Mercedes Benz C180K heater exchange hose connector

Heater hose connector replacement

My Mercedes Benz C180K W203 is in her mid teens and has become as temperamental as a 16 year old whose hormones are fluctuating due to puberty changes, body development and other emotional changes. Over the past few months I witnessed these changes and developments on my car, among which are, remote control issues, heater exchanges issues, door unlocking issues, oil level issues and oil leak issues, overheating issues, water leaks, idling issues and several others.

 

 

Overheating

Whilst driving home from the office, the Merc's dashboard cluster computer beeped and the LCD displayed "coolant level low", seconds later the white radiator symbol disappeared as quickly as it appeared. A few minutes later it beeped again and the image flashed again. I was in traffic and had the full intent to go add coolant and  recollected that the closest filling station was roughly a kilometer away, so I slowly made my way towards it. Seconds later the beep was back but, the  LCD now flashed red showing a thermometer image. The heat gauge which I looked at a few seconds ago which was at approx 80 degree had climbed to 120 degrees very quickly.

I just had to pull off and as I did so; before I could stop, the engine cut out. I was kinda worried that I may have pulled off too late. So after allowing the engine to cool off for a few minutes I cranked the engine and it started by which time the temperature gauge had fallen below 100 degrees. I then opened the bonnet to determine what had gone wrong but there were no tell-tail or visible signs. Reluctantly, I opened the expansion tank cap and saw that there was no coolant inside of it. I knew there and then that either the radiator had  popped or one of the hoses had sprung a leak and all the water had already leaked out. I decided to take a brisk walk to a nearby tyre repair establishment to get some water.

Water Leak

On my return, I added water to the expansion tank and expected to see water running out somewhere but there wasn't any. I then decided to crank the engine just to get the water pump moving the water through the system yet not start the engine. As I turned the key over, the car actually started and the water pump did its thing but I switched the engine off immediately.  As a consequence, a large wet mark had formed on the ground under the left side of the engine. Water was leaking out somewhere but I wasn't going to crawl under because the ground clearance isn't much beside the engine was hot. That was sufficient evidence that my C180K had to go to my DIY workshop. A telephone call later and my W203 was getting a ride on a rollback home. I didn't have the time to determine the problem, so I left the repair for the weekend.

Problem found 

Like I mentioned above I needed to take a peek under the car to see where the water was leaking from but it was just way to close to the ground to do so.  So I popped the bonnet, did a visual inspection and still didn't see anything obvious. I then added water to the expansion tank, jacked-up the car on the right ride allowing water to flow towards the left. As I jacked the car, I could hear water spilling onto the paving. I quickly shoved a stand under the suspension and slid underneath the car. Water was pouring from above the bell-housing, at the firewall and close to the starter. I climbed on top of the engine and looked down between the engine and the firewall and saw a rubber hose with a clamp lying loose. When I managed to get it out in the tight space, I realised it was the heater exchange hose that was severed.  It was a plastic NORMA “Push & Seal” quick connector attached to the firewall that had perished.

Access to hose connector

Reconnecting the hose and working in that confined space was going to be a problem as it was sitting almost behind the oil filter housing which is almost against the firewall. The only way to get to it was to remove the air-filter box. So I did just that but as per normal, Mercedes Benz is famous for torx head bolts. There are two 8mm torx bolts at the rear holding the air-box in place but the left one is difficult to remove because of the sleeve above it which is part of the air-box.

I modified the air-box with a hacksaw blade and a stanley knife and used a 8mm hex socket to loosen it. The ECU plugs also need to be removed, as well as the brake booster pipe and a vacuum hose and a the MAF and a few other sensor plugs. With everything out of the way,  I could finally remove the spring clip holding the connector in place and pulled it out of its female part.

 

Make shift repair

Mercedes Benz agents were out of stock of the part and I was hit with a 2 week waiting period before delivery. I just couldn't wait that long. My initial thought was to attempt to repair the connector with a steel nipple attached with plastic steel but on second thoughts it wasn't worth it because it was going to break again and I couldn't risk the possibility of overheating problems and the likelihood of blowing a head gasket, so I went hunting for a second user connector as a temporary repair.

Repair completed

All the popular motor spares outlets either didn't have stock, saying its and agents only part , with some not even knowing what it was. Some saying its the same as the VW part but without the spring clip. Anyway, several kilometers of driving and hours later I eventually  found a connector at Merc Centre and it wasn't cheap considering it's just a piece of plastic. 

