DIY: Thermostat Replacement DC2

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21-04-2005, 09:53 PM
mikes94

DIY: Thermostat Replacement DC2

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!

Opening remarks:
OK, a general writeup on this has been done before for civics and integras by another OH member. I've decided to do one specific to a DC2 Integra.

Aim: Replace faulty thermostat on DC2 Integra (Symptoms of this include the car taking a long time to heat up, temperature gauge falling during high speed driving, temperature gauge flucuating during normal driving)

Required:
Before you start make sure you have:

1. Replacement thermostat + rubber gasket
2. Replacement coolant
3. Pliers
4. 10mm ring spanner
5. 12mm ring spanner
6. Large flat-head screwdriver
7. Funnel
8. Patience and/or a colourful vocabulary

Step 1.
Park your car on a level surface. It’s also recommended you park somewhere you don’t mind coolant will spill.

Step 2.
Wait for your car to cool down completely unless you like 3rd degree burns.

Step 3 (optional).
Drain the coolant if you don’t want to lose 3 litres of coolant.
I didn’t do this so wont document the process.

Step 4.
Find the thermostat housing cover. The easiest way to do this is to follow the lower radiator hose from the radiator to the housing cover.

http://www.avalon.com.au/mikes_www/i.../Car%20060.jpg

Step 5.
Loosen the hose clamp (where the hose meets the housing cover) using pliers and pull it back.
Note the area around the housing is incredibly cramped. Unless your triple jointed and have very small hands I’d recommend removing the intake tube from the airbox and bending it out of the way (the tube not the airbox!).

http://www.avalon.com.au/mikes_www/i...mo/a%20020.jpg

Step 6.
Detach the hose from housing cover. You may need to break the seal the hose has with the fitting by gently prying the edge of it against the housing with a large flathead screwdriver. A good yank should then dislodge the hose from its fitting. Expect some leakage of coolant when the hose is removed.
Bend it out of the way to facilitate access to the thermostat housing cover.

http://www.avalon.com.au/mikes_www/i...mo/a%20005.jpg

Step 7 (This is the fun part).
Remove the housing cover bolts. There are two in total.
The first is visible in the photo below. The other is on the opposite side underneath (just visible).
I struggled and swore for ages with various socket wrenches and extenders trying to get these as they are in a very awkward position. In hind-site a simple 10mm ring spanner would have been much easier. I recommend this unless you are a masochist (ie. the same people that skipped step 2).

http://www.avalon.com.au/mikes_www/i.../a%20021_m.jpg

Step 8.
With the bolts removed (and stored in a safe place of course), remove the housing cover. If it doesn’t come off by hand force, then a gentle tap with a mallet should dislodge it. Again, expect some leakage of coolant when the housing is removed.
Move the housing cover gently to the side (as it is still attached to the coolant temperature sensor).

http://www.avalon.com.au/mikes_www/i...mo/a%20013.jpg

http://www.avalon.com.au/mikes_www/i...mo/a%20007.jpg

Step 9.
The exposed mechanism (see diagram above) is the thermostat. Remove this. It may require a little force to pop it out (I used a large screwdriver to knock it out).
If you are like me and were too lazy to drain the coolant … at this stage 3 litres or so of coolant will pour out of the hole where the thermostat was.

http://www.avalon.com.au/mikes_www/i...mo/a%20012.jpg

Step 10.
Remove all traces of gasket from the housing and cover.

Step 11.
Install the new rubber gasket on the new thermostat. Use the old thermostat as a guide if unsure.

http://www.avalon.com.au/mikes_www/i...mo/B%20009.jpg

http://www.avalon.com.au/mikes_www/i...mo/B%20006.jpg

Step 12.
Install the new thermostat in the housing the same way as the old one. The jiggle pin (the little pin thing that jiggles!!) on the thermostat should be at the top with the flat head facing out (and the spring mech. facing in). The housing is cast with notches that should orient the thermostat correctly.

http://www.avalon.com.au/mikes_www/i...mo/a%20018.jpg

Step 13.
Replace the housing cover and re-tighten the bolts.

