Troubleshooting '03 Toyota Matrix

[Jason280]

2003 Toyota Matrix XRS, with 196k miles and 6-spd manual transmission. Car has run perfect since I bought it 5-6 years ago, and all I have needed to do to it is replace the starter.

About a week ago, hopped in and noticed that the steering was heavy and that it took a little while for the A/C to start cooling. Battery light came on, so I parked it in the shop. Went ahead and changed the serpentine belt, and replaced the battery. Cranked the car, and everything seemed fine....until I hit the A/C switch. Doing this causes the serp belt to slow considerably, to the point its dropping alternator output to under 12.5-12.6v and not allowing the PS pump to build enough pressure for steering. Kill the A/C, and the belt speeds back up enough for the PS pump to work correctly.

I'm assuming the A/C compressor is starting to seize up, but how else should I troubleshoot? I don't want to start throwing parts at it, anything else I should check?

 

[nadogail]

Just a wild guess, but it seems that either the AC compressor or the possible lack of tension on the serpentine belt would be logical.

 

[nickthorne33]

2003 Toyota Matrix XRS, with 196k miles and 6-spd manual transmission. Car has run perfect since I bought it 5-6 years ago, and all I have needed to do to it is replace the starter.

About a week ago, hopped in and noticed that the steering was heavy and that it took a little while for the A/C to start cooling. Battery light came on, so I parked it in the shop. Went ahead and changed the serpentine belt, and replaced the battery. Cranked the car, and everything seemed fine....until I hit the A/C switch. Doing this causes the serp belt to slow considerably, to the point its dropping alternator output to under 12.5-12.6v and not allowing the PS pump to build enough pressure for steering. Kill the A/C, and the belt speeds back up enough for the PS pump to work correctly.

I'm assuming the A/C compressor is starting to seize up, but how else should I troubleshoot? I don't want to start throwing parts at it, anything else I should check?

If it happens as soon as the compressor clutches on, then I'd say it's definitely the compressor that's the issue. Also important though, I'd check the system for possible leaks before removing the compressor because it might be that the A/C oil leaked somewhere. Or maybe it just worn out, that's an old, high mileage vehicle. But I'd check for leaks before throwing on a new compressor, so that you don't damage your shiny, new part A long time ago, I bought R-134a vacuum gauges and a vacuum pump from Harbor Freight, and they still work great for the stuff I do at the house. Just hook up the gauges, pull a vacuum on the system for a good 15-20 minutes, then turn off the pump and make sure it doesn't leak down

 

[Jason280]

Tension doesn't seem to be an issue, but I'm not sure how much deflection is normal...trying to find specs now.

 

[nickthorne33]

Just a wild guess, but it seems that either the AC compressor or the possible lack of tension on the serpentine belt would be logical.

That is possible too, and you can just check that by pulling on the belt a little and feeling how tight it is. It'd be a much cheaper fix

 

[Super Mech]

Does the engine rpm slow down or just the belt drive? If it’s just the belt you have a worn belt, weak belt tensioner, or a slipping balancer.

 

[Jason280]

Best I could tell it was dropping the RPM's, but the more I think about it the more it seems like the belt may have been slipping...if that's the case, then it would have to be the tensioner. Looks like I need to check it out again!