OneOfaKindTrini

+1.. You shoudl always warm up your car before you go especially in cold climates.

Dingleberry

that's a load of bs.

audi, mb, and bmw all instruct to start the car, wait for the idle to drop (30 secs), and then drive off.

acr2001

This is always a tough argument for me. Warming up the engine first, in my opinion, is definitely better for it even with new engines. I base this opinion on the fact that all of our cars start to sound like a bucket of bolts and don't run 100% when its, lets say, 15 degrees outside. Now if you drive very gently until the engine starts to warm up, that works fine too and you don't have to wait for it to warm up.

The problem with my C240 is that the engine is a FREAKING SNAIL (you C230 and even C280 guys aren't much better off!), so I will get going without warming it up, and then I'll end up trying to blend with traffic, or making a turn into a somewhat tight gap in traffic, which requires 50% or more of throttle unless you want to inconvenience the guy behind you. At that point my engine usually cries out what can only be translated as "please stop, you're killing me here!"

Oh and about the transmission mount and my rubbing noise from the rear, problem went away this week. It has been warmer out. I guess that eliminates the transmission mount (rear engine mount).

LILBENZ230

Not necessarily. My rear transmission mount only made the noise in the cold, and only when the car was cold. It was very strange.

But you should start the car, wait 30secs, and go - drive gently. The C230 and C280 (especially) are a lot better off. 21hp and 53hp additional are quite a bit - not sure why so many people seem to think that's not significant. BMW thinks 22hp is so significant that it is now charging a $7,000 premium for a 335iS (322hp) over the 335i (300).

It will take the car a long time to warm up to normal operating temp if its idling, and it will run in open loop - I'm pretty sure (need expert) that I've been told repeatedly this is not good for the engine. The transmission will still be stone cold, anyway.

acr2001

Thanks, good to know about the transmission mount.
I agree about waiting 30 seconds and driving gently... but I do wish I had remote start for the really cold days.

Can't really agree with you about the additional HP. Sure it's better, but I have driven both of those models a handful of times and I really couldn't discern much of a difference from my car (compared to my car the engine in the C230 felt much more rough, while the engine in the C280 felt very refined). These cars are heavy, so that probably reduces the gains you would feel from an addition 20 hp compared to a Civic. Even our E320, which does of course feel more powerful than my car, still doesn't feel like that big of a difference.

My next car will hopefully be an AMG

Dingleberry

it will run in open loop for a longer period of time. this may cause excessive carbon buildup. it's also a waste of fuel.

in summary, if you warm up your car for 5 minutes because you want to baby your car, FAIL

i have no objection if you warm up your car for 5 minutes because you want the cabin to be warm and toasty.

LILBENZ230

Exactly. But the ideas that cars "need" warming up is flawed.

My car stays in my temp controlled garage. If I ever leave it out in the cold somewhere it is not a happy camper.

Glyn M Ruck

You guys are all acting like dumbos.

I'm not suggesting idling a car until at operating temperature. I'm talking about taking the chill off of things and allowing the engine to achieve stable quiet running & then driving sensibly until you reach operating temperature before making full demands on the vehicle - this goes for engine & transmission. This is especially true of the M271 on very cold start up. It's like a bucket of bolts until it achieves stable running & all clearances normalise.

The greatest wear takes place in an engine when cold. The quicker you can get it warm the better which means drive gently once it's stable until warm.

The best way to bugger up an engine from very cold start is to rev the thing a few times to clear it's throat & then burn off down the road. I'll prove this in side by side oil analysis any time.

Fuel injection tends to make engines run very well from cold. This does not mean they are ready for full load & RPM.

Dingleberry

i do believe that the greatest wear on the engine is just at the exact moment of the cold start - due to unequal lubrication.

acr2001

I assume you're pointing this comment at me?

In response I have to say this:

Duh! I was only saying that it's annoying when it is cold and I need more power. My normal routine is to let it warm up for a minute or two (which I never have the time for because I'm always running late) and then drive it as gently as possible until it warms up.

Glyn M Ruck

No acr - I was not aiming anything at you - quite the opposite & if anything supporting you. The greatest wear in an engine takes place as full hydrodynamic lubrication is being achieved throughout & then tapers off on a steady curve until full operating temperature & conditions are achieved & clearances normalise. Engine components expand with temperature & operating clearance per design is only achieved at normal operating temperature. This is exacerbated by rich running washing the oil film off cylinder bores etc. Sorry if I came over as being critical of you - not intended. You are one of the good thinkers on this forum.

acr2001

My fault! I totally agree with you (as always it seems). It's pretty obvious if you feel / listen to the engine to notice the change in characteristics as it warms up.

Our E class just had one of the brake caliper bolts sheer off - was a fun drive to the shop (barely made it). The side of the caliper was grinding against the rotor the whole way.