Step 14.
Re-attach the hose to the housing cover and re-tighten the hose clamp using pliers.
Re-install/unbend/re-fix any other items now (eg. intake tube).

http://www.avalon.com.au/mikes_www/i...mo/a%20021.jpg

Step 15.
Loosen the air-bleed bolt on the engine with a 12mm spanner (do not remove it completely). This can easily be located by following the upper radiator hose to the engine. This will allow any air trapped in the system to escape during filling.

http://www.avalon.com.au/mikes_www/i...mo/a%20032.jpg

http://www.avalon.com.au/mikes_www/i...mo/a%20023.jpg

Step 16.
Move the heater controls to full heat (this opens the valve to the cooling system).

Step 17.
Remove the radiator cap and fill with coolant. A funnel is recommended here unless you played the stuntman in “Cocktail”.

Step 18.
When coolant flows freely from the bleed bolt, re-tighten it.
Continue to fill the radiator until full. Leave the cap off at this stage.

http://www.avalon.com.au/mikes_www/i...mo/a%20024.jpg

http://www.avalon.com.au/mikes_www/i...mo/a%20025.jpg

Step 19.
It’s a good idea to fill the coolant reservoir at this stage too. Fill to the MAX level marking (note this is NOT the maximum that the reservoir will hold).

http://www.avalon.com.au/mikes_www/i...mo/a%20026.jpg

Step 20.
Start and run the engine until the thermostat opens. A good guide to this is when the top radiator hose begins to get hot. This means coolant is flowing through the system. Shut off the engine.

Step 21.
Squeeze the upper radiator hose to expel any air from the system and top up the radiator with coolant. Replace the cap.

Step 22.
You are done!! Check for any leaks and run the engine to make sure it reaches normal operating temperature.

Now let’s hope we never need to do it again! :D
21-04-2005, 10:27 PM
wynode

Lots of pics but a few flaws

1. You need to run the car till the radiator fan comes on twice. Not just till 'top radiator hose begins to get hot'
2. You should drain your coolant before to stop it spilling all over the place.
3. Wash off any excess coolant with fresh water
4. Only fill up to MAX on the overflow bottle after the radiator fan has come on twice.

You might call it pedantic, but if you're doing something.........do it right the first time.

Apart from that nice work.
21-04-2005, 10:38 PM
kenshin

dunno if this is abit off topic...

but there seems to be a leak somewhere in my car cooling/radiator setup...

i top it up to the max level as indicated on the resevoir... a few days later it'll drop... i'll retop it up and a few days same thing happens...

doesnt seem to be leaking from the radiator itself... any ideas where i can be losing coolant?
21-04-2005, 11:00 PM
mikes94

Thanks for the feedback Wyn.
This was my first attempt ... someone here said I didnt need to drain the coolant and I could just top it up afterwards! I guess they were mistaken! If I did it again I probably would drain it first.

With regard to the radiator fan switching on twice ...the manual I use indicated nothing of this sort. But its's probably not a bad idea to be sure in anycase.

Mike
21-04-2005, 11:04 PM
wynode

You don't have to drain ALL your coolant. Just enough to stop it flowing out of the top radiator hose.

As for the radiator fan..........wait till it comes on twice. It's in the manual.
21-04-2005, 11:19 PM
mikes94

Quote:

Originally Posted by wynode

You don't have to drain ALL your coolant. Just enough to stop it flowing out of the top radiator hose.

I found that when the hose (lower radiator hose) is removed from the housing cover a small amount flows out (yes whatever is in left in the hose). When the thermostat is removed from the housing a large amount of coolant flows out. Based on the location of the thermostat (this may be different for other models) I would say that this is the coolant that is remaining in the block and yes the upper hose.

Quote:

Originally Posted by wynode

As for the radiator fan..........wait till it comes on twice. It's in the manual.

