Pennzoil - SN Plus and 0W-16 Q&A

Click here to participate in the Pennzoil Q&A

Recent Topics
Car broken into...
by InvalidUserID
03/17/18 01:22 AM
ATF adapter kit for ATF machine
by atfadapter
03/17/18 12:30 AM
Changing my oil too infrequently? PCV problem?
by BlakeB
03/16/18 11:50 PM
What is a spongy pedal?
by motor_oil_madman
03/16/18 10:57 PM
Leave it to UVa... .
by bbhero
03/16/18 10:25 PM
great hospital. Wesley
by red7404
03/16/18 10:24 PM
Oil Filter Opinions
by BigJakeChevy
03/16/18 10:15 PM
GM 89021806 ? Gimmick? Alternatives?
by mdocod
03/16/18 09:43 PM
Delco filters original vs. Ecore
by Oily_Thing
03/16/18 09:19 PM
that town again.
by Silk
03/16/18 08:54 PM
To change or not to change?
by dan_erickson
03/16/18 08:42 PM
CBC Marketplace OCI video
by maxdustington
03/16/18 08:15 PM
Leak tested?
by bbhero
03/16/18 07:26 PM
Oil analysis
by Joshontech
03/16/18 06:58 PM
Something is leaking from somewhere (photo)
by RichardS
03/16/18 06:26 PM
Ford F550 Tire recommendation
by mbacfp
03/16/18 06:22 PM
2006 sienna sloppy shifting with full fluid
by Huie83
03/16/18 06:04 PM
The Two Tires On A 4 WD Dilemma
by Warstud
03/16/18 05:44 PM
2000 Buick Century Code P1404
by JimmyJohns
03/16/18 05:39 PM
Does anyone has AAP 40% Coupon Code?
by maverickfhs
03/16/18 05:33 PM
Newest Members
bumpasmerc, SuperBird4404BBL, Oily_Thing, Altima2, jtwork
64478 Registered Users
Who's Online
26 registered (2009Edge, BlakeB, billt460, Char Baby, Black_Thunder, Bjornviken, 2 invisible), 759 Guests and 95 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
64478 Members
67 Forums
279925 Topics
4672325 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Topic Options
#4483771 - 08/09/17 02:34 PM A/C problem, '04 GM 5.3L, Rainier CXL, 2WD
DeepFriar Offline

Registered: 10/31/13
Posts: 1352
Loc: Georgia
I'v been lucky over the years with no A/C problems to speak of. By virtue of that I don't know much about diagnosing problems. Now suddenly I have two out of three vehicles with problems. My old '92 SE-R just appears to have had a seal failure leak (it's held up good though since the changeover to R134A back in 2000). The Rainier auto climate control is simply taking too long to cool down but goes great guns when it does. It seems sometimes to cool a little very briefly on startup (that could be a false impression) but immediately goes warm ambient for say 2-3 minutes before "going to work". It's not the usual delay that happens with hot soak. Another possibly wrong impression is that the system can seem like it has some trouble "making up its mind" if I change modes to try to get better cooling faster. I have read that there is an expensive valve of some sort that is known to fail on these but can't find any further info. Would appreciate any help you guys might provide. Thanks.

#4483826 - 08/09/17 03:39 PM Re: A/C problem, '04 GM 5.3L, Rainier CXL, 2WD [Re: DeepFriar]
mk378 Offline

Registered: 09/27/15
Posts: 1248
Loc: USA
When it is not cooling, open the hood and look if the compressor is engaged. Also feel the low side line from the accumulator tank to the compressor, it should be cold.

#4483868 - 08/09/17 04:16 PM Re: A/C problem, '04 GM 5.3L, Rainier CXL, 2WD [Re: DeepFriar]
WyrTwister Offline

Registered: 01/13/13
Posts: 1134
Loc: Texas
If the compressor is working , throw the manifold / hoses / gauges on it and report back .
God bless

#4484108 - 08/09/17 09:07 PM Re: A/C problem, '04 GM 5.3L, Rainier CXL, 2WD [Re: DeepFriar]
clinebarger Offline

Registered: 12/19/13
Posts: 1618
Loc: Fort Worth, Texas
Originally Posted By: DeepFriar
It seems sometimes to cool a little very briefly on startup (that could be a false impression) but immediately goes warm ambient for say 2-3 minutes before "going to work".

