Maximized Jiggs

iTrader: (1)

Whenever I have my AC on for a while and the car is stuck in traffic, it starts to overheat slowly. When I am cruising on the highway, the car resumes to normal operating temperature.

I tested the fans by putting the auto control on, both of the fans were working fine. There is no coolant leak, the coolant overfill reservoil was not boiling either. It was actually some what steady, shouldnt there be some coolant activity ?( like exchange of coolant from rad. to the reservoir or viceversa).

I felt the hoses around the rad. and they felt hot and not soft. There seems to be adequate pressure. Whenever I turn the AC off, the car magically resumes to normal temperature.

So this only happens when I am stuck in traffic and have had the ac on for more than 15 mins. Any idea what to do?

njmodi

iTrader: (4)

Try changing the radiator cap. I know it might sound silly, but I'm serious.

Oh ya - almost forgot- when you turn the AC on, do the fans turn on? They should be on while the AC is running.

Maximized Jiggs

iTrader: (1)

I will check the cap. Both of the fans do turn on.

Maximized Jiggs

iTrader: (1)

The check engine light came on and gave me the code 1005, pointing to the EGRC Solenoid valve. This cant be related can it?

FishyMan

well cel will tell u whast wrong. it may or may not be related.
fix teh CEL cuz its mostly important stuff. then do the overheat.

did u change thermo? bleed? have right ratio?

AllMaxxedOut

iTrader: (15)

Exhaust Gas Recirulation (EGR). Forgot what the C stands for though. I'm not sure how it's related to the overheating but you could have a bad coolant temp sensor. The EGR would cause poor idling and possible stalling. Of course that would set off the CEL also I believe. By the way, when is the last time that you had a coolant flush?

Maximized Jiggs

iTrader: (1)

I forgot to mention that I changed the engine coolant temp sensor 6 months ago. I also dont think its related to coolant because without the AC, the car never overheats and I can drive all day. It only happens with the AC.

Maximized Jiggs

iTrader: (1)

Buuuuuump.

zzx0281

I have a 98 SE that had the same problem you described. I had two well known shops diagnose the problem to the fans ( failed to believe the first shop) After the second shop checked all the fan relays and fan they said the problem was bad fans and that parts and labor would be $600 for a new fan assembly, however I was able to pickup a after market one for $170. After 3mo. I have yet to have my car run hot while sitting in traffic or when running the air condition. I did pay $25 and $40 for the diagnostic. Shop 2 said the fans were not turning efficiently in order to cool. When replacing the fans I did notice the original fans were more stiffer than the new ones.

Good Luck.

PAREDLINE

Get a colder temperature thermostat. Most open at 195. Get one that opens at 175 and your overheating woes will be over.

njmodi

iTrader: (4)

Your statement assumes that an engine with coolant running at 195degrees is overheating... which is not true.

PAREDLINE

no my statement doesnt assume anything. When a thermostat opens at 195 that means the fans have to bring the car down from 195+ degrees to whatever the temp they turn off is.

Its much easier to cool an engine at 175 degrees than it is 195.

have you ever worked on an engine?

njmodi

iTrader: (4)

1. Replacing the thermostat doesn't solve the root cause of the problem.
2. What is the normal operating temperature range for our engines?

PAREDLINE

Something else. With the engine on, the AC on, and the fans on put your hand near where the fans blow air. The air should be cool. Use your judgment. It should feel cooler than ambient air around the engine. If the air is not any cooler then your radiator is probably plugged.

I've never seen this on a maxima. A lot of chryslers. But the principal applies. You need to blow cool air from the radiator to the engine for the engine to cool.

So if the air is hot, look to see if the fins on your radiator and condensor are plugged. Consider changing your radiator too.

I think the thermostat trick will work

PAREDLINE

The root cause of the problem is this guys car is overheating in traffic with the AC on

Who gives a crap what the normal operating temperature is. As long as your car doesnt even come close to overheating and you get heat in the winter you're good.

Quite frankly, if you dont have any productive advice to give someone that's better than 'replace the radiator cap' I think you should think twice before you post.

You apparently have no idea what you are talking about. You post to analyze others thoughts with absolutely no clue.

Go to the library. Read up on how a car cools it's engine. Then come back and give some good advice.

This is why the old timers dont post on the org anymore.

I'm done with this thread too. If the poster needs advice just PM me.

You can analyze the properties of coolant and its reaction to hitting the rubber hoses and fins in the radiator all you want.

njmodi

iTrader: (4)

That is not the root cause, that is his problem. Maybe you need to read a little more carefully.

Now your expertise on engines is shining through there. The engine has been designed to operate best at certain temperatures. They didn't arbitrarily pick fans, radiators, thermostat ratings and cooling system designs out of a hat.

I'm the local .org shrink. You didn't get the memo apparently.

I'll get right on it.

ha ha - old timers... check our join dates.

I'll have to do it, since it sounds like finding the true root cause and fixing the real problem is beyond your skills. I don't consider masking the problem (by replacing the thermostat) an intelligent resolution to the OP's problem.

