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Knowledge Base

Electrical Repairs to smart cars

A Smart City-Coupe came to us with non working headlights which we traced to this badly damaged connector on the SAM unit. It looked as though a bodged repair had been undertaken previously. At Smart-TECNIC we were able to source a connector to replace the damaged one and light was restored.



Repair to Smart Roadster Headlight Wiring

We have seen a number of Roadsters now with corroded wiring to the headlamps, rendering them inoperative. This also sometimes leads to a damaged 11-3 connector to the SAM unit as seen above.
We snip off the relevant wires at the damaged SAM connector and connect them to a feed taken from their respective fuses. We then replace the wiring to both lamps, running the new wire through sleeving and cable tie-ing to the existing loom.  Result is two working headlights, fresh wiring which is still protected by fuses and no further heat build up in the vital connector to the SAM nor further damage to the expensive SAM unit itself.
As of 2016: To replace plug 11-3 only we charge £146.52.
To replace the headlight wiring and by-pass the SAM connector we charge £185 inc vat.
To replace the headlight wiring, by-pass the SAM connecter and replace the connecter itself if badly damaged, we charge £265.00 all inclusive.  Prices subject to change.
(When replacing a badly damaged plug 11-3 we may still by-pass the headlight connections because often the headlight terminals on the SAM unit have been damaged by excessive heat. So far we have found our repairs to be effective and have avoided the need to replace the SAM unit itself).





Please change your oil folks…


…Or have us do it for you. Call us (0121 350 0026) and pre-book with us we can change your oil and filter for just £40, while you wait. We use Fuchs Titan SuperSyn 5w40, which is of exactly the right specification and carries the Mercedes-Benz manufacturer approval MB229.3, and we use genuine Smart-supplied oil filters.
I was prompted to post this offer after a recent engine rebuild, during which I was getting quite depressed at how black and soiled the engine’s internals were, and took the pictures below to show what I mean:




This engine is mounted upside down in the engine stand and the sump has just been removed. The oil pick-up pipe can be seen and is naturally black in colour. The engine parts are the same colour as the pick-up pipe, but they should not be! They are soiled black due to a lack of oil changes. The metal engine parts should not be the same colour as the black plastic pick-up pipe.






(Right) This is the engine block completely stripped and mounted correct way up. The face of the engine nearest the camera is almost jet black in colour. It should not and need not be like this.







This is the underneath of the cam-cover, the uppermost cover of the engine. The natural colour of the metal can be seen underneath the oil-stained grime.






(Right) This is a close-up of the cam-cover.









 Now this is the colour it should be! This is an engine on which we were carrying out a scheduled timing chain replacement. We have drained the oil and removed the sump and timing chain case and this is what we find underneath – components looking exactly as they should, all nice and clean with no black gunge to be seen anywhere. All of the underneath of the engine was the same colour.  Lovely!




Bits, clips and fasteners

At Smart-TECNIC we have become increasingly saddened by the the amount of poor workmanship we have seen on Smart cars that have not been maintained by specialists. Here we have some pictures to show what we mean. The following pictures are all from one car:




(Left) A typical problem we have seen is damage to spark plug leads due to their being removed without use of the proper tool. Three leads can be seen in this picture, the one on the left has been cut and the red internal sheathing can be seen, whereas the one in the centre is not a Smart spark plug lead at all – presumably the original was damaged so badly that the lead had to be replaced with one from another car; we think this lead is from a Vauxhall Corsa.







(Right) This is not a spark plug lead for a Smart car.










(Left)   A missing hose clamp should have secured this pipe onto the turbo inlet.







  (Right) This is the turbo outlet pipe, which carries boost pressure into the intercooler. On this car the hose clamp (painted red for some reason) has been fitted too high on the pipe, thus when it was tightened it has squeezed the rubber pipe and pulled it off the very thing it is supposed to be secured to.







