When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It still directly contradicts what Charles Navarro says about fuel dilution, unless I missed something. Raby is constantly talking about how fuel is a solvent, emphasizing the importance of fuel dilution because of “old” or leaky injectors washing cylinder walls, etc. I’m OK spending a few hundred and a few hours on the weekend replacing if it prolongs the onset of serious borescoring. I just replaced my original fuel injectors (manufacture date on the injectors were 2-13-2006). When I button everything up and getting it running I’ll put some miles on it and then check fuel trims to see if there is a difference.
Last edited by TerrestrialFlyte; 11-12-2022 at 09:57 PM.
It still directly contradicts what Charles Navarro says about fuel dilution, unless I missed something. Raby is constantly talking about how fuel is a solvent, emphasizing the importance of fuel dilution because of “old” or leaky injectors washing cylinder walls, etc. I’m OK spending a few hundred and a few hours on the weekend replacing if it prolongs the onset of serious borescoring. I just replaced my original fuel injectors (manufacture date on the injectors were 2-13-2006). When I button everything up and getting it running I’ll put some miles on it and then check fuel trims to see if there is a difference.
I'll defer to Lake on his recommendations. I do want to add that I gave a talk yesterday on this topic and referenced an oil sample taken and sent to both Blackstone and SPEEDiagnostix. Blackstone's report said less than 0.5% but the SDX test (which actually does a separate GC test to check for fuel dilution vs Blackstone that estimates the value) reported almost 2%. That's a huge spread. My recommendations on fuel % go back years well before Lake added a separate GC test and we were going off estimated fuel % values.
I too am curious to see if you will see a change on fuel trims and if that will be reflected in a UOA.
Thanks for looping me into this @silver_tt . As you've pointed out, my fuel dilution has constantly been around 1.5 since I bought my car in '19 and started doing UOA's with Speediagnostix. Since you mentioned it, I asked for clarification from Lake and below is his response:
"Thanks for the questions. The fuel dilution of 1.5% is typical for these engines, so you are good. We flag fuel dilution if it goes over 2%.
In regards to the oil consumption, have you considered trying the Driven DI40? Some engines just tend to use some oil, so I would not be worried about it unless it increases."
When I emailed Lake, I was sure to specify that my car was a 997.1 with the M97 port-injected engine. However, he makes reference to DI40 oil which is specifically formulated for DFI cars. Perhaps he is confusing the two?
I don't see as many Speediagnostix UOA's posted compared to Blackstone, and we've already covered why the Blackstone fuel dilution results shouldn't be taken seriously, but it seems as though most of the 997.1 results I see with Speediagnostix have roughly 1.5 fuel dilution, mine included. Both @TerrestrialFlyte and @onnastick posted similar results within the last few weeks as well. For reference, and so we can keep this conversation going on the same thread, below is my most recent Speediagnostix UOA with previous results included. I use Millers CFS 10W50 NT+ oil.
I find it hard to believe, yet not outside the scope of possibility, that all three of us and many others need new injectors, so I'd really like to get some clarity on these measurements and if there is cause for concern. I have watched the YouTube video on why it is important to address fuel trim levels BEFORE a check engine light appears, but I'm also not the type of person who just throws parts at my car as part of a solution looking for a problem. I also asked my Indy a while back if I should consider proactively changing my injectors, and he told me not on my port-injected car.
You are using used oil analysis as intended. With trend data showing roughly steady state with no huge changes, I wouldn't be concerned. It's when you see a sudden change in values that you should question why that is occurring. I defer to Lake's expertise in this area.
I'll defer to Lake on his recommendations. I do want to add that I gave a talk yesterday on this topic and referenced an oil sample taken and sent to both Blackstone and SPEEDiagnostix. Blackstone's report said less than 0.5% but the SDX test (which actually does a separate GC test to check for fuel dilution vs Blackstone that estimates the value) reported almost 2%. That's a huge spread. My recommendations on fuel % go back years well before Lake added a separate GC test and we were going off estimated fuel % values.
I too am curious to see if you will see a change on fuel trims and if that will be reflected in a UOA.
Thanks for clarifying. Would it be OK if I PM you to make sure I’m tracking the right parameters, waiting the right amount of drive cycles, etc, so that there is accurate data?