Read the below TSB, At your vehicles age.....It would be wise to pull the radiator & thoroughly inspect the Condenser & Radiator for blockage & clean any debris build up between the two.

Bulletin No.: 04-01-38-019A

Date: June 07, 2005


Intermittent Slow to Cool HVAC Performance Concerns in High Ambient Temperatures and/or High Humidity Conditions After Start Up, Especially at Low Engine Speeds (Install New Engine Cooling Fan Clutch)
2004-2005 Buick Rainier
2002-2005 Chevrolet TrailBlazer Models
2002-2005 GMC Envoy Models
2002-2004 Oldsmobile Bravada
2005 Saab 9-7X

Some customers may comment on slow to cool Air Conditioning (A/C) performance or high A/C outlet temperatures after start up or that the A/C system is not cooling sufficiently, especially in high ambient temperatures. This may be an intermittent condition and the performance of the Heating, Ventilation and Air Conditioning (HVAC) system may not meet customer expectations.

This condition may be caused by the response of the Electro-Viscous (EV) fan clutch and can be related to airflow across the condenser. This low A/C system performance can occur for longer periods of time if the vehicle is allowed to idle or is driven in low speed conditions. The response of the EV fan clutch will affect A/C system performance. As higher road speeds are attained, the increased airflow across the condenser will usually improve A/C system performance and the response of the EV fan clutch. This condition may be more evident after the vehicle has set for a period of time and can be difficult to duplicate. The condition may occur after the vehicle has set for as little as 10 minutes or as long as overnight. It is most prevalent intermittently during the first 15 minutes of operation.

Technicians are to replace the EV fan clutch with a new design part, P/N 15293048, on vehicles built before June 2005. Vehicles built in June 2005 may already have the updated EV fan clutch and it will not need to be replaced. For 2004 model year vehicles and older, update the Powertrain Control Module (PCM) with a software calibration that was developed to improve coolant temperature gauge readings. This new calibration will cause the PCM to command small amounts of additional fan engagement to better control engine coolant temperatures. Model year 2005 vehicles already have this calibration installed. Refer to Corporate Service Bulletin Number 04-06-02-005 for more information about this calibration.

Proper diagnosis of any customer concern is essential. Refer to the Diagnostic Starting Point-Heating, Ventilation and Air Conditioning procedure in SI to begin a diagnosis of any HVAC concerns. Refer to the Diagnostic Starting Point-Engine Cooling procedure in SI to begin a diagnosis of any engine cooling or engine cooling fan concerns. If an attempt is made to diagnose an HVAC system concern, all parameters must be measured. As an example, both the low and high side refrigerant pressure readings must be measured. If only the low side pressure readings were measured, it would appear that the A/C compressor is disengaging at a higher pressure than expected. If both the low and high side pressures were being measured, it would be noted that the A/C compressor is probably disengaging due to the maximum high side pressure cut out point being reached. This occurs to protect the HVAC system from damage. The updated PCM software calibration along with the updated EV fan clutch will improve this condition due to increased air flow across the condenser. The new EV fan clutch has an increased minimum operating fan speed and an improved response time. Additional engine cooling fan noise can be expected with the updated PCM software calibrations.

The last area of customer concern is the operation of the HVAC system blower motor. For vehicles equipped with automatic control HVAC systems (RPO CJ2), the blower motor fan speed will be limited to 80% of maximum when the HVAC system is operating in the automatic mode. To obtain maximum blower motor speed, instruct the customer to manually adjust the blower motor speed to the highest setting.
2001 Chevy Camaro L92/4L80E
2006 Chevy 2500HD LBZ/Allison 1000
2007 Chevy Cobalt SS LSJ/F35
2010 Toyota Corolla 2ZR-FE/Auto

#4484125 - 08/09/17 09:32 PM Re: A/C problem, '04 GM 5.3L, Rainier CXL, 2WD [Re: DeepFriar]
DeepFriar Offline

Registered: 10/31/13
Posts: 1352
Loc: Georgia
Thanks for the input guys. I will follow up on these. I let it idle for three hours yesterday outside the emergency room (wife, no heart attack found thank God) because I forgot to turn it off. It was cold on return, engine normal temp, no apparent problems. New water pump, two years ago, no other apparent cooling system probs at that time but will recheck. Thanks again.