W203 running slow, 40mph max

[Tilly]

Wifes C200 CDi is running roughly. About 2 weeks ago I took it out for a spin, and after accelerating passed another car, the engine management light came on, and the car seemed to lack power. Took it home and left it overnight.. Next day, engine management light was off, and car was running fine.

Today, the wife was driving it to work, and she says it lost power, and refuses to get above 40mph. Engine management light is on.

She took it to a local MB dealer, and they put it on the diagnostics.

They told her it needs the inlet manifold removing, (4 hours) and a new MA646 140 08 96 "Air Guide" fitting. What exactly is this part that costs £573.00 plus vat.

Now, my experience with this dealer is pretty, poor so I need to know what they are wanting to replace. The mechanic also told the wife, that they might find other parts as they take off the manifold that "might have seized" and these parts will be at an extra cost... Ok, studs, bolts etc, I can go along with that, but why take off the manifold in the first place. A14131007 is the labour code for the manifold.. £330.90 plus VAT.

Reading the threads on this site, it looks like it could be a MAF sensor that needs cleaning/replacing... but Im open to offers on the cause..

Just about to take it for a spin, and have a poke around under the bonnet.

 

[Tilly]

Just took it for a spin. Engine has no power, and wont rev over 3000rpm. No kickdown either.. so you have to drop it through the box manually. Engine management light is now off....

165,000 miles, so barely run in.

 

[Tilly]

Well, just took the cover off the engine and had a look at the intake. Under the MAF sensor its caked in oily residue. Took off the air filter and found the MAF sensor to be dirty as well, but I couldnt see any dirt on the sensor itself.

Blew it out, as I have no iso spray this time of night.. Another spin and its just the same, even in neutral, it wont rev over 3000rpm

Might have to strip down the intake, clean it up and have a fresh look at it, with a hot cup of tea...


So far, looks like MAF, or due to the oily residue, a split pipe ??

Any hints out there ?

 

[Cole@MBS]

Well seing as your talking to yourself here Tilly,

If Merc have read the fault codes, i suspect the manifold flaps have broken up causing the import shut off motor to go u/s, have a 2nd garage look at it first and see what they think, it really could be so many things.........

 

[Tilly]

LOL, I was just adding info as I found it out..!!

Is that going to be a diy replacement, or will it have to go on a diagnostic to set it up ?

edit: cheers for the hint on the swirl flaps. Reading up, it looks like that would be the issue from the fault codes.

I take it the part: MA646 140 08 96 is the intake manifold ? Would it come with all the necessary parts to replace it, ie gaskets, o rings etc ?

It looks a pig of a job, but do able. Do you need any specialist tools, apart from Torx bits/sockets ?

 

[Tilly]

Just looking at the Haynes manual, I have a 646 type engine, and it says I have to drain the cooling system to remove the manifold, but makes no mention of removing any parts of the cooling system, or hoses. Is that correct, or a typo ?

Doesnt seem too bad a job, but thats always the case reading a book...

 

[Tilly]

Is Mr Television on today. If so, could you send me some info sheets, about replacing the inlet manifold. Thanks in advance....

richardtill "at" btinternet "dot" com

 

[Alex Crow]

this is not an easy job, MB give 3.8 hours to change it. can you do it yourself? how can we know that?

i suggest you remove the cover from the engine and have a look - notice all the cables and pipes that pass through the manifold? they include power steering fluid, coolant and fuel pipes to disconnect. then you have the EGR pipework to deal with... if you feel undaunted and you have done worse then go for it.

 

[Mick Hutcheson]

I have C250T had fault similar to your lack of power. Two things to try, Spray silicone lube into vacuum inlet pipe, should be by bulk head area. my car has pressure convertor which controls wastegate. problem went away but came back so bought s/h one off ebay £17 sorted. Secondly fitted new front exhaust pipe which has cat in, I have a new car goes like a bomb. I had never heard of blocked exhaust till one of brains on this forum suggested it. When I took it off it weighed a ton. Worth a try, good luck

 

[Tilly]

Picked up the part today. Big piece of kit isnt it....

Im happy with mechanics, and have had my MX5 in pieces so many times I could strip it down in my sleep. As for the merc, I've stripped down the suspension, replaced brakes and bushes... so its all about remembering where everything goes...

 

[Tilly]

Well, the job started, and it finished. Started removing the mounting bolts and putting them onto the new manifold, so I didnt loose them.... until I came to the EGR valve... The new unit does not have the threads machined into the fixing holes... Good job I didnt fit it then discover the error...

Just one question, the fuel lines that run through the manifold need splitting. One set has crimped joints, as in the second picture. Do these fuel lines need recrimping with the correct tool, or can they be joined with a new jubilee clip..

Back it goes to MB on Monday..!!

Last picture shows the two holes, which have not been tapped out....

 

[Alex Crow]

the holes are not supposed to be tapped out, if you look at the bolts you will see they are designed to tap a new thread - they are very slightly triangular in shape. the hose clips can be removed and refitted with a (not very) special tool, but yes normal 'jubilee' pattern clips are fine.

 

[Tilly]

the holes are not supposed to be tapped out, if you look at the bolts you will see they are designed to tap a new thread - they are very slightly triangular in shape. the hose clips can be removed and refitted with a (not very) special tool, but yes normal 'jubilee' pattern clips are fine.

Alex, you are a real star mate... I thought I'd bought a friday afternoon shift part, unfinished. I did think about taping the holes myself, with a tap set..

The EGR wouldnt budge when I tried to remove it. Is it quite a deep seated unit, and would it be a good idea to replace it at the same time, or just give it a clean...?

One thing I did notice was quite a bit of black oil residue when I took off the large intake hose... normal I guess...

I will be taking pictures, to help anyone else who is thinking about doing it...

If anyone wants the old part, for bits, let me know before I bin it..

 

[Tilly]

Im working away at the moment, so the repairs are scheduled for the weekend. Missus rang me today, and said the car is running normally again.. DOH..!!

Still, it needs replacing I guess...

 

[Tilly]

Just as a follow up, and I know its an old thread, but I hate to read an unfinished one..

I did replace the inlet manifold, took quite a while, and a lot of the bolts are quite fiddly. But, it worked perfectly, and still works ok...