I think it's time one of you guys stepped up to the plate and did an "Infinite OCI Test". Somebody has to do it...Just how far can you go before "Complete Engine Failure" (CEF) results from a maximum effort OCI..??
How long should I run Mobil 1?
- Thread starter SteelheadGuide
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Obviously there are more coolant leaks than I am aware of. I will check our database on Monday and see how many we have found. I know it's not nearly as many as with diesel engines but I'm not afraid to admit when I'm wrong.
The point I was trying to make is the practice of taking one oil sample once a year is of questionable value. The poster I was responding to basically was recommending to take one sample and decide if you need to change more often. The only time I recommend taking one sample is when you are looking a buying a used car and even then the results are frequently inconclusive. If you you want to maximize your chances of catching a failure you need to do it more often. If you are going to sample then do it right otherwise you are wasting money and will be disappointed when we can't tell you what you want to know. We have one customer who samples every 3rd oil change. He is always complaining when he has problems that we didn't detect. It's interesting to look at an engine with a long trend of 150 samples or so and then to go through and take out every other sample or every 3rd sample. What you see will be a completely different picture.
The point I was trying to make is the practice of taking one oil sample once a year is of questionable value. The poster I was responding to basically was recommending to take one sample and decide if you need to change more often. The only time I recommend taking one sample is when you are looking a buying a used car and even then the results are frequently inconclusive. If you you want to maximize your chances of catching a failure you need to do it more often. If you are going to sample then do it right otherwise you are wasting money and will be disappointed when we can't tell you what you want to know. We have one customer who samples every 3rd oil change. He is always complaining when he has problems that we didn't detect. It's interesting to look at an engine with a long trend of 150 samples or so and then to go through and take out every other sample or every 3rd sample. What you see will be a completely different picture.
Al, it is a 3.8 liter (I think). Your are right about the $15 bucks if it helps get a warranty claim pushed through, I can't argue about that.
I guess I am just overly sensitive to leaks having had two 3.1's and (both needed the infamous intake manifold rfeplaced.) And my son's 3.4 had it replaced.
My son's Grand AM showed elevated sodium/potassium readings in May of '02. At that time I wasn't aware these readings meant coolant could be present. I had a couple of analysis done after that-but sodium/potassium were not given in the report. In Dec of 04 I had Blackstone do the analysis. The Potassium showed high again. And then then on June of '04 I had another analysis done and this time Terry Read it. He concluded that there was a leak. Bear in mind-none of the reports showed up "antifreeze" per se. Finally in Sept of 04 antifreeze actually tested positive. This was 2 years and 4 months after the leak started slowly.
I'm not really trying to push a point or an agenda. Just giving information of an actual history. And since it happened to me it probably isn't a complete rarity.
I don't believe the 3800 is prone to leaks but I have heard of a couple.
Later,
Al
Stinky your a man with Broad Shoulders and Conviction. I like a guy that will review the facts and base his opinion on the information presented. "Good Job"
Definately agree
Wrong. If you see it there you have done damage to the vehicle. Leaks can and frequently start out small and give values of sodium/potassium in the range of 15-25 for a year or two. The oil analysis will most likely not even show up for a positive antifreeze test (and neither will the cap). But sodium/potassium are a dead giveaway. I personally have had 3 antifreeze leaks on GM vehicles in the last 6 years. None showed up on the dipstick or the breather cap.
I can't speak about V6 engine leaks but I can tell tell you that I have looked at the oil analysis results from 1000's of gas engines and we don't see coolant leaks that often. Now if there is a certain engine that is prone to leaks then by all means test the oil, but in most cases coolant will raise it's ugly head and be obvious to those who are paying attention and watching their coolant levels, checking their oil, watching for white smoke, etc.
Don I agree that extended drains are not safe without oil analysis and regular oil changes, but if you are not taking frequent samples then what do you expect it to tell you? There are events that happen in engines that will cause abnormal readings but do not actually cause problems. Suppose you develop a coolant leak the day after you take your oil sample, what happens then? does it go undetected until next year? If you are going to sample your oil then do it right and do it at every change. Use the information to identify operation and maintenance shortcomings and to prolong life. For gas engines it is cheaper to change oil than pay for an analysis so if the only reason you are doing it is for extending drains then it isn't cost effective.
Stinky
Don I agree that extended drains are not safe without oil analysis and regular oil changes, but if you are not taking frequent samples then what do you expect it to tell you? There are events that happen in engines that will cause abnormal readings but do not actually cause problems. Suppose you develop a coolant leak the day after you take your oil sample, what happens then? does it go undetected until next year? If you are going to sample your oil then do it right and do it at every change. Use the information to identify operation and maintenance shortcomings and to prolong life. For gas engines it is cheaper to change oil than pay for an analysis so if the only reason you are doing it is for extending drains then it isn't cost effective.
Stinky
Al, you are right about early detection of coolant leaks, in fact this can be a big problem because the leaks are so slight they can be almost impossible to find. There are other things that can cause sodium and potassium to be eleveated so you have to be careful.
Oh really? I guess that you do not have much experience with modern GM 3.1/3.4l V-6 engines where these things are very common.
By the time you see coolant on the dip stick damage is being done.
