Gibbo

Hi there

Had my bores recently inspected on a plug changed. The report came back saying no.6 cylinder was worse with minimal scoring and was no concern. The others either had very minimal scoring or nothing.

So is it time to worry or is it quite normal for there to be some scoring, engine has 50,000 miles.....

Or is it a case of once there is minimal amount it is on borrowed time or is it normal for them to have a small amount with age?

Car is using little to no oil at moment, zero smoking, making above stock power, should I worry, or keep enjoying the car?

USMC_DS1

Check with Hartech. They're the expert on this and did a nice write-up re the cause of it. http://hartech.org/docs/buyers%20gui...20part%205.pdf Basically proper engine cooling and a proper warm up cycle before working the engine hard is the key towards avoiding this issue. Did you happen to get any images captured of the scored vs. non-scored cylinder? I'm considering an inspection of my cylinders prior to the expiration of my CPO next year. I believe this is a much more prevalent potential issue then the IMSB failure... but the IMS internet scare/hype gets all the attention/focus. I think you're fine but it may be beneficial to invest in a 3rd rad and a low temp t-stat... especially if you're located in a hot climate. Regardless of hot or cooler clime... always allow the engine to warm up(keep it under 4K RPM) until it reaches operating temp, at least 200degF, before exercising it to it's limits. And I like to work the engine up through it's power bands gradually - 4K sustained, 5K, then 6K before I do any type of driving which requires working the engine from low to high RPM ranges - working the engine hard.

Gibbo

Hi there

I've got the 3rd radiator already.

Shall speak with Hartech tomorrow as plan on:-

1. Fitting low temp stat they sell
2. Changing my oil to Millers Nanodrive 10W-50 from the Mobil One 0W-40, anyone else done this?

PTParks

Proper engine warming is important but how you warm the engine is also critical. Easy revs on a cold engine until the correct operating temperature is reached is the desired method. However I would be critical of allowing an engine to simply idle itself to operating temperature. Low oil pressures and uneven cylinder warming during extended idling times would be my concern.

Luxter

Yes, CFS 5W-40 NT currently in.


More on scoring here:

http://www.pistonheads.com/gassing/topic.asp?t=1039296

Cheers,
=L=

Gibbo

My only concern with Millers is it's not Porsche approved, but reading about it it comes across as very impressive oil.

Maybe 10W-50 would be an even better choice?

Luxter

It will never be on A40 list since it's not fully miscible with ~100 other oils that are not NT. That's one of the premises required for approval.

5W-40 behaves just like X-Cess 5W-40 when it comes to pressures and engine oil temperatures.

Actually, that's kinda funny, after about 1.5 Mile long hill climb on my way home (and I climb pretty fast, let me tell you) I got to sit in traffic on top of the hill for a while and to my surprise, oil temperature was dropping slightly from just a tad over 200*F to a small bit below 200*F. Ambient temp. was in about 65*F range, please don't laugh, that was a nice evening over here .
Normally after a harder run, idling the engine would cause increase in oil temperature until you get air flow through the rads again.

I got an CFS 5W-40 UOA from Subaru WRX that I came across on BITOG. It contains a healthy dose of Zn & P, lots of Ca and Moly. Not much different than say Motul 300V in general terms. Obviously Blackstone analysis would not show the NT components in their report.

For warmer climates (TX, FL, CA, etc.) 10W-50 may be just perfect. I've settled for 5W-40 at the moment, unless I see an intelligent explanation from Hartech why 10W-50 is better in comparable climates. They indicated in email to me that they use 10W-50 indeed, but did not provide any explanation. The email response came back to me when Baz was away and it was rather brief.
Another option would be to contact Millers directly and seek their recommendation.

BTW, Baz Hart claims that their (Hartech) low temp T-stat is NOT the same as LN t-stat. Not sure what the differences are.

More questions, fire away...
Cheers,
=L=

Macster

I find it interesting that to "prevent" scoring a heavier oil is recommended. Along with a colder T-stat (not that this will result in lower max temps only that the engine takes longer to warm up).

This is kind of funny (sad funny as many swallow this lower t-stat BS like mother's milk) but a colder T-stat and a heavier oil...What a combination.

A 10w-50 oil. While the 50 is not an issue per se: Porsche has approved a 5w-50 oil (not a typo for 15w-50!) no 10w-xx oil is approved.

Why do you suppose that is? Because a 10w-xx can't lube the engine properly at start up and shortly after. Guess what this could lead to? Scoring.

Really it appears to me that anyone recommending a thicker oil, one with a higher "W" number for "bore scoring" protection along with a lower temp t-stat would put try to put out a wood fire with gasoline.

Luxter

Please let us know the outcome of that conversation.
Many thanks,
=L=

Gibbo

Think Hartech know what their doing. Many of the GT3 guys run the BMW M 10W-60 oil for it's better protection. Also a higher W oil has better filming properties I believe which helps keep things better lubed.

The engine running cooler surely means engine oil does not thin as much, oil looses it's protective properties when it gets too hot.

user 72902

I think Macster's point was that the potential for damage from a heavier oil and a lower temperature thermostat occurs while the engine and the oil are warming up. The lower thermostat will increase warm up times while heavier oil could limit lubrication initially.

USMC_DS1

+1 re the 3rd rad... I also added a deep sump oil pan plus baffle from FVD recently. http://www.fvd.de/us/en/Porsche-0/-/...otorsport.htmlIt may still be too early to note definitively but we've been seeing temps in the low 90's already and my oil temp e-gauge is still reading less than 225*F under hard driving conditions and my oil pressure is remaining at slightly less than 2 bars at idle with MB-1 0w-40... under these same conditions last year w/o the deep sump pan my temps were higher even with the 3rd rad.

I took an intermediate step re oil. The NT oils like Millers sound spot on and I may start lubing some of my firearms with it. But since my car is still under CPO I decided to try Motul 8100 X-cess 5W-40 which is on the Porsche approved A40 oil list. It's also about the same price as MB-1 if you buy it in bulk. ~$142 for 2 oil changes... http://www.amazon.com/s/?ie=UTF8&key...l_2nkjnrdd7q_b

Skootnasty

But cylinder scoring happens from the piston rings dragging against cylinder walls without the proper "oil skin". The skin is at its least on cold startup after the oil has drained from the cross hatches. It takes heat to thin the oil so properly sling onto the cylinder walls where the rings can scrape it along the bore. I think Macster is simply saying adding a heavier oil and lowering coolant temps will result in longer times before the proper amount of oil is slung onto the cylinder walls.

You are absolutely right that cooler oil will protect bearing, rotating, and pressure fed parts much better than over heated oil. Slung oiling is the one exception to the lubrication rule. Oiling ports at the base of the cylinders do help, but they are actually designed to reduce cylinder temps. They do not achieve optimal performance until the oil thins some as well, due to the relatively large passage through them.

Skoot

Luxter

Here:

http://www.pistonheads.com/gassing/t...+scoring&mid=0

As bare minimum.

And Hartech guide 5 for those with bigger appetite.
I am not taking any sides, merely trying to understand and hopefully prevent this issue.
Happy reading,
Cheers,
=L=

CAVU

Skoot,

Any idea for our engine types, how long the "oil skin" lasts? Sometimes I'm driving everyday, sometimes I may go a week or two ('cause of the J.O.B.). I'm probably not going to change my starting habits: start, let idle for about 30-60 seconds while I square the cockpit away and off I go aware of the oil temp rise.

Thanks!