Boxster986S

It's now pretty cold in Indiana. My GLA is parked outside overnight and in the mornings I'm finding it takes a long time the for car to warm up. I do not let it idle after starting. I just fire it up and start my 6 mile, 17 minute commute to work. In 23 degree weather, I find that the engine only comes up to 60 deg C by the time I get to work.

Is this normal? Doesn't seem so. Time for a trip to dealer to check out thermostat?

Germancar1

I honestly don't get what the problem is?

M

Boxster986S

The problem is normal operating temperature is 90C. I would think it would get up to that after 6 miles and 20 minutes of run time. My wife's GLK gets to 90C during her commute which is shorter than mine. Maybe you think my expectations are too high, but I disagree.

Germancar1

Ah I see, I still don't think there is a problem especially in freezing cold temps. Even if it doesn't reach 90C, is the vehicle driving any different? I'd call the service dept and ask one of the reps about it. Does it ever get to 90C in longer driving?

M

natrat

in the 45 at least it limits power until various systems are warmed up. This 6cyl glk loaner i have seems fine from cold so it must have something to do with the smaller motor

Boxster986S

I think natrat has a valid point. My wife's GLK warms up quickly, even in 7 degree Fahrenheit weather. On the other hand, had a CLA loaner last week. It was just as slow to warm up as my GLA. Must be small motor.

PWGUNNY

Yes. It's cold in NY and the GLA does take longer to warm up than any recent cars I've owned. The heated seats get going pretty quick though. I like the car and am happy so far, but a heated steering wheel would be nice.

Boris_Balkan

Small 4-cylinder engine, intentionally-very low 'eco' rpm's, decent-sized underhood space, and big exposed grill and lower opening for the radiator and intercooler. When it drops below 10, it's going to take some time to warm up.
A 6-cylinder in a cramped engine bay (like on the GLK) is going to warm up faster.

PWGUNNY

That seems like a pretty good explanation. I just realized that it's been many years since I owned a 4 cylinder. The last 4 cyl. I had was a Fiat Spider and that was just a play toy.

orgchem

I too find this exact issue in my GLA, i thought i was doing something wrong. But thanks for the explanation. Let us know if anyone find anything different.

paglan

Very cold here in the Northeast this past month. I get heat within a couple of miles driving but the temperature gage doesn't always go up to 90 like it does on warm days. I Google translated the Wikipedia.de page on the engine and it has some interesting information on the coolant management system for the M 270 DE 20 AL engine:


http://de.wikipedia.org/wiki/Mercedes-Benz_M_270/M_274




The M 270 is a petrol engine with four cylinders in-line arrangement of Mercedes-Benz, which was presented in November 2011 in the second-generation B-Class (W 246). So he replaced the Series M 266 and M 274 medium as well as the model M 271 [1]

The production takes place in the Mercedes-Benz plants in Stuttgart-Untertürkheim and at MDC Power GmbH in Kölleda. The production of the independently developed by Daimler Motors began on 29 July 2011


The most striking technical feature of this engine is the ability to transverse and longitudinal installation. While the motor in the compact front-wheel drive models A and B classes transversely installed and there is designated M 270, it is disposed in the other models longitudinally and is referred to herein as M 274. This requires a very compact design of the unit. For this purpose, the auxiliary units were densely arranged and designed the cylinder spacing with 90 mm ​​narrow. Another design goal was weight reduction. The all-aluminum engine was a hollow cast crankshaft, which reduces to the compact design, the weight in the basic version to 137 kg.

All motors of this series are charged by a turbocharger. Despite charging the engines with a ratio of 10.3 are: 1 highly compressed. First, the engine with 1.6 l displacement is (1595 cc, bore 83.0 mm, stroke 73.7 mm) built. In September 2012, followed a variant with 2.0 liter displacement and 155 kW (211 hp) in the A 250 BlueEFFICIENCY model. [3]

The M 270 and M 274 is closely related to the Blue Direct-V-engines M 276 and M 278. He accordingly has a direct injection with spray-guided combustion third generation, which is realized through an A-nozzle piezoelectric injector. In addition to the conventional homogeneous mixture formation and the layer charge is implemented in the large-displacement derivatives, which is a novelty in the engine technology in connection with the charge.


