loosing coolant please help on merc komp 230

[k6auk-mercclk230]

hi every one been told this is the best site for advice so here goes..
i bought a 2001 black merc komp 230 2 months ago been 100% until last week when the water light come on the dash poped the bonnet and needed about a small jug of water to top up i then did 300 miles and light come on again so re topped up needed 2 jugs of water any way went to a few mechanics some said head gasket but it does no signs at all no over heating no oil /water mix some times bit of smoke comes out of exhaust buy will go away after 2 mins ish i have noticed damp patch out of the over flow pipe so obviously pressurising then this is my main question my friend said his bmw 330i was doing all the symptoms of headgasket failure steam coming from exhaust over heating bla bla bla he booked it in for head gasket when his dad said have you checked viscous fan he put a newen on and his cars been right ever since.
so i did the carrot test on my viscous and you could stop the fan at 80 degrees with a dandelion lol no effort at all could my viscous fan be causing me loss of water ?? it never goes over 85 degrees even on tick over heaters blow warm and the car runs like a dream and never boiled over once in a wile steam seems to come out of exhaust but not all the time and not a great dea please helpl

 

[Frontstep]

Could be your coolant pressure cap,

 

[k6auk-mercclk230]

reply

how would i test the cap is there any givaways?

 

[Frontstep]

Look for cracks, sticky seals.

 

[wireman]

At less than a tenner a new cap is a good test.

Other first checks are the radiator for corroded tubes which become porous after a few years of winter salt (mine eventualy sprayed a very fine jet of water to finaly prove its demise), the water pump gland which might drip a little from its drain holes on the water pump nose (behind the pulley), or a tired hose/hose clip.

Any water loss which occurs when the engine is hot might be difficult to trace since the water will dry up before a puddle can form.

If it is not getting above 85 the head gasket would fall well down my list of first checks.

 

[umblecumbuz]

Tried back-flushing the radiator?

Long shot, buy if there is sediment (or damage), you could get the symptoms you describe.

 

[Steve@Avantgarde]

If you have a clylinder block test done, that will confirm whether or not you have a blown h/g. Does the engine misfire on start up when cold? Have you had a pressure test carried out to determine if there are any leaks?

I had one in the other week where the customer suspected h/g as he was loosing coolant and could see water running down the front of the engine, turned out to be a tiny pipe that comes off the water pump had split.

I would get a second opinion from an Indie as headgaskets are pretty uncommon. Where are you so we could recommend somewhere?

 

[horgantrevor]

yes i would check rad and change cap

also look at all the hoses engine off pull move and squeeze and see if you have a leak

after words run the engine to hot and turn off engine do the same again remember hoses will be very hot old glove and move them you may have a very fine split


i had this happen to a car lately very fine hole in pipe only found when running hot