Picked up a 2000 civic yesterday. Dude said it drove fine and had no problems. I did a quick test drive and all seemed well. Driving home, I notice the temp gauge isn't moving. I was on the highway at night, not stop and go traffic, but it didn't seem to be pissing coolant or overheating(because highway probably)

Some basics...

I can jump the radiator fan, so it, the fuse and relay are fine.

Via some reading, I know of the coolant temp sensor near the distributor, and the one wire sensor next to it that feeds the gauge.

I let the car idle 5-6 minutes in the driveway. Both radiator hoses got hot to the touch, so I'll assume the thermostat is opening and functioning properly.

However, I didn't see the fans kick on. If the gauge isn't working, will that prevent the fans from kicking on? My thinking is the temp sensor measures the temp clearly. The fan sensor next to the thermostat, that feeds off the the temp sensor correct? So if the temp sensor is bad, not only will the gauge not read anything, but also the fan will never kick on. Correct?

 

The fan and the gauge are not interconnected. The radiator fan is controlled by the switch at the thermostat housing. The smaller fan on the left side of the car is dedicated to the A/C.

The only thing the one-wire sensor on the engine does is drive the gauge. Make sure the wire is secure. Resistance of the sensor should be about 90 ohms with the engine warmed up (and considerably more if it is cold). If you unplug the wire and ground it, the gauge should go all the way up to hot when you turn the key on.

 

Hmmm, ok. Maybe I didn't let the car run enough to kick on the fan then? Yeah, I know the drivers side fan is for the AC. I'm pretty good with cars, but civics are not my speciality.

I'll see if I can find some junk wire to ground the 1 wire and see if the gauge moves. I've read to not let it go up too high, so I'm already aware of that before someone replies saying to be careful.

 

Where was the needle when you were on the highway?

 

It didn't move. I thought I saw it come up a bit, but I may have been wrong. No matter what, it was never above the lowest mark, from my my prior civic, I know the gauge should read about half way up.

 

https://honda-tech.com/honda-civic-d.../#post39830585

 

I'm starting to think I got royally ****ed.

Here's the car running with the radiator cap off. I can't tell if that's bubbles or vibrations. Yes the rockers seem a little loud.


Here's the coolant. No it's not brown, it's green, the flash makes it look brown, but the flash also brings out the sparkle effect I could see.


I saw some coolant earlier, and dried it off. Now it's wet in these spots:

https://i.imgur.com/583fUCjl.jpg

and back here:

https://i.imgur.com/dJW8iX0l.jpg

He said it has a fresh oil change.

Pic: https://i.imgur.com/qGB2fWGl.jpg

 

anyone?

 

I saw no bubbles in the radiator coolant.

Check for a coolant leak from the ECT sensor, thermostat housing and radiator hose, and the heater hoses. Post pictures.

Upload your pictures directly to H-T. Here:

 

I'm simple thinking worst case scenario and that I was sold a lemon with a blown headgasket and the car is pushing coolant out the head while it runs. I hope I'm wrong, but with the temp gauge not working, and I'm not getting the fan to come on unless I jump it, and it's leaking coolant...

 

Locate the coolant leak. It may turn out to be something very simple.

 

I suggest you do a combustion test, compression test, and check for any coolant leaks.

 

So, I haven't touched the car in 2 days, and popped the hood to see this: https://i.imgur.com/4pLZMaL.jpg

So it's leaking oil, not coolant. He did mention he replaced the vtec solenoid gasket at one point. Looks like that is the leak I'm seeing then?

 

The site is having problems with imgur images. Please upload as I mentioned in post #9.

 

 

Check for an oil leak from the distributor and/or VTEC solenoid.

Some oil leaks from the VTEC solenoid require sealing both gaskets with HondaBond.

 

The back side is wet/dirty so something more central like the distributor might be a good call. Plus the coolant temp gauge isn't working, so perhaps oil soaked into the one wire piece making it go bad.

 

Do yourself a favor, brake cleaner. Start cleaning it up. You'll easily be able to spot where the oil is leaking from.

Back to the temp gauge, you need to test that sensor to confirm if you need to replace it or not.

 

More oil on the firewall side seems like a better fit with a leak from the VTEC solenoid rather than the distributor, though be sure to check both.

 

Good news everyone.

So my earlier posts may have been a jump to conclusion. I started the car with plans on letting it run till I heard coolant bubbling or the fan come on. 5-6 minutes, and the gauge was still at nothing. Then I thought I saw a slight bit of movement. I held the gas at 2K for about 2-3 minutes and sure enough I got the gauge to come up and the fan to kick on.

That still seems like a bit much, but maybe I'm just use to seeing the gauge come up quicker because I would jump in my old civic and take off. Then again, I swear it was begged at zero while driving this one home. Maybe the one wire was off, and since I've messed with it, it's now working?

Secondly, I cleaned up any oil residue I could wipe, and as already said started the car. wiping my fingers under the vtec solenoid, I was easily picking up fresh oil, so that is the leak. Now I know what to do.

 

Local dealer has the main gasket on hand, so I decided to yank the old one before going over. Come to find out whoever installed it used like a half tube of RTV. That **** was everywhere. No wonder it wasn't sealing. Since there's not THAT much work to remove the solenoid, I super cleaned both surfaces, gently removed all the RTV from the gasket itself and slapped it all back together. Worst case it still leaks. Best case, I fixed it for free.

 

If it still leaks, seal it with a small amount of HondaBond.