NOT happy - Gold GC 4,778mi '99 Nissan Maxima
- Thread starter sky jumper
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it ran fine, although my fuel economy took a hit. I'd recommend you do 2 rinse phases (but not 2 clean phases). I put the GC in right after the rinse phase, and it turned dark real quick. I think there was still quite a bit a gunk floating around in there. which surprises me because this engine saw 4k OCIs with GTX since new, and inside the filler cap is spotless.
they say nothing about dino vs. synthetic, only spec an SJ rated 5W30 or 10W30. I think all mfg's recommend against oil/fuel adds, but its hard to argue with the great results terry dyson's customers get with LC/FP in higher doses, which is why I doubt that's the issue here. I think it's the regane. I doubt it was the GC, although the add pack looks way off to me.quote:
Originally posted by Bill in Utah:
Doesn't Nissan state in their manual to use conventional oils??
Sure looked better with the Group III (is that not what ST Syn is?)...
and yes, the engine did great on the GrpIII ST. I may just go back to it.
Flashpoint on "green" GC in my '05 STi after 5,800 miles was also 385°F, as shown in my UOA here:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic&f=3&t=003237
Yeah, I agree. It looks like he started to (over)treat a problem, which looking at the previous UOA, wasn't there to begin with.
please clarify - what do you see in the previous UOA that tells you I do not have excess CC build up? then please reconcile that with the photos I provided in the link above and the fact that my compression reads 210-220 psi on all cylinders (>25psi too high). the "over treatment" of fuel adds is an attempt to correct this condition after 9 months and many thousands of miles using lesser dosages without success. the LC20 was a light dosage to control thickening (a point which is open to debate), but there's plenty of evidence on this board to show that it does not cause high wear metals, even in much higher dosages. after listening to people's opinions, I believe the use of Gumout Regane to be cause of the high copper. unfortunately, it does not appear to have cleaned up the carbon and I will not use it again.
Whatever the problems you mentioned (CC build up, compression), looking at your past UOA, they didn't appear to be doing any harm to your engine (ie. no elevated engine wear). But of course, UOA does not tell the entire story.
I'm just saying, is it possible you're overreacting a bit? Are serious issues with the VQ30 engines widespread? Do people end up needing new engines?
I'm just saying, is it possible you're overreacting a bit? Are serious issues with the VQ30 engines widespread? Do people end up needing new engines?
overreact? me? never! seriously, I think we can all agree that chamber deposits are a bad thing regardless of their impact on wear metals. but how bad is bad? I guess the scenario I'm trying to avoid is this: as carbon and compression increase the ECU will have to retard timing to prevent pre-ignition. initially this will mean less power and poor fuel economy. left unchecked the variable timing will reach its limit and pre-ignition will be inevitable, causing a broken valve or blowing a hole in a piston. now the VQ is known to be bullet-proof, and I have never heard of this happening. but when I posted a pic of my pistons on a maxima forum I had about 12 guys blast me for having a "serious" carbon build up. of course when I asked them to post pics of their pistons nobody did. only one other maxima owner (Dave H here on bitog) has reported the condition of his pistons - and they look just like mine. so probably not too big a deal, but the high compression does scare me. 220psi.
You could always water clean or Mola-soak and see if that cleans the piston tops off...
quick question, just to be sure...
The gold GC you used...is it M05/M06, or is it M01 (date code on the bottom)?
Matt
The gold GC you used...is it M05/M06, or is it M01 (date code on the bottom)?
Matt
sky jumper,
I just checked my FSM for my '97, and the "standard" compression is 185 while the minimum is 142. That's a 43 point spread. There is no listing for "maximum". I would think that a 43 point spread would be acceptable going the other way, too. Your '99 should be similar, if not identical. Is it possible your compression gauge isn't accurate? If it has a margin of error of +/- 5%, then your compression could actually be 209 (or it could even be 231).
The "carbon" or whatever is on my pistons looks like yours, but doesn't seem to be causing any problems. I haven't checked compression, but will break out my gauge and check when I get a chance (and good weather). I'll post the results in this thread and PM them to you. I'm betting they'll be similar, or possibly a little lower because I have 111,000 miles on mine.
I have consistantly used MMO for 2+ years or so. I have also run Techron, Regane, Lucas, and some others during that time period. I've done several each of Seafoam and water through the intake, and even sprayed the piston top with Seafoam Deep Creep and let soak for awhile. There wasn't really any change. I also primarily use Shell V-power gas, with an occasional tank from other big companies.
