I have 92 Civic DX, 166K miles. In august I replaced the radiator with a new one from Autozone, but had to top off the coolign system with Prestone b/c Honda Genunine (Green) was no longer avalible (dealership switched to Blue). After I got everything bleed and what not I initally had two problems; 1) My fan barely came on 2) My hoses felt like they were under enormus pressure. I tried bleeding it two more times the best I could but didn't help.

This past November my top radiator hose gave way, developed a small rip while on the highway. Since then I replaced the hose, and radiator cap (as a suggestion).

What would you do now? I have not noticed any oil or combustion products in my coolant nor vice-versa. Car does not overheat, always gets to running temp and stays there, does not take too long to warm up.

It was suggested to me that I have have the sytem flushed, new thermostat installed, new lower radiator hose, and then I'd guess refill it the new (Blue) Honda Genuine Coolant.

What would you do?

 

Well if your honda place knew what the hell was going on you can mix the new blue and your old green.

 

I've mixed Honda blue and green and didn't notice any ill effects. It wasn't in there long though, I flushed it out and went all blue.

I would never use anything but, honda coolant though.

I'd do a drain, including the plug on the block and simply fill it back up with blue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paprika &raquo;</TD></TR><TR><TD CLASS="quote">
It was suggested to me that I have have the sytem flushed, new thermostat installed, new lower radiator hose, and then I'd guess refill it the new (Blue) Honda Genuine Coolant.

What would you do?</TD></TR></TABLE>

That would be best. Building pressure in the top hose is usually a problem with the thermostat. Repalce with a honda thermostat and refill with any coolant. Honda is good stuff but not anything special if you would rather use another brand.

 

um..yeah.
i've never heard people discussing the color of their coolant like it made a difference.

just don't dump dexcool in it

 

Yeah I thought that the blue coolant was really different so I didn't mix it, but then used instead some of the Prestone that said it could be added to "Any color coolant"... so it seemed like the perfect choice for my situation.

I want this fixed by the time I go back to school in a week, and with christmas around the conerer I dunno if I can get a genuine Honda thermo by then unless the local dealership happens to have one on hand..

What about Autozone's Duralast Low Temp Thermostat?

Also just not note incase I didn't make it clear earlier, both the upper and lower hoses are experiancing this excessive pressure, not just the upper one; incase it makes a difference as far as if there is a problem with the thermostat.

Thanks for your replies

 

Excessive pressure is really one of two things, blown HG or a bad radiator cap. That cap controls how much pressure is in the cooling system. Sometimes with a blown HG, there seems to be so much pressure the cap can't keep up. Another sign of a blown HG is that the coolant tanks bubbles or "boils" after a drive.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MasterKwan &raquo;</TD></TR><TR><TD CLASS="quote">Excessive pressure is really one of two things, blown HG or a bad radiator cap. That cap controls how much pressure is in the cooling system. Sometimes with a blown HG, there seems to be so much pressure the cap can't keep up. Another sign of a blown HG is that the coolant tanks bubbles or "boils" after a drive. </TD></TR></TABLE>
Strange how the blown HG shows up AFTER i change a radiator...
And I replaced the radiator cap already... no bubbles in my coolant tanks/resivour...

I hope its not a blown HG. If the head has to get pulled I might as well do an whole onslaught of other junk too :-p

 

Imagine the cooling system. It's a closed loop, like an AC system. There's only one openning which is the cap. If you have pressure build up on on both hoses (which might be normal) then you have to look at the pressure relief valve, which is the cap.

I bought an upgraded radiator for my EK, the cap that came with it was 5 PSI higher then the factory honda one. I still have to run the heater on hot days when I'm, lapping the race track.

 

Yeah with that thinking you'd think it was the cap to blame, but as I understand it, the cap also allows coolant to be sucked back into the system, right? When does this happen?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paprika &raquo;</TD></TR><TR><TD CLASS="quote">Yeah with that thinking you'd think it was the cap to blame, but as I understand it, the cap also allows coolant to be sucked back into the system, right? When does this happen?</TD></TR></TABLE>
Only when the engine is cooling down and the pressure in the system drops.

I'm guessing that you have an incorrect aftermarket radiator cap on there causing the excessively high pressure.

Edit: The correct rad cap should open at 0.95-1.25 kg/cm (13.5-17.8psi). Does your cap list the pressure on its label? You may want to have it pressure tested, or just pull an OE cap from a junk Civic somewhere.

If you don't have an OE Honda thermostat, you may want to test that out too. The themo should start opening around 172*F (plus or minus 4 degrees) and be fully open (8mm) by 194*F.



Modified by Targa250R at 7:18 AM 12/24/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">
Only when the engine is cooling down and the pressure in the system drops.

I'm guessing that you have an incorrect aftermarket radiator cap on there causing the excessively high pressure.

Edit: The correct rad cap should open at 0.95-1.25 kg/cm (13.5-17.8psi). Does your cap list the pressure on its label? You may want to have it pressure tested, or just pull an OE cap from a junk Civic somewhere.

If you don't have an OE Honda thermostat, you may want to test that out too. The themo should start opening around 172*F (plus or minus 4 degrees) and be fully open (8mm) by 194*F.

Modified by Targa250R at 7:18 AM 12/24/2006</TD></TR></TABLE>

I had the OE Nippon Denso Cap on there when the problem started, and then got a new cap from Autozone (CTS Inc), problem existed with both caps.

 

ttt
should i get a professional system flush?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ReDemoN &raquo;</TD></TR><TR><TD CLASS="quote">Well if your honda place knew what the hell was going on you can mix the new blue and your old green.
</TD></TR></TABLE>

Ya I kno, I called again today to get the price of the Blue coolant and dude made sure he told me I couldn't mix it with the old green before he'd even tell me the price