Coolant Hose at Coolant Flange--need inside diam.

The coolant flange on my 1999.5 Golf was repaired, at the dealer, under warranty, due to persistent coolant system leaks. I recently noticed a small crack on the coolant hose where it meets the coolant flange. I also noticed that the coolant hose seems to be severely stretched around the coolant flange...plausibly the cause of the split in the hose. I also noticed that the replacement flange is metal whereas the previous one was plastic. I presume that the metal one comes from a later model engine (2003+?). And so I also wonder if the hose that attaches to it also has a larger inside diameter.

Is there anyone out there with both vehicles, or someone that has both parts in stock? Could you please measure the inside diameter of this hose for me? Here are the two part numbers:

1999.5+ 1J0-121-109C
2003+ 1J0-122-109CD

Thank you!

My observation is the autos came with the plastic and the manuals all have metal. Seen several hundred and they are all like that. Sorry I don't have the measurments though.

Why would they (the designers) do that?

The manual cars have 3 extra coolant plugs right there for heating coolant. The autos use the heat from the trans to help heat coolant. So it's a strength/heat thing with the 3 plugs and the hose hanging off the end.

So I'm stuck with a mixed bag of parts--a flange for a manual on my automatic--and the hose does not appear to be the same either. The hose is about $117, so I want to make sure I get one that's going to fit.

Anyone?

I found the coolant hose on sale at a web site for *really* cheap ($17.00) and decided it was worth a try. The part arrived last week and I spent a good 4 hours removing the old and replacing the new one. I sure snakes its way through the engine compartment!

My observation is the autos came with the plastic and the manuals all have metal. Seen several hundred and they are all like that. Sorry I don't have the measurments though.

Click to expand...

The manuals are metal with a plastic inner sleeve. Mine has had a weep for 40k. I need to get around and change it. It leaks where the sensor plugs in. Leak is not really the right word. There is always some dried crud there and I notice a small drop in the expansion bottle every 10-20k.