2008 Pontiac Grand Prix V6 what oil?

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Originally Posted By: Merkava_4
Originally Posted By: LeakySeals

No tint, blacked out lights and black offset rims yet. Considering just painting those rims dark. Not sure about that.
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What do you mean by "offset rims?" I hope you're not getting rims other than the factory offset. It's important
to maintain the factory offset for the health of your wheel bearings and other suspension components.


What I meant was taller rim, shorter tire. Same overall dimension so the speedo and computer stats (OLM, MPG, etc) are correct. Maybe used the wrong word.
 
Originally Posted By: LeakySeals
Observations after 200 miles:

No vibrations, no shakes as AC and fan cycle on and off at a light in drive. No ticks, cant tell its running idling. Much better than I'm used to. Weather has been 90-95F here since purchase, may be 100F today. Temp gauge just below middle, goes to middle when idling in this weather. Transmission "clunks" in and out of gear. More than I'm used to. During operation, transmission shifts smooth.

1200 on the oil, its dark already. Just off full. The used car dealer offered 2 free 3k oil changes, will use them for cleanup before switching to synthetic. Wondering if prior owner was using the OLM, stretching the interval. Its either the engine is dirty. Or..these engines are hard on oil.


It could also mean that, that particular motor oil turns dark more quickly when exposed to high heat operation conditions. the 3.8L are generally very easy on oil. My 3.8L would turn some oils dark within 1000 miles but when I used PU, it was still amber gold at 5000.
 
I have 2 old timers as toys with Gen II engines.
The stock GTP (60K) runs great on PU 5w30, zero consumption over 5K OCI.
The other a GT uses Mobil 1 0w40 but its a modified turbo engine and has nothing relevant to offer as far as OCI and weight.

This is interesting. Both are 2000 model year the original GT had 10w30 on the cap and in the owners manual but the GTP had 5w30.
The 5w30 works well in both stock, neither engine had consumption issues at all and were tight as a drum.
On the old ones the OLM was overly pessimistic (i like that) and it went on at about 3000-3200 miles.

By 2008 GM had gone crazy with their OLM and gone way too optimistic 10-12K was not unheard of and the engines could varnish badly and more than a few did.

PU at a 5K OCI seems to be a nice combo for this engine.
The only issue i notice on both cars is even though these have never seen winter and are super clean both oil pans are rotten and need replacement.
 
Thanks Trav. I have been researching the UOAs, they back up what you recommend (PU 5k). UOA's were not an exact match (Gen II, Gen III GTP, GXP etc.), but there is a common theme. High (relative to other UOA's) metals. Especially copper. More noticeable with M1, my preferred oil. Best results appeared to be PP, but I'm no expert.

PU (according to Pennzoil website) is a step up from PP, so think I will go PU for 5k to start, maybe 6-7k after a few OCI's. P1 or Fram Ultra filter if I can find one.

I plan to use the 2 free 3k conventional oil changes for a cleanup. Have some extra Kreen and MMO hanging around. Was thinking about tossing it in at the end of each. Then make the switch to PU. Good idea?
 
Doesn't sound too bad to me. If it's not making any noise or doesn't look like it has excessive sludge under valve covers, I wouldn't bother using Kreen or MMO. Just a few "short" oil changes and switch to synthetic.

Mine seemed to like Valvoline syntec for another oil to consider. Very little consumption and seems to keep the engine pretty clean. I'm giving some Rotella T6 a try in it this round, and so far I'm liking it a lot. No lifter noise at all. Pop the hood and all I can hear is the light "click" of the fuel injectors.
 
I don't think a little Kreen like 8oz or so for 1K would be a bad idea, just to clean up the PCV passages.
Maybe look into swapping the PCV out also.

Gotta love these engines though. They are one tough nut thats for sure, one of GM's very best IMHO.
 
Originally Posted By: LeakySeals

What I meant was taller rim, shorter tire. Same overall dimension so the speedo and computer stats (OLM, MPG, etc) are correct. Maybe used the wrong word.


Yes, you had me worried there for a minute.
shocked2.gif
 
Don`t do it. They`ll have the Pontiac logo on them. It`ll make the Buick look ghetto`d-out. Leave it stock. It`s beautiful just the way it is.
 
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Originally Posted By: aquariuscsm
Don`t do it. They`ll have the Pontiac logo on them. It`ll make the Buick look ghetto`d-out. Leave it stock. It`s beautiful just the way it is.


+1
 
Originally Posted By: LeakySeals
Originally Posted By: xxch4osxx
You have any pics of this car?

whip.jpg


No tint, blacked out lights and black offset rims yet. Considering just painting those rims dark. Not sure about that.
crazy.gif



If you do swap rims, remember your car has a TPMS built into the valve stem and you will need to switch those to the new rims or buy new ones. First change I wanted to make with my 'o7 GP was getting a set of new Mustang bullits and Pirellis from a dealer new car take-off. The new ones would have been a net $0 upgrade by selling my stock rims/Michelins. I didn't factor unmounting and remounting 8 tires to move the TPMS. I still have my stock rims.
As far as the Pontiac logo to the other poster, they sell decals for any make model.
 
Originally Posted By: Nickdfresh
Originally Posted By: Ram01
Clean the throttle. Body also


+1, spray out the air-intake...


How do I do that?
 
Don't forget to change the PCV.

Be careful not to overdue things. This engine is "drive by wire". The throttle body is driven by the computer. The gas pedal is not connected to anything! A sensor determines the pressure on the pedal.
Disconnect the tubing between the air box and engine. On the throttle body, you will see the butterfly that controls the air into the engine. If you force it open, you may damage it. Some say it's OK to push it open with the key turned to "on" but not start. While everyone wants a shiny throttle body, a little carbon buildup is not as important as forcing a butterfly open that isn't being told to open. My throttle body is attached to my supercharger but yours should be the same or similar with yours connected to the intake manifold.
In the intake tubing is the "mass airflow" sensor. An electrical charge that runs between the wires controls the gas based on the amount of air passing over the wires. When the wires get dirty, it can affect your mileage. Use MAF cleaner on what looks like a screen.
Of course check the air filter and look for any leaves or debris in the filter housing and tube running into the tube from the front of the engine (behind the headlight). Once I found two maple leaves the size of my hand pressed against the filter. Imagine how much air was being blocked. I checked because my car started running like ****.
 
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OK. The Camry TB is DBW so I'm familiar cleaning them. I usually have an assistant open the plates at the gas pedal. I've been told that so long as power is removed from the TB, manual opening of the plate wont damage the motor. But I'm too afraid to find out. Is that true? What does power removal mean? The connector at the TB, the battery, or just no key in ignition?

Also when you mentioned intake I was thinking about the intake manifold. Suppose the right way would be a removal rather than ingest all the junk.
 
Originally Posted By: LeakySeals
OK. The Camry TB is DBW so I'm familiar cleaning them. I usually have an assistant open the plates at the gas pedal. I've been told that so long as power is removed from the TB, manual opening of the plate wont damage the motor. But I'm too afraid to find out. Is that true? What does power removal mean? The connector at the TB, the battery, or just no key in ignition?


I'm not sure. Will leave for others to answer. I just leave it alone since I found out it does not work like a carburetor.
 
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