill the rad until the coolant pours out ( or until its just about too)of the coolant temp sensor opening, re-install the temp sensor and top off, that way you have a place at the highest point of the engine for the air to escape while filling and it avoids having air pockets. id double check the rad cap and maybe redo the coolant fill, and with the swooshing sound, im thinking there is an issue with your heater core but could be wrong.

edit: just read your post again and saw that the shop did a flush and pressure test, i bet they did do the pressure test, but im betting they didnt check the rad cap. id honestly replace it again and go from there and buy OEM so you have the right PSI rating. also if you have a scanner, hook it up and watch the coolant temp during the warm up and make sure you dont have a faulty thermostat or installed backwords lol.

also, did you replace all of the components because of this specific issue?

DennisMik

iTrader: (2)

If this was not a problem before you did all the work this summer, then the replacement thermostat could be the problem. There are many threads about people who have used aftermarket thermostats and had problems. Was the thermostat installed backwards is a question that needs to be answered.

If your car is a 2000 or 2001, another possibility (rather remote) is the water control valve on the engine. The water control valve is a second thermostat located about 5 - 6 inches behind the ECTS. It controls coolant flow through the engine block. Not very much is known about this little experiment as Nissan dropped doing it.

Will

iTrader: (2)

Was the water pump and thermostat OEM? I would recommend always going OEM for engine parts because of specific specs and tolerances that aftermarket manufacturers don't always care about, so long as it drives revenue and meets approx specs (not good enough in newer cars these days that trigger fault codes readily).

I've never had a problem bleeding air from a 5th gen, only in my 3rd gen. I use a Lisle-brand spill-free funnel (http://www.amazon.com/Lisle-24610-Sp.../dp/B001A4EAV0), and it never fails me. When you're bleeding the air, the heat setting (i.e. the red zone) has to be on full as the engine idles and bubbles off the air. You might have to hold the revs around 2500 rpm in 30 second increments the odd time to speed up the process and promote coolant circulation until the cooling fans kick in, but I've never had a problem.

fyristus

Thanks for the recomendation of an OEM radiator cap.. I'm going to order one today and hopefully solves my issue.

What made me replace everything over the summer was it was overheating and stupid me bought an autozone t-stat. Drove it around and it still overheated. Said screw it and and changed the water pump (also autozone). Drove it a long distance and BOOM cracked my radiator. So i changed the radiator. Realized the t-stat wasnt opening up fully so i replaced it with OEM (its acutally cheaper) and i have not had any overheating issues since (even in 100 degree weather with A/C cranking).

@Dennis - Its an 02 so i do not have that sensor

@Will - I bought that funnel (its amazing) and it does me no good.. just bubbles after bubbles. I've tried at least 30 times (no lie). Did the whole lift the front end trick and everything.

After writing all this i realized that an OEM cap might not be my issue (going to get it anyway). I'm still getting constant bubbles while burping the system so there is always going to be air somehow getting in

user name001

let us know how it goes when the new rad cap is in.

fyristus

sorry for the late reply guys.. been pretty busy. So the new Nissan Rad cap is in and same ol issues

mjhuffer

I'm having a similar issue. After a radiator clamp failure, I limped my car home and replaced the clamp and burped my radiator with new fluid. Recently topped it off today and reburped again along with making sure the overfill reservoir is in between the max and min.

I know where the Coolant Temp Sensor is on the car but I have no idea where the thermostat is. Hopefully someone can help me with the answer to this.

I have no codes on my car at the moment.

Car blows luke warm air but will not get hot. My A/C is also messed up due to a leak somewhere in the system. My car maintains a good temperature and will not overheat.

I did not have this problem before my car went into limp mode and completely shut down a block a way from my house. My thought is a fried heater core or thermostat. I'm wondering what is the best way to test the heater system.

Here is the Service Manual for Insufficient Heating. I'm going to flush and refill the radiator according to the service manual. Do I absolutely have to use 50-50 or can I use straight radiator fluid? Do I really need to pull the engine block coolant plugs or can I simply drain it through the radiator? I'm thinking I need to do everything by the book. I'm also going to autozone and replacing the radiator cap and the coolant temperature sensor. Should only cost around $25.

https://www.dropbox.com/s/05pbel8pubw6q4d/HA.pdf
Page 208

mjhuffer

For some reason on my drive home my heat started working perfectly. I think that when my radiator drained, so did the fluid in the heater core. It took a little bit of time with the car running to get the hot fluid back into the heater core. Next step is fix my air conditioner.

fyristus

Just thought i'd bump this thread to see if anyone new has any input. Going on about 8 months with this issue with hardly any loss in coolant.

dwapenyi

iTrader: (3)

When you bleed the system is the car on flat ground? Try bleeding the car when its on an incline, like parked on a hill going up. This way your radiator is the highest point of the car and any bubbles will rush to the radiator due to gravity. Also, exercise extreme patience when bleeding, like at least an hour. This will give time for the car to not only warm up, but also get the tstat to fully open. While bleeding, rev the car every once in a while to like 2500 rpms.

