drraulduke

If anyone is interested I'm attaching my oil analysis that I got from Blackstone Labs. They seem pretty decent, and I got the report emailed to me within a few days. Seems 2% of the sample was fuel, which they consider excessive, and I have slightly higher bearing wear than normal probably due to dilution. Guess I need to look for a faulty fuel pressure regulator, vacuum leaks, O2 sensor, leaky injectors? Any other ideas?

No HTwo O

It's only one report. Don't get too worked up, just yet. It at least establishes your base-line.

When you drive your car, how many miles in a typical drive/trip? I suspect you do a lot of short trips. Longer trips will help to burn off the fuel contamination in your oil. Before your next sample, do a good long drive (+100 miles), just prior to taking the sample. Your numbers may improve.

But, overall, I bet you do a lot of short (<25 miles) trips.

drraulduke

yes...you're rightd. Mainly 3.5-4.0 miles to work, and I don't necessarily drive it every day. That's good advice, thanks. Before I do the next oil change I'll go for a nice long drive. I've been doing changes every 6 months because I don't put that many miles on the car. Would you recommend a different interval? Thanks, again.

No HTwo O

Well, you are doing the right thing to increase your interval, since your driving style would be classified as "servere" (due to the very-very short trips). I think unless you start driving it more, you'll continue to see those high fuel cont. levels.

Bottom line.....you really need to drive her more.

A couple miles here....a few miles there....is bruttal on any car. Especially a Porsche.

drraulduke

Yeah....I guess I can take the really long way to work and back :-). I know short trips are terrible on any engine. That's why I did the oil analysis. Any other preventative measures I can take?

bgiere

as was already pointed out, it is just one UOA...you cannoy really draw conclusions until you have multiple UOA's and start to look at trends. Lead could be from high fuel and the fact that you never get the engine up to operating temp. Either way you can't tell from one UOA. you need to drive it farther and more often. Good thing you used the 50 weight because the fuel diluted it down. Doesn't Brad Penn advertise a higher Zn number?

No HTwo O

I wonder if a full synthetic oil would hold up (viscosity) any better, to the fuel cont., than the Brad Penn? Just a thought.

drraulduke

I'll do another oil analysis when I change again in 6 months. Yeah, Brad Penn does advertise higher Zn. It's also a partial synthetic, but maybe a full synthetic would hold up better. I don't know. The only reason i'm not using a full synthetic is that I've read some horror stories with the 944 and full synthetic, plus a personal experience with a friend using it in his 944 and not getting good oil pressure. Thanks for the suggestions

chrisc

I would like to hear more about the horror stories and poor oil pressure with full syn. Mobil 1 seems to work well in my track car. Did a preventive bearing replacement at 84,000 miles and they still had plenty of life left in them. Did a recent valve job and everything also looked fine. (Mobil1 15 50+Lindsey ZDDP)

drraulduke

I apologize Chrisc. I was probably being a little over dramatic there with that statement. I guess when I was researching what oil to use, I found some posts from mechanics writing that many times when they saw a 944 with what looked to be excessive engine wear it turned out that they were running full synthetic. My friend may have used the wrong weight Mobil 1 (I can't remember if it was 15W50 or not). The shop I bring my car to, Ryland's here in Atlanta, who were highly recommended to me, told me to use conventional 20W50 (that may have been because of older seals). I split the difference and went with Brad Penn which is partial synthetic with higher ZDDP. That also seemed to be recommended by a lot of poeple. I don't want to start an oil war here (i've seen them on rennlist before). I am not an expert by far, but I would fully agree on a track 944, Mobil 1 is the way to go.
I like your idea of using Lindsey ZDDP with Mobil1 though. Do you think that if I went with Mobil 1 it would hold up viscosity better than Bradd Penn against the fuel dilution? Also do you think I would start getting leaks from the seals if I started using a full synthetic?

chrisc

I'm old school, I don't like switching types of oil, much less brands. Many years ago all I used was Kendall GT1 (I think the original Brad Penn). I bought my car from an old friend who had it from new and it's only had Mobil1. The guys at J-3 thought it best to stay with it in my case. They they have full engine rebuilds they've done that use Brad Penn and Joe Gibbs so they're not locked in to Mobil1. J-3 did my rod bearings and valve job recently. Based on what Todd saw he saw no need to move from Mobil1. The 15-50 Mobil1 does have a higher content of the nasty chemicals the EPA would like removed so the Lindsey ZDDP may be overkill. I contacted Mobil1 to ask if the new Mobil1 Racing Oil would work in my car - think it's 0-50 and according to the specs it's really loaded with the nasty stuff (should be at $9.99/Qt). Don't have a reply from Mobil yet. If Ryland told you to use the Brad Penn I would stay with it. Likely the short runs are the problem with the dilution. I was told anything consistenly less than 15 - 25 miles is really hard on an engine and cars driven that way on a daily basis need more frequent oil changes based on the calendar, not mileage.

Oh - re the oil pressure, with the old Porsche gauge mine was all over the place. With an aftermarket mechanical gauge the pressure readings are right where they should be.

Mike C.

I've run the M1 15-50 in my car pushing 200K miles with no ill effects (including some track time). Compression, cylinder walls and cams all looked good when I did a head gasket about 10,000 miles ago.

drraulduke

I think we are pretty much on the same page chrisc. You have a lot more experience than i do. I am relatively new to this. I don't really want to switch oils around because I think conventional is what has been in this car, I can't be 100% positive though, just going on what Rylands told me. I also have no oil preference as long as it is good for the engine and the type of driving I'm doing. I guess because I am driving only a few miles to work and back perhaps I should do another oil analysis in 6 months and if I see the same thing, cut the interval time to 3 or 4 months? Does that sound reasonable? I
Thanks for the heads up on the aftermarket oil pressure gauge. I'll pass that along to my buddy.

No HTwo O

No. Until you alter your driving style (very-very short and infrequent trips) I think you'll keep seeing high fuel levels in your UOA. Plus, you'd be wasting good oil, your time and money on 4 (unnecessary) oil changes per year.

Some would suggest, that oil changes this often (4) would increase engine wear, due to the detergent package and the inherent properties of new/fresh oil.

Just drive it more. Instead of another oil change, go for a long drive, save money and enjoy the car.

drraulduke

OK, I thought that more often oil changes were bad, but this made me question it. I'll take it for a long drive up to north GA. Thanks!