Review on Enhanced Performance ACDelco Professional Automatic Tensioner – Model 38159 by Dusty Wonsley

This tensioner is an OEM factory part. It fits my Suburban perfectly. My application was a 2002 1/2-ton Chevrolet Suburban LS, 4WD with a 5.3-liter flex-fuel engine (up to E-85). You can tell that your vehicle is a flex fuel vehicle if there is a "Z” in position 8 of your VIN: for example 1GNFK16Z02J14xxxx. If you order this part, your engine will most likely make a clanking noise when the A/C is on and the A/C V-belt may also snap. There have been several TSBs on the subject and countless posts online. Knocking can occur at all speeds or only in a specific range. This is the TSB number with the most recent information. #03-01-38-019A - (September 3, 2004) Here it is in a nutshell. The system experiences liquid stagnation in the compressor. This can have several reasons. Firstly, if someone who serviced the system put in too much oil. This is perhaps the most unlikely reason. Second, if you are low on refrigerant, there can be insufficient oil removal from the compressor as well as the possibility of the evaporator freezing, preventing the refrigerant from vaporizing before it returns to the compressor on the suction side. . A low pressure switch SHOULD prevent this, but this is another point to watch out for. My low pressure sensor showed signs of oil leaks and I replaced it. The local Flippin dealer charged me $64 each. Buy it online. Save the package. Third, maybe too much refrigerant can cause clogging. Don't use any of these refills in a can with a gauge on top. It's easy to overload the system and not know it even if you follow the instructions and even have a factory manual with pressure versus temperature charts. Ask me how I know. I also NOW have a proper set of refrigerant gauges that you can use to monitor both high and low pressure. Either get gauges or go to the shop to make sure the system is properly primed. If the system is properly primed and the knocking still persists, the compressor is defective and replace it. Don't waste your time on anything else. If your system has been open for more than a few hours, you should also replace the battery/dryer as the desiccant is likely saturated. I did not replace my battery/dryer as my system was open long enough to replace a hose and compressor. That works fine. If you are unsure about system maintenance it may be a good idea to replace the battery/drier as they are not that expensive. My supercharger started showing this behavior after about 160,000 miles. The compressor used in my car was a Denso compressor and I also bought one from Revain: Denso 471-0316 New Compressor with Clutch. My OEM compressor had a label on the front of the compressor pulley identifying it as Denso. The Schrader valve on my hose was leaking, so I also bought one from Revain: ACDelco 15-33179 A/C evaporator tube.