[chrisBenz90]

Hi everybody!

Three months ago, I bought a MB W202 C180 '96, 175'000 km. Petrol, manual transmission.

Please read this through, as I am now in desperation and I don't know what to do...There seems to be a very serious problem, but I want to fix and keep the car.

Facts and Timeline:
1)Took it to a mechanic for a full inspection after buying it, told me there is a minor oil leak from the head gasket. He also told me that I can live with it, and it is common for this type of vehicle to have this type of small leak, so I left it as is.
2)Water pump broke, huge coolant leak. Had to drive the car around because I needed it for work. If the temperature was going above 100 degrees C, I would stop immediately, so that I wouldn't hurt the gasket. That kind of overheating wouldn't happen very often, and I was really careful to stop right away. The worse I got was like 105 C.
3)Finally found the time, and went on to replace the water pump myself. The coolant leak was gone, but there seemed to constantly be airlocks in the system. Also the car would still overheat and reach temperatures above 100 C.
4)Tried to get the airlocks first by flushing the radiator but the airlocks were still there. Put a funnel onto the expansion tank, filled it with coolant and tried to see if I could get the airlocks out with a lot of patience. The coolant was constantly bubbling, and when I stepped on the gas, the bubbling was much more violent, with the coolant going crazy and splashing around.

Conclusion (by, other much more experienced DIY mechanics and a couple of professionals): The head gasket leak is now a real issue and has grown even larger, thus affecting the cooling system. The temperature is out of control, even though there is no coolant leak anymore.

Now I want to fix the head gasket on my own. I have a Haynes repair manual which I think is excellent, and I have found many sources on the internet to do it as well. Getting it to a mechanic is out of the question, since I live in Switzerland and they ask for 3'000 CHF (about the same as USD) to do it. So I will dump the car in my garage, and take my time to do the job, with the help of other more experienced people.

Questions:
1)Was my mechanic right when he told me that it is common for this car to have this initial small head gasket leak? Or the previous owners just didn't treat the car right?
1)Ordered a K-seal for head gasket leaks. Will this mitigate, or even cure the problem? And if the problem goes away, shall I go ahead and replace the head gasket anyway when I have the time, and risk the whole car?
2)The K-seal arrives in two weeks. Shall I drive the car at low rev and for short distances until then? Or every single minute of it with the engine on makes the leak worse?
3)Do I need to lift the car to do the head gasket replacement job?
4)Do I need to get the entire engine out, or just the cylinder head? So the question is, can I do it in my home garage?
5)Since I will get the cylinder head out, will it be worth it to buy a new or reconditioned one, or reconditioning it myself? Will it be very hard for me to do it myself?
6)Shall I replace the timing chain as well?
7)Even if I replace the head gasket and install a new/reconditioned cylinder head, since I am not a pro, will this make the car worse in the long run? Even if the car seems fine after the job, will it be fine for a month and then die on me? How many things can go wrong? So, is it worth it to even try it, or shall I just drive the car around for another year or so, and try to save money to buy another one?

Please help guys...this is a very nasty situation I am in, and I need your experience and expertise!

Cheers! :smile

 

[RES]

Patman1 has provided several excellent videos on Head Gasket replacement on a C220. If you watch them you will see what is involved in the job. Scroll down to see his post.

 

[andy_1100]

Hi chris.
Find Patman's youtube channel, it will answer most of your question on head gasket replacement.
.......
I think you have a deformed head, this is the result driving the car with a coolant leak.
The airlocks you are getting are from combustion gases getting into the cooling system. You need to replace the head gasket for sure.
An average dyi mechanic can do it in a home garage.
You dont need to pull the engine out, you dont need a lift. You will have to lift the car (i think) to get under to disconnect exhaust from exhaust manifold, on my C280 its done from under the car with long extensions.
You will not need a hoist as the head is not heavy, u can lift it by hand.
Take lots of pictures!!!

Main things to pay attention:
1. MARK TIMING CHAIN AND TIMING SPROKETS before removing the head.
2. THE HEAD.
You have to check the flatness of the head, most likely you will need to machine it.
In Canada its 200$ to rebuild the head by a shop, consider doing it by a professional shop unless you you want to do it youself, in this case yoy will have to get a valve spring compressor to take out the valves.





Sent from my LG-D852 using Tapatalk

 

[chrisBenz90]

Hi guys, thanks for your replies so far.

I understand that the cylinder head might need to be machined in order to be completely level. Is there any possibility that the damage is even greater, and that even the cylinder block could be warped as well?

 

[andy_1100]

W202 c280 head install

Sent from my LG-D852 using Tapatalk

 

[andy_1100]

w202 C280 head rebuild, for reference

 

[georgebuhr]

Depending on how hot it got, yes, it is possible that the block is warped also, but its not nearly as likely as just the head being warped. When I did mine, the head wasnt even warped that bad to be machined, the head gasket just failed.