Checking once a year for $20 is a complete no brainer in my book. Just do it. Less than the cost of one tank of gas. If you can afford to run a vehicle, you can afford an annual oil analysis. Otherwise you should be on the bus/train/bicycle.
John
If you're an average driver that is just concerned with using quality oil with a good filter, while protecting your engine, you will be fine. I don't ever plan on doing an analysis for any of my vehicles. I use Mobil 1 and Purolator filters and go about 5k for my oci. Your plan of 7500 should be fine unless perhaps you drive very hard. If the science and minute details of analysis thrill you, go for it! You may learn a thing or two, but in my opinion it would be nothing of any real consequence.
quote:
Originally posted by Stinky Peterson:
Thats true..sodium can be in oil..but that can be spotted by the VOA on this board...especially the RedLine. And it can be a part of the silicon. But after a few readings on this board even a piiker like me can get it right. Now I have had my oil analyzed by Terry and information that he gave me helps a lot. And really for a few bucks Terry will spot the leak 100% of the time. Not really arguing-just making a point
Oil analysis recently saved me 600 bucks for a head gasket. No leaks evident. GM replaced it at 50K miles.quote:
Originally posted by andrews:
You may learn a thing or two, but in my opinion it would be nothing of any real consequence.
After making the statement that we didn't see very many coolant leaks in gas engines I decided to check and see how many there actually were since several of you have obviously seen more.
Here's what I found:
Gas engines tested: 9318
Gas engines with coolant: 372 or 4%
By Brand:
Chevy-GM 118 of 2431 - 4.9%
Ford 50 of 2308 - 2.2%
Chrys 27 of 530 - 27 5%
Many these were probably people looking for problems as opposed to regular samples so this is no doubt skewed.
I had thought that we see more coolant leaks in diesel engines but I was wrong. Out of 273397 samples 4016 were positive for coolant or about 1.5%. We do see more coolant leaks but only because we see a lot more diesel samples.
Stinky
Here's what I found:
Gas engines tested: 9318
Gas engines with coolant: 372 or 4%
By Brand:
Chevy-GM 118 of 2431 - 4.9%
Ford 50 of 2308 - 2.2%
Chrys 27 of 530 - 27 5%
Many these were probably people looking for problems as opposed to regular samples so this is no doubt skewed.
I had thought that we see more coolant leaks in diesel engines but I was wrong. Out of 273397 samples 4016 were positive for coolant or about 1.5%. We do see more coolant leaks but only because we see a lot more diesel samples.
Stinky
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Let's put the "one UOA" in context for SteelheadGuides desired outcome.
For wear related issues ..one UOA will not do much for anyone ..especially on the first pass on a new oil. One UOA will tell you if the OIL is holding up to the service its being subjected to.
So, SHG can go his 7500/6month OCI ...do a cheaper UOA ..or for that matter a full blown TBN/Dyson test ..and see if it's working out for the service interval.
So, an ongoing UOA program is preferred, but not necessary if your object is ONLY to determine if the OIL is good for the distance/service. It won't tell you if your engine is responding well to the oil.
We have it tough compared to most heavy or industrail equipment. We've got a tremendous variety of weights and compositions to choose from. There's also a wide variance between one xw-30 weight and another and many engines, from various manufacturers, respond differently in metal retention/production. I think that this "fine tuning" is still a rare craft.
For wear related issues ..one UOA will not do much for anyone ..especially on the first pass on a new oil. One UOA will tell you if the OIL is holding up to the service its being subjected to.
So, SHG can go his 7500/6month OCI ...do a cheaper UOA ..or for that matter a full blown TBN/Dyson test ..and see if it's working out for the service interval.
So, an ongoing UOA program is preferred, but not necessary if your object is ONLY to determine if the OIL is good for the distance/service. It won't tell you if your engine is responding well to the oil.
We have it tough compared to most heavy or industrail equipment. We've got a tremendous variety of weights and compositions to choose from. There's also a wide variance between one xw-30 weight and another and many engines, from various manufacturers, respond differently in metal retention/production. I think that this "fine tuning" is still a rare craft.
SteelheadGuide: To answer your original question, you can most likely go 1 year or 15,000 miles between changes. Read this post:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=009069#000012
for more information.
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=009069#000012
for more information.
A used oil analysis is still worth it to detect coolant even if you can see it yourself. because even with the visual evidence of the coolant reservior becoming empty. The Nissan dealer on convington pike road still said the cooling system pressure tested 100% I got ****** off and did two used oil analysis with potassium and sodium freakishly high, they were still reluctant to do anything. Until the check engine light came on indicating a misfire in cyclinder 2. The engine wouldn't start at all. The headgasket failed. It looked like they were trying to give us the runaround while he was under the 5 yr/60k powertrain warranty. Car had about 48k miles when it failed. My dad drives 30k miles a year. But the service writer found out my dad had the 7/75k extended warranty. They had to fix it unless they want to put in a new engine LOL Then the service writer gave us a guilt trip to give him a good score on some survey that corporate nissan sends out when they do warranty work.
The used oil analysis is proof in small claims court if they didn't do anything and the engine failed after warranty.
[ January 12, 2005, 12:24 PM: Message edited by: Cutehumor ]
[ January 12, 2005, 12:24 PM: Message edited by: Cutehumor ]
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