spAdam

iTrader: (1)

Could be one of the components of my 250,000 mile HVAC system finally starting to give up the ghost, but I've never seen this particular set of symptoms before.

- System has never been opened in the 8 years/150k that I've had the car. I replaced the clutch about five years ago without pulling the compressor and did the swap three years ago also without pulling it. Tensioner assembly was also brand new at time of swap.

- AC blows cold.

- While driving, you can feel when the compressor kicks on. Definitely more than normal, and I can feel a good amount of drag on the engine while the AC is on. Otherwise everything is fine while driving.

- When coming to a stop and idling down, over the course of a minute or so, you can feel the compressor slowly loading down the engine until it starts to vibrate and eventually the belt begins to slip. The engine is trying to idle up but is running into its clamps and can only do so much. At this point, I always hit the button so I have no idea if it will actually run until the pressure switch shuts it off or what the deal is.

I'm going to head to Autozone in a bit to rent a manifold set, see if I can get a read on the pressures, and figure something out from that. It's going to be tricky since I can't just sit there with the car running and watch the pressures like I normally would.

I'd hate to just throw a compressor at it and then find out it's something simple or something else in general, but it seems to me that possibly it's ready to let go.

Anyone else ever seen this particular set of symptoms? What ended up being the root cause?

domdambrogia

I have a very similar set of symptoms in my 243,xxx mile 98 civic. Makes it miserable in the summer time, especially here in northern california when it hits 110. Have yet to find the problem, but I get the idle shaking and 'engine drag' too. although my engine drag seems to go away once i start getting in the 2900 RMP range. Would love to hear someone share a fix to a similar situation.

spAdam

iTrader: (1)

I haven't had a minute to get the gauges on and see what's up, yesterday was a 14 hour day, today is lining up to be longer, and I'm flying east in the morning. I'll be back on Friday night, hopefully I'll get some time this weekend to check it out.

slowcivic2k

Compressor overload is a symptom of poor compressor lubrication (excessive internal friction), or excessive refrigerant level. I personally find it hard to believe the system was not serviced at least once, that would be a record for me personally, and one to strive for.

If the belt slips, inspect the belt tension and the pulleys. the adjustment pulley is known to dry out and seize. If the pulleys and the belt tension are okay, the compressor or the refrigerant charge are the only real culprits. If your vehicle steers when standing still without a huge drop in engine speed with the A/C off, the idle boost signal is okay, leading to the previous causes.

spAdam

iTrader: (1)

I'm aware of the usual causes of compressor drag and that's why I'm halfway expecting that it's on it's way out. If the pressures seem normal I'll probably just get after it before it grenades itself and leaves me having to disassemble and flush the entire system... Which I might do anyway at that point because I'm a bit ****.

Belt is new with the timing belt as of a couple of months ago. The symptoms were starting before the belt but have progressed slightly. Tensioner was inspected and is in good shape, it was brand new from the dealer at time of the swap. I always err on the loose side of belt tension (with a tension gauge) on my personal cars, if they start to complain a couple of days after I replace I just nudge them a little tighter. Better than over tightening.

As far as it never being serviced, I'm pretty amazed myself. I can't vouch for the first 93k of the car's life, but it did come with maintenance records and there's no AC work in there. The car was in a minor (but bad enough to require a core support) accident with the PO, if they replaced a condenser or anything at that point they used OE parts which is kind of surprising. I've had the car for the rest of its life and I've done every bit of non-body work on it so yeah, the system has not been opened in that eight years.

It's kind of become a science experiment of sorts... How long can it go? It already outlasted and engine and is at 75k on the current one!

DCFIVER

Yes many times, particularly on Honda 4 cyls for some reason.


A low charge can cause the compressor to drag(low charge=low oil level)



First thing to check before doing any sort of AC troubleshooting is the charge.



Still at the end of the day, you're likely still going to need a compressor if it is dragging already.

spAdam

iTrader: (1)

Found it. Condenser fan hot wire had backed out of the connector to a point of making intermittent contact:



Explains why it was working fine until idling at a stop. It was just dumb luck that when I looked at it originally it had contact and the fan was running. This time I noticed that the fan wasn't kicking on until the car started to shake from the compressor loading up (poly engine mounts), and I was able to duplicate by wiggling it manually.

Pressures are good now, everything seems normal and I was able to lower the AC duty cycle idle adjust. The 250000 mile system carries on...