You will for sure want to take your head to a place that can check it and also check all the valves, check for cracks, etc. Not sure where you are from, but around here our local parts store has a place they send them to, so I just tooked mine to them, they shipped it off, then called me when it came back. And actually the machine shop that did the work called to let me know that the head surface was fine and asked if I wanted the valves done, which I had done while they had it.

You'll only need basic tools like a socket set, wrenches etc. with the exception of the head bolts which need a spline socket(and a good one at that! they are tight!) and breaker bar, a torque wrench to tighten them back, and there will be one pin on the front that you will need to fabricate a home made slide hammer or puller to remove.

 

[dirgesan]

If your car is not burning oil (and it's probably not) go ahead and get the head redone with new valves and seals. Valves and seats wear simply out, no matter well the car is maintained. With your mileage your valves probably have pretty good wear on them, meaning you're losing some compression and power. A rebuilt head, done right, can make your car seem almost new again. You should be then be good for at least another 100,000km, I hope. There are some very good tips here. I also recommend the Haynes manual, ISBN 978 0 85733 988 1. They do a complete engine rebuild and show how to remove and install the head. It's a UK publication but it still applies to your engine.

 

[Patman1]

Sorry I took a while to respond, had a very busy few days!

I used the Bentley service manual, but for all intents and purposes, as far as the Head Gasket goes, it's just as good a reference as the Haynes. It does sound like your HG is finished. The necessary parts for this rebuild will be: a new HG kit (it comes with a bunch of o-rings and other gaskets) and a head bolt kit. The head bolts are one-time use. You will also need camshaft sprocket bolts, at least one set (you'll be removing the exhaust cam sprocket). You might also need new cylinder head to engine block timing cover bolts if the ones present are a hex head. Service manual (and I double checked against WIS) makes you discard those and replace with Torx bolts. I would also recommend replacing all the coolant hoses and clamps while you're there.

Since your head has seen some abuse, I would send it out to a machine shop to have it surfaced, I would expect to see some slight warpage, mine was slightly warped, but otherwise everything else was fine. Didn't need to do a valve job because the cylinder head was tested for leaks and it was fine. The engine block is probably fine, Mercedes bottom-ends are hella strong. Just be sure to make clean the hell out of it before installing the new HG. If you want to be sure, you'd need to probe it with a straight-edge and some feeler gauges, but it's unlikely the block is warped. You won't need to replace the timing chain, by my educated guess, the timing chain is good for 500k km. I replaced my HG at 223k km and the chain was stretched by 5 degrees of crank rotation, out of an allowed 10 degrees before it goes out of spec.

No special tools are needed to pull the CH off, but if you have access to them, they do make the job easier. But otherwise everything can be done with easily obtainable tools.

I wouldn't mark the position of the camshaft just because as soon as the chain tensioner is released, your marks won't be aligned anymore, so you'll just sit there wondering what to do. Luckily, timing the engine is really easy, and it's probably covered in your manual. Just don't forget to reset the chain tensioner!

Trust the manual, follow it to the letter, and this is a VERY easy job.

My M111 HG video series on youtube isn't complete yet, I've got another video coming up soon. But as it is now, you've got enough information to remove the head and reinstall it, the rest is really just putting everything back together in the reverse order you put it in, so you're not missing much.

 

[chrisBenz90]

Hi,

Patman I would like to thank you for your reply and your wonderful videos.

I would also like to thank AndyP as well...really guys...your videos, in conjunction with the service makes this job seem like a piece of cake.

From my research so far, I think that a very difficult part of the disassembly procedure are the two manifolds...

Right now I don't have any tools to lift the car. Patman, in your video "Cylinder Head Removal" at ~1:40, you go below the car to remove the exhaust manifold connection to the pipe. So I guess that it is required to get axle stands and the hydraulic lift to jack up the car? Or maybe I can crawl in there? And concerning the intake manifold, you seem to take your time to do it...it seems difficult. Oh well...

 

[andy_1100]

Hi,
I think that a very difficult part of the disassembly procedure are the two manifolds...

chrisBenz90, exhaust manifold is not difficult, but you do need to lift the car in order to get access to the bolts connecting exhaust manifold to the exhaust tubes. Please, DO NOT GET UNDER THE CAR IF IT'S SUPPORTED JUST BY THE JACK. Anytime you plan to get under the car use something more solid. The ramps are really good if you have storage, just make sure they clear the bottom edge of the bumper before you buy them.

you can leave the exhaust manifold on the head and remove it later, it's not that heavy, especially on 4 cylinder.

Intake manifold...take your time and take lots of pictures. Note how all the wiring goes. Patman 's video is pretty good, just follow.

 

[Patman1]

I drove my car up on ramps to get underneath, that's a lot safer than axle stands. That also freed my axle stands to support the exhaust You just need a u-joint and a long ratchet extension to get to the bolts from the pipe to the manifold. You can leave the manifold on until the head is removed. Heck I used the manifold as a grip to lift the head. I did remove it afterwards to replace the studs.