As a high-pressure pump is a single-piston pump is used with a built-in pump module flow control valve. This produces a map-controlled working pressure up to 200 bar. The fuel injection into the combustion chamber takes place depending on the load range up to five times per cycle. There ignited a multi-spark ignition, the air-fuel mixture.

The engine has two overhead chain-driven camshafts. Both camshafts [4] the timing is adjustable. This, in conjunction with the turbocharger, the so-called scavenging, in which the opening times of the intake and exhaust valve partially overlap. Here flushes the cold fresh air sucked in the combustion chamber, which is still in the hot exhaust gas in the exhaust manifold, whereby the filling cylinder substantially improved. The turbocharger to talk much faster due to the increased gas flow in the exhaust system, especially at low speeds. Thus, a turbo lag is avoided. By direct the fresh air is not mixed as it flows into the cylinder with fuel, whereby gas loss (leakage of unburned gasoline into the exhaust manifold) can be avoided.

The 1.6-liter engines are optionally available with the so-called CAMTRONIC system. This may change in partial load ranges to a smaller intake cam, which allows a higher intake manifold pressure and thus avoid throttling losses. In conjunction with the variable intake camshaft This allows a load control to the camshaft at respective loads. In the M-and M-274 270- engines a three-stage load control is thus realized in the operation with a small intake cam: At very low loads, the air flow rate is conventionally set by the throttle valve. For medium loads, the cylinder charge is set on the intake camshaft, while the throttle valve is opened at higher loads, and the intake manifold pressure is further increased through the turbocharger.


The compact design of the engine and the combustion processes require a sophisticated engine cooling. The coolant flows through a two-piece water jacket with cross flow cooling and by only three millimeters thick cooling channels between spark plugs and fuel injectors to the heat-stressed areas. To ensure an acceptable fuel consumption at higher speeds, thanks to the efficient engine cooling, a full load enrichment for cooling the cylinder head only at speeds above 200 km / h is required. In a cold start flowing thanks to a demand-driven water pump with flow-optimized ball valve no coolant through the engine. This leads to a rapid attainment of the operating temperature, thus contributing to lower fuel consumption and better wear characteristics. The vehicle interior is thus also heated as quickly as possible. Also, the thermostat includes a flow-optimized ball valve. This is electronically controlled by the engine control depending on driving style and ambient conditions and sets the optimum coolant temperature.

With a demand control the oil pump was fitted, contributing to further fuel savings. This is also the objective of the ECO start-stop function during short stops, such as traffic jams or red lights, automatically stops the engine and restarts without delay. It is the result of the simultaneous development of engines and transmissions for transverse installation. For example, the control unit of the dual clutch transmission 7G DCT communicates with the engine control unit in order to ensure the best possible response. [6] [7]

As power transmission has the following gear types:
Six-speed manual transmission with start-stop system
Seven-speed dual-clutch transmission 7G-DCT with start-stop system for front wheel drive vehicles
Seven-speed automatic transmission 7G-Tronic Plus with start-stop system for rear-wheel drive vehicles


One other piece of semi-useful/less information. Based on the numbers on the side of my turbo, it looks like its made by IHI (P/N A2700901880)

orgchem

Another case i found, if car is very low in gas then engine is not going anything above 50 C. I waited for 30 minutes on high did not get any warm air. As soon as I put the gas, warm air started to flow and the engine went to 90 C. Are they related ? Or is it just my imagination ? Temp was - 4 F outside when it happen.

Today morning temp was -10 F outside with full tank gas it was not able to reach 60 C when i drove for 5 miles (I reached my office otherwise I would have tested it how long will it take for it to reach 90 C). Will do some more tests and see how it goes.

orgchem

Another observation.

Today morning temp was 10 F outside with full tank gas it was able to reach 80 C when i drove for 4 miles.

Boxster986S

I can't conceive of any way that fuel level can affect warm up time.

Your ambient temperature varied 20F between two tests, so think that is the difference.

orgchem

Another test I did was when the temp was around 20 F, same issue when the fuel level was low it's not heating as much as it used to when the gas tank is full. I am trying to set up an appointment with my dealer.