Gone are the days when two rubber hoses are connected with a short length of galvanised pipe and hose clamps through the fire wall, but that would have been my permanent repair if I couldn't find this connector. I find peculiar that a plastic part manufactured for a 16 year old car can be sold out at such a ridiculous price and  an open ended waiting period. I suppose they will blame the scarcity thereof on Covid-19 as they do with everything else.

Brake Pads Service & Replacement

Replacing rear brake pads on Mercedes Benz W203

Like everything else in life, brake pads also have a finite life span. Since I bought my Mercedes Benz  C180K, I guess it was just more than two years ago.  I've never had the need to replace its brake pads, probably because I hardly ever drove her but also that my preferred mode of transport is my BMW R1100RS motorcycle. However, since my Merc was being used by a sober drive team to  transport  Europe Assist clients, who exceeded the alcohol consumption legal limit, to their homes, I was compelled to replace its brake pads. 

The average distance that this team drove each night varied between 300-400 km per 8 hour shift, thrice per week.  In a matter of one month they raked up close to 5000 km.  For the 3 months they used the car prior to the announcement of Covid-19, had put 26 000 km on the odometer. In my estimation that's about the same distance I normally travel in one year. Something had to give, and it was the brake pads and my tolerance; as my Merc was returned to me with the screeching sound of metal rubbing on metal when it stopped. The Europe Assist driving gig may have seemed a good idea at the time but right there and then I decided that it wasn't. Effectively the wear and tear by far exceeds the income. 

Anyway, after jacking up the car and removing its wheels, I checked the front brake pads which seemed to be at half life but the rear ones were completely kaput. See pics above and below. The other side was even worse.

Mercedes Benz brake pads are not expensive and replacing the rear break pads are relatively easy. It's purely a matter of knocking out the Mercedes Benz brake pad retainer pin and removing the spring clip. Then prize open the calipers and slide the new pad into place on either side of the disk and reassemble in the reverse. Fortunately, the metal to metal screech didn't damage or score the discs. It takes as little as and hour to replace the rear brake pads on both sides. 

As can be seen above, spring clip gets inserted and pin knocked back in place. But in my case, the calipers had pushed our that far that it was difficult to get it to retract. A few squirts of Brake and Parts cleaner quickly resolved the issue. 

NB! Do not spray Q20 on or into the caliper. Q20 is an oil based liquid and will soak into the ceramic material of the break pads and the brakes won't engage properly or rather wont stop the car in the distance expected. 

Mercerdes Benz C180K Wiper Switch Problem

WIPER SWITCH PROBLEMS

In the not so distant past I took my Mercedes Benz C180K for road worthy at one of the AVTS centers but it failed horribly. Not because the car was in a poor mechanical condition  but  rather that I needed to know exactly what was wrong with it, in order to fix it to at least roadworthy standards.  So this was deliberate on my part but it cost me a good R500.00 but it was worth it. I also needed there to be a record on file that it had gone through the necessary checks. So there!

However, even though  I was able to register the Merc C180K on my name, I couldn't get its licence disk because of some issue I had with City's Motor Vehicle Registration Offices regarding the licence for a Renault Megan. I had failed to draw its licence for almost 3 years. Since, the engine had given up the ghost and I kinda abandoned it. Anyway the issue I had, involved a 12% monthly penalty fee  added to the principal amount including interest. It turned out to be a ridiculous about of money. But that's a story for another day. The image below gives you an idea of what was wrong with the Mercedes Benz C180K. A total of 13 issues that needed sorting. 

I intend to cover item 1&2  on the list and give you a rundown on its processes and procedures. As can be seen the rear wiper blade was torn which needed replacement. My personal opinion is that the examiner was being petty because the rear wiper worked and wiped away water off the rear screen just fine but had a 2cm piece at the end of the wiper blade that was delayed and dancing about. Be that as it may, it compelled me to replace it, as can be seen below.

 

I bought three Hella wiper blades, from their Cleantech range which are definitely not as good as the original Mercedes Benz wiper blades but a far cry cheaper. Buying cheaper certainly doesn't mean better because I ended up with a handful of plastic parts which was of no use to me. I only needed two pieces for the front wipers, as came be seen in the image below. Fitting the front wipers was a basic clip-on whereas the rear wiper needed a 10mm spanner to remove the old and replace the new.

Next on the list is the "front wiper not working". As far as I was concerned they worked on the intermittent setting,  but as far as the anal examiner was concerned, the front wiper wasn't working at all. When the push button on the indicator stalk was pressed it worked just fine for two wipes. But it also meant that it has to be pressed continually during rainy weather to keep the windscreen clear. But I'm not going to complain any further, and decided to repair the problem. To get to the indicator/wiper stalk assembly, I needed to remove the air bag, the steering wheel and the steering wheel hub. 

