Hi,

I want to change the spark plugs in my 97 c230.
I never done it but it should be fairly straight forward. (done honda cars before).

But MB engine bay is somewhat intimidating. Where should I begin?

Should I take out the plastic cover in the top middle of the enging that two screws are holding? and then take out the intake pipe?
I took out the MAF sensor already and wondering what to do from there. Don't have a manual with me at the momeny.

Please help.
step by step will be very appreciated.

Thanks in advance.

YJ

OK,

I took out the cover. it was held by 3 screws not 2. I took out the intake pipe to the TB and I found another screw.
I now see wires that connect to the spark plugs.
How do I take them(wires) out? Just pull? or screw it out?

YJ

I'm not familiar with the particular layout of your engine, but with any spark plug change you want to make sure you don't damage the ignition-wire-to-endclip connection. If you simply pull on the ignition wire, you're sure to damage the wire end.

They make a special tool shaped like a plier called a spark plug boot remover. In the absence of this tool the first thing I'd do is twist the boot back and forth to break the baked-on seal. Then grab the boot - ideally right where the clip goes on the spark plug end under the boot - and pull the boot off.

Two things you should do for a proper spark plug change is to lightly coat the threads of the new plugs with an antisieze compound and to butter the inside of the spark plug boot with silicone grease for easy removal next time. Both are available at any good auto supply place.

__________________
95 E320 Cabriolet, 159K

Is the spark plug boot remover mercedes specific tool? or I can get from auto parts store.
for Anti freeze for the plug threads, WD-40 good enough?


YJ

I know Sears (in Canada, Simpsons?) carries the spark plug boot remover.

For the threads you can only use an antisieze compound. The most popular is Neversieze by Permatex. It's a metal paste.

__________________
95 E320 Cabriolet, 159K

Ok, so the tool is not for mercedes specific.
I'll try the auto part shop called "canadian tire" first for all the things you mentioned.

thanks

YJ

on my 4 cyl 1998 C class engine the ignition coil has to be removed from the spark plugs by unscrewing four screw on two of the four plug leads,

be sure to remember the wiring route so you can reconnect properly,

it is nice to have one of those plastic ties handy to replace the one you need to cut to work on the wires.

be careful to install the new plugs with stripping any threads, and use a torque wrench to final the tighness.

correction

WITHOUT stripping the threads

What is the torque for the spark plugs?

__________________
Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

It's done finally.

I went to Canadian tire for the spark plug boot remover and none of them knew what the hell that was. They pointed me to the package with a wrench and the deep socket for the plugs. I told myself, forget it and came home. Took the engine cover off and took 2 ignition coil boxes off. The boots connected to the coil boxes came right off. The other 2, I had to pull with a little force and then they popped right out. No sweat. After that, I took the old plugs and then put the new ones. I did final tight with a torque wrench 15-20lb-ft (correct unit?) as stated in the manual.
While the intake pipe was taken off, I cleaned the Throttle Body with TB cleaner. Disconnected the battery (I had CEL on) to reset the code, and reconnected. Started the engine, CEL went off.
Old plugs looked pretty worn out. (first time change over 7yrs, 71,000km) But after driving about 200km today, CEL came back on. I may need to change MAF sensor.

YJ

A code reader will steer you in the right direction, but won't perform the diagnosis. You'll need to be able to read the adaptation values to get close to determining if the AMM is shot. Steve Brotherton has some terrific posts on this, do a search. High adaptation values (max at 1.32) indicate the AAM is probably bad. Low values (lean) indicate other fuel problems, since the system is compensating for a lean burn, not rich as a bad Air Mass Meter indicates.

Find the codes, and then begin to find the cause for the codes.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

I've done the diagnosis from the dealer.

Here's the post about my situation now.:
http://benzworld.org/forums/forums/thread-view.asp?tid=1175849&posts=9&fid=15

In short, I had CEL on for a while and went to dealer to check.
They did check and diagnosed that I needed MAF sensor and 72,000km maintenance service came up total of $1300CAD. First I told them to proceed but I wasn't feeling good to spend all that money. So I called them up and not to do it. I took the car back only paying for 1 hour of diagnosis charge. Now I know where I am headed. Having done the plug change, I think it's time for MAF sensor.

Well, here are the results of dealer's diagnosis.

