Mark: Hi, it’s Mark from Top Local Lead Generation and we’re here with Bernie Pawlik
of Pawlik Automotive in Vancouver they are 15 time winners of Best Auto Repair in Vancouver
as voted by their customers.
How’re you doing today Bernie?
Bernie: Really well.
Mark: So we’re going to talk about a Mercedes Benz ML320, it had some exhaust fumes - what
was going on there?
Bernie: What was going on, well so our client brought, it’s an ML320, it’s a diesel
engine vehicle, a 3L diesel and they were getting diesel exhaust fumes in the cabin
of the vehicle.
We did some diagnosis and first step was road testing the vehicle to verify that concern
and could smell it right away in the car, it was pretty noxious, we could understand
why they were concerned about it.
So we proceeded to do the diagnosis on the exhaust system and what we found was interesting
was it wasn’t actually an exhaust problem at all.
The problem was actually a crankcase breather valve at the back, right near the engine,
right where the cabin air would be sucked into the engine and it was leaking crankcase
blow by gases which are, you know when an engine runs, there is a certain amount of
combustion gas that escape past the piston rings, these are called blow by gases.
Every engine, any internal combustion engine has to deal with that whether it’ gas or
diesel and they have a ventilation system where it sucks the gas back into the engine
and re-burns it.
The crankcase vent valve was leaking so it was leaking exhaust fumes, even worse than
car exhaust, more noxious right by the cabin air filter area.
So that’s the first thing we found.
We’ll just go to a couple pictures here.
Mark: Are these common problems on this engine?
Bernie: Well, this is the first one we’ve seen but there are a number of issues with
the crankcase vent systems on these vehicles.
The other issue that we found that was interesting…
so here is the engine cover that you would see when you open the hood of the vehicle.
Not much to see, the crankcase vent valve is hidden actually, well if you’re looking
down at the hood, at the back left corner of the engine and this is what things look
like with the cover off.
There’s an awful of of bits and pieces, there’s a lot of complexity with this engine
as I talked about before, that yellow arrow points to the crankcase vent valve and unfortunately
you can’t see it because it’s kind of in that darker corner of the engine compartment
but that’s where the vent valve was.
Now to get to it and check things out, we had to remove a number of other items where
the green arrow points, that points to a fuel injector, sorry that points to the air filter
box and underneath that is a nice foam cover, a noise reduction cover and we found something
interesting under that cover as well - you were asking about common problems.
We found this.
This is the centre fuel injector and all that black guck in that area is not normal.
That is combustion gas and a bit of diesel fuel that has leaked from a blown injector
seal at the bottom of the injector.
So this is another thing that we found that is contributing to the smell in the customers
vehicle.
Is this common?
This is the first time we’ve actually seen this particular concern on this vehicle but
from what we’ve read it does happen from time to time.
This engine is a commonly used engine, it’s in Sprinter vans, it’s in Jeeps, so this
is the first time we’ve found it but it is something definitely that happens from
time to time.
Mark: Wow, it doesn’t look good.
Bernie: No it isn’t and unfortunately it’s an expensive repair which gets me to the other
interesting question about where to buy parts for these engines.
So you shop around, because we’re an independent shop we can shop a variety of sources and
actually the cheapest place to buy this fuel injector, and is brand new is directly from
the Mercedes Benz dealer.
Substantially cheaper from any other source we can find and everyone else sells remanufactured
fuel injectors which are good but not as good.
It’s one advantage that people don’t think about dealing with an independent auto repair
shop, a good one that’s conscientious, we’ll shop around for the best price on parts and
based on what the best quality and price is, which is an option you don’t get when you
go to the dealer, you’re only going to get what they sell, the dealers brand and sometimes
they are cheaper but if they’re not then you’re stuck with that anyways.
Mark: So what else did you find?
Bernie: Well, what else we found was interesting.
This is a picture of the turbo air inlet duct and I’ll just go back to our original picture,
that’s the red arrow, points to where this photo was taken with the duct off.
Now there’s a lot of oily guck there and this is another common problem on this 3L
Mercedes engine.
There are some big rubber seals, the red seal you see on the left, that’s the small seal
from the vent valve which we’ll replace when we replace the crankcase vent.
But there is also a very large rubber seal where the duct, and I’ll go back to this
picture, that sort of Y shaped piece that goes across the engine, there’s a big rubber
seal in there as well that leaked.
What happens when these leak, and I believe we’ve done a post on these before, the oil
leaks down and there’s an expensive valve underneath called a Swirl Valve and if enough
oil leaks down it eventually gets into the valve and wrecks the valve.
So this is something that you want to fix on one of these 3L Mercedes engines, you want
to keep an eye on them, you want to make sure you fix these seals.
Another thing that is good about the Mercedes engine is you can buy these rubber seals for
a very reasonable price from the Mercedes dealer, whereas with a Jeep they use a different
type of air intake duct and you have to buy the complete duct pipe which is substantially
more costly.
But fixing it is infinitely cheaper than waiting until it leaks and wrecks your swirl valves.
So with just one last picture to look at, this is the fuel rail with the new injector
in and you can see where that black guck was once has now been cleaned and removed and
everything is all good.
That is our picture show for today!
Mark: How did the vehicle run after you repaired everything?
Bernie: Oh it was great, ran really well, no more fumes.
We also changed the cabin air filters because these filters were right near by the area
where these fumes were being sucked in and they do need to be changed on a routine basis.
But we figured it was a good time to change them with any extra particles that got in
there and they were quite dirty.
But yeah, the engine ran great.
With that fuel injector leaking as well there was undoubtably some engine performance being
lost but these engines have very sensitive management systems so if anything was severe
the check engine light would of come on and nothing did.
But definitely the vehicle ran great, no more fumes and makes for a happy customer.
Mark: So if you’re looking to be a happy customer with your vehicle and it could have
problems even before the check engine light comes on because they are not foolproof, the
computers are just computers Give Bernie a call, you can reach him at 604-327-7112 or
check out their amazing website pawlikautomotive.com - give them a call.
Thanks Bernie
Bernie: Thanks Mark, talk again soon