NB! Before even thinking of removing the air bag, it is mandatory to remove the negative battery terminal then the positive then wrap each terminal in a cloth to prevent them from accidentally making contact with the battery terminals whist you busy with the airbag. Alternatively just remove the battery. Failure to do so could cause the airbag to deploy whist removing it, and it may cause severe injury to your hands and face.

So this is what I started out with. Behind the steering wheel, there two holes with a torx screw in each. Loosening them both allows you to remove the airbag but please don't pull the airbag off, because the wires are actually fairly short and fragile. Flip the airbag over and remove all three plugs as can be seen below. The plugs have anti slip-out locks, so fist unlock them and remove the plugs carefully.

Next the steering wheel needs to be removed. It is held onto the splined steering column shaft with a single countersunk screw. To remove it you would need a hex allen socket with a power-bar. This screw will have to be re-torked on re-assembly. I don't have one so I made a mark on the steering where the power-bar touched its outer rim and re-tightened it to the same position but added a few drops of locktight liquid to the screw.

Now that the steering is ready to be pulled off the splined shaft, notice that I've made two black pen marks on the splined steering column shaft that coincides with the key slots in the steering wheel. This is to ensure that the steering wheel gets replaced in exactly the same position. Failure to do so, will cause you to end up with an offset horizontal axis.

Now that the steering is out of the way, the steering wheel hub is clearly visible. The most important thing to look at in the image below is the visible torx screw head. See that it is exactly in the centre of the hole. The next image will show that I've moved the top ring of the hub ever so slightly to demonstrate that is moves even though it shouldn't be allowed to. The hub will ensure that the steering wheel returns to the correct position after going around a corner as it determines the direction of the front wheels. See the two relief diagrams on either side of the triangle. It represents the car with its four wheel, its front to at 45 degrees angle.

Notice that I've inserted my torx key into the slotted hole below. This lines up all three screws so that two pieces of tape can be pasted on the top movable part of the hub and its side. Once this is done, the three screws can be removed. Also notice the arrow head below the triangle lines up with the two  black marks on the splined shaft. 

Here all three screws are visible inside the holes. Ensure on re-assembly that they stay in this position. Refer to the images above to make sure they stay that way. After the screws are removed the hub can be lifted vertically off the shaft. The image below exposes the  wiper and the speedo-cruise mechanisms. The speedo-cruise mechanism isn't held down by screws and also just lifts out. be careful not to loose the two plastic slides that sits directly above both the wiper and speedo-cruise stalks.  

Now that the speed-cruise unit is removed, the screw on the right side on the opposite side from where the stalk protrudes. As can be seen below, the torx key is pushed through a hole in the plastic housing from the bottom, to undo the clamp screw. And the next image shows the screw almost totally removed. Thereafter the entire unit along with its plastic housing can be lifted off the steering column shaft.

This is what all the fuss was about, getting to the wiper switch. The image below shows the underside of the housing and the three visible screws than needs to be removed to get the switch mechanism out of the housing. 

The image below is the reason why everything had to be taken apart. So you can either replace or repair the Mercedes Benz combination indicator light wiper switches assembly assembly which costs well over R3500.00. The only problem is that the blue wire broke off. In fact the blue wiper wire  was cut by the sharp edge of the black wiper stalk at the point where the wires go into it. I believe this is a fairly common problem and that Mercedes Benz has somewhat modified the wiper stalk in later models to prevent the blue wire from being cut. 

As can be seen, I just didn't solder the broken wire back together again. I extended it with a 2cm length of wire to prevent it from pulling light. By so doing provided some play in the blue wire for movement.

The switch assembly fully assembled, ready to go back into its housing.

What you may notice on the above pic is that a filed away a piece of the wiper stalk exactly where the four wire enter into into it. The sharp edge of the black wiper stalk is what cut the blue wire in the first place.




Make sure the cream slide which moves to two different position when the indicator stalk is move up or down.  Failure to see that it moves correctly when the wiper stalk is move may need you to disassemble and redo it.



Assembly is the reverse of disassembly. It's a good idea to take photographs of every step just in case you forget the assembly process then you can at least revert to those pics.

Once everything is back together, the wiper turn switch at the end of the wiper stalk should work seamlessly. Do not reconnect the battery to test its functionality mid-job. Fully assembly before the battery is reconnected. It would prevent the airbag from popping, or leave you with a dash board airbag lite that won't go off.

