Anyone come across this oddity? For weeks I've been losing coolant: I get the warning light every couple of hundred miles. My mechanic changed the water pump (assuring me that this would be the cause of the problem) but the situation is exactly the same. He also replaced the thermostat and I have put a new expansion tank cap on (just in case there was some way coolant was escaping via that route). Today I was under the bonnet (= hood) looking around again for clues and I was tweaking all the hoses I could see. There is thin hose, max1/2" diameter -- the radiator overflow hose, I believe -- which runs from the top L.H. side of the radiator (i.e. the left hand side of the car itself) up to the top of the plastic expansion tank. I gave this a gentle pull to test that the hose clip was secure and suddenly there was a whoosh of pressured coolant all over my left shoulder and side of my face!! Luckily the water wasn't *too* hot and I wasn't scalded. When I looked to see what I'd done, I found that the hose connects to a small plastic 90-degree elbow which appears to be a push fit into the top of the radiator. I am a bit confused. If the coolant system is designed to run under pressure, how come this overflow union is a simple push fit?? If this elbow piece were a bit loose -- which seems likely since I dislodged it with a gentle tug -- would this be the source of the coolant leak? I have inspected the piece carefully and it is definitely designed as a separate piece: the housing moulding in the top of the radiator has two protruding vertical lugs which neatly align with two grooves on the elbow piece. It looks very odd to me.

Any ideas? Is it really just a push fit? And do these elbow bits come loose occasionally?

 

Jem;
Yes, it really is just a push/snap fit. I don't believe that it should release pressure and coolant, though, when you exert sideways force on it. Perhaps the "O" ring is defective. The part, along with a new "O" ring, is available from your friendly dealer - just a couple of dollars here in the US. Apparantly, it does break off, causing loss of collant and all the other things that can occur with coolant loss. It is curious that this part is made this way.

 

Sorry to tell you this Jem but this is a a very common problem. The only cure is a new radiator. Don't even think of using a second hand one or trying to 'fix' the leak. Try Eurocarparts or GSF. (about £150 from memory)

 

Jem,

You may not need a new radiator....the problem you describe is similar to my E280.

I had an air lock in my system after the garage changed the coolant and it caused the car to overheat, which lead to the elbow that goes into the radiator blowing off and blowing coolant all over the place.

Luckily no damage was caused.........the elbow was replaced along with a new O ring seal at very little cost.

Try this before you embark on a radiatior replacement.

I notice that you either have a e280 or 320. I also suffered from a persistent coolant leak. All the usual suspects were checked, pump, thermoststat, etc etc. It turned out to be an O ring right at the back of the engine. As you look at the engine it was on right at the back on the right rear. If you shine a torch under the intake manifold, have a look to see if the block is wet. If it is your O ring will have blown.......my garage replaced this for little cost. Since then the car has lost no coolant.

Cheers

 

Yeah...that lil' elbow is only a few bucks and they usually fail. Try it first.

If your car is close to 100K miles....maybe think about that fresh new radiator.

 

Yeah...that lil' elbow is only a few bucks and they usually fail. Try it first.

If your car is close to 100K miles....maybe think about that fresh new radiator.

 

Yeah...that lil' elbow is only a few bucks and they usually fail. Try it first.

If your car is close to 100K miles....maybe think about that fresh new radiator.

 

I wish I'd known this.
When my 300E-24 leaked just over a year ago my mechanic told me I needed a new radiator.

 

The thing is that at least for older radiators. You try to get the elbow off and then the snap on mechanism breaks, and this calls for a new radiator. So my suggestion: is if the leak is little, let it leak. If the leak of course is big and requires refills, try this first, but dont be disappointed if the trail fails.