Hope this helps.

DennisMik

iTrader: (2)

What do you mean by "hardly any loss"? You should have no loss. Losing coolant means you have a leak. You either need to explain this better or check for leaks better.

But losing coolant would mean an overheating problem, so if you are not getting enough heat, then the bleeding air out of the cooling system is step one.

fyristus

@dwapenyi - I've tried every way possible with no success

@DennisMik - I say "hardly any loss" because after 8 months of transferring fluid from the overflow tank to the radiator you tend to lose some fluid.

dwapenyi

iTrader: (3)

your Tstat is now OEM
Your rad-cp is now OEM
Was the water pump OEM?

noahrexion

First you should test the thermostat to make sure it is functioning fine (let alone installed correctly).

Then you may have to consider a slight head gasket leak - it is very possible that you gave yourself problems last summer when you let it overheat. This could be pressurizing your system and causing the spew into your overflow.

DennisMik

iTrader: (2)

I am concerned that when you burp the radiator you say that it keeps bubbling and bubbling. That is not right or normal. I would get a cooling system pressure test done on the car by a mechanic, not an oil change place. Oil change places are notorious for not doing things that they claim to have done.

fyristus

Hey guys going to bump this thread again. So same issue. This time i got around to doing a compression test of my cylinders. All around 120-125. So no head gasket leak like the dealer said it was. This is so confusing and frustrating. Car still runs strong and great with still no antifreeze loss.

Quickywd01

iTrader: (16)

Start posting videos and pictures because something ain't right.

dwapenyi

iTrader: (3)

When u replaced stuff, did you replace the hoses too?
Also, did you clean the hoses connections properly? I had an altima once which had ALOT of flaky white powder where the hoses mount to the radiator. My hose connection wasn't tight due to it and sometimes air got in.

A very good scrubbing off of all that flaky white powder and replacement of the old hoses, as well as tightening the clamps REAL tight fixed everything.

fyristus

All hoses have been replaced except the 2 heater core hoses and the overflow tank hose. All new clamps on the hoses also. I actually just ordered a new overflow tank and hose. Figured why not since everything else has been changed

fyristus

Also good call with cleaning the hose connections. I will tear them all apart this weekend and scrub them.

fyristus

Well cleaning all the connections did me no help or replacing the reservoir tank. Also did a new cooling system pressure test.. no leaks at all. Stayed at 13psi for an hour straight. The only other thing that I guess i can try is replacing the autozone waterpump with a OEM. Would an after market pump cause my issue though?

DennisMik

iTrader: (2)

Does your overflow tank still fill up and not get sucked back into the engine? The coolant gets sucked back into the engine by the vacuum created in the cooling system when the coolant cools down and shrinks in size.

This would happen if the radiator cap was messed up, but you have replaced it. If the cap were bad, there would be a vacuum in the radiator that you would probably hear when you took the cap off.

Another way for that to happen is that there is an air leak into the cooling system. If the radiator or hoses were to be letting air in, it would also leak coolant when the engine was hot. At least I would think so.

But there is one hose that could allow an air leak during cooling off and not leak coolant when the engine was hot. The hose between the radiator filler neck and the overflow tank. Check that this hose is not drying out and becoming brittle, that it has no holes or cracks and that it fits tightly on the radiator neck.

dwapenyi

iTrader: (3)

This would explain the coolant not draining back into the radiator, but would not explain the no heat issue. Besides, he just replaced the tank and hose you are talking about.

It must be the autozone water pump then.


Fyristus, does the autozone pump look different, ie smaller, than OEM? Also, before you replaced the water pump, was the heater acting strange? If not, then it must be the pump. Replace it. With some aftermarket parts, you just never know. For example, the aftermarket thermostats for our cars look considerably smaller and less sophisticated than the OEM one, so I definitely stick with OEM on that regard.


Good luck.