Quick Test
1. Gasoline engine -F-
2. Chasis & Drivetrain -F-
3. Body & Accessories -F-
4. Climate Control -F-

Actual Values
04 Engine Speed 742rpm
06 Air Mass 8kg/h
62 HFM Voltage 1.51V
09 Throttle Valve Angle 2.2'
10 Ignition angle 11'CKA

DTC memory
P0170 B Self adaptation CTP(idle) at limit (A61)
P0300 B misfire TWC damaging

C1000 Control module
- 018

C1313 Voltage supply
- 004 solenoid valves

Well, that's all the results I got from dealer.

Can anyone comment on this?

thanks

YJ

Don't pay any labour to install that Air Mass Meter. As you have seen installing your plugs, changing the AMM is a snap. Many dealers charge $80-$200 for a five minute job. What is the part cost? I think the AMM for the ME 2.1 M111 is about $600. Is the "service" the rest of that? Yikes!

Most of the jobs in the 72K service you can do yourself in about an hour, excluding "inspections." You should change the oil and filter, cabin dust filter, engine air filter, and possibly the fuel filter depending on if it's been done before. Check the book. Most dealer's "pad" the service to include stuff that is not in the book, and most is useless stuff anyway. On my 1998 car, the "B" service is about $700, and it includes little in the way of filters or fluids. It's hours of stuff like making sure the lights and horn work. The basic A service is $200+ and that only includes an oil change and a cabin dust filter. Way too high for me! I can do those jobs at home in about 15 minutes with $70 in parts.

Get your service booklet out. Your 1997 does not use the FSS, so I'm not familiar with the schedule. I bet 99% of the jobs you can do yourself without any difficulty. You could figure out the specific jobs you don't wish to do, and have the dealer do those. As an example, I don't like changing the coolant. My dealer has a flat rate of $40 to change the coolant (for labour) so I have them do it. Most other things I do myself, and with a very basic set of hand tools, it's possible. One of the GREAT things about owning an M111 equipped W202 car is the ability to do your own service work.

BTW, the adaptation value at max pretty much indicates the AMM is shot.

(As Steve Brotherton has kindly pointed out, our cars are not actually equipped with a Mass Airflow Sensor, but an Air Mass Meter, which technically, is different.)

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

blackmercedes,

I totally agree with you. That's why I'm trying to tackle stuff myself and save some ($500 or more) money, though it takes some time. I didn't know how to change plugs, but I learned it now in 2 days. I don't think all oter maintenance items are related to the CEL other than plugs, Air filter (maybe). So I'll just order air filter and Air mass meter and put them on in 2 min.
with some of the saved money, I could invest in OBD II reader for future use. I also ordered a repair manual CD from Ebay, for future use as well.

YJ

As to the AMM, my 98 C230 has 160K now, and its got it's original AMM. There is some thinking that changing the engine air filter frequently increases AMM life, and I think there might be something to it. Based on that info, and also wishing to keep clean air going to my engine, I changed my air filter every 15,000km's or so. So far, it seems to have worked. (Touching wood!)

Here is the schedule that I keep (using the FSS)

1. Engine oil and filter changed about every 7500km's with Mobil 1 and OE filters. I do it every time the FSS counts down 5000km's which works out to about every 7500km's.

2. Cabin dust filter every 15,000km's. This keeps the load on the blower motor and evaporator down, and keeps nice clean air in the cabin. Easy job I can do in less than five minute now. Use the updated W210 combi filter. I don't think you can get anything else now, but just in case...

3. Engine air filter every 15K. I vacuum the housing and change the filter.

4. Coolant every other spring.

5. Brake fluid every other spring, or when changing pads/discs.

6. Final drive oil every 80K.

7. Tranny fluid and filter every 100K.

8. Spark plugs every 60K. They just don't last out to 72K in my experience, and by 60K need doing.

9. Fuel filter every 60K.

During each 15K service, I also get under the car and check the suspension components, exhaust system and flex discs. I look for leaks (all kinds) and have a gander at the final drive unit. I also pop a front and rear wheel off and check the pads.

Things to know...

1. The M111 engine is tough as nails, but don't overfill the crankcase, as you'll damage both main seals. My dealer did this, and both had to be replaced. It was the last oil change I did not do myself.

2. Watch for front lower ball joints. They are a wear item on the W202, and in Canada we don't have glass smooth roads, so they tend to wear quite quickly here. They often squeak when beginning to wear.

3. Final drive units often sweat. My seals were replaced at 80K when the final drive unit was serviced, and they've been drum tight since. If not replaced under warranty, I understand they can sweat for years without really leaking.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif