I need some help trying to figure out what is going on with my car. Basically coolant is being pushed into the reservoir but not coming back out. I have replaced the radiator cap. This didn't seem to help. My next step is to change the thermostat.
Also, one very strange thing. I'll drive the car park it in the garage for a day or so and take the cap off, there is still pressure. What is going on? I am looking or anyone that has had a similar experience and what you did to fix it.
I haven’t had to add any coolant and the oil is in good shape as well.

 

does the car overheat?

 

Correct me if i'm wrong but the over flow tank would be a degass bottle. Therefore if it was filling up all the time and pressure was not being let off after such a period of time there would be something wrong with either the degass bottle or rad cap. Just trowin all that out there not sure.

 

I forgot to mention, the over flow tank I just replaced two weeks ago. I thought it was part of the problem. The car does not overheat on the temperature gauge.
The needle will move around in the normal range. Which is not normal for my car. Normally it goes straight to one point and stays.
My concern is the lack of coolant in the top of the radiator, the upper hose and the cylinder head, warping the head concern.

 

Is there any residue or corrosion either in the upper hose or radiator? If so, Have the system flushed really good and refill with 4 liters coolant, 1 liter water. Make sure the ventilation hole on the Resevoir bottle is not clogged, And double check to make sure your fans are still working when they are supposed too. The only reason why your reserve tank takes in any coolant is when the pressure in the radiator exceeds the Rad Cap Rating. And that only happens when it gets too hot. That is why there is a spring on the Rad Cap. As far as I know the Coolant never goes back into the Rad. from the reserve tank. I dont see how it could do so. You may have a bad Temp Sensor and that may be why your fans arent coming on to cool the system.

 

I had the same problem. I'm in the midst of replacing my whole cooling system with a new aluminum rad and a new slim fan. I already installed the new thermostat.
Like sweetsystem said try buying a new thermo fan switch. The part # is 37760-p00-004 I'll be buying one soon. A seller on Ebay has OEM ones for a good price.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sweetsystem &raquo;</TD></TR><TR><TD CLASS="quote">Is there any residue or corrosion either in the upper hose or radiator? If so, Have the system flushed really good and refill with 4 liters coolant, 1 liter water. Make sure the ventilation hole on the Resevoir bottle is not clogged, And double check to make sure your fans are still working when they are supposed too. The only reason why your reserve tank takes in any coolant is when the pressure in the radiator exceeds the Rad Cap Rating. And that only happens when it gets too hot. That is why there is a spring on the Rad Cap. As far as I know the Coolant never goes back into the Rad. from the reserve tank. I dont see how it could do so. You may have a bad Temp Sensor and that may be why your fans arent coming on to cool the system. </TD></TR></TABLE>


actually when the rad is low it creates a pressure difference and actually sucks the extra coolant from the reserve tank until the pressure difference is gone. It sucks and spits coolant back in forth in the reserve tank as the car goes from cold to hot and hot to cold everytime you drive it. Everything in a car is there for a reason.

 

I thought thats what the Reserve tank would do. Although I dont understand why there would ever be a Vacuum on the Radiator pressure that would be below Atmospheric pressure. Even if you froze the coolant I still dont see how it would vacuum the coolant back in. I thought the Reserve tank was designed to simply catch the toxic coolant when it overheats. After looking at the Rad Cap it looks like it would be a One Way Valve. Kinda like a Blow Off Valve only designed to let off PSI when it exceeds the desired holding pressure, but only as a one way valve. My reservoir tank has never emptied but im not always under my hood either. PV=NrT for whoever remembers Physics class.

 

I have the same problem it never gets past half way but i no it should be on high

 

So did you ever get the Coolant issure fixed?

What was the problem and how did you fix it?

 

My girlfriend's Accord Had the same prob. I would put coolant in the radiator because it was a little low and it would eventually end up in the resevior, making overflow after a while. After having the car for about 2 years I finally found out what was happening. A couple of days ago I took the resevior off to clean it a noticed there was something stuck inside it. I pulled it out and was the hose that connects to the cap (the black hose that goes from the bottom side of the resevior cap to the bottom of the resevior). I reconnected it and haven't had a problem since then. Without that hose there's absolutley no way for the coolant in the resevior to be recirculated back into the radiator, it will just keep accumulating until it overflows. Hope this helps.

 

I knew there was a reason for that hose in there!

 

I still haven't had the thermostat replaced yet. Next Friday. I am about 90% it is the thermo. My Del Sol's thermostat went bad at about the same mileage 120k, and the car was taking a bit longer to warm up than is normally does.

 

Update.
The shop that is trying to fix my car did a Leak-Down test, 6% on #1 and #2 12% on #3 and #4. Not to bad for pistons with 50,000miles on them. Also no luck on the root cause of my trouble. I give another updated when I get the car back later today.

Got the car back with a new thermostat in it. NO GOOD. Still has the same problem. Is there anyway possble to confirm that it is a head gasket issue without taking the head off? I guess I better start planning the work for the head.

Modified by OH_1fstgsr at 12:26 PM 1/26/2007


Modified by OH_1fstgsr at 2:49 PM 1/26/2007