Coolant change on W202

[240-singh]

Hello again. Sorry for all these questions i've been poting up the last week or so. My cars temp has been sitting at about 85-90 degrees which i think is a tad high. The coolant has not changed in a while so i think if i change it maybe that should sort out the temperature?

I've changed the coolant on a few of my older cars but not on a merc. im guessing there should be a easily accessable bolt plug sort of thing at the bottom of the rad? has anyone done a write up?

 

[recycled]

No need to be sorry. There are a lot of good people in here happy to help. mine sits about 80ish but rises close to 85ish in heavy traffic. so i think that is normal.

 

[gina2201]

My w202 also sits just above 80. So sounds normal!

 

[gurpz]

Hi no guide Im afraid but I guess I have just made one for you this could also go into the How To page also

In order to flush the radiator, you stand on the side of the car with the air filter box right in front of you, and when you look directly down from there you should see the following picture


There should be a hose clip on the hose shown below.

Carefully check the direction in which the screw is pointing and turn slowly, if you can see that the screw is rusted (in most cases will be) make sure you have another hose clip to replace. It is advisable to replace the hose clip if rusted as it will get worse!

While opening the screw be very careful about your position under the car or above, as radiator fluid is not one of the best skin treatment fluids, also if possible have a GOOD drainage tub also present as if you simple drain the fluid in your driveway it will take weeks to dry out (as happened to me)

Once this screw is open, gently pull off the hose with a side to side motion, being extra careful and not applying any kind of jerks.

Let the fluid flow and wait. Once you think all fluid is gone, open up a similar hosepipe (not shown in pictures) which is situated on the very TOP right hand side of the radiator and BLOW HARD through this pipe, this will clear out any excess fluid present in the main engine block as well. Keep repeating this process until all water stops coming out at the other end.

Now it will be advisable to close all hose pipes, top up radiator with water and repeat the same draining process again but it is not necessary however i would recommend it for a good clean.

Once all drainage is complete, top up with any Anti-freeze or Summer Coolant, easily available from any Halfords or MB Dealer store around you, My C180 1997 easily took a 5L gallon, and I know can take another at least 2L ! So be well prepared!

GOOD LUCK

 

[tikw2124]

I brought the TEMP page up on screen whilst driving and mine did not go above 60, is this normal, if not, what could be wrong?

 

[240-singh]

Hi no guide Im afraid but I guess I have just made one for you this could also go into the How To page also

In order to flush the radiator, you stand on the side of the car with the air filter box right in front of you, and when you look directly down from there you should see the following picture


There should be a hose clip on the hose shown below.

Carefully check the direction in which the screw is pointing and turn slowly, if you can see that the screw is rusted (in most cases will be) make sure you have another hose clip to replace. It is advisable to replace the hose clip if rusted as it will get worse!

While opening the screw be very careful about your position under the car or above, as radiator fluid is not one of the best skin treatment fluids, also if possible have a GOOD drainage tub also present as if you simple drain the fluid in your driveway it will take weeks to dry out (as happened to me)

Once this screw is open, gently pull off the hose with a side to side motion, being extra careful and not applying any kind of jerks.

Let the fluid flow and wait. Once you think all fluid is gone, open up a similar hosepipe (not shown in pictures) which is situated on the very TOP right hand side of the radiator and BLOW HARD through this pipe, this will clear out any excess fluid present in the main engine block as well. Keep repeating this process until all water stops coming out at the other end.

Now it will be advisable to close all hose pipes, top up radiator with water and repeat the same draining process again but it is not necessary however i would recommend it for a good clean.

Once all drainage is complete, top up with any Anti-freeze or Summer Coolant, easily available from any Halfords or MB Dealer store around you, My C180 1997 easily took a 5L gallon, and I know can take another at least 2L ! So be well prepared!

GOOD LUCK

Thanks mate, great write up. Ive just realised that the next mark on the temp gauge after 80 is 100. i thought it was 90. So my car actually constantly sits between 90-95ish. i rem in my old bimmer it never went above half way. even in heavy traffic, thats why i'm a tad concerned. will use your notes and give it a collant change. nothing to lose. cheers mate.

 

[Kompressor_Dude]

mine sits at 80, will rise to 90ish if its hot and there's traffic....... but i've always got the air con on full which I dont think helps!

Thanks for the guide, i'll be doing mine soon as i've got no idea when it was last done!

