Coolant leak back of engine

All of a sudden I'm leaking a fair amount of coolant. On a short trip, I am losing maybe 12 oz. and I'm leaving a puddle where I park. I have searched the threads and read about the radiator hoses disintegrating from IP diesel dripping on them over time. However the front of the engine is dry; this leak is coming from the back of the engine somewhere.

I can't tell exactly where it is coming from. Before I resort to starting the car and lettting it heat up to see the source of the leak, are there any known issues back there (common leak sources) that might be good suspects?

Check your EGR cooler. It is not uncommon for these to fail and develop leaks.

1996 No EGR Cooler???

tditom said:

Check your EGR cooler. It is not uncommon for these to fail and develop leaks.

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I did some searching and a DIY on intake manifold cleaning for B4's (on myturbodiesel.com) specifically noted that the 1996 does not have an EGR cooler.

Is this correct? I am going to go have a look at the back of my engine and see if I can find it.

I do believe you are correct that the 96 Passat did not have the EGR cooler...but I own a 98 Jetta so wait for others to give 100% verification on this.

Take a look at the coolant hoses right below the injection pump. If you have a bit of a fuel leak from the IP it can erode the hoses leading to a coolant leak. Have you gone under the vehicle with a strong flashlight and taken a good look at the radiator and lower rad hoses? Also, check your coolant overflow tank, I have read that sometimes these can develop a crack.

If you have G12 coolant it really forms a nice pink crust where the leak is occurring. Take a look and see what you can find.

96' has no cooler.

Check your hose running from the side of the block to the heater core connection at the firewall. Check the one running back from the firewall to the engine. One of those has to be the culprit.

The large hoses between the engine and the radiator are bone dry as are the smaller hoses from the side/back of the engine to the firewall. The hoses are not stiff or brittle at all. As a matter of fact they feel fairly new. I do not think they are the culprits.

The area around and below where the coolant glow plugs are looks kind of wet/shiny, but that may just be a bit of oil coming down from the valve cover.

I may have to run over to the car wash and give the engine a good cleaning and let it dry. Then start it up and let it heat up and start to look for leaks. It'll have to wait a few days as we are heading out of town for the weekend in the morning.

I wonder if that o-ring for that flange is leaking.. There isn't very many options of where it could be coming from back there.

Giving it a good cleaning is a great idea. If it turns out that oring is the culprit it's a fairly simple job. Only thing is those bolts holding that flange on are one time use.

What type of coolant are you using? G12?

I'm wondering if one or more of the coolant glow plugs are leaking, the flange is cracked, or the flange has corroded and won't seal.

Tony

TonyJetta said:

What type of coolant are you using? G12?
I'm wondering if one or more of the coolant glow plugs are leaking, the flange is cracked, or the flange has corroded and won't seal.
Tony

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The coolant in the reservoir is pink, so I added G12. Hope that's OK.
I got home this evening and gave the engine a good washing. I am going to let it get good and dry for a day, and then fire it up tomorrow night and look for leaks. Thinking it won't be too hard to find the leak once the engine reaches operating temperature.

richmondvatdi said:

The coolant in the reservoir is pink, so I added G12. Hope that's OK.

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G12 and G12++ is pink and should be compatible.

Tony

Do you mean the leak is on the firewall side of the engine or the transmission side of the engine?

whitedog said:

Do you mean the leak is on the firewall side of the engine or the transmission side of the engine?

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Somewhere between the firewall and the back of the block. I think it is closer to the driver's side.

UPDATE: Found Leak

After cleaning the engine and letting it dry, I started it up today. After warming up, I found a very slow leak. The source of the leak was the supply line to the heater core. It's just a pin hole and it was covered by the bracket that holds it in position.

I'm going to try to paste the pic below



Thanks for the help. Now all I need to do is find the hose (the easy part)!

check my sig for a source to locate the part number

Cool. Thanks.

Everything back together and running great. Thanks all.