A/C compressor failing: vibrating when on now...

[MarkRobinson]

How odd, Just completed a 500+hp engine transplant into my '91 C2 turbo & finished the exhaust last night; so quieter now & less vibrations.

As soon as I turned on the AC I could fee an odd vibration coming from the chassis/engine, that's directly related to the AC & RPM.

I can run the AC at idle but as soon as I rev the engine a little it feels like it's running on 5 cylinders or so (it's not, the power is there). Verified this all the way home last night, all the way to work this am.

It's like my clutch is starting to slip or so when the revs are up: belt is new & adequately tight.

Thoughts???

Mark

[kuehl]

1) Compressor pulley is not bent, nothing in the groove?
2) AC belt has no tears or breaks?
3) Crank pulley not bent, nothing in the groove?
4) All AC bracket bolts in place and snug?
5) Refrigerant not overcharged? (what are pressures and temperatures at idle?)

[MarkRobinson]

1, no
2, no (new, 2k miles on it)
3., nope
4. need to check.
5. Nope, had it checked 4 weeks ago

:/

[MarkRobinson]

starts vibrating at exactly 2,000rpms: regardless of load: if the AC is on, the car/steering wheel vibrate at 2k+. As soon as the AC is off, vibration goes away. Wierd!

[kuehl]

Wonder if using a tach light on the belt might show you something?

[TMc993]

I had my belts changed and now have a similar "rumbling vibration" between 1900 and 2100 RPM...The difference between my situation and yours is that mine is there regardless of whether the compressor is running or not...I've had everything checked to no avail...I don't have the time or inclination to chase it, so I figure I'll find out what it is when something fails.

[MarkRobinson]

Mine's AC dependent for sure: been living with it for a week now :/

Gonna have my system discharged, pull the compressor tonight to be rebuilt tomorrow to be reinstalled/re-charged saturday am. Finger's crossed...worried they're gonna find something damaged inside it though rendering it un-rebuildable or $ rebuildable when there's a used one on Ebay for $175. Hmmm

[kuehl]

Originally Posted by MarkRobinson

... gonna pull the compressor tonight to be rebuilt tomorrow, to be reinstalled/re-charged saturday am. Finger's crossed...worried they're gonna find something damaged inside it though rendering it un-rebuildable or $ rebuildable when there's a used one on Ebay for $175. Hmmm

There nothing that can be 'rebuilt', but you can replace the nose seal, manifold seal, case o-rings, maybe a bearing. When you have it apart, look at the pistons, if scratched or the coating is worn off, toss it. If the bores are scratched, toss it. If the wobble plate is worn, toss it. Otherwise give it a go. And "used"? Grass may not be greener on the other side of the road.

Else, this a great value:
Pelican Parts - Product Information: 964-126-121-01-M11

[MarkRobinson]

rebuilt = reseal: About $110, however if I'm getting a vibration then I feel something has failed & would be better off getting a used compressor or so since mine has 257k miles on it.

If a rebuild on mine is $110 + parts, & I feel a part has failed/broke internally to cause the vibration, then might as well get the used one for $175 & take a chance that there's nothing broken internally & that it has far less than 257k miles on it.

M.

[kuehl]

Maybe you just want to take it apart and see what is what before you 'reseal' it,
however 257,000 miles? New seals are not going to give you another 50K unless you don't turn it on.

[MarkRobinson]

I don't need new seals, I need whatever's broken inside to be replaced; therefore a rebuilt (ie, resealed) compressor won't address the broken parts which might be unobtainable locally.

I understand you're an AC Master: didn't see 965 units on your site: If we weren't pressed for AC so suddenly in Texas, I'd send it to you...might send it to you anyway

Mark

[kuehl]

Mark...

Ok, Ok ! , Not bustin chops, just trying to offer 3 cents.
Just so you know, I'm not aware of that many ac compressor parts suppliers that sell
'bores' since they are part of the case, or pistons to match scored bores, nor wobble plates as they are attached to the shaft. Ya might find a shaft or thrust bearing, lucky if you can get reed valves, I recall the pulley bearing may be pressed in. Bottom line, just want you to have an open mind for the solution. If you can't fix the tired puppy, and I'm hoping the vibration is not the pump, I'd suggest you try the host here first for a new Denso replacement.
If you get stuck, we actually do have your compressor in stock .. I think (serpentine pulley if I recall).

But, you have to try the host first.

PM if you get stuck on the rebuild.

Free advice - thoughtless but free.
Sound advice - a six of Becks.
Solutions - priceless

[MarkRobinson]

I wasn't trying to be defensive, just stating my intentions: Since i feel that my compressor has so many miles and has an internal vibration, I don't see the point in trying locally to get it rebuilt since they probably don't have/have access to the (broken) parts needed to remove the vibration.

Like I said it still works, just the vibration that starts at 2k rpm is not tolerable.

I have a wife back in college so I'm trying to be frugal. PM me on a price (+ core I assume) for the one you have in stock, I might go for it).

WorldPac has a new Denso that's not available at the moment for $200, or AutoZone shows a Texas-mfr compressor for $350, or I have a line on a '94 3.6T 30k unit (used) for $200.

Mark.