Sucked in upper radiator hose - PeachParts Mercedes-Benz Forum

ksing44 · #1 07-01-2007, 07:20 PM

My upper radiator hose gets sucked in. When I open the overflow cap it goes back to normal and I can hear the air getting sucked into the system when I open the cap. I think it must be because of my head gasket leak. On occasion, I have to add just the slightest amount of water to my cooling system. I don’t have to add much water and I do not have to add it frequently, but I do seem to loose just a bit of coolant over a number of months. I do not loose oil. At least I never have to add any between oil changes at regular 3000 mile intervals. I am sure I have the classic head gasket leak, since it was diagnosed as such by the dealer. I also ,have the front timing cover leak and I also need a new wiring harness.

I just want to confirm that my sucked in hose is probably related to the head gasket leak and not some other new weird failure that may be common to these W124 cars.

Also, if I add tap water, at about 1 cup per 3 months, will that be a bad thing for my cooling system. Answering my own question, I guess I should buy a gallon of distilled water.

I may get the head gasket repaired pretty soon, along with the wiring harness, but this year I already spent for brakes, new exhaust, and now the AC compressor. I am just trying to spread out these stupid repairs on this car that I love even though it sucks big time.

loubapache · #2 07-01-2007, 07:49 PM

Bad coolant recovery tank cap.

junqueyardjim · #3 07-01-2007, 07:52 PM

Usually with a head gasket leak which is leaking into the cooling jacket of the engine, you would not get a sucked in condition on the radiator hose. The gasket leak does put a lot of outward pressure on the cooling system, causing a swelled or bloated look, and a hard hose. I would look at a "sucked in" hose as being pretty normal on a cold engine. That is why some hoses have that coil of wire installed in them and I would not worry about it. Do keep an eye on your coolant recovery bottle and add when it gets to the low level line when cold. Why tap water? Why not have a gallon of premixed antifreeze on hand and pour a little straight from the gallon when needed. Your antifreeze protection will always be good and it also refreshes the additives in your antifreeze.

ksing44 · #4 07-02-2007, 05:26 AM

Thanks for the replies. I will get a new cap, some MB antifreeze, and some distilled water.

david s poole · #5 07-02-2007, 11:36 AM

replace that hose it's worn out.

Mike Murrell · #6 07-02-2007, 03:22 PM

I've experienced this on 2 different occasions. On both, the problem turned out to be what loupapache pointed out.

ksing44 · #7 08-10-2007, 05:58 AM

I replaced the cap back when this thread was new, but I wanted to complete the thread and say that in fact it was just a problem with the cap.

With the new cap, I have no issues!

By the way, my system has been flushed at 30K intervals, I have a new water pump, new thermostat, and all new hoses, so it makes sense that it was just the cap. I am so glad it wasn't the head gasket causing the issue.

Thanks for the tip. If only all things were so simple to fix.