| darrylburke |
Problem:
I'm seeing heat from the MO but only when the RPM's are above 1000 rpm.. it does not depend on vehicle speed. When the heat drops of, it's a gradual drop and gradual increase.
I've seen something similar a long time ago when the dealer replaced the rad fluid, and there was an "air lock". I've checked the fluid under the cap and it's right at the top, however the fluid in the overflow is HIGH (and I noticed a very small amount around the cap of the overflow).
I'm going to try the AC diagnostics this aft, but are there other things that people would recommend to check???
Thanks.. |
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| Warhammer |
Are you referencing the water temp gauge on your gauge cluster? If so, then it could be a couple things.
Maybe your water pump? Maybe your thermostat is sticking? |
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| darrylburke |
the engine temp as reported on the dash was constant. its the temp of the air out of the vents that was changing.
with the scanguage the air temp of the intake was the same as well
the dealer is suggesting I check the concentration of the coolant (too strong can cause problems)
quote:
Originally posted by Warhammer
Are you referencing the water temp gauge on your gauge cluster? If so, then it could be a couple things.
Maybe your water pump? Maybe your thermostat is sticking?
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| Warhammer |
That makes sense. If the concentration of the coolant is too rich on the antifreeze side then the heat would not transfer as effectively to the heater coil. It's the water that transfers the heat...not the antifreeze.
On the other hand, maybe that also points to a restriction in the heater coil somewhere. If your engine water temperature is staying constant then that means the antifreeze/water mixture is doing its job.
It will be interesting to see what you find. |
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| darrylburke |
quote:
Originally posted by Warhammer
That makes sense. If the concentration of the coolant is too rich on the antifreeze side then the heat would not transfer as effectively to the heater coil. It's the water that transfers the heat...not the antifreeze.
It will be interesting to see what you find.
I had it in for the lube, oil, filter, and they did a quick check for me, and it's at -45, (they say it should be -40)
it's been about 13 months since the last flush. The service is recommended every 24 months..
can I just dilute it a bit ??? |
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| Warhammer |
That's what I do. Every time I flush any cooling system, I put in my own 50%/50% mix. Then I empty out and rinse out the overflow. If I notice the overall level of fluid start to drop, I put in some more water. I believe the overflow helps the water to evaporate over time since it's not a comletely sealed system. Adding some more water helps to balance out he system and keep it where you need.
It's always worked for me. I've never had an engine overheat due to bad fluid in the system. It's always been due to a stuck thermostat or a bad water pump. Just be sure to use distilled water when you top off your system. Not the stuff from your tap or hose.
But the diagnosis from the auto shop doesn't explain the characteristics of your heater issue. A misture being a few degrees off shouldn't cause those kind of symptoms. Maybe a full system flush will solve your problem. |
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| njjoe |
quote:
Originally posted by darrylburke
I had it in for the lube, oil, filter, and they did a quick check for me, and it's at -45, (they say it should be -40)
it's been about 13 months since the last flush. The service is recommended every 24 months..
can I just dilute it a bit ???
There is really no need to dilute it. The difference between -40 and -45 is insignificant.
If you have made no changes to the fluid in 13 months and the problem has only recently started then I would look elsewhere for the source.
-njjoe |
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| darrylburke |
quote:
But the diagnosis from the auto shop doesn't explain the characteristics of your heater issue. A misture being a few degrees off shouldn't cause those kind of symptoms. Maybe a full system flush will solve your problem. [/B]
that's what they suggested, I just wasn't sure I could get another 6+ months out of it with a little dilution.
It's getting cold up here, so I need the heat!!
Thanks for the help.. |
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| darrylburke |
quote:
Originally posted by njjoe
There is really no need to dilute it. The difference between -40 and -45 is insignificant.
If you have made no changes to the fluid in 13 months and the problem has only recently started then I would look elsewhere for the source.
-njjoe
I've gone through the manual diagnostics on the AC unit and everything checks out good..
The last things to check are
Hoses (Have to check, but no leaks are seen)
Coolant level (Good)
Rad Cap (Good)
Air in cooling system.
