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When I got my car a year ago, I noticed that it did not come with Hood Insulation Liner that I had on all my cars in past 20 years. My thought process behind having a sound liner that it should make cabin quieter, in theory anyway.
After looking online for a while I could not locate MB part number for it, and could only find aftermarket liner on Aliexpress. At the time I was very hesitant to purchase one.
Finally last month I found a decent deal ($52) on Aliexpress and decided to take a chance and pull the trigger. While I am still waiting for it to arrive from China, I mentioned it on other thread on this site and one of the members kindly pointed me to a German forum discussing this subject.
Members on that forum discussed installing hood liner from GLB220d (which comes standard with liner from the factory) to their GLB 250. (insulation mat: MA 247 682 9500 - EUR 39.07, Clips: A 001 988 0325). Interesting enough, if you enter 2476829500 into MB USA online parts supplier, it comes up as a current part “Damping, Hood” but does not specify which model it is for.
Some members on that forum stated that the reason turbo charged gasoline versions of GLB do not come with Hood Liner is due to possibility of trapping heat from turbocharger and catching engine bay on fire.
Logically it might be a plausible explanation, however I gather that any engine bay liner would be made from fire retardant material. I researched this subject a bit further and found the same discussion on Porsche forum. Same fire hazard reasoning was mentioned, however some members mentioned that identical models with same engine configurations had a hood liner in Europe vs. US, and one of the reasons mentioned was possible stricter noise compliance in EU vs. US. I also saw similar discussions on prior model year GLA forums.
As I mentioned earlier the fire hazard reasoning sounds plausible, except I found the picture from German dealership showcasing GLB35 with hood liner. I cannot imagine that turbo on GLB35 is somehow less hot or located in different spot. From what I read GLB35 has the same engine, however it is tuned for high performance.
At the end I have two questions to members of this forum:
1. Did your US version of GLB35 came with Hood Liner?
2. Do GLB35 and GLB250 owners in countries other than USA have hood liners from the factory?
Below are the pictures I found online. First one is your typical US version of GLB250 without liner, second is diesel version with liner, and third is the German GLB35 version with liner. GLB 250 GLB 220d GLB35
Last edited by Vladimir Livson; 12-10-2021 at 08:48 AM.
When I got my car a year ago, I noticed that it did not come with Hood Insulation Liner that I had on all my cars in past 20 years. My thought process behind having a sound liner that it should make cabin quieter, in theory anyway.
After looking online for a while I could not locate MB part number for it, and could only find aftermarket liner on Aliexpress. At the time I was very hesitant to purchase one.
Finally last month I found a decent deal ($52) on Aliexpress and decided to take a chance and pull the trigger. While I am still waiting for it to arrive from China, I mentioned it on other thread on this site and one of the members kindly pointed me to a German forum discussing this subject.
Members on that forum discussed installing hood liner from GLB220d (which comes standard with liner from the factory) to their GLB 250. (insulation mat: MA 247 682 9500 - EUR 39.07, Clips: A 001 988 0325). Interesting enough, if you enter 2476829500 into MB USA online parts supplier, it comes up as a current part “Damping, Hood” but does not specify which model it is for.
Some members on that forum stated that the reason turbo charged gasoline versions of GLB do not come with Hood Liner is due to possibility of trapping heat from turbocharger and catching engine bay on fire.
Logically it might be a plausible explanation, however I gather that any engine bay liner would be made from fire retardant material. I researched this subject a bit further and found the same discussion on Porsche forum. Same fire hazard reasoning was mentioned, however some members mentioned that identical models with same engine configurations had a hood liner in Europe vs. US, and one of the reasons mentioned was possible stricter noise compliance in EU vs. US. I also saw similar discussions on prior model year GLA forums.
As I mentioned earlier the fire hazard reasoning sounds plausible, except I found the picture from German dealership showcasing GLB35 with hood liner. I cannot imagine that turbo on GLB35 is somehow less hot or located in different spot. From what I read GLB35 has the same engine, however it is tuned for high performance.
