The Mercedes Benz OM651: Is it a good engine?
Summary
TLDREl vídeo ofrece un análisis detallado del motor Mercedes-Benz OM 651, utilizado en varios modelos como los E, S, C-Clases y GLS. Se discuten temas de fiabilidad, mantenimiento y problemas conocidos, como el sistema de tensión de la cadena de tiempo, el sistema de inyección de combustible y los componentes del sistema de emisiones. El presentador también explora la accesibilidad de piezas como el bomba de combustible y el sistema de escape, y destaca la modularidad del sistema de emisiones para facilitar futuras reparaciones.
Takeaways
- 🚗 El motor OM 651 de Mercedes-Benz se encuentra en varios modelos, incluyendo clases E, S, C, GLS, GLK y MLS en Europa y EE. UU.
- 🔧 Aunque el motor OM 651 es menos conocido que sus predecesoras OM 648 y OM 642, el vídeo busca desentrañar sus características y posibles problemas.
- ⏱ La cadena de tiempo del OM 651 se ha movido a la parte trasera del motor, lo que puede complicar el acceso a otros componentes.
- 🔗 La tensión de la cadena de tiempo es un problema común en muchos motores Mercedes, y no es una excepción en el OM 651.
- 💧 Los sistemas de inyección de combustible, incluyendo los inyectores y la bomba de inyección, son similares a los del OM 642 y son considerados bastante confiables.
- 💰 Reemplazar todos los inyectores en un motor OM 651 es más económico que en el OM 642 debido a la diferencia en el número de cilindros.
- 🔧 El acceso al bomba de combustible y la bomba de vacío es más complicado en el OM 651 debido a su ubicación trasera y la necesidad de desmontar otros componentes.
- 🌡 Los sistemas de escape del motor OM 651 incluyen un sistema de dos filtros de partículas (DPF) y un inyector de fluido AdBlue (DEF) para reducir las emisiones.
- 🛠 La ubicación del motoriza del OM 651 en la parte trasera del motor complica el mantenimiento y la reparación de componentes como la bomba de agua.
- 🔋 Este motor no tiene una bomba de dirección hidráulica, sino una dirección eléctrica, lo que reduce la complejidad y el riesgo de fugas de fluido.
Q & A
¿Qué motores de Mercedes-Benz se mencionan en el video antes de profundizar en el OM 651?
-Se mencionan los motores OM 648 y OM 642 como parte de la generación anterior de motores diésel de Mercedes-Benz.
¿En qué vehículos se utilizó el motor OM 651 en Europa?
-En Europa, el motor OM 651 se utilizó en una amplia gama de vehículos, incluidos los modelos E-Class, S-Class, C-Class, GLS y GLK.
¿Qué problema común se menciona en relación con la cadena de distribución del OM 651?
-El problema más común relacionado con la cadena de distribución no es la cadena en sí, sino el tensor, que se desgasta con el tiempo y necesita ser reemplazado.
¿Cuál es la diferencia entre las cadenas de distribución del OM 648 y el OM 651?
-El OM 648 utiliza una cadena de distribución de doble fila, mientras que el OM 651 solo utiliza una de una sola fila. Sin embargo, esto no es un problema grave en el OM 651 debido a que la cadena solo impulsa los árboles de levas.
¿Por qué es más complicado trabajar en la bomba de combustible del OM 651 en comparación con motores anteriores como el OM 642?
-La bomba de combustible del OM 651 está ubicada en la parte trasera del motor, lo que requiere más tiempo y desmontaje de piezas como el filtro de combustible y los enfriadores de EGR, lo que hace que el trabajo sea más complicado.
¿Qué tipos de inyectores puede tener el OM 651 y en qué se diferencian?
-El OM 651 puede tener inyectores piezoeléctricos, que no utilizan solenoides tradicionales. Son más confiables y similares a los inyectores del OM 642.
¿Cómo afecta la ubicación de la bomba de vacío en el OM 651 a las reparaciones?
-La bomba de vacío está ubicada en la parte trasera del motor, lo que dificulta el acceso y requiere más tiempo para su reemplazo, a diferencia de los modelos anteriores donde estaba en la parte frontal.
¿Qué beneficio ofrece la dirección asistida eléctrica en el GLK en comparación con la dirección hidráulica?
-La dirección asistida eléctrica es más sencilla y no requiere mantenimiento de fluidos ni reparaciones complejas asociadas con las bombas de dirección hidráulica.
¿Cuál es uno de los posibles problemas con el sistema de emisiones del OM 651?