FanaticalKilla

I seriously can't see the water pump causing you grief. Are you water lines the same temperature in and out of the heater core? Are the doors opening properly for the heater assembly? Are you sure the heater isn't just air locked? Any access to a vacuum filler? They work great and you would be able to find where it could be sucking in air.

fyristus

Thanks for all the responses and input as this is driving me crazy

@Dennis - that is correct fluid fills into my overflow tank but doesn't flow back into the radiator. I may have forgot to mention that this ONLY happens when i take the highway. I can drive city miles for days and not have this issue. Its only at HIGH RPM's were this happens. Once i take it on the highway and notice my overflow tank has 2 much fluid you can hear and feel the suction of the radiator cap as you take it off. Yes its a new OEM cap and new overflow tank with new hose that leads to the filler neck.

@dwapeny - from what i remember the autozone waterpump didnt seem different in size or anything. and yes i found out about the autozone thermostat the hard way.

@Fanatical - I don't think its the waterpump either but i am literally running out of options. I dont have heat because i am getting air in the system somehow. I get heat after about 1500 RPMS, its not a no heat at all situation. both heater core lines feel the same temp. No i've never heard of a vacuum filler.

ac max 92

iTrader: (13)

Was the thermostat installed or lined up correctly? Sounds like it may not be lined up or is stuck which may explain all that coolant filling the resevoir.

dwapenyi

iTrader: (3)

I bet it's the Duralast waterpump.
You say that this issue happens only after highspeed operation.
You say that when this happens, you bleed the system and air does blurp out. Every time.

I believe this is whats happening:

The duralast pump has a blade shape that is not quite as smooth as oem (compare PICs below.)
During high speed operation, this imperfect wave shape in the pump is churning the coolant so much that is separating the oxygen from the liquid. Air pockets are created. Like with boat motors, the impeller blade can only spin so fast, any faster and the motor essentially becomes a blender, instead of pushing water they're churning the oxygen out.

I couldn't quite think of the name, but the internets has been good to me....the process is called cavitation;

http://en.wikipedia.org/wiki/Cavitation
Now, these air pockets are created deep down at the bottom of your car motor by the water pump and they cant get out unless you give the car a proper bleeding.

Because of that air pocket deep down in the motor, coolant pressure, and flow, are disturbed, hence no heat.

Solution? Say it with me now....OH-EEE-EMMM, OH-EEE-EMMM, OEM

Change the water pump.

Of course, my theory gets totally blown out the water (DO NOT EXCUSE THE PUN!!) if you were having this problem before you changed the water pump, but I can't tell from the way you worded your first post that started this thread.

Anyway, hope this helps.

Autozone Duralast waterpump;


Remanufactured valucraft (assuming from OEM parts) waterpump;

fyristus

My god dwapenyi you just might of solved the mystery. I am unable to tackle it this weekend but i should have time the following to test this theory of Cavitation and Duralast water pumps. No I did not have this problem with the pump prior to it dying on me. Now i just need to find a great deal on an OEM pump.

dwapenyi

iTrader: (3)

Crossing fingers. Let us know how it turns out.

fyristus

If it does work i'll need your Paypal account to buy you a beer

The_Fixer

iTrader: (1)

I just think its not bleed correctly.put car on ramps or stands take cap off let motor run about 30 minutes the go out rev engine turn heat on full let sit 30 minutes running again.top off then test.

dwapenyi

iTrader: (3)

No worries, man. Just glad to be of help.

fyristus

Well the new water pump was not the magical fix. So now I have new OEM Water pump, thermostat, radiator cap, all new hoses, new overflow tank. Still same issues. I'm beginning to loose hope.

dwapenyi

iTrader: (3)

Really??

njmaxseltd

iTrader: (19)

I'm going back to the start of this thread, it contains the clue everybody seems to be missing.

The cooling system becomes pressurized as it heats up. To compensate for the expansion, coolant is allowed to bypass the radiator cap and flow into the reserve tank. When things cool down the system will go under a vacuum state and the radiator cap will allow a draw from the reserve tank back into the cooling system.

The dealer told you that you've got a blown head gasket and I 100% agree.
Your compression test and cooling system pressure test isn't seeing this. Why? Because the leak is so small that it's only pushing a slight bit of combustion gas into the cooling system path after combustion has happened in the cylinder. 120 PSI is nothing compared to what the PSI is while your driving, under load. That's when you've got combustion gasses entering the cooling system, driving coolant out and replacing it with air. It's not really air, it's combustion gas.

Your dealer probably used an analyzer to detect the presents of combustion gasses in your cooling system. That's the constant gurgling and bubbles you're getting over and over again no matter how many times you bleed them out.

My guess is the leak is so small, that even at idle the gasses are not getting past the gasket. But when you put a load on the engine, compression goes way up, that's when the combustion gasses are getting into the cooling system.

You have a very minor leak in your head gasket or maybe a defect in the head.

fyristus

I'd like to think your wrong njmaxseltd, but it seems to be the only logical explanation now that everything has been replaced