PAREDLINE

You're still an idiot

njmodi

iTrader: (4)

old-timers... I'm still laughing at that one.

kcryan

iTrader: (1)

I would say disreguard everything said by PAREDLINE-changing the thermostat is not the right answer, in 1960 it may have been but with our ECU it will cause poor gas mileage and other problems.

Also im not sure if i got this but according to Paredline, if the rad and evap core are working good then they blow cooler air than the surronding?

kcryan

iTrader: (1)

Could be EGR i guess t, erase the code and see if it comes back

njmodi

iTrader: (4)

kcryan - thank you for bringing some sanity back to this thread.

PAREDLINE

This is false. What do you think the computer does regarding engine temperature? It reads 2 levels. Cold Engine and not cold engine. A thermostat opening at 170 will still enable the engine to reach operating temp.


How do you think a radiator works? How would anything get cooler if Hot air is blown onto a hot engine. So yes the air coming from the radiator and CONDENSOR should be cooler than the ambient air around the engine. If its the same temperature then something is not getting cooled.


So now I ask what do you suggest this guy do? Since you don't propose any suggestions but you strike others down.

Nothing I suggest comes off the top of my head. I've been working on cars for a long time.

PAREDLINE

So Rmodi says change the radiator cap. Kcryan says the car is overheating because of the EGR.

Anyone suggest checking tire pressure? What about a Type R sticker on the hood. That'll make everything cool.

njmodi

iTrader: (4)

PAREDLINE - I don't doubt your ability to solve this heating problem, and I say that sincerely. The only part I contested was that you said replace the thermostat. This does not address the root cause - it works around it. That's all I said.

If you are really the expert you claim to be, why not suggest things that might be the root cause, rather than provide work arounds. If the root cause is something that is costly to fix, e.g. replace radiator or fan trays, then let the OP decide if he wants to do it right, or use the cheaper, (and perhaps equally effective) workaround.

I don't intend to get into a post-war with you. I'm here to learn and as eager as the OP to find out what is really going on with his Maxima.

Cheers.

kcryan

iTrader: (1)

I siggest he checks to see if the systems pressurized when it shuld be, id bet its a hose but a small one somewhere. however there are many possibilities.



And no it doesnt read 2 levels, if you hook up a good scan guage it will tell you exactly what the coolant temp is, so the ECU knows exactly what temp the engine is at, and this engine was designed to work optimally at a certain temp. I say fix it the right way.


If you feel the air coming from the fans, it has just been pulled through the evap core and then the radiator, it should be hot, it just passed over all of those fins full of hot fulid, it should be hot.

WhiteMax96

Common, stop the bull****ting time guys.

First, before changing anything do a good diagnostic.

I assume that the 2 fans goes on when you put A/C on.

Try to find an infrared thermometer ( the ones that you can point a surface and tell the temperature).

Put the A/C on, wait till the car reach it's normal temperature.

Mesure the temperature between the two principal prestone hoses, the upper one and the lower one, The temperature between the hoses should not have a difference bigger than 5 degres Faraneight approximately.

If you have a big difference between the two hoses, remove the radiator, and see if you can see the light through the rad everywhere. If not, he's clog and need to be clear with water or compressed air. Be carful.

At that time too, be sure the condenser is clean and you can see through it too. Use a light behind to see through.

If you can't have an infrared thermometer, the only way to see if the rad is clog is to remove it and see by yourself.

Good luck.

Maximized Jiggs

iTrader: (1)

Thanks for the suggestion guys. I havent had much time to tackle this problem. I dont know when my coolant was last flushed so some time this week I will get the cooling system flushed and have some one check the hoses as well.

Its weird that I can drive all day on a hot day with the AC off and it does not over heat. But once I am stuck in traffic and put the AC on, the gauge moves slowly towards the Hot and that scares the **** out of me.

skytzo

Thank you for getting this thread back on track. My '97 GLE just started this same exact problem this past weekend, only I didn't figure out the correlation between the AC being on and the overheating until today since it's been so hot and I've had it on pretty much constantly. My wife and I were coming back from a weekend trip on about a 2 hour drive when I noticed the temp guage shooting up as we were about 15 miles from home. I automatically assumed it was a bad thermostat, so I picked one up, rode my ZRX to work, then put the t-stat in the car after work yesterday. I ran the car for a good half hour or so afterwards and the temp stayed in the normal range. After I cleaned up I took a quick ride and again it stayed normal. So, today I took the car to work and about halfway to work I noticed the temp guage starting to creep up. At lunch time I had to go to the DMV to renew my license and it pegged the line right before the top H. I was baffled to say the least - I thought maybe it was the waterpump. I called an ex-mechanic friend of mine and he said to bring it up to his house after work.

