rattle coming from engine when A/C on

[D is for DENALI]

Went to the ac guy today, he put a few ounces of pag oil in thinking its low, clutch works properly, compressor bearing spins fine when not on at all, and blows cold under idle, but the tugging on the tensioner under idle made him think it's a bad bearing inside,the compressor ,not outside.

Sucks cause I've got some slam grooving in my ac tensioner from the smacking action... I hope it isn't roached.. but what I'm gonna do in the meantime is go to auto parts and buy a new tensioner, maybe its a bad new tensioner, and see if the problem gos away... if not, return!!! Lolz (it's possible that the new one i bought is bad, the reason I think it's not the tensioner is because when I jump under the truck with no ac or temp control on at all, it is not tugging or bouncing, it's doing what it should, even under engine acceleration)

Then I will pull the trigger on the ac parts and test my newly acquired truck repair skills...

Compressor, condenser, accumulator, and orifice tube for 325 shipped.. all new ac delco.. then recharge for 75... whole new ac system for 400!!! **** yea!!!

Windows down at 97° is bruuuuuutal.

 

[Chubbs]

Went to the ac guy today, he put a few ounces of pag oil in thinking its low, clutch works properly, compressor bearing spins fine when not on at all, and blows cold under idle, but the tugging on the tensioner under idle made him think it's a bad bearing inside,the compressor ,not outside.

Sucks cause I've got some slam grooving in my ac tensioner from the smacking action... I hope it isn't roached.. but what I'm gonna do in the meantime is go to auto parts and buy a new tensioner, maybe its a bad new tensioner, and see if the problem gos away... if not, return!!! Lolz (it's possible that the new one i bought is bad, the reason I think it's not the tensioner is because when I jump under the truck with no ac or temp control on at all, it is not tugging or bouncing, it's doing what it should, even under engine acceleration)

Then I will pull the trigger on the ac parts and test my newly acquired truck repair skills...

Compressor, condenser, accumulator, and orifice tube for 325 shipped.. all new ac delco.. then recharge for 75... whole new ac system for 400!!! **** yea!!!

Windows down at 97° is bruuuuuutal.

That's HELLA' good bargain! All the parts you need to do it RIGHT, 1-time & the 1st time, for $325 plus the 'frig vac? That's crazy: you will have a completely rebuilt AC system with factory parts even. Can't beat it. What's your plug on those parts? I just bought an old Yukon that will need an AC rebuild sooner or later. Guy who sold it to me said he had the compressor shimmed. I never heard of that but it sounds like a bandaid.

 

[Sevenevez]

i am going through this EXACT situation as well. I replaced both belts and AC tensioner. Figured that was it.

then like 3 days later it came again.
so, for me.. when the AC is on, and you Rev your engine, as the rev comes down it makes a pretty loud rattle. i believe it is the clutch on the compressor going. I am going to replace the compressor now. Also, it doesnt always happen. But when it does, it sounds like your engine is about to throw a rod through the block!

 

[D is for DENALI]

Rock auto is where im purchasing my parts

Parts geek couldnt beat these prices this time.

 

[Sevenevez]

Rock auto is where im purchasing my parts

Parts geek couldnt beat these prices this time.

me too. nobody can beat rockauto

 

[D is for DENALI]

Well im glad I could help with the diagnosis.

Id be so salty if I found out that it was inside the compressor after buying a new clutch kit..
Clutch kit is 150, new compressor assembly is 200.. easy choice.

If you climb under your truck and take a look at your tensioner you probably have some slam grooving too from the rattle and clacking.. I'd buy a new one of you are spending the money on a compressor.. peace of mind for $30..

 

[JetBlackNali]

Its called oil slugging and very common. Its oil drain back into the pump. Because of where the pump is located (bottom of the system) the oil builds up and for a split second stops the pump causing the tensioner to jump hard or in my case years ago break the belt and then the tensioner. Did alot of digging and gm has a filter that goes inline to prevent oil from draining back.
Did reply to older post with part numbers for filter but can't locate post.

Will keep digging.

Found the part 89016656 (*A/C Delco Part# 15-10413)
Universal In-Line A/C Filter

Hope this helps.

 

[Sevenevez]

i just bought a new AC compressor and that fixed all my issues

 

[bldn10]

Crap, I wish I'd found this thread in Nov. I had already replaced the tensioner and compressor 4/2016 but I started hearing the noise again. I just put another tensioner [that showed the result of the slamming] on it to no avail. Does the inline filter solve this obvious Chevy design mistake?