At the end I have two questions to members of this forum:
1. Did your US version of GLB35 came with Hood Liner?
2. Do GLB35 and GLB250 owners in countries other than USA have hood liners from the factory?
Below are the pictures I found online. First one is your typical US version of GLB250 without liner, second is diesel version with liner, and third is the German GLB35 version with liner. GLB 250 GLB 220d GLB35
Hi There, GLB 250 Owner from Australia. Mine does not have a bonnet hood insulation as well. I have been looking around and found a few options on aliexpress and an online store ebuy.com based in china. They both say it fits GLB however the postage cost is ridiculously expensive. I have seen pictures of GLB on other forums that have hood insulation. Personally i don't believe its an hazard, however not sure if this will void your warranty. hence I am still hesitant to install one. I also do believe it should reduce the engine noise. Really surprised why Mercedes excluded installing this on GLB models. May be they have a very valid reason, Who knows. Anyway keen to read about your experience once you have installed it.
Cheers.
I had a Subaru Forester Turbo, similar 2500cc engine with 225hp. Subaru later increased to 250hp. The hood had a big airflow opening... GLB comes with smaller engine and boosted the hp even higher with GLB 35 (biturbo) /GLA 45, etc... I don't know how MB achieved this, eg what kind of insulation, etc.
So I was searching for the turbo heat and found these...
"Turbochargers are regularly exposed to very high temperatures, but a blanket keeps the heat contained. Turbo blanket is normally attached to the turbine and it keeps the engine bay at a lower temperature. When an engine bay gets too hot, it could possibly overheat and cause permanent damage to your engine. This is why people use a turbo blanket to overcome this issue by keeping your engine bay at lower temperature.Tackling the excessive heat problem, you should not switch off the engine directly after some heavy throttling. Instead, you should let it sit idling for a few minutes to allow the oil to circulate and cool down the turbocharger more effectively.
Personally, I have installed this turbo timer that I got from Amazon to let the engine idle for 3 minutes after I lock my pickup truck. It is suitable for all vehicles with 12 volt switching power supply, equipped with instructions for easy installation.
You will not get obvious improvements on power when it comes to the turbo blanket, because it doesn’t directly affect the performance figures in any way. The purpose of this blanket is to keep your engine bay cool.
However, if your engine bay is cooler, it does benefit the engine’s health and efficiency by breathing in cooler air."
Here is a GLA 45 engine shows the biturbo jacketed, from c-net:
" this application is a different beast compared with the 2.0-liter engine found in the GLA35. Rather, AMG engineers turned the engine 180 degrees on its vertical axis to put the turbocharger and exhaust manifold at the rear of the engine compartment. The move gave engineers the chance to create a more aerodynamic front and improved air ducts to construct shorter pathways."
Looking at GLA/GLB 250 & 35, the engines looks similar from top:
Turbo is located in the front (GLB 35):
So how the hood liner affects the heat dissipation with this set up?
Just wanted to provide some update. I received a cotton hood liner and clips from Aliexpress (see below), however I did not install it until I talk to the dealer regarding fitting GLB35 liner onto GLB250. Parts Department rep. told me that GLB35 engine runs hotter therefore it came with hood insulation from the factory; however when he searched GLB35 liner part number he said he is not able to order one nor does he know why GLB250 did not come with one. He confirmed that GLB35 liner would fit GLB250 hood.
So before I install it I want to email MB tech support to see if there are any potential issues fitting a liner onto GLB250. First time around they declined to provide any information until I speak to the dealer.
Just collected a new GLB 200 before Christmas and asked dealer to order the hood insulator at the same time. He said they could order that (around £80) but will not install the hood insulator for me. They treat this as a modification in GLB 200/250.
Originally Posted by Vladimir Livson
Just wanted to provide some update. I received a cotton hood liner and clips from Aliexpress (see below), however I did not install it until I talk to the dealer regarding fitting GLB35 liner onto GLB250. Parts Department rep. told me that GLB35 engine runs hotter therefore it came with hood insulation from the factory; however when he searched GLB35 liner part number he said he is not able to order one nor does he know why GLB250 did not come with one. He confirmed that GLB35 liner would fit GLB250 hood.
So before I install it I want to email MB tech support to see if there are any potential issues fitting a liner onto GLB250. First time around they declined to provide any information until I speak to the dealer.
