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1998 Merc- Loss of power

  • 25-04-2012 04:36PM
    #1
    tyview
    Registered Users, Registered Users 2 Posts: 210 ✭✭


    Hi, my 98 merc suddenly loss power today. I limped the 15 miles home at max speed of 25 mph which was very unpleasant. I stopped and rested it a couple of times for about 5/10 mins to see if that would help (and take my embarrassment away) but it was still as bad. Engine making a weird noise, cant really describe it though, louder than normal and a bit screechy or rumbley...

    I'm flat broke but rely on my car daily to get kids to and from school. Also have interview tomorrow too which I need car for so I'm stressed to bits! Would anyone have any ideas what it could be?

    The only thing that came to my mind (being a woman who knows little about cars) was spark plugs but I really dont have a clue :o


Comments

  • #2
    Mena
    Registered Users, Registered Users 2 Posts: 3,180 ✭✭✭Mena


    Could be the MAF (Mass Air Flow) Sensor. Happened on one of mine as well. If I recall it cost me around 500 from a dealer but would be considerably cheaper to get replaced at an indy.

    Assuming of course that's what the issue is...


  • #3
    tyview
    Registered Users, Registered Users 2 Posts: 210 ✭✭tyview


    Mena wrote: »
    Could be the MAF (Mass Air Flow) Sensor. Happened on one of mine as well. If I recall it cost me around 500 from a dealer but would be considerably cheaper to get replaced at an indy.

    Assuming of course that's what the issue is...

    Thanks for the reply Mena. Gonna try gettin it to a garage tomorrow but it wouldnt be a dealer. At least I wont fall over from shock if they tell me its the MAF (baring in mind I have a ball park of 500 or less)

    I did a really stupid thing and decided I'd have a look under the bonnet, but in popping it I broke the handle off :eek: Things could not get much worse for me today!


  • #4
    Pottler
    Closed Accounts Posts: 5,073 ✭✭✭Pottler


    Blocked CAT is common on Mercs of that vintage and causes the symptoms you describe. Short term cure(if that is the fault) is to ram a brush handle through the CAT repeatedly and then turn the motor on to blow out the bits. Long term cure new CAT.(or weld in a bit of flexi and hope on the next NCT


  • #5
    Onwardandupwar
    Closed Accounts Posts: 130 ✭✭Onwardandupwar


    Pottler wrote: »
    Blocked CAT is common on Mercs of that vintage and causes the symptoms you describe. Short term cure(if that is the fault) is to ram a brush handle through the CAT repeatedly and then turn the motor on to blow out the bits. Long term cure new CAT.(or weld in a bit of flexi and hope on the next NCT


    Please don't listen to this
    Firstly the brush won't get n e way near the cat.


  • #6
    argosy2006
    Banned (with Prison Access) Posts: 4,210 ✭✭✭argosy2006


    Pottler wrote: »
    Blocked CAT is common on Mercs of that vintage and causes the symptoms you describe. Short term cure(if that is the fault) is to ram a brush handle through the CAT repeatedly and then turn the motor on to blow out the bits. Long term cure new CAT.(or weld in a bit of flexi and hope on the next NCT
    Side-Brush-Cats-Teeth.jpg

    Yea try this


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  • #7
    Wheelnut
    Registered Users, Registered Users 2 Posts: 977 ✭✭✭Wheelnut


    tyview wrote: »
    ... Engine making a weird noise, cant really describe it though, louder than normal and a bit screechy or rumbley...

    Is it safe to assume you have oil in it?

    As mentioned already, the MAF sensor was a weakness in those models. It usually limited acceleration rather than top speed so maybe it's the catalitic converter (AKA: the cat) but you really need a diagnosis.

    You should be able to get a MAF sensor for a fraction of what has been quoted. The CAT can be broken out if that's the problem but you won't do it with a brush handle up the tailpipe. It would need to be disconnected further up the exhaust system, and you might need to replace it to get through the NCT.

    What about the clutch, is the engine reving without an increase in speed?


  • #8
    Pottler
    Closed Accounts Posts: 5,073 ✭✭✭Pottler


    Onwardandupwar wrote: »
    Please don't listen to this
    Firstly the brush won't get n e way near the cat.
    Shows what you know. I've done this for heaps of lads whos Converters broke up and blocked the exhaust, killing all power in the car. Open exhaust behind the Catalytic converter, poke a piece of wood through, breaking up the honeycomb, start the engine, blows out the debris, reconnect exhaust and voila, you now have a noiser exhaust, worse emissions, but a car that will get you to work until you can afford a new CAT. Please feel free to have a go, but also be aware that I give a toss and that I weld about 5-6 exhausts a week for people who need their cars to get to work and can't afford to replace them at the mo. Bite me.:)


  • #9
    SilverBell
    Registered Users, Registered Users 2 Posts: 431 ✭✭SilverBell


    Onwardandupwar wrote: »
    Please don't listen to this
    Firstly the brush won't get n e way near the cat.

    Good point! The observant mechanic will realise that the brush will not be able to pass through two silencers and the many bends, plus it would need to be about 20ft long. :D


  • #10
    tyview
    Registered Users, Registered Users 2 Posts: 210 ✭✭tyview


    Thanks for all the replies. The car was towed to a garage just before lunchtime. Mechanic rang diagnostic on it but that came back clear. He rang this evening but the line was really bad. He definitely said something about Airflow and reckoned the part new was about 600 euro. he said he is trying to get a second hand one for me so I'll wait and see what happens.