-Un problema común es que las piezas del sistema de emisiones, como los sensores de oxígeno, pueden fallar con el tiempo, pero suelen ser reparaciones relativamente sencillas y económicas.
¿Cómo se pueden solucionar los problemas con los filtros de partículas diésel (DPF) en el OM 651?
-Los problemas de obstrucción del DPF se pueden resolver limpiando el filtro en lugar de reemplazarlo, ya que es raro que el catalizador dentro del DPF falle completamente.
Outlines
🔧 Introducción al motor Mercedes-Benz OM 651
El vídeo comienza con una revisión de las últimas tres generaciones de motores diésel de Mercedes-Benz, incluyendo el OM 648, el 642 y el OM 651. Se menciona la ubicación de estos motores en diferentes modelos de vehículos en Europa y Estados Unidos. El objetivo del vídeo es profundizar en los detalles del OM 651, abordando temas como fiabilidad, valor y problemas conocidos. Se destaca la importancia de comprender completamente el motor OM 651 debido a su uso en varios modelos de vehículos.
🛠 Problemas conocidos y acceso a componentes del motor OM 651
Se discuten varios problemas comunes asociados con el motor OM 651, como los problemas de la cadena de tiempo y su tensión. Se aclara que la cadena de tiempo en sí no es un problema, sino más bien el tensión que puede debilitarse con el uso. Se describe la ubicación de la cadena de tiempo en la parte trasera del motor, lo que afecta la accesibilidad de otros componentes como la bomba de combustible y la bomba de vacío. Además, se menciona la necesidad de reemplazo de inyectores y la accesibilidad desafiante de la bomba de agua, que se encuentra en la parte delantera del motor y es de control vacío.
🚗 Sistema de dirección eléctrica y mantenimiento del sistema de transmisión
El vídeo aborda la ausencia de una bomba de dirección hidráulica en el vehículo, reemplazada por un sistema de dirección eléctrica que utiliza un motor de servo en la palanca de dirección. Esto elimina la necesidad de preocuparse por fugas de fluidos y la complejidad de una bomba de dirección. Se menciona la ventaja de esta configuración en comparación con sistemas hidráulicos tradicionales. También se discute la necesidad de mantener los fluidos en el sistema de transmisión y la complejidad de acceder a componentes como la caja de transferencia y el eje delantero en vehículos con tracción en las cuatro ruedas.
🌐 Sistemas de emisión y su fiabilidad en el motor OM 651
Se explora el sistema de emisión del motor OM 651, incluyendo el sistema de particulas (DPF) y el sistema de aditivos (como el adBlue). Se menciona que, aunque estos sistemas añaden complejidad y costos de reparación, han sido modularizados en las generaciones más recientes de motores para facilitar futuras reparaciones. Se discuten los componentes individuales del sistema de emisión, como los sensores de oxígeno, la inyectora de adBlue y el catalizador SCR. Se aborda la fiabilidad de estos sistemas y se sugiere que, aunque es probable que se produzcan fallos en componentes individuales, estos suelen ser relativamente baratos de reemplazar y no requieren la sustitución de todo el sistema de emisión.
Mindmap
Keywords
💡OM 651
💡Cadena de distribución
💡Bomba de combustible
💡Inyectores
💡Emisiones
💡Sistema de dirección eléctrica
💡Transfer case
💡Sistema de vacío
💡DPF (filtro de partículas diésel)
💡SCR Catalyst
Highlights
深入探讨梅赛德斯-奔驰OM 651发动机,这是欧洲多款车型使用的发动机。
OM 651发动机的可靠性、价值和潜在问题全面解析。
讨论了OM 651发动机的定时链问题,特别是张紧器的磨损问题。
OM 651发动机的定时系统位于发动机后部,与其他系统相比有所不同。
解释了从双排定时链到单排定时链的变化及其对发动机的影响。
讨论了燃油泵位置的变化及其对维护工作的影响。
OM 651发动机可能有两种不同类型的喷油器,与OM 642喷油器相似。
真空泵的位置变化及其对发动机维护的影响。
OM 651发动机的水泵可能有两种类型,讨论了真空控制水泵的潜在问题。
OM 651发动机没有动力转向泵,而是采用电动转向系统。
讨论了4MATIC系统中前传动轴的维护复杂性。
展示了OM 651发动机的排放系统,包括DPF和DEF系统。
讨论了排放系统组件的可靠性和维护成本。
预告了下一个视频将展示OM 651发动机的变速箱油更换和前传动箱维护。
Transcripts
hello everyone uh in my last video I
went over the last three generations of
Mercedes-Benz diesels the OM 648 642 and
then this engine which is the OM 651 I
went over just you know General uh uh
reliability value of these engines uh
but this video I'm going to get real
deep into the OM
651 this is everything you need to know
to get up to speed on the mercedesbenz
OM
651 reason being Mercedes put this
engine in quite a few different vehicles
in Europe they were put in everything
they were put in uh e-classes s-classes
c-classes the GLS the gks they were
putting everything um here in the United
States they were put in the E-class the
GLK and then later I believe in
2016 uh they were put in the uh MLS or
glees now if you're an older diesel
owner or you know you know a bit of
information about the older diesels like
the 648 or the 642 this engine is a
little bit more of a mystery there's not
as much information out there on these
engines so my goal here is to dig deep
into this engine and show you guys
exactly all of the issues that this
thing has we're going to go through the
reliability of every single system I'm
going to get underneath the car and show
you the emissions equipment we're going
to go through the fuel injection system
we're going to go through the injectors
the injection pump the timing chain
issues that these engines are are known