Mercedes Benz problems

Mercedes Benz C250D

My experimentation on my Mercedes Benz C250D started after I was totally and utterly disappointed by the lack of commitment and utter incompetence displayed by a "diesel mechanic" who came highly recommended —by my brother of all people. When I initially bought the C250D she started with difficulty, besides the  injectors were a bit noisy. This wasn't too huge of a problem, because once she started, she would continue to start and drive perfectly normal throughout the day. However, if left overnight, air would somehow seep into the fuel line and the struggle to get the engine started resumed the following morning.  To alleviate this problem, I went and bought a can of "Spanjaard Quick Start" spray for diesel engines; in order to get the engine started for the "first start of the day"... everyday!   It's what I needed to do and was willing to do, to overcome her "morning sickness".

Spanjaards Quich Start Spray

 My dad had a fleet of BMC diesel trucks for several years, so my elder brother who subsequently qualified as a diesel mechanic and I were assignment with the responsibility of fleet maintenance.  As such, I was exposed to truck and car engines and general mechanical repairs for several years, in fact throughout my high school career. During this time I learnt much about the internal combustion petrol engine, indirect injection diesel engines, injector pumps, injectors, spill timing, glow plugs and working of the Otto engine and so much more. 



 However, even though I understood mechanicals fairly well and was pretty much able to do all my own repairs; I disliked always smelling like oil or fuel and detested that my hands and nails always looked dirty, even after I had cleaned them thoroughly. I therefore preferred outsourcing my mechanical work to a qualified mechanic or two. Always thinking that they could or rather would do a better job than me. But boy, was I wrong!

The replacement set of injectors with complete threads

One day, whilst driving  my Mercedes Benz C250D I got the very distinct smell of diesel inside the car —which definitely wasn't normal. So I popped the bonnet; and on further investigation found a pool of diesel inside each of the "Injector wells". The  "Injector well", closest to the firewall was almost completely full whereas the amount of diesel in each of the other four, varied towards a lesser amount. I suspected the leak-off pipes had become brittle or had reached their end of life hence not seating properly. Ostensibly the cause of the air leak that prevented the engine from starting in the morning. 

The injectors that were in the engine. Look at the rightmost injector
- the treads are all damaged with only 4 left as opposed to 7

I really didn't fancy doing the the job myself,  so I consulted by brother  who suggested I should take my Mercedes Benz C250D to this "highly recommended diesel mechanic"  mentioned above. My elder brother was my first choice to do the repair and he could quite easily have repaired it for me. However he had fallen from a scaffold onto protruding bolts whilst working on a ship and permanently injured his spine. He therefore couldn't do any physical work in a bent over position.  For the sake of brevity, I'll call the mechanic Joe.

My initial contact with Joe was somewhat moronic. After I explained about the "morning sickness" and the diesel in the injector wells and the noisy injectors, he gave me a song and dance about having to remove the injectors. Adding that they would have to be serviced, and that they needed to be pressure tested, blah blah blah and the repair cost would be R5500.00. Ending off  that it would take four days. I felt he was a a bit expensive but since Joe didn't know that I knew exactly what needed to be done, I gave him the benefit of the doubt and the go-ahead. Especially considering that he was one of my brother's fellow diesel mechanics. 

Engine with replaced Injectors

I later came to realize, it was the mistake of my mistakes. I might as well have distributed my cash among the street beggars because I would at least have felt that I had gotten more bang for my buck than the flack I received in return from Joe. Four days later, I went to fetch my car and it wasn't ready. His excuse was that Mercedes Benz agents only had 3 copper Injector Heat Shield Washers in stock and that he needed 5, promising that I could get my car back in within a week. I eventually got the car back; and the very next morning the C250D wouldn't start —and in the process I drained the battery. Some  "Spanjaard Quick Start" spray later and a jump start got  the C250D going once again.

Slightly pissed, I took the car back to Joe. Enroute I smelled diesel as before and stopped along the road, only to see that my black plastic rocket/cylinder head cover wasn't replaced and that each of the wells were partially filled with  diesel. I was furious, because in exchange for my payment, at the very least I expected Joe to fix this problem, as well as the no cold starting problem and he did neither. Joe wasn't in that day, so I dealt with his son Abe. He asked me to leave the car with him and that he would relay my complaint to Joe. Three days later I phoned Joe to get a progress report. I was told to collect my car the following day. 

