mannn

As titled.... just wondering if anyone is doing this...
as I researched that most engine failed in scoring is due to cold weather cold starts.... would a block heater help to prevent this?
thinking if i can warm up the block before i start the car, it shouldn't have the issue, right??

KrazyK

I would think anything that gets the engine and/or fluids closer to operating temp would be better for a cold start.

gnat

Cold starts are certainly a common correlation, but it's not 100% and there doesn't seem to be consensus about a specific temperature where the risk goes up significantly.

That said, I can't see that it would hurt though, just don't know how much it will help (mainly depends on how warm it keeps the block/oil).

Chiamac

IMO and really just IMO

These cars run really rich when starting to (learned on here) heat up the cats. Combine really rich starts with not bringing the engine up to temp as in short drives will lead to carbon junk building up in the chamber. Enough of that junk builds up and you're going to start seeing either detotnation due to that junk heating up and igniting the mixture to then that junk getting loose and scratching things up. In order to score, you need to have something like that to scratch, or else it's mostly smooth on smooth.

Another theory would be, along those lines, that when cold fast acceleration would go above and beyond what the oil can handle, and now you have piston on cylinder, which could lead to friction and eventual scoring.

Or a combo of the above.

IMO, and again IMO, these engines need to be warmed up a little before taking off as per "keeping it under 3k" until the heat builds up, or else you run the risk of the oil breaking down, and these engines need to be driven up to temp often enough to keep junk from building up. It would help cold starting though...

So in a round about way, yes, the block heater would help, but you really need to warm them up and drive them.

Again IMO and I could very well be wrong, but I'm able to sleep at night.

Imo000

Loose carbon build up will not scratch the bores. They are too soft for this. An oil sump heater pad would be ideal for this. Someone needs to make an adapter plate that goes into the webbing of the sump pan and create a flat surface on the other side to allow the heater pad to properly bond (glued) to it. I had this on my old TDI and (the oil pan was smooth so it was bonded directly to it) and it warmed up the oil enough that the engine easily started even in -32C. After a couple hours of plugging it in, the oil pan next to the heating pad was too warm to touch it for more than a couple of seconds.

Chiamac

Thanks! I stand corrected.

KrazyK

If your really worried, use climate control, block heater, and automatic accusump accumulator to pressure up before start and circulate after shutdown. Prelube is great from what I hear.

Macster

Lot of owners cold start the engine in their cars with no problems. And bore scoring is as common as dirt in the UK it seems and it doesn't get real cold there.

My point is I'm not sure a block heater would help all that much.

There are different kinds of heaters. The heater pad style -- my own terminology -- just applies heat to a local area of the sump. The oil is warm while the amount of warmth the rest of engine has is anyone's guess. A car inside an unheated garage is going to be one thing while one parked outside is going to be something else. Then if the car is driven someplace where the heater can't be plugged in there's that too. Even in the midwest winter my Boxster would get darn cold, near ambient, just being parked out side at the office for 8+ hours.

Another style is one in which the coolant is heated and circulated by a pump. The benefit of this style is the engine gets heat to all regions that the coolant gets to but of course the oil in the sump may not be as warm as it would be with the heating pad heater attached to the oil sump plate.

In both cases, the problem is still one of possibly inadequate lubrication at cold start. Inadequate possibly due to the oil being cold or just past its change by date given the climatic conditions, vehicle usage. I'm thinking contaminated oil of course.

Some bore scoring arises at least in a few cases from the wrong oil being used for the ambient temperature. For temps -25C (-17F IIRC) and lower Porsche states to use 0w-40. I'd be inclined to use 0w-40 starting around 0F. No science to offer just a feeling.

Another contributor to this bore scoring could be the driver failing to adhere to the keep RPMs under 4K until warmed up guideline. Now in defense of the driver in some cases it is hard to next to impossible to know when the engine is warmed up, I mean fully warmed up.

It is one thing to have the coolant temperature gage needle on the "180" hash mark. It is another thing for the coolant to be at that temperature or above it and for the considerable volume of oil to be up to that tempeature as well.