for not actually an issue I'll explain
why later potential vacuum pump problems
emiss systems problems we're going to go
through all of it now we're going to
start with the timing chain uh you know
if you if you browse forums reading
about these om 651s you're going to see
stories you're going to hear every now
and then about the timing chain issues
that these engines have there's several
videos out there of you know cold
startups on these engines where you hear
timing chain
rattle um you hear of people needing to
do timing chain replacement it's it's
not as big of an issue as what people
think the issue is not actually the
timing chain it's the tensioner and this
is actually a common problem across
numerous different Mercedes engines the
the tensioners themselves do wear out
they're a wear item and they do need
replacement every once in a while now
anybody that's worked on Mercedes
diesels before would probably be
familiar with the timing chains being on
the front of the engine down here that
is not the case with this engine the
entire Timing System on this engine is
on the back now that now that does
complicate things with other systems
that are typically run off the timing
chain like the vacuum pump the fuel pump
we will get into that a little bit later
now there's a little bit of controversy
around the timing chain itself Mercedes
with their older 648 647 and 646 engines
the inline predecessor to this engine
those engines used double row timing
chains with this engine it only uses
single row timing chains now several
people speculated that because they went
from a double row to a single row that
the chain is not as strong it's subject
to more stretch now while that is true
it's not technically a problem on this
engine and the reason being the only
thing that the timing chain drives on
this engine is the cam shafts I'll throw
up another video here for you to see
what that looks like the oil pump the
fuel pump the vacuum pump the balance
shafts on the bottom of the engine
everything is gear driven off of the uh
crankshaft the only things that are
driven by a chain as I said are the cams
themselves the benefit of that is that
the chain itself is shorter and it has
less stress on it when running this
engine was also used on the sprinters
from I believe 2014 up and there are
numerous engines out there with over you
know 2 300,000 Mi on them with regular
maintenance and the tensioner being
replaced as I mentioned earlier the
chains themselves seem fine even people
that have gone in and have replaced the
chain because of the tensioner issue
have noted that the chain didn't really
need to be replaced now the location of
the timing chain being on the back of
the engine opens up a couple other
issues that make this engine just a
little bit harder to work on
um number one being the fuel pump
location now on the 642 and the 648 the
fuel pump is located on the front of the
engine right around here benefit of that
being that the pump is easy to get to
from the front of the engine you don't
need to really take anything else off
other than maybe a belt to be able to
access it problem on the 651 is that you
can see here the fuel rail is right down
here follow the fuel rail back over here
and you can see another metal fitting
right down there that goes down
way deep into the engine down here we're
not quite in the back of the engine but
you know we're towards the back way down
there underneath all this junk is where
the fuel pump sits so if you need to
change the fuel pump which you know
higher mileage Vehicles you will have to
do it is more of an in-depth job than on
the older diesels you're going to have
to remove the uh fuel filter you're
going to have to remove I believe people
said the the EGR coolers and everything
in here you're going to have to remove
I've been doing some reading on the
forums and from what I could tell people
say it's about a 4-Hour job to get out
the the pump now the injectors
themselves uh these engines apparently
can have two different types of
injectors the injectors that are on this
engine that I have here appear to be
very very similar to the uh om 642
injectors uh they're Paso Electric
injectors they don't use typical
solenoids um the return line is a little
bit improved from what we're used to on
the 642 um but the injectors themselves
are pretty foolproof and you can get
om642 injectors which again I I know on
the OM 648 that you can use 647
injectors I I have a couple in my car
that I've been using for like six years
and they're they're perfectly fine I
don't know on the 651 if you can use the
642 injectors I think that would be
worthwhile looking into um but I know
that these exact injectors with the 651
part number are around 340 bucks a piece
so being that this is a four-cylinder if
you needed to replace all the injectors
it's going to be cheaper than on the
642 now same story as fuel pump access
is the vacuum pump the vacuum pump on
these things is engine driven uh
obviously drives the brake booster back
there but you can see this vacuum land
rather than going to the front of the
engine as we're used to on the 642 it
