Mercedes SLK World banner

Status
Not open for further replies.
1 - 10 of 10 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Hi guys,

It seems that my 230K has a (I think) serious issue with the cooling system:

1. Coolant completely disappears from the reservoir after dynamic/fast driving and... it's coming back after a while after turning off the engine... opening pressure cap (new, original) speeds up returning of the fluid.
2. If I turn on the (hot) engine again, coolant again disappears before my eyes.
3. I don't know how but coolant is getting to the air filter box!!! :confused: Not much, but enough for me to notice it (it has a sweet taste).

Anyone have any idea what can be happening? I am of course loosing some coolant...

And how the hell can coolant get to the air filter box? :confused:

Also my car has issues with starting cold - sometimes it starts on 3 cylinders and needs about 15 seconds to bring the fourth one to life. Code scanner shows misfire on cylinder 1 but maybe it has something to do with coil - it's a no-name with a cracked housing.
There is no white smoke, no oil in the coolant and no coolant in the oil.
 

·
Premium Member 2002 SLK230K
Joined
·
17,144 Posts
Coolent should not disapear like you say, the level should always be at the top. The only thing i can think of is the coolent is getting into the air box via the oil separator which would mean a head gasket issue. I will have a look at my setup tomorrow morning to comfirm, hope i'm wrong here.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
Logic tells me that disappearing coolant would mean that there's an air bubble creating when the system gets higher pressure, i.e. aggressive driving...

But what about coolant in the air box... I think that if it was going through oil separator I would see some sings of coolant in the oil on the oil filler cap.
But now that you said about it, I must say that the hoses that are connected to the separator (mounted on top of the engine head) are a little wet from oil.

If it's a head gasket - no problem, It's not that hard to change it by myself :) There's even a great DYI available.
 

·
Premium Member 2002 SLK230K
Joined
·
17,144 Posts
Logic tells me that disappearing coolant would mean that there's an air bubble creating when the system gets higher pressure, i.e. aggressive driving...

But what about coolant in the air box... I think that if it was going through oil separator I would see some sings of coolant in the oil on the oil filler cap.
But now that you said about it, I must say that the hoses that are connected to the separator (mounted on top of the engine head) are a little wet from oil.

If it's a head gasket - no problem, It's not that hard to change it by myself :) There's even a great DYI available.
Lets assume for now its just an air bubble, refill the Rad. and work out the air then drive it for a few days and check the level. Also keep an eye on the air filter for any signs of fluid. Pull the dipstick,oil fill cap and see if the oil has any signs of a milky white goo. Let us know what you find.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
If it is, you better hope it is just a gasket. :hail:
What else could it be? Oil level is steady so I don't think I'll have to put my hands into lower body of the engine.

As for coolant level - I have to add some fuid every week so air bubble is no one-time thing :(
Today I've read the error codes - misfire detected on cylinder 1 and 4 (+ multiple misfire error code of course). Before swapping coils I had only errors at cylinder 1... so now I figure that I have a faulty coil and a possible pressure leak at cylinder 1.

Tomorrow I'll take out sparkplugs to check how are they doing. I'll make photos and put here for you to check also.

About gaskets - any suggestions? What brand to look for? I don't want to put any sh*t inside...
 

·
Premium Member 2005 SLK55 AMG; 2005 SLK350
Joined
·
4,959 Posts
I don't know your engine at all but the expansion tank should *fill* after you restart a warm engine, not *drain*. It does sound as though you have some air present. Did you drain and refill your coolant recently?

I would speculate it's going out the tail pipe. Can you smell the coolant at the tail pipe?

I don't think you should be tasting even tiny amounts!
 

·
Premium Member
Joined
·
166 Posts
Hi
one of your issues with coolant loss could well be caused by a small pinhole leak in one of the hoses.
With the new overflow Reservoir is that if there is a small pinhole leak in one of the hoses, when the motor is run and reaches operating temperature the coolant expands as the pressure increases fluid is forced out off the leak. When the system cools air is drawn in to the system and rarely flows to the overflow container. This causes the container to be full when cool and the level to drop as it warms to temperature.
Worst case scenario is that the overflow container presents as full but the engine may well be extremely low.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #10 (Edited)
Today I've done a 240 km drive and one thing is for sure - it's either a headgasket or cracked head... In the morning engine started again on 3 cylinders, then new thing came up - I can't fully accelerate, at about 4k rpm it chokes and I get a misfire code (cyl 1 again). And idling is very rough with more smoke than before... can't tell the colour because I was driving after dark.
Before driving I took out the sparkplugs from cylinder 1 and 4... guess which one was sitting in cyl 1 ;)



Uploaded with ImageShack.us

UPDATE

Car is being taken care of by a mechanic specialized in MB cars... Today I've received information that the most possible reason for my issue was pressure leaving from cylinder 1 to the cooling system and my (recently changed) coolant pressure cap - made by Febi, it wasn't able to keep it's 1,4 bar limit so the cooling fluid was being thrown out much quicker :( They looked inside combustion chambers and 3 cylinders looked ok, only the first one was wet.

Tomorrow they are taking off the head and everything will be clear. Also they found out that the timing chain was very stretched and soon it would damage the engine! So at least there's one good thing that came out of this.
 
1 - 10 of 10 Posts
Status
Not open for further replies.
Top