2009 HCH- Possible Internal Coolant Leak? - 8th Generation Honda Civic Forum

Go Back   8th Generation Honda Civic Forum > Model Specific Civic Information > Civic Hybrid

LinkBack Thread Tools Display Modes
Old 01-05-2015, 01:36 PM   #1 (permalink)
Junior Member
Join Date: Jan 2015
Posts: 1
808_guy just put it into 1st gear on 8thcivic
iTrader: 0 reviews
2009 HCH- Possible Internal Coolant Leak?

I have a 2009 Honda Civic Hybrid that I am working on for a family friend. Car has 49,000 miles. The car is well-maintained and not driven hard. He called me initially after the car would start, run rough, and die out within a minute. By the time I got there, the car started and ran fine. We laughed it off and went our separate ways.

Two days later (last night), I get another call. Engine is running weird, temperature gauge is pegged to the max, and there is no cabin heat. Also, engine smells of overheating. He was within a few hundred yards of home so finished the drive and parked it. Let it cool down and restarted it- he said that it would not idle, but if he gave it gas the engine would smooth out and rev up.

I finally got to look at it today. Checked all fluids and found the coolant tank empty. Began adding water, not realizing how much would be needed. I ended up adding just about a gallon of water to a 1.6 gallon cooling system. No coolant leaks noticed or observed. I asked if he had ever seen a puddle underneath the car, he said no, nothing of the sort.

Car started and ran fine. No DTCs set or stored. Drove around the block with no issues. Did not observe any coolant leaking. Parked it, let it sit for a bit, and it started back up just fine.

Also of note is that the engine oil was changed by the Honda dealer last week. They do a multi-point inspection as part of the service, and made no mention of low coolant (recorded on the inspection form).

I would be set that it is an internal coolant leak, but there are none of the classic indicators- no milky oil on dipstick or oil fill cap, no (abnormal) pressurization of the cooling system, no sweet smell or excessive steam out the exhaust. The only thing I think is happening is that the car starts and runs fine, but once stopped, whatever is leaking opens up due to heat expansion and then when the engine is restarted, that leak allows coolant into the cylinders, which causes the extremely rough running and inability to hold an idle. That's my theory, at least, which unfortunately leads to an engine tear-down on a car that is 4 months out of powertrain warranty.

Experienced automotive folks (and smart folks in general!), what do you think is wrong given the information provided?

808_guy is offline  
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the 8th Generation Honda Civic Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Coolant leak! ItsOnlyASingleCam Mechanical Problems & Technical Chat 13 07-31-2012 04:38 PM
Coolant leak forgot Mechanical Problems & Technical Chat 4 11-22-2011 01:45 PM
coolant leak ! nuclear Mechanical Problems & Technical Chat 8 09-28-2011 07:43 PM
Coolant Leak KT06SiGGM Mechanical Problems & Technical Chat 3 01-05-2011 06:14 PM
Coolant Leak untouchablesi Civic SI 1 10-06-2006 03:23 PM

All times are GMT -4. The time now is 03:09 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
copyright 8thcivic.com - all rights reserved