Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Ant-freeze leak from behind timing chain cover

My '95 Taurus GL 3.8L V6 has been leaking antifreeze the past couple of weeks. I brought the car to my local heating & cooling specialists who replaced the radiator a couple of years ago. They traced the leak from behind the timing chain cover and told me to find a good mechanic as they don’t fix that kind of problem. Price quotes start at $800 and go up from there depending on what other work I want to add like timing chain, water pump, etc. Since the car’s only worth about $1,000 naturally I don’t want to spend the money to fix. The leak starts with the radiator full and the car fully warmed up only after I then turn off the engine. I’ll get a steady drip with the engine off of up to 16 to 32 ounces and then no more antifreeze leaks out. I can then run the car without overheating and no more leakage of antifreeze. I want to emphasize the car never overheats with the antifreeze low. My question is since this doesn’t appear to be a major leak will a good sealant effectively block the leak. It has been suggested I try KW Block Seal. Do you suggest any other sealants or try another method to fix this problem? Thanks

If the water pump on this vehicle is behind the timing cover that’s what will be starting to leak.

It will save you labor charges if you do other maintenance while the timing chain cover is off.

Besides a chain and gear tooth inspection and water pump replacement, (IF it is leaking) a replacement of the chain tensioner may be wise.

Someone who believes sealers work may recommend one to you. Personally, I never use them, but that’s JMHO.

i"v tried silver seal for a radiator leak and it worked more than once. if it"s the water pump i don’t really know? it won"t hurt anything. good luck

There could be a casting plug in there that is rotten. They are often called “freeze plugs”.

Has this leak been verified by another shop or mechanic? This sounds more typical of a failing water pump, leaking out the weep hole on the bottom. Have someone verify that the pump is or is not leaking and go from there. A water pump would be far cheaper to replace, and may look like a timing cover leak.

Check the water pump weep hole for leaks or stains caused by a leak.

Yes this area is a common leak point for V engines. I believe the block is cast iron and the timing chain cover is aluminum. It is quite costly to replace the gasket in that location as the front part of the engine has to be disassembled. Unless the mechanic finds that the timing chain and gears need replacement, I would forgo replacing them IMHO. Usually the water pump does not need to be dismounted from the timing chain cover so you needn’t replace that gasket. The mechanic will have to know what he is doing as usually the oil pan gasket has to be refreshed where it mates to the timing chain cover and any seams created sealed with RTV sealant.

You might get by with a can of cooling system sealant. You risk plugging up the radiator or the heater heat exchanger. One possiblity is to use a lower pressure radiator cap or the radiator cap on the first notch to relieve the pressure on the cooling system. This would slow the leak but raise the risk of overheating during the heat of summer. What you could do is put the cooling system sealant in; run the engine through one or two warmup cycles; and then run for a little while with pressure relieved. This allows the sealant time to harden in the leaking area. Then when summer comes around go back to full pressure and see if you are okay.

Hope that helps.