I bought this car 6 months ago and was noticing in the hot South Florida summer, that the car would run hot (3/4 up the gauge) after driving with the AC on for about 10 miles of street traffic.

Having owned used cars before - my first instinct is to turn off the AC, crank up the heat to max and let the heater blower act as a temp radiator to keep the car from overheating. When I did- the temp would drop to normal (about 1/3 up the gauge). Fortunately, this would happen when I was blocks from where I was going, so I was able to shut the car off and let it cool.

When this happened, I noticed that the coolant was bubbling into the reservoir. About once a week, I would check the coolant level. I would have to fill it up about every 2-3 weeks.

Summer passed and the cooler weather came in. I didn't have this issue for a while until this morning.

Let me preface this by stating that I replaced the radiator cap last night. The old one was a little worn and I figured a tighter seal might make the cooling system operate better.

I noticed this morning, at the same area I was getting this before- my temp gauge started creeping towards the mid-range. As I am sitting in traffic, the gauge starts to jump up in the high area and I immediately dumped the AC and maxed the heat. However, this time- the temp remained high (never made it to red, though- just underneath). I thought that once I go the car moving that the gauge would drop (usually does), but it didn't. Again, I was only a couple of blocks from my office- so I had one eye on the road and the other on the gauge.

I made it to the parking garage and took a look under the hood. Car has 2 fans, but only one has been working since I bought this. The "operational" fan was on and I could feel that upper rad hose was hot. I couldn't get to the lower hose to check the temp. I could smell coolant, but it was not bubbling into the reservoir like it usually does.

I know to check all the usual suspects- stuck thermostat, faulty fan switches/relays, bad water pump, air lock in the system. Just don't have all day to cycle through the possibilities. Anyone able to narrow this down, or have a similar issue and guide me where to go?

Thanks.

 

4 cyl or 6?

Thermostat, cheap start IMO.

Check coolant level, bleed while there. Start car and turn ac on, do BOTH fans come on?

On the 4cyl, thermo a is on the t-stat housing where the lower hose connects-pull the green connector, jump the two wires together (paperclip or something), turn the key to on, do BOTH fans come on?

 

To follow up on Poorman's suggestions, when the engine is cold, remove the radiator cap and fill the radiator with fluid.

You can rent a pressure tester for the radiator for free from some parts stores. Call ahead to see if they have them as a loaner tool. Your radiator should hold around 16 psi.

Let us know about the V6 or I4 engine. Which fan is not working, the passenger or driver's side?

Inspect the fins of the radiator for deterioration and/or debris.

 

This is a 4cyl.

At lunch yesterday- I took it out to get coolant when I noticed that the temp spiked after 5 minutes. I happened to be next to a Walgreens, so I went there and got a gallon of Pennzoil 50/50,

Filled the radiator and the reservoir and bled the system. I noticed a leak coming from the area where the lower hose connects to the engine. Tried to drive it to Pep Boys to get the part when the temp spiked again. Pulled over and called for a tow.

When I got it to Pep Boys- I went through everything that had happened. they told me that it would be a while before they could look at it and they would call me. When they did- I was told it would be $1300 and that I had to replace EVERYTHING. Needless to say- I was shocked. I made it back there and the guy pointed out everything that they need to replace. They didn't realize that I knew what I was doing and I found that 90% of what they told me was not correct. I told them to just put coolant in and I would drive it to my father's house 2 blocks away. Drove it back there fine- filled up the radiator and took a look for myself. Fans were not turning on and there was a leak from the lower hose. Did not know where to short the fan, so i didn't check that- thanks for that tip.

I plan to go back to my father's tomorrow and replace the hoses, thermostat and check the fans.

If I find that by shorting the fans at the lower hose sensor and the fans work- is there any issue by keeping this shorted configuration until I replace the sensor?

 

If you are shorting the temperature switch on the thermostat housing, it won't hurt anything. It will keep the fans running at all times.

 

Sounds more like a coolant leak than a fan issue but as the doctor says, there is not any real harm in the jumping the wires for a temp fix....gas milage, heat slow to get to temp and a few other minor things compared to engine replacement...

Be sure to check the "small" coolant hoses under the dist for a split...they can split and spray coolant back towards the t-stat housing making you think it is the lower hose.........let us know how it turns out.

 

Was able to finally get a good look at it today. Shorted the fans and the AC fan only came on. This was after I reconnected it (Pepboys disconnected and tried to tell me it was broken). Looked around for coolant leaks and discovered that it was the heater hose that connects under the Distributor and runs back to the firewall, where it connects to the switch. Runs under the lower rad hose where it connects at the engine, so it was confusing where it was coming from.

Had to disconnect the distributor to access and then disconnect the line from the air filter to the throttle to get to the back end. Then I discovered that it travels through a brace halfway through. Replaced it with a new hose from NAPA and reconnected all.

Other issue was the Rad Fan. That was a hassle. I didn't want to have to disconnect the radiator to get to it, but that may have been easier. Disconnected the 4 bolts holding the housing (after disconnecting the radiator braces), and was able to pull the unit out after disconnecting the power connection. The problem I faced after this was that the 3 screws holding the motor to the housing were rusted and jammed pretty bad. Ultimately, I had to cut off the screw heads and tap out the motor. The new unit I got from NAPA did not quite fit in the way the old one did- I improvised by using 3/4" sheet metal screws and connected the motor to the plastic (rather than using the designated holes in the housing).

Reinstalled the housing and noticed after I started the AC that the Rad fan blades were hitting some relay box that was right behind the fan. Rather than unassembling the unit again, I took a pair of tin snips and clipped the protruding corners of the blades to give them clearance.

Filled the radiator and bled the system, ran the car in idle for 30 minutes and then took it for a test drive through the streets and then on the highway and the gauge never went above 1/3. Checked for leaks- found none and we are good to go. Bottom line- $100 in parts and about 4 hours labor (only because my big arms/hands cant fit into the tiny spaces).

I plan on going back to PepBoys tomorrow with my $87 receipt for the BS diagnostics they did (they told me that I had to replace everything, except the heater hose which was the issue) and demand a refund and tell them where they can put their $2500 estimate.

Thanks to all for your advice!

 

I also had a coolant leak from a split heater inlet hose...No fan issues though. I replaced the hose and clamps with new Honda parts, and for under $25 I fixed it. Congrats to you on your successful outcome with your repair...BTW, I wouldn't even consider allowing Pep Boys to touch my car...They are notoriously inept and in the biz to rip you off...

 

cander71---- glad you got it