Thanks for clarifying. Would it be OK if I PM you to make sure I’m tracking the right parameters, waiting the right amount of drive cycles, etc, so that there is accurate data?
Please open a support ticket on the LN website. It'll get forwarded to me for review. I'd be more than happy to help.
Speaking of fuel dilution. I'll add mine to the lot as well since I have a history of changes now. I don't know whether to be concerned about mine or not. It's a DFI and I always take on long drives, nothing short. The exception is pulling out of the garage to wash every now and then. Besides that, everything else looks pretty stable. All were below the 2% discussed above. These oil changes all had M1 5w50. The 1st change likely had some residual 0w40 from the dealer but was 8 qtuarts of 5w50 plus residual. My latest change, I switched do Driven DI40. We'll see what those numbers look like after the next UOA.
Your fuel dilution at 1.5% is nothing to worry about for DFI but the history just shows how noisy Blackstone's metric is: It went from 1.0%.....to TR (trace).......to 1.5%. Given that you said you mainly take it on long drives and didn't drastically change your driving, there is no way there could be that degree of variability except just to say that flashpoint is a poor approximation.
Here is my first 997.2 oil analysis. She burned about .75 quart in 2500 miles. I’m not sure which oil was in it originally and. I didn’t do a driven flush before hand so it will be curious to see what my analysis looks like next year.
Here is my first 997.2 oil analysis. She burned about .75 quart in 2500 miles. I’m not sure which oil was in it originally and. I didn’t do a driven flush before hand so it will be curious to see what my analysis looks like next year.
Iron is a little high for only 2,500 miles, but see what the next one looks like with less contamination from what was in the car previously. Otherwise, good report.
I predict that when you sample again after another OCI or two that your fuel dilution will decline significantly (DI40 will inherently hold less fuel in suspension). This will also make your wear numbers, which do not look bad, look better.
Case in point. When my car was under warranty I did dealership oil changes . As soon as the CPO expired I switched to DI40 and my fuel dilution dropped from 1.94 to 1.3 between the first sample of DI40 and the long-term average 40K miles later (exact same number of miles, exact same driving habits, sample taken at the exact same time of year to control for winter blend gas etc).
Just throwing this up here for another reference point:
Ignore the ridiculous silicon level in prior report, i stupidly collected the sample in a soft TSA compliant bottle that obviously leached Silicon into the sample. Blip in Aluminum is more concerning but I’ll wait for further confirmation in subsequent UOA.
Just throwing this up here for another reference point:
Ignore the ridiculous silicon level in prior report, i stupidly collected the sample in a soft TSA compliant bottle that obviously leached Silicon into the sample. Blip in Aluminum is more concerning but I’ll wait for further confirmation in subsequent UOA.
The more of these reports I see the less I like the results from LM oil. They always have very high Iron content vs other reports and as you mention the aluminum increase is concerning, but your iron has been double digits in the last two reports, which isn't good. Also, if this is the report from your 2009 DFI car, high levels of calcium actually contribute to LSPI (low speed pre ignition). This oil also has virtually no Moly in it with is a great anti-wear additive and why LM sells it separately.
If this were my car, I'd go back to the 3,000 mile change interval where the wear numbers looked much better and I'd also switch to Driven DI40 and look at 2 of those samples in a row and I bet there is an improvement in metal wear that's better in the first one and even better in the next one.
@Petza914 thx for the feedback, I def will return to shortened oil change intervals, really wanted to stay around 3k but I took some longer drives that really added the miles, combined with being a procrastinator, led to a 5k mile average these past 2 cycles. I also plan on switching to Driven DI40 (yes this is my 997.2 DFI engine) and see how the next 2 or 3 reports look.
If it's the 2009 it's a naturally aspirated 4.0 so LSPI is less of a concern than it would be on the newer DFI engines that are forced induction (turbos). I agree though that DI40 is still a better oil even if you don't need LSPI protection.
I know Jake recommended the LM. Still fascinated why he thinks it's better than DI40 since he always has solid logic.
I also personally switched to 3K OCIs once my engine hit 100K miles. Oil is cheap compared to engine work......
11-12-2022, 09:43 PM
