Car is still running cool, but I checked the overflow tank this morning and it was low again (with engine hot) so I topped it off and will check it again in a few days.

Now I can't find that FAQ on overheating on this site (tried about 10 different searches and keep getting "no record found". Can anyone point me to thatFAQ thread?

I want to check this thing over to see why it seems to be loosing coolant. I do not see coolant anywhere around the car (external leak) and the oil looks fine (no coolant in oil) and I'm getting no white smoke from exhaust after initial warm-up. If I were checking for a head gasket don't I just warm it up to operating temp and look for bubbles in the overflow tank? Anything else I should check for?

Thanks again. Thing still runs like a top and drives fine, but this low coolant has me a little worried.......

 

Go to DIY section and page through them to find your FAQ. There's only a few pages to parse.

I had a leaking head gasket (HG) on my 94 EX that I replaced a year or so back. It would only leak a little water into the cylinder, mostly when stopped. On startup the engine would miss till water was blown away. I could not detect any steam. Coolant loss was small but steady. I tried to use radiator "stop leak" (small aluminum flakes), but this had no effect.

I would suggest trying a cold, pressurized leak test. You can borrow a leak tester from ORiellys, and likely other chain auto parts stores to perform this test. If no visual leaks, pull the spark plugs and look for water on the plugs. Water on plugs is definite HG.

good luck

 

Thanks for the tip. I am hoping it's not a head gasket, but we'll see. Thanks for the advice. I tried about 10 different searches today and got no responses on any of the searches.

 

Search engine is down. Find a post by Finch13 and use the google search he developed instead.

good luck

 

Well, the thing started going up on me last week when I was coming home from Columbia MO. The weird thing is, the gauge ACTS like it works (goes to its normal spot, then IF it decides to get hot, when I turn heat on full blast it goes down a bit, and if I coast to a stop it will move up, and when I start moving again/ rev the engine, it goes down), but the other day while driving the gauge had moved up to about 75% to hot, and then just cruising down the highway, it dropped down (sudden drop) to it's normal spot, stayed there for about 100 miles, then started easing up again.
This morning I drove about 250 miles with it doing fine, then it started creeping up. I stopped to check the level in the overflow (doesn't seem to be losing any coolant) and fiddled with the rad cap, and heard a whoosing sound as coolant was allowed to go into the overflow. I dove for about 45 min with it in the normal spot before it started easing up again. I thought it might be a bad cap (not allowing fluid to go in/out of overflow tank) so I replaced and still no change. This thing will run warm for an hour, then go to the normal spot for an hour, then run warm for another hour.
The good news is, I'm buying a family member's 94 accord to use for my traveling. The bad news is, I need to figure out what's wrong with the cooling system on this one before I can sell it.
Anyone have any ideas? I'm going to check the sending unit next (when I get home), but I'm not sure how to measure If gauge checks OK measure resistance of sensor relative to ground. Resistance at 133F= 142 ohms and at 185-212F = 49-32 ohms. Anywhere close to these values would probably be a good sensor that TexasHonda suggested. Can someone give me the "idiot with a voltmeter" lesson on checking the sensor?
Thanks for the help, this is driving me nuts.

 

Symptoms do suggest head gasket but could be slow loss of coolant from a small leak that is evaporating or dripping on exhaust pipe. A cold leak down test is best method to determine your problem. Based on what's happening (loss of coolant and intermittent overtemp condition), the coolant temp sensor is unlikely the source of your problem.

To check sensor, remove single wire connector to sensor and place VOMleads on sensor single contact and nearby ground point. Set ohms range to measure 0-200 ohms or as your VOM allows.

good luck

 

I've put 2K miles on the car in the last week and it's not loosing any coolant. I thought for awhile it was, but apparently the overflow tank was going down only after I opened up the system (replacing tstat and fan switch in tstat housing, each time removing tstat housing).

So not loosing coolant, and same symptoms today, so when I got home I decided since the Oreilly's rad I bought had a lifetime warranty that I would pull it and take it in to swap. When I took the top rad brackets off I saw a big pile of bugs and other junk between the condensor and the radiator. I sprayed all the junk off and cleaned both the rad and the condensor off well and we'll see how it goes the next few days.