goes to the back of the engine back here
all the way down Focus you all the
way down to the back of the engine back
here next problem we have on the front
of the engine it is below all this relay
mess down here and it
is the water pump which sits right back
there uh these water pumps on these
engines um there can be two different
types I I don't know what the
delineating factor is on on you know
which vehicles use which pumps or not
but I know that the majority of the USC
cars have vacuum controlled water pumps
and I believe the reason for that is
that they can open and close very I
valves in the water pump to make sure
that the engine can heat up faster uh
that's one thing that I've noticed on
this engine that is very interesting is
this thing less than a mile down the
road is already up to 60° C this thing
heats up really fast and it is wonderful
in the winter time you've got heat out
of the vents almost instantaneously in
this thing however problem with this
vacuum controlled water pump that and
this is all going off of uh third hand
information I've never actually had to
do this repair but people say that the
just like any other water pump the main
shaft seal can can go bad and can leak
uh coolant all over the front of the
engine the second problem that I've
heard however is that these vacuum pumps
when they go bad a seal can fail
internally that can put uh coolant into
the vacuum system and can wipe out the
vacuum pump kind of an oversight on
Mercedes if you ask me but from what
I've heard on these you will get an
immediate low coolant light that will
show up if that uh pump actually fails
enough to cause the the vacuum system to
be affected now as I mentioned in the
last video this vehicle does not have a
power steering pump you may notice it
missing down here what you're looking at
down there is the AC compressor this
vehicle has uh an electric steering
option code now this is the first
Mercedes I've ever owned that has
mechanical option codes usually option
codes for vehicles that are attached to
the VIN um options you can get to the
vehicle are cosmetic um maybe they have
a bigger fuel tank uh maybe they have a
heated steering wheel or a wood steering
wheel or something like that um this
vehicle actually has numerous option
codes associated with Mechanicals of the
engine and transmission electric power
steering is one of them here is the
steering rack you can actually see two
pretty large gauge looks like maybe
eight gauge wires going into a Servo
motor uh this rack does not use
Hydraulics it's entirely electric um
advantage to that is you don't have to
worry about fluid leaks like you have on
the older MLS or
gl's um and you don't have to worry
about the extra complexity of having a
power steering pump now in my opinion
that makes these electric steering racks
a better option compared to the
Hydraulics because it's more of a
self-contained unit and you don't have
the added complexity of having a power
steering pump the hoses that can go bad
on them the pump itself can go bad you
don't have to worry about adding and
maintaining the fluid levels now on this
GLK they only came in formatic for the
Diesels but I know that the e-classes
the e250s you can get in either the
formatic or just standard rear wheel
drive uh one additional thing to keep in
mind as far as maintenance goes for the
uh formatic system is you do have the
added complexity and uh fluids that need
to be maintained for the uh front
transfer case above the DPF and exhaust
here you can actually see the drive
shaft right here coming through up to
the front transfer case as well as the
ujoint up there that is a bit of a pain
in the ass to get to if you need to
replace it another thing that can happen
which this uh GLK appears to be
suffering from is I believe the the
shaft seal uh for the front axle here as
it goes out the shaft seal up there I
believe is leaking pretty slowly it it's
kind of hard to see here but you can see
that the transfer case over here is a
separate casting from the oil pan Which
is over here this complicates things a
little bit because you have multiple
shaft seals as the axle for driving the
front wheels goes from the transfer case
through the oil pan and out to the other
side when these shaft seals go bad that
is an absolute nightmare of a job to
replace those things I can tell when I
remove the bottom covers off of this
thing there's not even a single drip
onto the aerodynamic panels so this is
not even leaking slow enough to drip I'm
just going to keep an eye on fluid
levels of the transfer case here but I
don't believe this warrants repair yet
I'm going to try and show you guys the
fuel pump location here from the
underside of the vehicle this might be a
little bit hard to get the camera to
focus on but I'm gonna attempt it I'm G
to come up right up here
kind of slightly behind the bell housing
for the transmission there is a metal
line you see that that shining metal
line that is the main uh pressure line
coming from the fuel pump and going to
the rail it skirts up underneath
the that skirts up uh next to the engine
and goes up to the rail uh where I