On the way up to his house, the temp again pegged into the danger zone, so I did the old trick of turning up the heat full blast (really pleasant on a humid day in the 90's) and it came back down to normal. At this point I still didn't realize it was AC related. My bud checked things out and determined that the waterpump was operating fine - thank God, because I saw what it took to get that thing out when I consulted my Haynes manual....no thanks! He did spray out the front of the radiator and condensor with a hose and said a bunch of pollen looking crap came out, so that probably had something to do with it. Then we played with putting the AC on full blast while it was running then shutting it off and that's when we figured out that there was a link between the AC being on and the overheating. BTW, both radiator fans were fully functioning. We went out for an extended ride and sure enough, after a little while with the AC on, the temp needle started to creep up and when we shut it off, it would creep back down - and this is in regular driving, not stop and go conditions.

When we got back, he remembered he had a few cans of refrigerant that he recently picked up, so he freshened up the system. I don't know if that had any kind of effect or not, but we were able to let the car run with the AC on full blast set all the way down to 65 and it stayed in the normal zone for quite awhile, but eventually started to creep up again. At this point we were kind of stumped, so I went home. Halfway home I just left the AC off with the windows down and things were fine. Then I decided to try the AC again - it was ok for about 15 minutes, but sure enough, the temp rose yet again until I shut it off and blasted the heat for a few minutes.

So, what next? Could the radiator still be clogged up? Could the system use a really good flushing? I only drained the radiator when I changed the t-stat. Is there anything else I'm overlooking? I'd really like to be able to resolve this issue on my own without having to turn it over to a shop and getting raped.

kcryan

iTrader: (1)

Rad cap/ hoses, most likely some small hidden hose has a hole in it, also oboviously check the level

skytzo

There aren't any leaks anywhere and coolant levels all check out. I'll try replacing the cap - how expensive could that be? Anybody else wanna chime in on this issue?

PAREDLINE

The reason the temp gets hotter with the AC on is because of the condenser. Condensers (the radiator-like thing in front of your radiator) takes hot gas from the AC system, cools it, and turns it into liquid.

If everything is working properly, your radiator is able to accomodate for this extra heat radiated in front of it.

Skytzo, when you put the heat on (to facilitate engine cooling) is the AC on as well? When the car gets hot again try leaving the AC on but putting the temperature on full hot. See if the temp needle goes down.

The fact that your car cools very fast once you put coolant through the heater core (another mini radiator) makes me believe that you have a bad radiator.

As far as flushing your cooling system. That would be a good idea. There's a way I do it that leaves the engine off. This way cold water isnt being circulated through a hot engine. I just remove the thermostat. Put the housing back on. and pump water with a hose backwards through the engine. I pump water into the top radiator hose and it drains from the bottom radiator hose. This is the opposite of the way the car cools the engine so if there is a plug, its pushed out back where it came. Then I pump water through the radiator in the same manner. Opposite of normal flow.

My recommendation is to give the cooling system a flush using plain water. Remove the radiator. Clean the fins on both the radiator and condenser with compressed air or a strong spray of water. Sometimes gunk builds up between the condenser and radiator blocking the flow of cool air.

Make sure you bleed the system of air and use a good coolant. Look at the bottom of your radiator cap as well. If the gasket is cracked, brittle, or compressed, change the cap. Check the hoses and make sure there are no pinholes or cracks, of course.

Sorry for the long post. I feel like I have to defend everything I post now. This shouldnt take more than an hour. Let us know what you choose to do and if it worked.

kcryan

iTrader: (1)

Give that a try, just be careful on the rad. fins they bend easy

skytzo

My car has the automatic climate control, so there's no on/off for the AC, you control everything via what temperature you set it to. I just jacked the temp all the way to 85 - I have no idea if the AC compressor stays on when you do that, but I would assume that it doesn't. I talked to my mechanic buddy again and he thinks that I should take it somewhere to get a coolant system flush done because their equipment will be able to generate much more pressure than his garden hose - plus, they'll take care of the mess. I figure it's worth it to spend the $50 or whatever it is to make sure the system has been completely and thoroughly douched out. I'll see how it turns out and keep you guys posted. Thanks for all the suggestions.

wikidminds

what happens if u dont bleed the system after draining/filling the radiator with fresh coolant??

is it a must that u bleed da system or is it something u can skip?

alpicone

I also suggest checking the radiator cap. See if the rubber on it has some cracks. I have seen a few times when a car was overheating and the prob was the cap. $5 fix. Hope thats your prob.

kcryan

iTrader: (1)

Ok first, on the CC if its OFF or on Econ mode, the AC is off, if its on auto, the AC is on.

You dont want as much pressure as a graden hose, they make upwards of 50PSI which will pop your radiator wide open. a flush isnt a bad idea though

alpicone

If you have air in the system and you dont bleed it you WILL overheat. It is very easy to bleed the system so why skip it?

wikidminds

aight...so quick question....whats the process on bleeding the sytem out? is there a write up o nthis? how do i bleed the sytem?

im thinkin bout flushing my coolant this weekend and wud like to kno how to bleed it when im done, thanx a lot

sdoherty_tjm

another way to turn AC on is to turn on the defrost/defog thing. that turns ac on in most cars i know of, but not totally sure about a max, i dont have auto climate.

kcryan

iTrader: (1)

yea, defrost will set it to "auto" mode, so ac will be on