Just collected a new GLB 200 before Christmas and asked dealer to order the hood insulator at the same time. He said they could order that (around £80) but will not install the hood insulator for me. They treat this as a modification in GLB 200/250.
Does your GLB200 come with gasoline or diesel engine?
QUOTE=Vladimir Livson;8485933]I am still waiting for MB Tech Support to reply. Could not get any answers from the dealer.
Do you mind sharing a picture of the Hood Insulator, once you receive it?[/QUOTE]
After months of waiting for a response from a local dealer or MB Technical support, I gave up and installed the hood liner.
I figured it's cold enough outside to test it, and overall, if the heat from the turbo was a concerned I would imagine that hood paint would have some kind of protection from the factory. Besides the hood liner is pretty thin.
The difference in sound improvement is insignificant. So if you do not have one, I would not loose sleep over it. During idling, I saw drop of approximately 2 dB on outside 61dB to 59dB, and exactly same sound level inside around 53 dB. I only drove it a short distance but the difference is very minimal. Best guess 1-2dB if any.
Last edited by Vladimir Livson; 02-10-2022 at 07:52 PM.
Update: After 5 days of driving with Hood Liner I took it off, due to engine bay smell getting sucked into the cabin air vents, while sitting in city traffic. I am not 100% positive if it is solely engine bay smell or liner is "off gassing" when moving at very slow speeds, when there is not enough air movement through the engine bay. I did however notice increase in engine noise inside the cabin, when I took it off.
Too bad it did not work out. I take noise over smell.
Update: After 5 days of driving with Hood Liner I took it off, due to engine bay smell getting sucked into the cabin air vents, while sitting in city traffic. I am not 100% positive if it is solely engine bay smell or liner is "off gassing" when moving at very slow speeds, when there is not enough air movement through the engine bay. I did however notice increase in engine noise inside the cabin, when I took it off.
Too bad it did not work out. I take noise over smell.
In contrast Vlad. I ordered my GLB 250 hood Liner from Mercedes in Dec/21. Installed it in early Jan /22. Cabin much quitter , engine outside quieter and absolutely no odor at all in city with stop and go traffic. All engine temperatures are exactly the same as prior to the install. I have no intention of removing it. The liner is working very well.
Update: After 5 days of driving with Hood Liner I took it off, due to engine bay smell getting sucked into the cabin air vents, while sitting in city traffic. I am not 100% positive if it is solely engine bay smell or liner is "off gassing" when moving at very slow speeds, when there is not enough air movement through the engine bay. I did however notice increase in engine noise inside the cabin, when I took it off.
Too bad it did not work out. I take noise over smell.
Did you try leaving it outside in the sun for a few hours/days to see if that helps the smell
I discovered that smell is not related to the Chinese made liner, after I took it off. I was getting a burnt plastic, maybe burnt oil smell from the vents. It only happened while I was stuck in heavy traffic with hot engine or parked for a while with engine on (basically when there was no air flow across engine bay). The smell goes away when I close outside air intake damper with AC controls. So my best guess it's coming from the engine bay. Took the car to dealer and they claimed they could not replicate the issue. I did notice that oil cap had a slight leak, so I installed the new cap ($8) in case it was oil getting it's way down to the hot enigne block or exhaust. However I have to wait and see next month when I get the car back from my wife. We swap cars every months to keep the milage down, and she only drives locally, so no issues with being stuck in heavy traffic.
I inspected the crankcase plugs and they are solid and not leaking, just in case it was blowby gases leaking through.
Until I can solve the smell issue, I do not want to install the liner back on the car.
Last edited by Vladimir Livson; 04-06-2022 at 04:08 PM.
I still have it in my garage. Never got to re-installing it. Had to order new push pins and by the time I got them it was too cold outside. I might put it on next time it gets wormer, since you reminded me .
I still have it in my garage. Never got to re-installing it. Had to order new push pins and by the time I got them it was too cold outside. I might put it on next time it gets wormer, since you reminded me .
Haha.
So are the push pins different than what was shown on the pdf you shared in this forum?
They are. It's been a while and I forgot that I posted the part number. In fact, after re-reading the thread, I found these on Amazon and ordered a bunch.
12-10-2021, 08:45 AM
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