(Left) Another picture showing the same. These pictures show that this car is effectively not turbo-charged and thus can be described as ‘Naturally Aspirated’







 (Right).  Worse is to follow. This is the pipe that carries boost pressure out of the inter-cooler into the throttle body and inlet manifold. Again the hose clamp is missing and the pipe is completely disconnected from the throttle body.





(Below). Then we discover that not only is the pipe not fixed to the throttle body, but it has also not been attached to the throttle body properly and has been shoved in to the throttle opening, crushing the pipe and reducing the intake air supply even further, as these photographs show.




The following pictures were again all taken from just one car. This car had clearly had quite a bit of work carried out at some time in the past, but again the standard of workmanship was very poor. At Smart-TECNIC we know what to look and check for and we can put things to how they should be:



The pipe marked with the white line is the main brake servo-vacuum pipe and should be routed over the large pipe pointed by the arrow. We routed the pipe as it should be. The large pipe is an after-market performance intercooler pipe.







 (Left) The connection being pointed to should not be there. It should be clipped to the top of the engine subframe, and again we were able to put that right.






(Right) The nut-and-bolt circled should not be there. It is holding the front undertray to the upper wheel-arch lining, but there should be a plastic push-pin fastener there…





… attaching both undertray and liner to the steel bodyshell by being pushed into the yellow clip. (Undertray removed in this picture).









(Right) Both front and rear undertrays are hanging down below the sills…









… due to broken and missing clips. All put back as it should be by ourselves.








(Right) Here the front driver’s side wheel arch liner is unfixed…








(Left) … due to missing plastic push-pins.








(Right) As shown correctly fitted on the passenger side



(Left) This is very serious: This is a picture of the main battery power cable where it emerges from the battery box formed in the steel bodyshell and which sits beneath the passenger’s feet.
Circled in white is a large rubber grommet which should have been inserted into the hole in the yellow circle to protect the power cable. The cable is free to chafe against the hole and this could very easily cause a major power failure and in the worst case, it could cause a fire. It took only a moment to fit that grommet properly into it’s hole.






(Right) In this picture, the clip arrowed in red should be fastened to the casting pointed by the yellow arrow, and the white arrow points to a missing small bolt which helps holds the intercooler housing in place.



(Left) This is the alternator, with new drive belt fitted as part of the ‘C’ Service. The alternator is missing it’s plastic protective cover…




(Right) … we had a spare so we popped it on.




There is nothing magical to keeping Smart cars as they should be, but all too often the ordinary mechanic working in the average garage just does not have the time or experience to put everything back on the car in the correct order that he took things off. At Smart-TECNIC we pride ourselves in doing the very best to keep the cars as they were when they left the factory.





