Mercedes glow plug system

[wanderer44]

I have a 2019 Dynamax Isata 3 24 fw motorhome powered by Mercedes. When I start it in cold weather, the glow plug indicator light only comes on for about a second or two. Having a Mercedes before, I am sure that it needs to stay on longer to do much good. We are in the lower 20's now and worried that when it gets real cold it will not start.
Do you have any experience to share???? Thanks Leonard

[Wileykid]

Originally Posted by wanderer44

I have a 2019 Dynamax Isata 3 24 fw motorhome powered by Mercedes. When I start it in cold weather, the glow plug indicator light only comes on for about a second or two. Having a Mercedes before, I am sure that it needs to stay on longer to do much good. We are in the lower 20's now and worried that when it gets real cold it will not start.
Do you have any experience to share???? Thanks Leonard

I don't own a Mercedes, but have owned a number of diesel's. They are all now computer controlled, and will only stay on to get the temp up to what is needed. I have seen a flash, to 6-7 seconds. If it wasn't working correctly, it will throw a code. The computer checks the plugs every time you start the engine, even when they are not needed.

Your newer one may have "hotter" plugs then the old one, or the cylinder displacement is such that it may not take as long to heat up.

[Jim34RL]

My wife's VW TDI Jetta glow plug light will only stay on for a few seconds when the ambient temperature is in the 20's. The engine starts fine with no cranking issues. Even when the temps drop to the signal digits or into the minus range, the glow plugs only take a coupe of seconds to warm up for starting.

[ferrisjc]

Having a 2018 Isata 3 Mercedes engine the warm up time is almost non-existent. When I asked Mercedes about this the tech mentioned just as previous posts have stated that the technology is computer controlled and so much quicker that you can basically crank without a wait. Having a Chevy Cruze Diesel as well I would give it a second or so especially in colder regions. The Chevy Cruze Diesel does have a specific wait time indicator but it is only for 2 sec or less even in sub freezing weather.


Retired Army CWO//DoD Civilian//2018 Dynamax Isata 3 FW, Apr 13 2018

[aircommuter]

I have been a Mercedes mechanic as well as others for 56 years, they use a pencil glow plug that heats almost instantaneously,that along with the very high fuel pressure systems giving better atomisation the delay is almost gone. There have numerous advancement in the glow plugs over the years. The older ones actually had an additional glow plug on the dash so the operator could watch it glow while he or she was pulling out on the starter cable.
Some engines like Cummins don't even use glow plugs rather just an intake heater which is more for smog reduction when it starts with cold ambient air.
I still do some work on these in my home retirement shop, check it out on my registry.

[rlh1957]

Mercedes cars, trucks and RV platform engines... really Diesel glow plug systems have come a long way from the old wait for the light to go out days. The electronics and plugs are all different and faster. Unless you are in really sub cold in Canada and your vehicle is cold soaked for a few days then the light goes out quickly and starting sequence is ready or starts automatically. Those that live in these sub cold areas all have the pre-heat oil and engine system installed.

[Cowracer]

If it starts in the low 20's, the glow plug system is working fine.

Tim