The next major step it says is to backflush the core. |
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| njjoe |
The MO has two seperate air flow paths for the HVAC system. One for the driver and the other for the passenger-side. Do a temperature check on both sides to determine if the problem is with one of the two air-mix doors. If the problem is only on one side then you can rule out the coolant circuit.
-njjoe |
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| darrylburke |
quote:
Originally posted by njjoe
The MO has two seperate air flow paths for the HVAC system.
checked that and it works fine in the Diag, as well as when I get cold air, it's on both sides. |
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| Gonzo |
| Sounds like a bad thermostat. |
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| darrylburke |
quote:
Originally posted by Gonzo
Sounds like a bad thermostat.
I'm not that familiar with how they work.. if it was the thermostat, would you also see a big change in engine coolant temperature ?? |
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| Warhammer |
| Yes you could. I don't think it's the thermostat because the water gauge on the cluster is constant. |
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| 3riverssouth |
I had a similar problem in another vehicle and it was the thermostat getting stuck open so there was no heat. Replaced and all worked well until I got rid of the vehicle.
I never noticed any other change (engine temp) just no heat and in the middle of Feb with lots of snow and not heat it was a bit cold. |
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| njjoe |
quote:
Originally posted by darrylburke
I've checked the fluid under the cap and it's right at the top, however the fluid in the overflow is HIGH (and I noticed a very small amount around the cap of the overflow).
Have you or anyone else added fluid to the coolant reservior recently? The reason I ask is because I know of only three ways for the tank to overflow - 1) too much fluid added, 2) overheated engine, and 3) a leaking head gasket forcing air into the system which displaces the coolant.
-njoe |
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| darrylburke |
quote:
just no heat and in the middle of Feb with lots of snow and not heat it was a bit cold.
That's not my problem though.. I get heat.. but only when the RPMS's are above 1000. on the highway it's fine and I don't even notice it.. but in stop and go traffic (or warming up in the driveway) I get no heat.. |
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| darrylburke |
quote:
Originally posted by njjoe
[B]
Have you or anyone else added fluid to the coolant reservior recently?
Nope.. I've never seen the heat get high on the dash..
leaking head gasket :O that does not sound good.. I'm going to lower the level a bit, and keep and eye on it just to make sure.. |
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| Eric L. |
| If the water temp guage reads normal, I doubt that it is a bad thermostat. I would suspect more of a stuck valve for the heater core, or that the system just needs to be bled. One way to do this is to run the heater on max, then max cold, then max hot again - this will cycle open and closed the heater valve, and maybe unstick it if that is the cause. Or at the very least it should push the air bubble out of your heater core. |
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| njjoe |
E-
I may be way off base on this one, but I do not think the MO has a valve controlling the water feed to the heater core. The water is always flowing through.
-njjoe |
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| darrylburke |
quote:
Originally posted by njjoe
E-
I may be way off base on this one, but I do not think the MO has a valve controlling the water feed to the heater core. The water is always flowing through.
-njjoe
I don't know.. speculating here.. but if they did.. would they not have it as part of the diagnostics test which test all the other motors in the AC System?? it seemed pretty comprehensive.. |
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| Eric L. |
| That might be possible, and if so, it is interesting that all there is is an air mix door which blocks air from passing through the heater core. |
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| matik |
Hi guys,
I just recently faced the same problem. Last days, get more cold in Poland, and when was going longer trip I've faced simmilar problem: while drinving on highway, the temperature in the car was ok (althought, in my opinion, fan was blowing at to high speed for all the time - my wife drives the car mostly, so I had a comparison with last time I've driven). But wen I went threw stop and go traffic in the city, suddenly I find out the temperature dropped down, and the air comming out of vents was cold!
Observations and what I did:
1. Operated manual, to see, is it because of wrong settings - no effect. While at stop, pushed air was cold.
2. Temp gauge is showing normal engine temp. in the middle of scale.
3. Checked coolant level, at this moment, coolant reservoir was FULL!!!, even some coolant went of out!!
4. Checked coolant level on cold engine - level is fine, as it suppose to be.
5. At the cool start (first in the morning for example), while slow driving on the whloes, Ive noticed some sound around shifting lever area, like leaking, like bubbels, like watter will tapp on smth. Later, while driving it is immpossible to hear.