Turbocharger Units: The options…

(Updated November 2013).
When rebuilding engines, naturally we look out for any other potential problems in an effort to ensure that our customers money is being well-spent.
The turbocharger unit, which includes the exhaust manifold and waste-gate actuator, is an ancillary part of the engine and is not covered by any engine work. If customers would like us to check the turbo unit out please let us know when booking the car in.
The Turbocharger and exhaust manifold unit can be a problem on smart cars, because neither the turbo or exhaust manifold is available separately; both must be bought together as a unit, which comes with a new waste-gate actuator also. The turbos on smart cars are very reliable, but sometimes, when a cylinder head exhaust valve burns out, the particles of molten metal can damage the vanes of the turbo itself. This does not happen very often, but it is a possibility and unfortunately the only remedy is a new turbo unit.
The far more common situation with smart cars is that of cracked exhaust manifolds.
We charge £550 to supply and fit a new turbocharger unit, which we believe is the cheapest in the country.
However, at Smart-TECNIC we totally recognise that this is a considerable cost. Our experience with these units has brought us to consider that the owner has four options when it comes to the subject of cracked exhaust manifolds:
Option 1. Leave it as it is; At Smart-TECNIC we firmly believe that every single smart car out there is running on a cracked exhaust manifold, yet they all appear to be running fine. We have seen some very badly cracked manifolds, yet the owner has been totally unaware because the car has been running completely normally. If we are asked to check the manifold, we will advise the owner honestly on what we think the best option for this particular manifold is.
Option 2. Have the manifold repaired; Update: Unfortunately we have decided not to carry out any further repairs to these manifolds as we have found that the repair does not last much beyond 12 months.
Option 3. Have the engine rebuilt, and consider having the turbo-manifold unit changed at a later date; We have found that owners are often delighted with how their car is performing after having had the engine rebuilt. All the car’s previous issues, such as poor performance, indifferent fuel consumption and a thirst for oil disappear after a rebuild. The owners often finds that their cars are very nippy indeed, the car returns to doing 45mpg around town, and the oil consumption stops.
Therefore, rather than facing one big bill, it might be better for the owner to delay having a turbo fitted, have the car back after the engine rebuild and get to enjoy again all of the brilliant attributes of the smart car. Then, perhaps some months later the owner may feel that it is worth having the turbo unit replaced for peace of mind.
4. Have a new turbo unit fitted; The units are supplied by Smart/Mercedes-Benz and come with a 12 month guarantee. This will ensure that the newly rebuilt engine will give years of fresh service and give great economy,  reliability and peace of mind.
If you’re having your smart car engine rebuilt by us here at Smart-TECNIC, we will be only too happy to advise the customer and give a totally honest appraisal on the condition of the turbo unit if required. We will always be happy to answer any questions the owner might have, as indeed we would be anyway about all aspects of smart car ownership.




Smart Car Servicing

Let’s talk a bit about car servicing, particularly with Smart cars in mind:
Q. Is car servicing still important nowadays?
A. In our opinion, yes it still is, and particularly so on Smart cars because they are city cars which have small and eager, hard working engines.
We think that regular servicing is the one main course of action which makes the real difference to not only prolonging the life of your Smart car, but also to ensure that your Smart car operates as economically as possible. This is why we offer a cost effective intermediate oil change at a price which the owner will not be able to match even if he or she were to do the job themselves.
Q. Are there any other benefits to servicing?
A. Yes. It’s a simple fact of life that all mechanical items wear out – be it your domestic boiler, the lawn mower or of course your Smart car. With simple preventative maintenance you can reduce the wear that takes place, maintain optimum fuel economy, maintain the safe operation of the braking system, increase the resale value by providing a proper recorded service history and cut down on the cost of putting your car through its annual MOT. All of these savings can more than recoup the cost of having your Smart car well maintained.
Q. Why don’t I just use my local garage?
A. Smart cars are not constructed like ordinary cars – (they are much better than ordinary cars, in our opinion) and they are different to ordinary cars. Smart car owners normally have two options for which type of garage to use to maintain – the network of Mercedes-Benz dealerships, which are all fully equipped to maintain Smart cars – but at high costs – or a local independent garage.
This is where problems can arise; most local garages will not see Smart cars on a regular enough basis to enable them to learn how Smart cars are put together, and are often too busy to take the time to learn. Many garages operate a bonus scheme for their mechanics, so when the mechanic is confronted with a Smart car, impatience and lack of knowledge can lead to important clips and fasteners being broken, and indeed sometimes the plastic body panels themselves have been damaged. Sadly we can normally always tell when non Smart-knowledgeable people have worked on a car before us, when we find these missing or damaged clips and fasteners or wrong connectors and leads fitted, etc. If for no other reason, this is why we would urge the Smart owner to let us work on their cars, because we know these cars, we know how they’re put together and we strive to ensure they remain built as intended. We have put a lot of time and effort into identifying all the different types of clips and fasteners that go into these cars – and not all of these fasteners appear on the Mercedes Electronic Parts catalogues either, so we offer our thanks to the helpful people at the Mercedes-Benz dealership who supply us for their help to us in this regard.
Q. Which parts do Smart-TECNIC supply and fit?
A. Almost all parts fitted are genuine Mercedes-Benz/Smart supplied, and Unipart is our supplier for other parts or parts to the other makes of cars that we also maintain. There are some engine parts which Mercedes-Benz do not sell separately (such as pistons) and in these cases we source components from the manufacturers agents who supply Mercedes-Benz tthemselves – Kolbenschmidt, in the case of pistons, for instance.
All items are genuine and branded, spark plugs are either NGK or Bosch and oil is supplied by Fuchs or Mobil. Only the highest quality grades of oil to the latest manufacturer specifications is used, currently to MB229.3 or MB229.5 ACEA A3/B3 Fully Synthetic in the case of Smart cars.
High quality oil is vital to Smart cars, but we believe we can change your oil for you for less than you’re likely to buy the oil for at Halfords. And whilst we’re changing your oil we will cast an eye over the car as well and have a chat with you about how your car is running. In our opinion it simply isn’t worth letting anyone else change your oil and we can probably do it cheaper than you can yourself too.