Also, seems obvious but DONT do this after driving the car. Under compression the water can get to be above boiling temperature, and if the car's even warmed up the coolant will be hot....... I know someone who's come off VERY badly from making this mistake so please dont do the same!

 

[1998K]

just to add a little suggestion over gurpz procedure:

once you have drained as much as possible the coolant, set the internal climate control to "hot" and than WITHOUT run the engine (you'll put off the water pump!!) turn the key to operate the dash display and controls: further coolant fluid will fall down. This at least on W202 like yours.

 

[Kompressor_Dude]

So turn the heaters on WITHOUT starting the engine??

 

[1998K]

So turn the heaters on WITHOUT starting the engine??

yes exactly

 

[rajinder_1]

Guys thats great i was toying with the idea of changing the rad fluids, couldnt remeber what i done last time its been that long!!!!!

good reminder thanks gurpz

Raj

 

[1998K]

Guys thats great i was toying with the idea of changing the rad fluids, couldnt remeber what i done last time its been that long!!!!!

good reminder thanks gurpz

Raj

here you'll find further information, unfortunatelly the pictures are missing

http://club202.com/forums/showthread.php?s=&threadid=6993&perpage=15&pagenumber=1

 

[Patronfrey]

I don't know your car but, assuming the engine is a straight six like my C280, I found my engine coolant drain plug up under the exhaust manifold on the r/h side of the engine slightly towards the rear of the block. The plug doesn't need to come right out as it has an integral nozzle which you can fit a rubber hose on to, just turn the plug anti-clockwise with a spanner and the coolant will come out through the hose. When I did mine I didn't make any mess at all, not even a drip, with the hose directed into a large bowl. I did need the car on ramps or axle stands to do the job. There is also a drain tap at the left hand side bottom of the radiator on my car.
Good luck,
Ron

 

[Kompressor_Dude]

Forgot to add, lots of the photo's posted here dont match my car. Went to change the oil and check the radiator hoses and there's a big black plastic sheet covering the whole underside of the front of my car

Is this on every model? I assume it's just some sort of protector?!

 

[gurpz]

Forgot to add, lots of the photo's posted here dont match my car. Went to change the oil and check the radiator hoses and there's a big black plastic sheet covering the whole underside of the front of my car

Is this on every model? I assume it's just some sort of protector?!

Yea i believe thats on the facelift models or either im missing it maybe, not shure to be honest really

Edit:
Yes its there for protection

 

[Dieselman]

I don't know your car but, assuming the engine is a straight six like my C280, I found my engine coolant drain plug up under the exhaust manifold on the r/h side of the engine slightly towards the rear of the block. The plug doesn't need to come right out as it has an integral nozzle which you can fit a rubber hose on to, just turn the plug anti-clockwise with a spanner and the coolant will come out through the hose. When I did mine I didn't make any mess at all, not even a drip, with the hose directed into a large bowl. I did need the car on ramps or axle stands to do the job. There is also a drain tap at the left hand side bottom of the radiator on my car.
Good luck,
Ron

I agree.
I would expect there to be a drain plug on the radiator underneath and on the block under the exhaust manifold on all Mercedes cars, no need to undo any hoses.
As also mentioned both drain and refil with the heater set to hot and the ignition on.

 

[Patronfrey]

Forgot to add, lots of the photo's posted here dont match my car. Went to change the oil and check the radiator hoses and there's a big black plastic sheet covering the whole underside of the front of my car

Is this on every model? I assume it's just some sort of protector?!

Yes, dead cinch to remove and put back. Just 4 screws. Undo the two at the front first and let the cover rest on the lugs. Undo the two at the rear, let it down at the rear and pull it backwards off the lugs, then out from under the car. When putting it back, rest the front on the lugs, two back screws in first (don't tighten yet!), two front screws so that everything is in position and held up. Then tighten the screws, but don't overtighten them, they're only a small diameter.

Ron

 

[big x]

bump

 

[big x]

BTW. Anti-freeze is poisonous, don't drain where animals and wildlife can drink it. Take it to your council dump.
One way to get all the old stuff out is to remove the thermostat and back flush the system with a garden hose after removing the rad and block drain bolts.
The Haynes manual covers this in detail.

adam

 

[Patronfrey]

The job of renewing the coolant is so easy there is really no excuse for not renewing it every 3 years. MB coolant is not particularly expensive and I will always use the MB product in my Merc. Much cheaper than blocked radiators, failed head gaskets and heater matrices.
big x is quite right about the environmental aspects though, dispose of the old fluid correctly.
Ron