Losing coolant

Tiny
PMP
  • MEMBER
  • 1998 HONDA CIVIC
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 151,000 MILES
Hi I brang my car to the shop and they pressure tested it and found no leaks under 15lbs of pressure and ran a leak down test and said everything is good. Today I drove about 25 miles and before I left my house the radiator was full on cold engine and after the 25instrument miles the Guage went up a little then went down and I opened the radiator and sure enough it was low again. It doesn't overheat and there no coolant in my oil and no oil in coolant and no white smoke. Where could my coolant be going? Im bringing it back to the shop again tomorrow. Ty
Monday, December 12th, 2011 AT 12:46 AM

34 Replies

Tiny
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Are the floorboards wet? It HAS to be leaking somewhere. Tell them they need to test is to 17PSI with the engine at operating temperature.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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The floorboard is dry ill check it again tonight
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Ok. Let us know what you find out.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Ok, the floorboard is totally dry. I even used a flashlight and checked everywhere underneth the dash for any drips and saw nothing. I waited till the car was warm and filled the radiator up again right to the top and stood there and watched it get lower and lower. Earlier in the day when I did the 25 mile drive some coolant spilled out of the radiator because I had the car running and letting air bubbles out of the cooling system. I drove 25 miles home when I checked this. There was what looked like a leak on the bottom cornor of the radiator with a little coolant on the ground. Now im starting to wonder if its the radiator?
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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That's what it sounds like. The pressure test will tell for sure.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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K the shop called me today its gonna be 270 and hes getting all the parts from honda.

Upper radiator hose.
Some piece on the black that connects to the upper radiator hose. What is this piece called?
Heater control valve
heater control valve hose
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Upper radiator hose to block is most likely the thermostat housing. All of these items are things you can do yourself, and save a significant amount of money. The hoses and control valve are 2 clamps each; the valve is secured to the bulkhead by 2 bolts. The thermostat housing is secured to the engine by 2 bolts also. Remove those 2 bolts and pull the housing off the engine. Clean both sides with a wire brush or scraper, use gasket sealant on both sides, replace the thermostat, and reinstall the bolts. Make sure you pay attention to thermostat orientation. A $20 investment in a Haynes or Chiltons manual (from a store like Pep Boys, Advanced, or Autozone) will give you detailed instructions with pictures.
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-1
Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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I got the car back today and everything is good except for one more problem now. The coolant is leaking from under the cap. I replaced the cap about 2 months ago from one from auto zone. When I put my ear next to the cap I hear a sizzling and air sound. How can the cap just start leaking? What do I do now
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Let it cool. Remove it. And see if there is any grit or foreign objects on the radiator filler neck, or on or under the gasket on the cap. If these are all clean, check to see if the cap or filler neck is dented.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Well it cant be dented its a plastic radiator. The cap looks the same as it did before. I drove it to advance auto earlier and opened the hood 5-10 mins later and I opened the cap and it had no pressure in it.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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How long of a drive was it to Advanced?
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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I drove for about 10-15 minutes
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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That isn't long enough to build up much pressure. Advanced ought to be able to pressure test the cap for you. The radiator filler neck may not be able to be dented, but plastic can be chipped or gouged.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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The radiator looked good to me but is it possible they damaged the filler neck just by pressure testing?
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Will they be able to fix this
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Not if they knew what they were doing. If the mating surface is damaged, you should be able to use a very fine sandpaper to smooth it out. If the neck is cracked, a good waterproof epoxy will patch it.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Well I went back on the highway today and drove 25 miles and I got off and it did the same thing again. And I checked the radiator and it was really low this time. It was good all week. Im bringing it back to the shop tomorrow. Im sick of this ****box already im ready to dump it. Every week its in the shop. What do I do now
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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If you have the time, stand by your car as they are looking at it and working on it. Check the gasket on the cap. Make sure there are no rips or tears in it. Again. Is it a pressure vent release safety cap or no? Also, make sure it's the right size. Not oversize.
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Its a brand new cap and the right cap and there is no safety thing. On. It
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Thursday, January 28th, 2021 AT 9:34 AM
Tiny
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Hmmm. Have you had it pressure tested yet? The cap? And the cap is where you believe the leak is coming from, right? Might it be the filler neck?
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Thursday, January 28th, 2021 AT 9:34 AM

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