Air lock

[properwounded]

Today i got told old w202's are renowned for airlocks in engine system causing temperature to heat up faster than usual. The cure was to take off expansion cap whilst cold, heat engine to running temperature, squeeze hose, and shoul see bubbles come through water.

Is this true????

 

[television]

It is not true, plus there were many different engines fitted to the 202

 

[hotrodder]

That's pretty much standard procedure for any car when doing a coolant change along with making sure the the heater is set to full hot. Some cars also have bleed points in the cooling system, don't think there's any on a w202 and i'd expect them to be pretty much self bleeding like any other MB i've owned... after a coolant change running the engine upto temp will result in the level in the header tank dropping air is purged from the heater etc.

Airlocks don't spontaneously appear and getting old doesn't make a car more prone to air locks but does increase the chances of the waterpump being tired, the cooling system to be innefficient due to scale/corrosion from neglect, the rad being tired due to blocked fins/internal silting/corrosion etc

 

[television]

There are no bleeding points on any MB that I know of, when filling and running squeezing the bottom hose forces any air out once the thermostat has opened

 

[WG M-B]

When they do suffer from air locks I usually backfill through the top rad hose.
I then bleed from the heater return. It very rarely happens on mercs but it does sometimes