All this leads me to think that what we are seeing is not really a problem. I may try some chemtool poured directly on a piston top to see if it has any affect. It should dissolve any carbon on contact. Now would be a good time for me to do it as I'm about to change oil anyways (starting my AutoRx rinse phase). I'll take your advice on doing 2 rinse phases before going back to GC.
Getting back to your UOA, I honestly wouldn't be concerned with the 12 ppm copper. I would continue what you're doing, and get another UOA in 5000 miles just to check on it. Like others have said, it may be from the additives. It's possible one of the additives stripped some copper from something and put it in your oil.
As for the PCV system someone mentioned on checking, I installed a PCV catch can a few weeks ago. In just 680 miles, I've removed 0.61oz of black oil from it. That means I would only lose about 3oz of oil through my PCV system in 3000 miles. I think one of the benefits of it would be that my combustion chambers and backs of my intake valves will remain cleaner without having to burn the oil residue. Maybe that is where our crud on our pistons is coming from. Only time will tell, unless someone else has more info on them.
Hope this helps.
Dave
I just checked my FSM for my '97, and the "standard" compression is 185 while the minimum is 142. That's a 43 point spread. There is no listing for "maximum". I would think that a 43 point spread would be acceptable going the other way, too. Your '99 should be similar, if not identical. Is it possible your compression gauge isn't accurate? If it has a margin of error of +/- 5%, then your compression could actually be 209 (or it could even be 231).
The "carbon" or whatever is on my pistons looks like yours, but doesn't seem to be causing any problems. I haven't checked compression, but will break out my gauge and check when I get a chance (and good weather). I'll post the results in this thread and PM them to you. I'm betting they'll be similar, or possibly a little lower because I have 111,000 miles on mine.
I have consistantly used MMO for 2+ years or so. I have also run Techron, Regane, Lucas, and some others during that time period. I've done several each of Seafoam and water through the intake, and even sprayed the piston top with Seafoam Deep Creep and let soak for awhile. There wasn't really any change. I also primarily use Shell V-power gas, with an occasional tank from other big companies.
All this leads me to think that what we are seeing is not really a problem. I may try some chemtool poured directly on a piston top to see if it has any affect. It should dissolve any carbon on contact. Now would be a good time for me to do it as I'm about to change oil anyways (starting my AutoRx rinse phase). I'll take your advice on doing 2 rinse phases before going back to GC.
Getting back to your UOA, I honestly wouldn't be concerned with the 12 ppm copper. I would continue what you're doing, and get another UOA in 5000 miles just to check on it. Like others have said, it may be from the additives. It's possible one of the additives stripped some copper from something and put it in your oil.
As for the PCV system someone mentioned on checking, I installed a PCV catch can a few weeks ago. In just 680 miles, I've removed 0.61oz of black oil from it. That means I would only lose about 3oz of oil through my PCV system in 3000 miles. I think one of the benefits of it would be that my combustion chambers and backs of my intake valves will remain cleaner without having to burn the oil residue. Maybe that is where our crud on our pistons is coming from. Only time will tell, unless someone else has more info on them.
Hope this helps.
Dave
the date code is M05075. I believe this is an early vintage Gold GC. it was made in Germany. either the lab is wrong, or this GC was watered down somewhere in the mfg process.
Dave - thank for the info. it would be interesting to see a UOA from your engine with your judicious use of adds like MMO. do you plan on doing one soon?
sky jumper,
I will be doing a UOA after my current AutoRx treatment is through. I just completed the cleaning phase last week, and will be doing 2 rinse phases. Then I'll get a UOA that won't be skewed from the cleaning process. I'll use that UOA and a visual inspection of my internals to make a decision about a 2nd AutoRx cleaning. Unfortunately, it may take me about 4 months or more to put 4000 miles on my car. I've actually been looking for reasons to drive so I can speed this along. That may get real expensive if gas prices keep going up....
Dave
I will be doing a UOA after my current AutoRx treatment is through. I just completed the cleaning phase last week, and will be doing 2 rinse phases. Then I'll get a UOA that won't be skewed from the cleaning process. I'll use that UOA and a visual inspection of my internals to make a decision about a 2nd AutoRx cleaning. Unfortunately, it may take me about 4 months or more to put 4000 miles on my car. I've actually been looking for reasons to drive so I can speed this along. That may get real expensive if gas prices keep going up....
Dave
Castrol Syntec 0W-30 with a date code "M01..." would not be GC, as it was not made in Germany back then (IIRC).
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