Intake manifold is one of those stories that didn't make the cut, but it shouldn't be a problem for you. Way back when I replaced my wiring harness, I struggled to remove the connector to the air pump. I ended up damaging the air pump trying to remove the plug. Although I did succeed in remove the plug, it cracked the air pump housing, so when I first started up the car with the new harness, that crack caused air to leak out of the air pump, making a loud hissing noise. Not wanting to spend 700$ on an otherwise perfectly good air pump, I JB-welded the crack, but I accidentally overlapped the connector as well (so now the JB weld was partially holding on to the plug as well). Figuring I'd never have to unplug that connectors again, I just let it be. Fast forward to the HG replacement, I couldn't unplug the air pump connector, which would have given me enough slack in the harness to easily remove the manifold. Eventually I did give up because I couldn't do it, so in between edits I climbed under my car, chipped away the excess JB weld on that connector, unplugged it (you can see it in the video, it's the long wire dangling in front of the radiator) and that gave me enough slack to remove the manifold. It still wasn't terribly easy, because the entire harness basically hangs around the intake manifold, so all the connectors and wires catch on the manifold as you are trying to remove it. Once you get it out of the wiring, well that's it, you've got the manifold out.

Now imagine doing that on a modern engine, which has WAY more sensors and wires than this.

 

[chrisBenz90]

So today I got access to a lift, just to examine the lower exhaust manifold connections.

Patman, in your video, you got only one pipe connection to the exhaust (you go underneath to show that you got the bolts out and have supported the pipe).

It seems that I got two connections, and the bolts of one of them is totally obstructed by that "thing" that I have encircled with black pencil on the pics. Is this part of the control arm? It seems like I have to get it off...the manual doesn't mention anything though. I have also confirmed the fact that you need extensions and a u-joint for the job.

Also, those bolts are very very rusty...

P.S. I also show the top view of the manifold. This is the hot air shroud, right?

 

[georgebuhr]

The first piece you circled looks like an exhaust heat shield. It should remove pretty easily, ande hopefully will give you enough access to get your wobbly socket and extension in there.

 

[Patman1]

That thing is the steering idler arm in case you ever need to know, it looks to be in really good condition so I reckon it was changed some time in the past! It is indeed covered by heatshield and should be easy to remove.

 

[chrisBenz90]

***DAY 1***
1)Bled coolant, drained engine oil. (Will attach more pictures in next post, it is MILK)
2)Removed bonnet
3)Removed viscous fan and belt
4)Unscrewed exhaust manifold flange bolts that connect to exhaust (it wasn't that hard after all :wink)
5)Removed intake manifold (a pain, did not completely remove the intake manifold support like patman)
6)Removed thermostat housing
7)Removed camshaft cover, and front cover

9 hours afterwards, fainted on my table after having dinner :grin

I may have forgot some small in-between steps

Here are some pics, will attach more in next post. Have also some questions regarding the timing, as I am now in that sweet/crucial spot...next post it will be.

 

[chrisBenz90]

Second post from day 1:
You can see the mayo on the valve cover...it is horrible.

About the chain timing and beyond: After watching patman's and andy's videos, and reading through the manual thoroughly, I think the next steps are as follows:

1)Set the pulley at about 20 degrees after top dead center.
2)Insert pins into both sprockets
3)Mark the two sprockets with relation to each other's chain
4)Unbolt the tensioner
5)Unbolt the exhaust sprocket and then the intlet sprocket.
6)Tie the chain so that it remains engaged to the crankshaft.

Proceed with other steps before removing...

In the pic, you can see the pulley angle readings. The full readings are:
4|0|3|0|2|0|1|0|0|T|1|0|2|0|3|0|4|0
<----------------------------------------------

The arrow indicates the sequence of the readings, as you turn the crankshaft clockwise. The readings indicated by bold, are where the setup appears to be in its "sweet spot". Here I managed to insert the pins in both sprockets. You can see these in the pics below. So I have done steps 1,2 and later on today will proceed with removing the head. Wish me luck!

 

[Patman1]

Hey chrisBenz, I just put up a video on camshaft timing yesterday in case you need some extra help getting it right! It's actually not very difficult to time the engine and check the timing using the factory method. IMO marking the camshafts doesn't work because as soon as you release the chain tensioner, the marks don't line up anymore, so you can't know how to put it back together afterwards.

 

[chrisBenz90]

*DAY 2*
Removed chain tensioner
Removed guide rail pin (did it with a screw and a bunch of washers...kudos to patman and anyP)
Removed head gasket bolts and head gasket. Here are some pics! Questions next post...

 

[chrisBenz90]

*DAY 2 continued*
Some more pictures of cylinders, from 1 to 4:
Can you guys see some obvious damage? I can see in the 2nd cylinder that there appears to be some traces of rust, and coolant dropelts (this is more obvious in the 2nd pic). More photos coming next post.