Odd/Unusual AC problem

[SubyRoo]

Hi guys/gals. Its nice and hot now so naturally its time for my car to overheat/ac malfunction. Ive been having this issue lately since the temps here have been up. I drive the same route everyday to work on the highway and on the trip to work there are never any issues, the return trip is when the problems begin. Once I have been driving about twenty minutes (literally happens the same place on the highway everyday) I notice my temp gauge creep up just barely almost to the halfway mark and not long after the ac compressor shuts off and the temp drops back down to normal honda area on the gauge. When the ac has been off about five minutes I can hit the switch and it works again.

The car has new fans and associated relays. I have checked the fans and they do work and both kick on when the ac button is switched on. The car has a new factory thermostat and water pump as well.

Any help is appreciated. I just think its funny it always happens on the same one mile stretch of highway everyday.

 

[JHZR2]

Sounds like a fan issue.

Maybe an aux fan isn't working, once everything gets truly up to temp (which takes 10-20 miles), then the lack of fan causes AC condenser to work poorer, pressures creep up, heat is going from condenser to radiator without enough airflow, etc... Then the AC cuts out on overpressure, the condenser is no longer rejecting heat so things cool down a bit, and the cycle goes on.

Id check your fans.

 

[salv]

Originally Posted By: JHZR2
Sounds like a fan issue.

Maybe an aux fan isn't working, once everything gets truly up to temp (which takes 10-20 miles), then the lack of fan causes AC condenser to work poorer, pressures creep up, heat is going from condenser to radiator without enough airflow, etc... Then the AC cuts out on overpressure, the condenser is no longer rejecting heat so things cool down a bit, and the cycle goes on.

Id check your fans.


I second this.

 

[SubyRoo]

Originally Posted By: salv
Originally Posted By: JHZR2
Sounds like a fan issue.

Maybe an aux fan isn't working, once everything gets truly up to temp (which takes 10-20 miles), then the lack of fan causes AC condenser to work poorer, pressures creep up, heat is going from condenser to radiator without enough airflow, etc... Then the AC cuts out on overpressure, the condenser is no longer rejecting heat so things cool down a bit, and the cycle goes on.

Id check your fans.


I second this.


Is it possible that the fans stop working when the underhood gets nice and hot? Ive checked them after I get home and they both work fine at that point but by then the ac is usually working ok as well.

 

[ffl]

Next time it happens, pull over ASAP and pop the hood and see if all the fans are running. If so maybe your radiator is partially gunked up.

 

[eljefino]

You say you have two fans, I'd check the relay system as there could be a low/ high mode and you're missing high. Maybe low has them in series and high is parallel for more power. You should be able to stand by your driver's door and feel heat escaping from under the rocker panel with your fans going full bore on a hot day.

 

[C1KLTX]

One time my car would run hot after a few hours and using the AC. Had a plastic bag stuck between the condenser and the radiator.

 

[clinebarger]

Over about 40 mph, The Cooling Fans are not needed for the A/C condenser or radiator on most vehicles.

You would be surprised at the debris can collect in the condenser, radiator & the space between the 2!

 

[SubyRoo]

Thanks for all the input guys. I'm going to tear into it this weekend and I will update with what I find.

 

[SubyRoo]

I took the car apart this past weekend and inspected everything, the area between the rad and condesor was clean both fans are cycling correctly. I did find a small leak in the radiator where the end tanks attach to the core so I replaced it and so far it seems the problem is fixed. I made my usual trip yesterday without incident. Thank you all for the help.