[Attachment(s) from vwnate1@yahoo.com [diesel_mercedes] included below] Greetings from Waldoboro , Me. ! .
Last night we had dinner (lunch too) at The Narrows Tavern , , 15 Freindship Street , a nice little place .
We're staying with my Brother at his old farm house .
So far we've had to replace all four tires and add several gallons of coolant in quarts at a time , I'm happy this W-126 has a low coolant indicator .
I have been unable to spot any leak or wet spots so every time we stop I peer closely and finally noticed some road dust on the joint where the 7 MM coolant vent hose attaches to the top of the radiator ~ the hose was tightly clamped but looked a bit swelled so we went to the local NAPA Partshaus and bought a new bit of hose , upon removing the old hose I found two things :
First and foremost was a long bit if red RTV sealant some idiot had used elsewhere in the cooling system and before drying it had collected and mostly clogged the small hose nipple on the radiator .
The second thing was a steel tube jammed into the hose nipple in the coolant surge tank , it's a bit rusty .
I replaced the hose and snugged up the clamps , so far no troubles but we've not been on any high speed motorways yet either .
The symptoms were : on high speed runs going up hills the coolant temperature would slowly rise to about 110* C and the next time we'd stop the coolant level would be low .
Interestingly , the coolant level would raise up when I released the pressure cap ~ this leads me to believe the 7 MM return hose was blocked and wouldn't allow proper circulation of coolant .
Time will tell .
It's very pretty here ! rain of course , a lashing heavy thunderstorm followed us in after mid night Monday .
Attached are pix of the old hose , the red RTV clog I ever so gently teased out of the radiator and the chromed steel tube that was jammed into the coolant reservoir tank .
Things like this are why I like to take cars aprt when they're still operating , Tom was adamant to not touch it and he got *very* upset when I repeatedly asked him to allow me to clean and de grease the engine , he has the cleaner but doesn't like it that I try to begin diagnosis by cleaning things .
My bet is : the DPM/DPO replaced the thermostat or water pump and foolishly used RTV , goobing on a slab of it instead of properly smearing the thinnest possible amount so when he buttoned it up the excess mooshed out internally and was swept up in the coolant before it set and got caught in the top radiator's out let nipple ~ we're very lucky it didn't get sucked into the radiator's tubes where I'd never find it short of cutting the radiator in half .
We shall see if this fixes the coolant loss problem or not .
-Nate