Dirty engine oil and oil burning can  cause damage.

Q. My car only does a low annual mileage. Why should I stick to manufacturers service intervals?

A. Short journeys are hard on a car. A car that does a low annual mileage will be driven most times when the engine is still cold and has not reached optimum operating temperature and then typically just as the engine is reaching it’s ideal temperature it will be switched off again. Compared to the car belonging to a typical sales rep which spends most of its life on a motorway, a low-mileage car will be braking more often, accelerating more often, changing gear more often, parking and possibly bumping kerbs more often, traveling over speed-ramps more often, and generally spending more time in difficult urban situations far more often. Rather than needing less servicing, a low mileage car is often in greater need of servicing.
This type of usage, which Smart cars are ideally made for, is also hard on engine oil, and so it is very important that not only is the oil in your Smart car’s engine not be too old, it must also be of the correct specification.

I am still sure I can save money by cutting back on servicing, and in today’s economic climate money is tight…

Effects of lack of servicing

We can give a recent example of how an owner did not save money by skimping on servicing: A Smart car came to us with gear change problems, and investigation revealed that the clutch release arm had failed. On every service we always adjust the clutch mechanism, not only mechanically but electronically as well. The job takes minutes to do but the correct MB-Star diagnostic equipment is needed, which we have here at Smart-TECNIC.
The car in question had missed out on a number of services, and so because the clutch had never been adjusted it meant that increased wear was taking place between the clutch actuator rod and the clutch release arm. This increased wear is what caused the clutch release arm to fail, (see the pictures in our gallery). It is a big job to change this release arm, and the cost amounted to nigh on two major services.
This meant that this particular customer has had to pay the money for two major services – but still hasn’t had his car serviced. Had the customer had either one major or two minor services, the clutch would have been adjusted each time and this failure would not have taken place. The car in question was a busy, working Smart car used for delivering fast-food, so not only did the customer have the cost of the job to cover but the car missed out on a day’s work too. Definitely not cost effective, in our opinion.
It is true that money is tight nowadays, but money spent wisely is never wasted. Have your car serviced and let it work in the way it should whilst maintaining it’s value and your safety and well-being. It makes sound economic sense in the long run.

Where Smart-TECNIC can Make a Difference

Our main ‘C’ services differs in two ways from manufacturer’s specifications: Firstly, we change the engine’s ‘breather line’; this is a plastic pipe with a one-way valve, and in time this valve will fail and can affect the health and longevity of the engine. Having this pipe changed once or twice during the life of the car will greatly lengthen the lifespan of the engine.

We have earth straps made especially for us.

Secondly, we also change the main earth strap on the engine; the original earth strap is not protected from the elements and deteriorates over time. Our replacement earth strap is sheathed, and will outlast the original item. Having a good earth connection is vital to the sound and proper running of any motor car engine.

These additions to standard servicing have been brought about by our experiences of working on these cars, and highlights our enhanced knowledge and expertise with these cars. Both these operations are included in the price of the main ‘C’ service, and we are certain that neither main dealerships nor  local independent garages would know to carry out these tasks.