  • #11
    Pottler
    Closed Accounts Posts: 5,073 ✭✭✭Pottler


    SilverBell wrote: »
    Good point! The observant mechanic will realise that the brush will not be able to pass through two silencers and the many bends, plus it would need to be about 20ft long. :D
    Yeah, savage point, seeing as car would be on a lift and the merc exhausts separate with a clamp about 3 foot behind the CAT. And seeing as I've done it heaps of times as a "get you going for a month or two" fix. I've also cut out a heap of broken up cats and welded in replacement flexi-pipe sections for the same reason - Relay/Boxer/Ducato vans suffer a lot with this. Anyway, apart from the hilarity from the armchair experts at what is a fairly common thing to do, the OP probably just needs a Maf. But a lot of older mercs(and plenty others) suffer from collapsed and blocked Cats where a piece of the honeycomb matrix breaks away and turns, blocking the exhaust and killing almost all power.:) And yeah, I usually use a broom handle, cos its soft enough not to wreck the exhaust but stiff enough to smash the honeycomb. The broken pieces of CAT also happen to make very nice money as scrap due to the platinum content.


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  • #12
    tyview
    Registered Users, Registered Users 2 Posts: 210 ✭✭tyview


    Pottler wrote: »
    Blocked CAT is common on Mercs of that vintage and causes the symptoms you describe. Short term cure(if that is the fault) is to ram a brush handle through the CAT repeatedly and then turn the motor on to blow out the bits. Long term cure new CAT.(or weld in a bit of flexi and hope on the next NCT

    Well an update from the mechanic is that he got a second hand MAF put it in and the car went fine, for about 10 mins. He reckons the CAT and/or coils are now gone...

    Yee really know your stuff on here!


  • #13
    SouperComputer
    Registered Users, Registered Users 2 Posts: 6,946 ✭✭✭SouperComputer


    Yep your MAF sensor issue may have caused it to run rich leading to contamination and excess carbon on the cat. The cat is usually mounted as close to the engine as possible to maintain its operating temp and depending on where/how its bolted you could try and smack the honeycomb out. I'm not a fan of blowing all the stuff through the system and silencers though but sometimes you gotta do what you have to to just get going. Another option would be to cut the side off the cat(s), gut out the honeycomb and re-weld the sides. Have the mechanic do a back pressure test on the exhaust system to see if its clogged.

    You will want to be sure that all the sensors and soforth are in good nick before spending any money on cats. For sure you will want fresh air filter, fresh plugs leads and distribtor cap & rotor (not sure what the ignition setup is on your car so throwing that out there) and you will probably need a pre-cat (upstream) O2 sensor as well.


  • #14
    Onwardandupwar
    Closed Accounts Posts: 130 ✭✭Onwardandupwar


    Hey just one way that we use in checking blocked cats in the garage and is the easiest way is to remove the sensor out of the cat so the air has a way out try it it will answer ur question


  • #15
    pcardin
    Registered Users, Registered Users 2 Posts: 2,216 ✭✭✭pcardin


    Wheelnut wrote: »
    As mentioned already, the MAF sensor was a weakness in those models.

    lol. OP hasn't even mention any particular model. just 98' Merc. :D

    If it's E-Class and automatic then limbo mode on mine was caused by brake light switch (located behind brake pedal). Part cost €14 and is simple to replace. Not saying this is the case with OP car as not much info is given about car.


  • #16
    tyview
    Registered Users, Registered Users 2 Posts: 210 ✭✭tyview


    the car is a c180 with 180K mile on the clock, prob should have said earlier. radiator was done about 3 months ago. Really not sure at this point whether or not to cut my losses and scrap it or pump more money into it. head wrecking!


  • #17
    n900guy
    Registered Users, Registered Users 2 Posts: 288 ✭✭n900guy


    Original Bosch MAF for a C180 Mercedes (and for that matter, just about all Mercedes) costs around €200.

    For example:
    http://www.maf-sensors.nl/a-16541887/mercedes-benz/bosch-luchtmassameter-mercedes-0280217114

    It takes around 5-10 minutes and a screwdriver to fit. The ECU should be reset after it has been installed.

    As said already, if it was not done correctly or not a correct part fitted, the catalytic converters can become a much more costly problem (around €1k IIRC). If the the air filter is also not clean, it can also lead to MAF problems. Were they changed (properly) at the last service?


  • #18
    Pottler
    Closed Accounts Posts: 5,073 ✭✭✭Pottler


    The car ran fine for 10 seconds because thats how long it takes for back pressure to build up - the CATs collapsed and either needs replacing or breaking up. A CAT(genuine)for a merc is dear(they make €170 as scrap alone) so what I do for people who just can't afford a new one right now is break up the old one(via the joint behind the cat for the comedians) then turn on the engine to blow out the debris. It costs nothing and the car will run fine but the exhaust will be a bit vibey. THe OP's description is of a classic blocked CAT. If you are anywhere near Kildare, I'll do it for free, it takes 10 minutes.


  • #19
    Andrewf20
    Registered Users, Registered Users 2 Posts: 3,256 ✭✭✭Andrewf20


    It could be a bad cat. My E36 had a blocked cat but symptoms included a rattle from under the car where the cat is, and worsening performance as the engine heats up.


  • #20
    Pottler
    Closed Accounts Posts: 5,073 ✭✭✭Pottler


    Andrewf20 wrote: »
    It could be a bad cat. My E36 had a blocked cat but symptoms included a rattle from under the car where the cat is, and worsening performance as the engine heats up.
    You were supposed to be in for 8, where the feck were you??:)


  • #21
    Wheelnut
    Registered Users, Registered Users 2 Posts: 977 ✭✭✭Wheelnut


    pcardin wrote: »
    lol. OP hasn't even mention any particular model. just 98' Merc. :D

    Maybe the word "model" was a bit unfortunate, but I think you will find that around '98 many Mercs were having MAF problems.


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