jeff0093

Hi,

Hearing about bore scoring happening on cars that are driven in colder climates what is a "safer" average over night temps, for us North East cars to be pulled out of storage. Also had anyone have real experience with liqui moly ceratec additive, I'm currently running 0w40 Motul if anyone is asking.

lowbee

relex and enjoy the car, Germany has winter too

ebs3349

All service records for my 2005 997.1 C2S show Mobil One oil changes at recommended service intervals since new up to 27K miles for its first 12 years. Then it was my turn and I continued the same regimen except I have been changing the oil every 5K as my daily driver. I just turned 43K miles and have switched over to the Liqui Moly Leichtlauf 5w40 recommended from a local shop here in Richmond, Virgina (https://lufteknic.myshopify.com/coll...cayman-m96-m97) and I am pleased! The engine runs quiter and "feels" smoother as well. I was adding about 1 qt. of Mobil One every 1500 miles or so before the switch. Now I have 1700 miles on this new change and the oil level has barely moved. I just drove down and back to Amelia Island this past weekend expecting to have to add a little oil but to my amazement I didn't have to. That was 9 hrs. non stop, except for fuel, down and 9 hours back as well as driving around to the different venues for the Concours d'Elegance. The level has only dropped one notch. I'll continue to "drive it like I stole it" and follow up if any issues or concerns arise... wish me luck!

groovzilla

These bore scoring threads are so funny!

DC911S

Do you take your 911 on RT-33 in central Va? Harrisburg Va to Elkins WV is a blast!

DesmoSD

I heard the 991.2 GT3's also have bore scoring issues...
















Im crossing my fingers that this will go viral so owners will dump them and the prices will drop. lol

docdrs

An average safe over night temperature of 42F or 6C is quite adequate. This assumes no block heater. If you have a block heater then the outside temp can go quite lower but you will have to take an oil temp reading making sure it does not drop below 40 F. We usually use the dipstick tube for this, but as it can be quite difficult to find it or absent you may be SOL . An alternative is the oil filler tube but then you may require a special bendy thermometer, www.bndytmometr.gc.ca.com , or the micro oil plug adapter from lm Engineering ( the micro A.S.S. retrofit solution guys). Now if you are running snow tires then disregard everything above and squeeze your *** cheeks tight for the day you have to call to have a rebuild. (no monkeys were used or harmed in this response)

cosm3os

What exactly is the theory behind the theory that cold climate breeds scoring? And how do you arrive at 42 degrees?

jeff0093

I've read on hear about bore scoring and some of the engine builders saying it is happening more often in colder climates, so I decided to posted to see what people opinions were if I didn't have to drive the car during the winter which I'm lucky to have a winter ride, what was a good time/ temp to pull cars out of storage? Trust me if the weather was nicer here in CT. it would have been out two weeks ago. I'm not too personally concerned because, I use good oil 0w40 and have a extended warranty on the car. I was just thinking if it's that much safer to wait two to three weeks to pull the car out? My second question was on the liqui moly ceratec additive https://products.liqui-moly.com/cera-tec-1.html I guess no one is using it on this forum, the local LM rep is really talking it up and yes I know he sells it.

keynes

I believe the technical term for that post is "satire". Glad to help.

groovzilla

my lawnmower has bore scoring

bazhart

The problem relates to 2 issues. (1) cold starting and (2) the position of the thermostat.
(1) It takes time for the coolant to heat up and the oil to get hot enough to be viscous, but the piston heats up much more quickly - so if the piston to bore clearance is small (usually a good thing) and you drive the car too spiritedly from cold, the piston can expand more than the cylinders does and fit too tightly in the bore while the oil can easily sheer because it is still too thick and this can encourage "cold seizing" or scoring.
(2) Car's require sufficient radiator area for the hottest most arduous driving and in a car than can do 997 3.8 speeds and can be sold to very hot countries that needs a lot of radiator area.
The thermostat controls the flow. If the coolant is too cold it reduces the flow and if it is too hot it increases it.
In very cold weather the radiator area has such a huge cooling effect that the flow is reduced considerably.
In normal driving the amount of heat transferred to the coolant is a product of the heat generated and the flow rate.
If the flow rate is low but the heat generated is normal average then as the coolant flows through the engine it has more time to pick up heat and the temperature gradient between the coolant entering the engine and the coolant leaving it increases.
If the thermostat is on engine exit the hottest temperature is being controlled by the thermostat and it is the inlet to the engine that receives the coolant gradient lower on entry.
If the thermostat is on the inlet to the engine it controls the entry temperature and so if the flow is low and the temperature gradient is high - then the coolant exit temperature is higher than on a hotter day. This makes the oil thinner and less able to resit the forces pressing the piston face against the cylinder wall and can lead to scoring.
The best thing to do in cold climates is to reduce the available radiator area by fitting a blind or blank off some or all of it.
In our tests a 997 3.8 ran perfectly well with one radiator blanked off and the other partly covered in temperatures between 5 and 8 deg C.
We are developing thermostat housings that we tested successfully with different temperature rates so each radiator opened at slightly different temperatures to maintain a more consistent temperature gradient inside the engine and on our race car we fitted exit thermostats to each bank and removed the inlet thermostat.

Baz

cosm3os

This is satire. I was was actually looking for some explanation. Thanks Baz

groovzilla

This bore scoring thread has been strung along by worry warts - The failure rate is so miniscule - Any long term Porsche owner(me 40 years and have owned all models) knows there have always been issues with small percentage of almost every Porsche model.
Car forums blow everything out of proportion and whats worse, there are now commercial vendors who partake in making money on said problems and I'm sure enjoy stirring the pot. Conflict of interest for sure.
Every Porsche model over the years have had engine issues:
356 - poor cooling only able to get 60-70K miles out of engine = resulting in engine rebuild
1978-1983 911sc - failing tranny syncros, failing chain tensioners, broken head studs = resulting in top end rebuild/rebuilding transmission
1984-1986 911 - bad valve guides = resulting in top end rebuild
1989-1992 964 - engine oil leaks beyond repair = resulting in engine reseal/rebuild
993 - Air passages clogging and not able to pass emissions = resulting in top end rebuild

SoCal C2S