Not in my manual its not! I'm not saying your wrong Wyn.
22-04-2005, 08:29 AM
egSi

Quote:

Originally Posted by wynode

You might call it pedantic, but if you're doing something.........do it right the first time.

pedantic!! :D

nice write up man :thumbsup:
01-05-2005, 02:19 PM
ah8118

hmm might go a bit off the topic here, so delete if neccessary. but what does this thermostat do?? what are the gains (not power gains i know). lower temp in car?
01-05-2005, 03:36 PM
|N|

Quote:

Originally Posted by ah8118

hmm might go a bit off the topic here, so delete if neccessary. but what does this thermostat do?? what are the gains (not power gains i know). lower temp in car?

its not for any gain...

its abt fixin up a faulty part
09-05-2005, 10:07 AM
SPOOON

Quote:

Originally Posted by ah8118

hmm might go a bit off the topic here, so delete if neccessary. but what does this thermostat do?? what are the gains (not power gains i know). lower temp in car?

very helpful :D thanks for this,
jsut a question how much does a replacement thermostat from honda cost?

also i think ah8118 meant was what is the advantage of getting an aftermarket thermostat made by mugen over the standard honda one? correct me if i'm wrong.
thanks
09-05-2005, 10:20 AM
bennjamin

Quote:

Originally Posted by SPOOON

very helpful :D thanks for this,
jsut a question how much does a replacement thermostat from honda cost?

also i think ah8118 meant was what is the advantage of getting an aftermarket thermostat made by mugen over the standard honda one? correct me if i'm wrong.
thanks

A replacement thermostat from honda is ABOUT $40- $50 . Well spent for piece of mind.

The purpose of installing a lower temp thermo , is to circulate coolant into the radiator earlier ( thermostat opens up earlier to ciruclate coolant from the block into the radiator and back again etc. This helps with heat exchange , and increases resistence to overheating ( usefull on the track etc)
A Spoon thermo opens up at 65'c , where a normal B series thermostat opens at 88'c.
09-05-2005, 01:19 PM
SPOOON

Quote:

Originally Posted by bennjamin

A replacement thermostat from honda is ABOUT $40- $50 . Well spent for piece of mind.

The purpose of installing a lower temp thermo , is to circulate coolant into the radiator earlier ( thermostat opens up earlier to ciruclate coolant from the block into the radiator and back again etc. This helps with heat exchange , and increases resistence to overheating ( usefull on the track etc)
A Spoon thermo opens up at 65'c , where a normal B series thermostat opens at 88'c.

cool thanks for the info :)
very helpful
10-11-2008, 03:14 PM
tekung89

followed this to do mine today, i used a thermostat lying around from a d16y4 to my b18c teggy and it worked fine. also had to replace my rubber seal. total cost $3.50. drained my radiator fluids but still lost about 1 liter worth. trickey to get to but easily done, no leaks either

good stuff
07-07-2009, 04:47 PM
rookie_gsi_act

hey, did mine today. I turned on the engine after i did everything thermostat + coolant in the radiator, i left it on for 20+ mins and the fans didnt turn on. Does anybody know what the problem could be? the car heated up fine and i took it for a drive later on and the temp didnt go down like it used to before i replaced the thermostat. Could the fans not turning on be due to the fact that the weather is freezing cold now? any insight into this problem would be appreciated.
07-07-2009, 10:09 PM
vtesh

how about some sealant?
08-07-2009, 04:09 AM
rookie_gsi_act

i didnt apply any sealant as i was unsure of where it was required. I did pretty much all the steps in this diy. Anyway i have driven it about 3 times now after the thermostat change, the engine heats up to the 1/3 temp so much faster in about 5 minutes and its freezing cold outside so yeah thanks for the diy (rep up).... but yeah dunno what was going on with my fans

ps. i was charged $105 dollars !!!!!! for the thermostat + gasket + 4L coolant all from honda.
14-07-2009, 11:40 AM
buggo

Quote:

Originally Posted by rookie_gsi_act

hey, did mine today. I turned on the engine after i did everything thermostat + coolant in the radiator, i left it on for 20+ mins and the fans didnt turn on. Does anybody know what the problem could be? the car heated up fine and i took it for a drive later on and the temp didnt go down like it used to before i replaced the thermostat. Could the fans not turning on be due to the fact that the weather is freezing cold now? any insight into this problem would be appreciated.

Best thing to do while waiting for the fan to turn on in cold conditions is put the bonnet down so it will get hotter quicker.