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Honda accord 2.4 engine thermostat replacment

09-24-2007, 10:22 AM
Hi.The "check engine" light on my 05,2.4 Accord came on,so I took the car to Honda to have it checked .The reply was that the engine thermostat needed replacing(at a cost of $170.00 plus tax!!!:screwy:).I'm hoping I can replace it myself,but I took a look at the motor,and I'm not sure were the thermostat is.Looks like it might be at the end of the lower rad hose.Any one help? Thanks.

09-24-2007, 11:17 AM
Most if not all thermostats are located at the point where the top hose connects to the engine from the radiator. You remove the hose, then remove the hose adapter. The thermostat is between the adapter and the engine.

09-24-2007, 01:24 PM
on my accord the thermo is located on the lower hose and mines a 93 just look for the thermostat housing its round because i was a dork and pulled the top hose and it was just a water outlet and square no thermostat so just use common sense and save yourself alot of money but remember maybe its not that themostat that costs money it could be the new special honda antifreeze that they are charging you and if you want a second opinion then go to auto zone and ask them for the loan a tool obd2 scanner and hook it up to your car and find out for yourself

09-24-2007, 03:14 PM
Thermostat or temperature switch...?

The PCM doesn't have a code that indicates anything about the thermostat, just the engine temperature and temperature switch readings, and there could be as many as three engine temp switches.

Did it heat up as indicated on the gauge? If not, the thermostat is not going to solve anything. What was the actual OBD code?

You probably have a coolant temp switch for the guage, one for the PCM, and one for the fan relay, possibly one cylinder head temp switch...two functions may be combined into one switch, but you'll have at least two, I'm sure..

09-28-2007, 06:06 AM
Hi.Thanks for the help.I'll go back to the dealer today,and talk to the mechanic to see how he/she came up with the idea the thermostat was shot. I had a 95 civic,took it to Kitchener Honda(I thought the head gasket was gone,as the overflow bottle kept filling up),was told by them that it was the thermostat,changed thermostat,no change.Turns out it was the head gasket.This is why I'm doubting it's the thermostat on the Accord.(it wasn't the same dealer that looked at the Accord).
Thank's again for your advice...Larry.

09-28-2007, 08:52 AM
PS if the motor runs too cool due to a thermostat stuck open it will code because the emissions control system needs to see correct operating temp before various parts start working knows if the car has been run for long enough to be at full operating temp, if it still sees a cold coolant reading it forces it to run rich, which upsets the emissions system and triggers codes...

So if it was something like that I could see where they might draw the conclusion that the thermostat was bad....but again you would probably have noticed something odd with the temp gauge, and you'd definitely notice the lack of heat when it gets colder as we go into winter.

10-11-2007, 03:39 AM
Well,I went back to the dealer,spoke to the mechanic,and was told that there are two sensors between the thermostat,and this is what gave the error code.
I bought a new thermostat and put it in myself.It's a pretty easy job,as it is at the end of the lower rad hose,going into the block.
Thanks for the help.

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