300GE very slow coolant leak
I have a very slow coolant leak on my 300GE. Probably about 1l per 1000 miles driven. No oil in water or vice versa.
I added some of the radiation dye to the coolant so see where it was coming from - it looks like it is coming from somewhere at the front near side of the engine, running down the block and collecting on the front ARB and sump. Looking up under the vehicle it appears there are two hoses that travel up that route to somewhere under the air filter/throttle body area but I can't see exactly without dismantling absolutely everything.
Radiator is new and head gasket etc. all done within the last 5000 miles so my assumption is this is an old hose.
Anyone care to offer an opinion on the two hoses I mentioned? Where do they terminate? Tips before I rip into taking the pancake air filter housing and whatever else apart to investigate further?
From the 300GE; all I can ascertain that you have a W463 - 300GE which is likely to be the M103 engine.
Most probable coolant leak in particular if you say it emanates from the front, running down the anti-roll bar and sump is the water pump. These have a tendency to be self sealing and in the early stages of leak, the leakage is for a short periods during warm up and cooling of the engine when switched off. Inbetween these periods the leak seals up hence difficult to find. Assuming all hoses are tight and integrate.
The leak drains from a hole manufactured to the pump body at a its bottom in the 6 O'clock position.
Other small leakages tend to be the heater valve, or hoses connecting to and, or heater matrix itself. - Windscreen tends to condensate and water in either driver or passengers foot well with possible order of antifreeze.
Keep a regular check on coolant level until you cure the problem. Replenish on a cold engine - DO NOT open the expansion bottle cap when engine is hot!
At the front, side (O/S) of the water pump there is an O-ring seal fitted to a metal water pipe, these could leak but rare.
If the rubber hoses you mentioned are the one I envisage, these are the induction hoses; part of the idle circuit and carry no coolant.
I think Rakesh is correct in his analysis. Was the replacement water-pump an original MB part or an aftermarket one? I replaced one on the same M103 engine last year and found that most aftermarket versions are not built like OEM,
You might want to verify that the pump was fitted correctly with its gasket and that the hoses are correctly tightened... and that the O-ring in the thermostat housing is in place.
My memory is having difficult in envisaging the two hoses you have mentioned.
Are you able to post up any photographs of it. Unfortunately the Russian EPC site has shut down; my main free access to EPC from which I could derive much information.
It would be better to fix it properly and not add any sealant
Sealant often does more harm than good as it blocks radiator core and heater matrixes and any small water ways
Radweld was the worst and K seal not as bad. We have done many engines and had to clean out small important waterways where people have added the wonderful miracle cures. If it was me i would just fix it properly once and for all and forget about it
If its had a new pump then surely the pump will be fine for many 10000s miles. Is it not just the seal that need doing as perhaps they used the old one and did not replace with new
There is a bit of work to replace the water-pump, in removing all the other parts for access, but best to do things properly, if you want a good result.
Not sure on this K seal but I generally do not favor such sealants as they could block up the radiator cores unless in emergency but not as a fix.
Renew the water pump.