6. Let the coolant inspected. Freezing temp is up to -38 C, was changed in 2005 (when I brought it from US), by a Nissan dealer in PL.
I went to my mechanician, and let him changed the coolant. Thought, there is some air bubbles in the system, and the coolant is not circulating. He said, that this is not this reason. In his opinion, the in cabin radiator (i do not know how to name it in en) is stucked (like aluminium is blocking some small pipes) and the coolant has no possibility to flow.
This will explain why with higher speed it will work: pump is doing much more pressure to the system, and SOMETHING is going threw the pipes. This will also explain why in the reservoir is so much coolant: the presure is to high on the system, and the coolant is pushed back to reservoir.
Now ... my other friend said, it might be some kind of valve or thermostate. I do not know what is better, since replacing this radiator in cabin, is a huge load of work, and I think the part itselfe is also extreamly expensive.
I'm very interesting on that, was the problem found at your machine, since I think this is smth. similar by me.
Now I will go to other mechanician, to check what he say. I think, I will let him change the coolant anyway, maybe if these are some air bubles inside, they will go away by this operation ;)
best regards
matik |
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| zebelkhan |
| I thought another member had the exact same problem and according to him, he had air trapped in his in cabin radiator (we call it heater core). He resolved it by flushing the coolant and that took care of it. |
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| matik |
Thanks for fast reply!
This is what I thought at the beggining, but ...
Some says, that in today's, cars this is immposible, since the installation is made to prevent this kind of situations (air bubles will remove by themselve).
From the other side, I can not also understand, why the level in reservoir is going till the end. If there will be some air trapped, it should not make any diff, or?
Anyway, I think I will let them change the coolant, it cost nothing (around 26$ including coolant), and maybe this will give some answers.
BTW, I read, that lot of you mix the coolant together with destiled watter ... why?
When I asked here in PL for watter and coolant, they openned their eyes, and asked me what for, since, there is no coolant on the marked, which are not mixt already ... they told me, I have to order it specially. I've asked also my other friend, and everybody said, they use collant-to-go.
Does the MO need smth. else? I've checked documentation, and besides temepratures, there is no additional information, what type of coolant should be used.
Best regards
Matik |
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| Eric L. |
The coolant is an electrolyte which raises the boiling point and lowers the freezing point of whatever medium it is mixed with - in this case, water. You can't run straight coolant, but some coolant is premixed with water. The general recommendation is 50% coolant and 50% water, assuming the coolant wasn't premixed.
quote:
Originally posted by matik
Thanks for fast reply!
This is what I thought at the beggining, but ...
Some says, that in today's, cars this is immposible, since the installation is made to prevent this kind of situations (air bubles will remove by themselve).
From the other side, I can not also understand, why the level in reservoir is going till the end. If there will be some air trapped, it should not make any diff, or?
Anyway, I think I will let them change the coolant, it cost nothing (around 26$ including coolant), and maybe this will give some answers.
BTW, I read, that lot of you mix the coolant together with destiled watter ... why?
When I asked here in PL for watter and coolant, they openned their eyes, and asked me what for, since, there is no coolant on the marked, which are not mixt already ... they told me, I have to order it specially. I've asked also my other friend, and everybody said, they use collant-to-go.
Does the MO need smth. else? I've checked documentation, and besides temepratures, there is no additional information, what type of coolant should be used.
Best regards
Matik
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| njjoe |
matik-
If your mechanic intends to use a commercially-bottled pre-mix coolant, then that is OK.
In the past the only coolant available in the US was 100% anti-freeze and it needed to be diluted 50% with water. Some people prefer to use distilled water because it will not cause corrosion in the radiator. However, most coolants include a corrosion inhibitor so regular water can be used.
-njjoe |
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| matik |
Ok, than everything seems to be fine.
I bought this coolant as one of the best on the marked.
Accoring to label, it says, that it contains this inhibitors, and it has not to be mixed, since it is already mixed. It says, that it has also a lot of stuff ( ;-) ) securing the aluminium from beeing utilized.
So I think, it should be fine. Since there is no 100% pure coolants on the marked, I will assume, they put it to every car ;)
Thanks!
Matik |
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