On my arrival and in Joe's absence, Abe told me that the C250D wasn't done because the local Mercedes Agents didn't have the required thickness leak-off pipe in stock and that they needed to fetch the correct thickness from the Mercedes Benz Agency in Somerset West. Three days later I got the car back and it appeared that the leak-off pipes problem was fixed. However the no cold starting problem persisted which I only came to discover the following morning. Once again, I took my back and when I arrived that Joe's workshop they were in the process of moving to a alternative premises. Joe then asked me to give him a few days to settle in and bring my car to the new business premises. 

Two weeks later I took the C250D back and told Joe about the original no cold starting problem which he then said he would fix. Following day I got a call from Joe, saying that he checked every connection and that would have to replace all the transparent pipes at a cost of R1500.00. He assured  me it would solve the problem, so once again I gave him the go ahead. Three days later I got the car back. I then checked on the repairs that were effected, only to discover that the transparent diesel pipes looked like they weren't replaced. So I called Joe to inquire why he had charged me R1500 and didn't replace them. He replied that the transparent pipes were replaced, but with a "good second hand" set. 

I wasn't really unhappy because I was under the impression that I was paying for a new set of pipes. The following morning, the no cold starting problem was back. In fact it was never fixed, so once again I relied on the quick start spray  to get the engine going so that I could take it back to Joe. After haggling over the age of the car and the unknown pressure of the injector pump, Joe suggested that he fit an in-line electrical fuel pump to siphon the diesel from the tank, making it easy for the injector pump to get to the required pressure. All I can say is that I paid another R750.00 for the in-line electrical diesel pump and labour and it didn't solve the problem.

Electric fuel pump that wasn't needed in the first place

Whilst driving the car, I could hear a very high pitch whistle emitting from the engine but couldn't initially identify it, but after seeing the top of the engine was wet with diesel on switch off, I knew it had to come from some where. I then dried the top of the engine, covered it with brown paper, started it  and monitored it.  After a few minutes, I saw the oily marks of the diesel appear through the brown paper above the injector closest to the firewall.  I found that there was a very aerosol-like fine spray squirting from the injector well. On closer inspection, I heard that the high pitch whistle was coming from the injector and realized it was caused by the spray escaping from the cylinder. So looking down the well, I saw the bottom of the injector well covered with a wet black coal-like crusty substance, and knew I had it had a case of "black death".  

This problem commonly occurs with  Mercedes diesel engines when one or more of its injector seals leak. This "black death"  problem can arise when an already used heat shield washer is fitted or inserted upside down (wrong way round) or the injector isn't sufficiently torqued or the injector seat is damaged. As a result, uncombusted diesel and exhaust gases escape past the injector seal, or rather forced out of the cylinder by exhaust compression. This forms a black coal-like hard to remove crust in the injector wells , which will only get worse if not remedied. Installing heat shield washers upside down can damage the injector seat causing it to leak. The only way to correct this problem is to ream out the injector port with an injector seat cutter, insert a new heat shied washer the correct way and torque it to recommended tension.

The 5 heat shields and their used counterparts- correct way up

The 5 heat shields and their used counterparts- wrong way up.

This revelation required me to take the car back to Joe because they had removed the injectors and refitted them. By implication, this was plain bad workmanship. A week later I got my Mercedes Benz C250D back. There was no evidence of "black death" but  two weeks later it returned. By that time I just had enough of Joe because he had my car for a total of 84 days and my C250D was now in a worse condition than when I initially took it to him. I then decided to take my  car to another mechanic who was willing and eager to fix the problem but when I related my woes and told him about my misfortune with Joe, he was hesitant. Apparently he knew Joe fairly well and said they often loan one another's specialized tools, then added he doesn't have the specific spanner for my injector and therefore cannot do the job.

I always knew that if you want something done properly then it best to do it yourself. So that's exactly what I decided to do. I went online, found the requisite injector spanner and ordered it on e-bay, and it was delivered within 40 days. It is described as  1/2" drive, 22mm Diesel Injector Socket Tool For Mercedes Benz OM604 OM605 OM606 ... 1993–1995 W202 C 250 D. 

Assembled engine with replacement injectors.

Within two days, I had the injectors out and replaced them with another set, taken from a complete C250D engine I subsequently bought. It didn't take me long to identify the air-leak that initially caused the morning sickness. I turned out to be a hairline crack in the diesel pre-heater so  swoped it with the pre-heater from the other engine. Now that the fault that plagued me all the time was fixed, I discovered Joe and Abe left me with a new one. They had stripped the tread of the injector closes to the firewall because after I replaced the injectors the high pitch whistle was back.