I'm going to drop mine off next so that I can get the engine mounts checked. (I prefer to call the rear a transmission mount, but I know MB refers to them all as engine mounts) Might as well order a new belt tensioner for them to install while I'm at it. Oh and I have to get my oil changed. The wonderful stealership (Sovereign Mercedes in Brooklyn NY - AVOID) was having a special, so I was dumb enough to let them do it. They used the Mobile 1 oil that's MB approved for diesel (I forget the 229.X spec). Yesterday I got a "reduce oil" message in red. The oil is turning into pancake batter and foaming. Too many short trips.

I'm really getting sick of all these issues! The newer models better be as improved as they say reliability wise, otherwise it might be time to see the BMW stealer.

LILBENZ230

Which is exactly what I said. I don't know what sort of climates everyone here lives in, but in my C230 the idle will come down to 800rpm or so (the normal idle) and smooth out after 20-30 seconds. Hence the "start, wait 30 seconds, drive gently" advice. The chill has been taken off. And yeah the M271 is a b!tch on a stone cold start.

No need to let it sit and run for several minutes, unless you want the cabin to be warm. But if you're doing it to baby the car, as was said, you're doing it wrong.

Glyn M Ruck

You also said "But the ideas that cars "need" warming up is flawed."

It's not flawed - I started a M271 in Harbin in NE China last year at probably minus 30 deg C. That car required a full 5 minute warm up before driving made any sense. I note our Canadian members agree. They live with the problem more so than most of us.

acr2001

I have to agree, even with my M112, it's just ugly when its <20 F. out and you don't give it a good 5 minutes (and honestly, I usually don't, but I'm SURE I am putting undue stress on the engine, the thing practically sounds like it's crying).

I understand where you're coming from though LILBENZ, I think it's a matter of how cold it is and how gently you can drive it until it warms up. Good example is if I have to get to an on-ramp to the highway and the engine hasn't had time to warm up... it's a very disconcerting sound as it revs to 4k or so at which point I usually cringe and ease off the gas.
If you're driving on some nice empty side streets and you can be gentle, then by all means, no reason to warm it up more than 30 seconds.

LILBENZ230

Oh yeah. I have nothing but empty backroads for about 5 miles. Also, as I said, my car stays in a garage that's temp controlled to 70F year-round. There have been times my car has sat out in the cold, and I've driven it after 30 seconds.. it's not happy. It feels so old at times like that, where the 135i never feels that way cold or not. I guess because the BMW is so much newer.

It's very, very rarely below 20F here. I can't imagine how it would behave in temps like that. My older 2002 Acura TL used to sit out during the winter and it would never act different, cold or not. Strange how temperamental these Benz cars are.

acr2001

Seriously! When it's over 100 degrees here in the summer my HP (based on my butt dyno) is cut in half (not exaggerating). If I floor it, it will take over 3 seconds to respond. I took it to the dealer when it was under warranty thinking I had a bad sensor, but no codes.

LILBENZ230

My car loves 60F.. and for all the M271s otherwise roughness, my do I love the sound of a supercharger in the morning (admittedly an E55 supercharger would be more pleasing lol). The M271 is quite a bit rougher than any of the M112 or M272 V6s in the W203s but honestly I don't find it that offensive comparing it to other four-cylinders. The GA summer heat causes some supercharger heat soak during the summers and it can be felt, for sure, but never to an extreme.

Glyn M Ruck

I think we are all agreeing violently with one another that some sort of warm up is prudent dependant on ambient temp.

acr - the M112 sometimes sounds bad when the Cats are cold. It makes the engine raspy until the monoliths are at operating temperature.

LILBENZ230

The M271, on the other hand, is raspy regardless of temperature.

acr2001

Nothing like a good violent agreement!

JoeVal

Since pre-synthetic oils, cars in cold climates were "prepared" differently for freezing temp outdoor parking so that come morning they would start, warm up and go. From gas additives to rudimentary windshield/rear window frost protectors so that the vehicle would start, warm up while defrosters and spatulas "opened up" the lines of sight, and when this was done they were ready to go.

Today, progress has brought us advances in synthetic motor oils that reach the valve tops a few seconds after start up, and other fluids which perform their tasks equally fast due to improved formulations with highly stable viscosity.

Thus, Mercedes like other vehicle manufacturers recommend start and go techniques to apply with intelligence. So, if I leave my car in the cold I'll start it but will not go until I can properly see where I'm going, because this is more important than saving a little gas instead of standing still while defrosting. Of course, if I come out of a garage I don't need to wait, and nothing will harm the car if I use the recommended parts.

LILBENZ230

What?

Edit: Oh yeah, I noticed that I said before that during the summer months my car heat soaks. Oh my gaaaaaaaadddd it's been 100F for weeks here in GA and my car has to wind out to 4500-5200rpm between every shift just to move normally.

Glyn M Ruck

Synthetic oils are high VI (viscosity index). VI is a measure of the rate of change in viscosity for a given change in temperature.

In layman's language - synthetic oils thin less at high temperature & thicken less at low temperature.

Pumping rates of thinner oils in engines is a Myth. All modern engines have positive displacement oil pumps.

e1000

Lol, you guys do understand that Glyn deals with this stuff for a living right? As far as engine oils, lubrication, etc etc, I'd just sit up and listen to the guy.