2004 Frontier compressor engagement noise

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Cusser
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2004 Frontier compressor engagement noise

Postby Cusser » Wed Jun 03, 2020 8:16 am

Sept. 2018 the AC compressor on my 2004 Frontier seized up about 100 miles into our vacation. Oct. 2018 I replaced the compressor, condenser, receiver-drier, flushed the high pressure lines, evacuated and filled with R134 and added some UV dye.

Vent temperatures have been fine. Only concern was that on first use of AC each day (first time I pressed the AC on-off switch each day), there was a metallic grind-type noise the first half-second as the compressor engaged. When cycling, or turning on the AC switch on subsequent trips that day, no noise at all, silent operation. I even tried with engine cold first thing in the morning to turn the ac compressor drive plate by hand, turned readily, and smoothly; then I started up and when I pressed in the AC switch, got the same noise for the half second. Ambient temperature a first start of the day did not seem to affect this at all.

Jump to May 2020. On this Frontier I was still on the factory AC idler pulley at 105K miles, so I bought a new idler for $42 to swap that in (I'd had to replace same part on my 1998 Frontier previously when its idler seized up). So I installed the idler, and the factory one had just a twinkling of vibration when I spun it by hand. Anyway, after that, and with AC belt a little looser, I started it up; and when I pushed in the AC button, the noise appeared again for its usual half-second.

So next day, I decided that I wanted to hear the noise while being under the hood. Since my AC compressor won't engage unless the engine is running (or I jump its wire), I pulled the "AC compressor" fuse just rearward of the battery. I started the engine, turned AC on (switch "in"), and went up to the front. I inserted the AC compressor fuse and the compressor engaged BUT WITHOUT THE NOISE. So I pulled the fuse again and cleaned up its contact arms/blades, even though they looked OK, and re-inserted the fuse.

I fully realize that I'll jinx myself my writing this, but in two subsequent "first AC switch on of the day" situations, the noise has not occurred.

I'm open to any explanations, as to why somewhat-intermittent contact of the fuse blades would cause such a noise,and only on the first start up of the day.
Al9
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Re: 2004 Frontier compressor engagement noise

Postby Al9 » Wed Jun 03, 2020 8:30 am

A slipping clutch and a harder/weaker than normal engagement due to the higher current resistance maybe?

The fact you could readily and smoothly turn it by hand means lubrication issues are unlikely.

Have you got that rubber ring type of clutch hub peculiar of Denso 10 series compressors perhaps? In that case the rubber might somewhat loosen up as things warm up, and make engagement smoother as a result. Getting a stronger magnetic field from the coil might have fixed things up enough to remove that initial slippage.

I have the rubber ring clutch hub too and usually get a single "bang" or "ting" type of noise from mine in cold/mild weather first engagement of the day and cold engine (in warm weather it becomes a "click") instead of a grind type of noise (never got this one), but that's likely minor refrigerant slugging.
Last edited by Al9 on Wed Jun 03, 2020 8:44 am, edited 1 time in total.
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Cusser
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Re: 2004 Frontier compressor engagement noise

Postby Cusser » Wed Jun 03, 2020 8:43 am

Al9 wrote:The fact you could readily and smoothly turn it by hand means lubrication issues are unlikely.

That's what I felt too.


Al9 wrote:Have you got that rubber ring type of clutch hub peculiar of Denso 10 series compressors perhaps?

I don't have any idea. It's a brand-new (in 2018) UAC CO10607C compressor.

I'll update this thread as I try this on upcoming days to let folks know if the noise is gone or has reappeared and I'll just "live with it". This truck is at my summer place and we haven't really moved here for the hotter months yet, so cannot check every day.
Al9
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Re: 2004 Frontier compressor engagement noise

Postby Al9 » Wed Jun 03, 2020 8:47 am

Yes, your compressor definitely has the rubber ring clutch hub.

Definitely update the thread as days go by. Might well be weather related, like with my case.

If you want to clean the fuse terminals even better, use fast drying contact cleaner.
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Cusser
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Re: 2004 Frontier compressor engagement noise

Postby Cusser » Thu Jun 04, 2020 6:57 am

Update: worked fine/quiet again first thing this morning.

I'll be up here more in a couple of weeks, and will update then.
Al9
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Re: 2004 Frontier compressor engagement noise

Postby Al9 » Thu Jun 04, 2020 7:28 am

Now that i think of it, did you burnish the clutch (it's a matter of engaging and disengaging AC rapidly and repeatedly basically) right after installing the new comp?
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Cusser
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Re: 2004 Frontier compressor engagement noise

Postby Cusser » Thu Jun 04, 2020 5:37 pm

Al9 wrote:Now that i think of it, did you burnish the clutch (it's a matter of engaging and disengaging AC rapidly and repeatedly basically) right after installing the new comp?


Burnishing??? Not intentionally !!! I don't know anything about this burnishing of the clutch, I'm not a professional mechanic. Unless you count my work on old air-cooled VWs in 1971-1975 !!

I know "some things" about auto AC; I would say that I've installed about a dozen compressors in my lifetime on various vehicles - those compressors work hard, and most of the time - in Arizona. I never burnished one before - what does this do?

I believe our high today was 110F. And morning low was 85F.
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Cusser
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Re: 2004 Frontier compressor engagement noise

Postby Cusser » Thu Jun 04, 2020 5:48 pm

Al9 wrote:Getting a stronger magnetic field from the coil might have fixed things up enough to remove that initial slippage.


I'm guessing that is what I was observing: before I R&R'd the AC compressor fuse (and cleaned its blades), there were initially less amps delivered and I was getting a half-second of engagement/slipping noise. Thanks !
Al9
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Re: 2004 Frontier compressor engagement noise

Postby Al9 » Fri Jun 05, 2020 1:44 am

Cusser wrote:I never burnished one before - what does this do?

Clutch burnishing - intentional wear of pristine friction surfaces of a dry clutch so that they stick together better. https://ogura-clutch.com/pto-burnishing.php

Have a look at the Valeo TM21's service manual on the bottom of this page (http://www.valeocompressors.com/en/tm21).
Notice at page 4 how much the static torque increases after burnishing.
Read page 18 to know what Valeo means with burnishing.

Unless the compressor manufacturer's installation manual explicitly states that the clutch has been pre-burnished, on a new compressor installation i'd first keep the AC engaged with the engine idle and maximum evaporator heat load for a few minutes so to allow oil return, then i'd burnish the clutch.
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Cusser
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Re: 2004 Frontier compressor engagement noise

Postby Cusser » Fri Jun 05, 2020 5:47 am

Thanks - good information !

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