Knocking sound near orifice tube location

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, JohnHere, Tim

Post Reply
Westfalia
Posts: 2
Read the full article
Joined: Tue Sep 06, 2022 10:11 am

Knocking sound near orifice tube location

Post by Westfalia »

2002 Dodge Dakota (factory air)

Recently I've noticed a reduction of cooling (max low 56 degrees on a 90+ day So. CA) and a knocking sound coming from up near the evaporator or maybe at the bulkhead(I think that is near where the OT is). This sound happens only when the compressor is engaged. Could this be a sign of a clogged OT? The truck has 200k+ on it and I don't think anything has ever been changed.

I evac'd the system and recharged it with the correct weight of R134 +oil but the noise is still there.
Thanks for any comments
User avatar
JohnHere
Posts: 901
Joined: Sun May 13, 2018 10:20 am
Location: South Carolina Upstate - USA

Re: Knocking sound near orifice tube location

Post by JohnHere »

When you recharged it, did you put in the full amount of oil?
Member – MACS (Mobile Air Climate Systems Association)

Thankful for the responses you have received? Please consider making a monetary donation to the Forum.
User avatar
JohnHere
Posts: 901
Joined: Sun May 13, 2018 10:20 am
Location: South Carolina Upstate - USA

Re: Knocking sound near orifice tube location

Post by JohnHere »

The specs for your vehicle call for 32 ounces net weight of R-134a and 7 fluid ounces of PAG-100.
Member – MACS (Mobile Air Climate Systems Association)

Thankful for the responses you have received? Please consider making a monetary donation to the Forum.
DetroitAC
Posts: 243
Joined: Mon Oct 17, 2016 10:33 am
Location: SE Michigan

Re: Knocking sound near orifice tube location

Post by DetroitAC »

As compressors age they get louder as parts wear. Luckily as people age our hearing gets worse. :D

OT can make hissing or gurgling sounds, knocking is the compressor not the OT
Post Reply