showed you earlier all right next thing
I'm going to show you guys is going to
be the emission system and exhaust I'm
going to go tip to butt on this thing
and show you where the complexity starts
and ends uh you can see here this is one
of the dpfs I believe this thing
actually has two dpfs and I'm not
talking about the uh scr Catalyst back
here if you come over here and look
straight up it might be hard to get the
camera to focus on it let me see if I
can get up there and look at it if you
look right there do you see that that uh
round part of the exhaust right there I
believe that is a second DP DPF up here
on top of the DPF this metal line going
through the exhaust this is a pressure
sensor um there's two or three of them
on the vehicle coming back over here to
the other side this is your def injector
your diesel exhaust fluid injector this
is where the Ura coming from back there
in the back of the vehicle comes and
routes around here and injects into the
exhaust now the chemical reaction that
takes place with the def that eliminates
the majority of nox Emissions on these
vehicles does not take place here it
takes place here at the scr Catalyst
this is where the the uh nox and and
remaining particulate that makes it
through uh goes through a chemical
reaction with the diesel exhaust fluid
and that is where the majority of the
magic happens in this exhaust uh one
thing I forgot to mention up here by the
exhaust fluid injector is an oxygen
sensor right here post DPF uh you have
one pre- DPF and post DPF and then back
here behind the uh scr Catalyst you have
another oxygen sensor on both sides you
have another one over here as
well after this point however all the
way back it is a standard exhaust system
now the emission systems on modern
diesels get a bad wrap for a good reason
uh all of these components add extra
complexity as well as cost of repair
however on the newer generation of
diesels the
651 and the uh 2012 and up om 6 42s uh
the exhaust systems have been a little
bit more modularized so that when
something does go bad you don't have to
replace entire assemblies in order to
fix it uh like with the ad Blue System
here with the DF system all of these
components are separate now this uh def
injector if it goes bad um they're I
believe like 190 bucks so I've shown you
all the components of the emission
system of the DPF and the ad Blue System
um but what is the reliability like well
that's still kind of an unknown there's
not enough of these cars out there in
the hands of people that uh do DIY
repairs that that really speak about
them publicly uh but from what I can
tell and what I've read almost all of
these vehicles are 10 11 years old now
and every single one of them is going to
have something in the emission system
fail before it's 10 years old and that
could be something as simple as you know
an oxygen sensor that needs to be
replaced it could be something as
serious as the scr cataly list uh the
def heater uh something like that now
it's not all going to fail at once
you're not going to have to rip
everything out and replace everything in
its entirety it's most likely going to
be one individual component at a time
you might have the tank heater go out
you might have the def injector go out U
maybe it's a a exhaust gas pressure
sensor or something like that uh
virtually every single aspect of the
emission systems in these cars every
individual component uh you won't find
any individual component short of the uh
the DPF or the SC Catalyst that'll be
more than
$200 so as far as you know just
replacing them when they fail it's not
too big of a deal and I've talked about
the scr Catalyst but the dpfs themselves
um the dpfs typically do not go bad
whenever you get uh if you get a code
that shows up in the computer associated
with the DPF being clogged or DPF
performance issues um that can be solved
by removing the DPF and just cleaning it
uh on commercial vehicles uh commercial
diesel pickup trucks semis that have
dpfs they fix those DPF issues by just
cleaning them out it's very rare for a
DPF to actually go bad for the Catalyst
inside of it to actually go bad um and
in these engines it's it's no uh it's no
exemption
so I
would so I would say with these newer
diesel engines I I would not treat the
uh I am I am very interested to see what
this vehic uh what the emission system
is going to be like I've never owned a
car that's had the the ad Blue System
the the def system in it before so I'm
very interested to see what the
reliability of the system is uh is going
to look like if it goes bad you guys are
going to see a video on it that's about
it on the OM 651 I mean this engine has
a reputation of uh mechanically being
very sound uh next video that's going to
be coming out we're going to be doing uh
I'm probably going to separate it into
two separate videos but I'm going to do
a complete transmission fluid flush uh
also going to be doing um a service of
the transfer case uh changing the oil on
that looking at the condition of the oil
but that is it for this video guys
[Music]
peace
تصفح المزيد من مقاطع الفيديو ذات الصلة
5.0 / 5 (0 votes)