Recently I have been driving a new Cayenne Diesel. This has among other things a digital coolant temp display and a digital oil temp display. Coolant temp gets to 200F PDQ even though of course I'm taking it easy. And we are not talking about north of the arctic circle temperatures but maybe 28F is as cold as it has been where I live during my time with this Cayenne. But the oil temperature takes many more miles of driving before it is up to 200F. Roughly coolant temp reaches 200F in just a mile or two down the highway while 200F oil temperature takes another 10+ miles of driving.

My point is if someone without the benefit of an oil temperature gage/display relied solely upon the coolant tempeature gage/display and pushed the engine RPMs up over 4K he could do so with the oil at least still rather cold.

And it can be worse. Oil doesn't flow heat very well. I have watched the oil in the hydraulic oil tank of large (very large) machine tools and the oil return line puts warmed up oil in the tank and the pump of course pulls oil out of the tank. I can see the oil as it is being pulled in by the pump form a small depression at the pump intake and the warmer oil from the return line flow across the colder oil and downhill and right back to the pump pick up. But if the operator say does something to increase the oil requirement outlying oil, still very cold oil, then gets ingested by the pump.

The same or nearly the same can happen with these engines. Just a portion of the oil is being circulated through the engine and then the driver "steps on the gas" and of course the oil budget goes way up and the outlying colder oil then gets pulled into the pump. Now the engine has "cold" oil being routed through its oil passages and this cold oil may not flow as well at higher RPMs.

Bore scoring could be the result.

I am not arguing against a block heater. Enough car makers offer this option for cold climate usage. If I lived where it was colder I might have one but my problem is what to do about the car once it is away from its garage and the block heater?

So any solution that uses a block heater still has to rely upon good engine oil hygiene -- the right viscosity grade for the temperatures encountered and oil that is not past its change by date or mileage - and a driver sympathetic to the plight of the engine given the cold temperature and one who is religious in his allowing the engine plenty of time to get warm.

And in the winter it may never get real warm. I recall when I was back in the mid-west in Dec. 2014 and temps were in the single digits and even though I was careful with my Turbo -- which had 5w-50 oil in the engine -- to drive it gently until the coolant temp gage needle had been on the "180" hash mark for a while and the hot idle oil pressure was where it usually was when the engine was when driven in warmer weather I still avoided high RPMs. I don't think I took engine RPMs much over 4K the whole time I was back there. This was my concession to a large (and expensive!) engine with a lot of coolant and oil volume being used in extremely cold weather.

Gonzo911

Just park your car in your living room....assuming your heater and/or fireplace is on...

phil996cab99

Heat tape?

LexVan

200 watt shop light.

CptFun

Hot oil or cold oil, I thought that synthetic oil was supposed to remedy viscosity change with temperature? I don't understand how heating synthetic oil would help lubricate a cold engine.

Flat6 Innovations

The cold is just one of the variables that play into this. Actual running clearances vary from engine to engine, and the quality of the localism cylinders, and the protective piston skirt coating does, too. The adhesion of this coating to the pistons is a key player in the cylinder failure, as it often occurs first, before the cylinder fails.

No single thing is going to help this scenario. I have tested a block heater kit that we made up, but no one would buy it, and on top of that, when you truly understand the dynamics behind this failure, you realize that engines that are going to die from this are already injured as we talk about this as they have already had the perfect storm set up, and it just has to play out.
This is a failure where luck is the major variable.

The biggest mistake people make is firing the car up in winter and allowing it to warm the cabin before they get in, or allowing too much engine warm up time at idle. This keeps the cold start, and just started enrichment higher and for a longer amount of time. All the while the injectors are dumping excess fuel to help light the catalytic converters off, with help of secondary air injection. This fuel is pure solvent, washing down the oil thats the lifeblood of the cylinders and pistons.

Load= Heat. Get in, strap in, fire up and drive away lightly and the engine will not see nearly as much over- enrichment.

dan_189

Whilst on the topic, what does the secondary air pump actually do? I know it's to reduce emissions. We don't have them here in Australia.

peterp

Great info!

I have no experience with it (in other words, my opinion means nothing), but it seems logical that pressurized prelube would help more than a block heater.