FWIW, scoring and cold climes is attributed to different expansion rates. I wonder how many folks who live in very cold areas start their cars and let them idle until warm. I wouldn't be surprised to see top end damage from that practice.





From Mac's post: A Canada car -- or one used in extreme low ambient temperatures at any rate -- is more likely to suffer from a scored cylinder though I do not accept some of the reasons offered.

 

I wish I had more info on this cold weather climate thing. I m in very cold weather but do not daily drive mine and it comes out of a heated garage when I do. What does this mean if anything? On a clear day it could be below 0 and I ll take it for a ride if the roads are clean. I don t run it for more than a min or two and then slow drive it until warm.
Interesting... Good luck to the OPer and hope it ends better than expected.

 

Sounds like yours is the best case scenario. I still believe it is better to run the car q2wks or so as long as roads are clean. Welcome to the great experiment. I messed up, had coils and plugs changed this year, should have had them take a peak inside, at least #6, at that time. At ten years and 44k mi with the old girl I am curious. Performance wise she runs as great as ever but I do have (from day 1) some oil consumption and left side exhaust runs darker. Porsche scoped the motor and did leak downs etc at one year and found "no signs of wear." So who knows? 7200 rpm in 3rd makes all the worries go away Enjoy.

 

Maybe most of our concern is internet hypochondriac ...

 

so I ve been thinking on this subject..... and mine runs fine, quiet, no oil burn etc, but even if you have a scope check come back clean or have a car with no issues, one ride on a cold day and you have a scored cylinder??? Doesn t add up to me?

 

Actually I do not think that's the problem.

Letting the cold engine idle a bit until its idle speed drops is about when the DME switches from open loop mode to closed loop mode and the DME can then more precisely fuel the engine.

At this point too at least in those MY's that have the secondary air injection system the secondary air injection pump is shut off and the extra rich fueling is cut back. (Extra fuel is injected to combine with the extra air injected to burn in the converters to warm them up quicker.)

By letting the engine idle from cold start to where the engine/sensors and converters are hot enough to allow the DME to switch to closed loop control has engine running of course but it is producing as little heat as is possible.

Thus the piston's increase in temperature is reduced and any growth in size is also reduced.

In some cases too the wrong oil being used could be a factor. Porsche guidelines call for 0w-40 in cold (-25C or below) weather but some owners might be tempted to run 5w-40.

Yet another explanation, at least a possible explanation, is one of the oil jets may be partially or completely blocked. As a result the piston does not receive a full dose of cooling oil and it runs hotter. To make matters worse the piston/cylinder do not receive a good dose of oil which of course also helps provide more direct lubrication of the piston/rings/cylinder wall interface.

If in a bore scored engine a thorough post-mortum is not performed or if attention is not paid during the rebuild if the engine is rebuilt, a subpar oil jet may not be noticed or the obstruction is removed without the obstruction being noted other than in passing by the tech who probably won't mention this.

There is too a role played by how long the oil is run. A car that sees little use does not necessarily mean the car requires little servicing.

My reasoning is winter driving will probably not get the oil hot enough to boil out all the water the oil accumulates, water being a combustion by-product.

(As an aside, when I had my 2002 Boxster's oil analyzed -- on a whim -- after just 4K miles from new and these 4K miles accumulated in the dead of a KC Mo area winter -- the oil had 7% water in it. My usage consisted of some short drives, approx. 10 miles long, but a number of longer drives, too, some around 150 miles at freeway speeds.)

This water then affects the oil's abilty to provide sufficient protection against metal to metal contact and bore scoring can occur. The only way to remove this water then is to replace the oil. And the timetable to do this may not be the miles in the owners manual but fewer miles.

I adopted a 5K mile oil/filter service interval but if my driving during the year didn't amount to this much, my preference then would be to change the oil just before the winter season and if I continued to drive the car during the winter to change the oil again as spring approaches.

 

Can't be that simplistic. It is cold in Europe but it is worrisome.


Here's my advise to you for a little extra piece of mind, and I'm not gonna bother with the flame suit:


As heretical as it sounds, I recommend you do a search and read ALL the literature on Mliltec-1. Forget the "snake oil" nonsense. Seriously, Militec-1.


I sleep better at night and worry less about cold/dry starts. Been using it over past 15 years in 4 cars. I think it is especially important for those that are not started daily. Consider it. (no affiliation, blah blah...)