Automotive Air Conditioning Information Forum

2004 Saturn Vue 3.5L V6. 134K miles on it. AC does not cool well at idle and from what I have been reading I might have a bad scroll valve in the compressor. It cools well enough when at driving speed and even better at 2k RPMs.

I can live with the poor idle cooling, but I see what looks like a leak on one of the bolts on the compressor body.

I cleaned the area around the compressor with paper towels and then turned on the car and started the AC. Ran it idle for a few minutes and saw no new fluid.

Put my foot on the gas to get the car to a steady 2k RPMs so the system would start putting out cool air. Held it there for maybe a minute and then turned off the car and checked again.

Now with the UV light it was pretty obvious where it was leaking at on the compressor.

It leaks at the back seam of the circled bolt area then runs down the compressor so it looks like the whole seam is leaking but it is just from the one small spot. Is there any way to patch that seam so it stops or severely slows down the leak?

https://photos.app.goo.gl/Dit5Loryve5hndHU9

I really don't want to pay a shop to replace the compressor ($800-$1000) and replacing the compressor on the VUE myself would be quite a chore. Not only have I not done anything like this before and would need to buy a vacuum and gauges, but to remove the compressor you have to loosen some frame bolts to make room to remove it from the bottom, or you have to remove engine mounts and the alternator to remove it from the top.

Just looking for some advice.

A 14 year old scroll compressor that is leaking oil...

One choice A/C or NO A/C.

The compressor is shedding metal in to the condenser. It is also losing lubricant. The fix is a new compressor, a new condenser and a new dryer.

As a Vue owner I can tell you the job is not a driveway job. The service manual says to drop the front subframe, and replace the subframe bolts with new parts when you are done. You need a lift & The temporary engine support fixture. I twist a wrench on most anything & I sent the wife's car to the dealer for a compressor.

Find an independent shop that knows the Saturn near you. Try the Saturn owners group forums. Make sure they replace the condenser and dryer. If you are close to needing the timing belt done, the engine mount comes out for that - so the compressor could come out the top at the same time. If you do the timing belt, do the water pump & engine mount at the same time.

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Forgive my ignorance, but how do you know compressor is shedding metal?

Is it because of the bad scroll valve? Users on the saturn forums have replaced just their scroll valves and never said anything about the compressor being bad.

Is it because of the age? Do all compressors that old start shedding metal?

Is it because it is leaking oil? It is a very small leak and I do not think I have lost too much oil. The compressor does not make any odd noises and it is practically silent when running.

Is do not disagree that when the compressor gets replaced that the dryer and probably condenser should be replaced at the same time, and I was told as much when calling around to get a price quote on a replacement. In fact a couple places I called said they would not warranty the work unless all three were replaced.

There is no such thig as a "scroll valve".

The Scroll type compressor has 2 scroll shaped elements, one that is fixed, and a second one that orbits within the fixed part. When they wear, they touch each other & shed metal. This increases the clearance between the elements, and the pumping capacity goes down. So if you rev the engine up it cools somewhat because it manages to pump in spite of the internal leakage from wear.

Your compressor is quiet because it has already removed a lot of metal from the internal parts, and they are just swishing past each other now.

The seal failure at the front of the case is a secondary issue. You would need to remove the compressor to replace the case seal - so just replace the compressor.

I would be suspect of all advice given by someone who claims to have replaced a "scroll valve" - they have never actually worked on the system at all and are just making things up.


The good news is your Vue will still be drivable when the compressor locks up & breaks the drive belt.

As Band of Brothers we sometimes offer to complete a thought (scroll shedding).
Scroll compressors use one hard anodized scroll and one soft aluminum scroll.
A scroll system with several hundred hours will have aluminum gray oil due to the soft scroll conforming to the shape of the hard anodized scroll. A permitted orbiting radius coupling (POR) restricts and limits wear. Actually the first 1000 hours of operation increases the volumetric efficiency and performance as the scrolls conform with each other. If the OEM system contains metal scrap, then the scrolls early shred. The circulating aluminum fines do tend to eventually grind some soft scroll wall. I usually install a good liquid line filter (100 mesh min.) on scroll systems for long durability of bearings and scrolls.
Ford scrolls are a special adaption of the TRC, controlled capacity to reduce cycling by hot gas bypass at a mid compression location. Unfortunately this design allows re expansion and lowers volumetric efficiency 5 to 10%.
Some guys in high ambients drive around in low gear to keep the scroll compressor barely cooling in stop and go and accelerate the wear and complain.....
hotrodac

Yeah Ice it is a great design from a corporate standpoint - it begins grinding itself to bits from day one, generally making it to the 50k mark still working...

The scroll in the 2007 VUE wore out @55k. It would no longer cool below 2k engine rpm, and the dealer replaced it under an extended warranty. The replacement cooled as well as the new one. Of course it is a bother to drop the Front K member to swap a compressor...

Ford simply screwed the pooch on that Explorer. Too small on the compressor to cool in traffic, because the scroll is weak at idle. The last 3 Fusions cooled well, and they cooled in stop & go traffic.

I assume the 2018 Equinox has a scroll. It cools well enough, but the race has just started. Let's see how it works at 60k. At least GM got the transmission programming in line with the powerband of the 1.5L turbo engine. It gets 6 to 7 mpg better mileage than the 2015 Fusion did on the same trip.

I am still not fond of the scroll compressor in MVAC. I know you like them.