GC M03 0w30 10K / '00 Grand Am GT 3.4L V6 115,000

[mshu7]

Hey all, this is my third UOA on my Grand Am GT.

History: First UOA was a 7K run of Mobil1 5w30. Blackstone indicated that my intake manifold gasket was holding up fine (the original gasket was replaced at 36K). Second UOA was a 3500K run of Havoline 5w30 on a rinse cycle of Auto-RX.

Year: 2000
Make: Pontiac
Model: Grand Am GT
Engine: 3.4L OHV V6
Miles on Engine: 115,000
Sample Date: Dec. 11, 2006
Oil: German Castrol 0w30 (M03 - Green)
Miles on Oil: 10,000
Make-up Oil: 0
Oil Use Date: April 28, 2006 - December 11, 2006
Oil Filter: Purolator PureOne PL24011 (oversized)
Air Filter: Purolator PureOne PA35227
Additional Info: Used suggested dosage of FP60 from April to June. Used Lucas UCL from June to December. Both products were used at every fill-up.

Blackstone indiciated the sodium level could be caused by the Lucas UCL. However, I use it at every fill-up in my '05 Mazda3 and my only UOA on that engine came back great. Unfortunately, I'm starting to think the intake manifold gasket is heading south, even though I had it replaced under warranty (36K).

My driving consists mostly highway miles, probably a 70/30 split of highway vs. city.

Something I noticed when I last changed the oil was that looking through the oil fill hole, all the metal parts were stained brown. I used Mobil1 from 15K to 100K in this Grand Am and the parts inside have always been spotless with no staining from the oil (nice silver color). Would GC have caused this change in color of the metal? There's no signs of sludge, just staining.

I would greatly appreciate everybody's input this report, particularly the sodium levels. I guess I'll suspend my use of Lucas UCL until I can get another UOA on this engine.

 

[drewjp]

The sodium could be the start of a coolant leak...otherwise it looks nice for 10k on GC...I just picked up my first batch of GC and am excited about trying it out when the weather gets warmer here(Michigan)...

 

[ToyotaNSaturn]

10K on a GM 3.4L? You ARE a daring soul!

Another UOA will tell the tale if it's a coolant leak or just trace additive given the tiny Potassium amount.

Fuel is too high for my tastes. Check the injectors for any problems?

 

[mshu7]

Quote:

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10K on a GM 3.4L? You ARE a daring soul!

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You're telling me! LOL

I did the previous UOA's to make sure my intake gasket was holding up. After that 7000 mile run of Mobil1, everything appeared to be fine. I thought the elevated sodium on the short Havoline run was because it was the rinse phase of Auto-RX.

I'll definitely be doing another UOA after this next run but I think I'm going to drop it down to 7500K intervals unless people think I should continue with 10K intervals. Regardless, I'm going to ditch the Lucas for now and just use FP60. We'll see how it turns out in about 6 months.

I'm not sure what to think about the fuel. I do mostly highway driving so it doesn't make a lot of sense. The only thing I can think is that a few weeks before I changed the oil there was a strong gas smell coming from the car after it had been parked in the garage for about 30 minutes. I haven't had the problem since. Any ideas?

 

[TeeDub]

Assuming this engine is using the GM DexCool, I believe you'd see potassium in addition to sodium if you had an intake manifold leak here. I would recommend discontinuing use of the Lucas additive; I don't think it's doing anything for you here and may be causing the yellowish varnish deposits you are seeing.

Regular use of the FP60 at a low dose rate (you CAN overdue fuel additives and cause problems with bearing wear), should help optimize combustion efficiency and reduce the fuel dilution. Given the # of miles on this engine, a simple tuneup may also be in order (plugs/filters/PCV valve, etc).

 

[mshu7]

Thanks for the input TeeDub.

The coolant is definitely DexCool. I also ordered a gallon of FP60 on Friday. I was using FP60 about a year ago but when I ran out I thought I'd give the Lucas a shot. I always use suggested dosages so that shouldn't be a problem. I'll just go back with FP60 here on out.

Also, I did a complete tune-up on this car at 100K. Everything should be in tip top shape.

Again, thanks for the input.

 

[Drew99GT]

All in all, 10K on an engine known for intake leaks, I'd say this analysis looks great!

If it were my vehicle, I'd drop the interval down to maybe 4,000 miles and resample to see about the coolent.

 

[mshu7]

Thanks for the input, Drew.

I'm going to drop this interval to 7500K. I'd drop it more but I don't want to waste the M03 batch of GC that I have in there. Hopefully, since I'm not using Lucas UCL anymore, the sodium levels will drop to a normal range on my next UOA.

 

[Rand]

Maybe sample at 4k but dont change the oil?

 

[mshu7]

Yeah, I don't know why I didn't think of that. Good idea Rand...thanks!

 

[nascarnation]

Shu is using Lucas to help us pay for that new $700 mil stadium downtown.

 

[mshu7]

HAHA, that's no lie!

 

[ATS-V]

This report looks great. I'd run another 7.5k to 10k interval to monitor sodium and possibly add the GM seal tabs as preventive maintenance.