Hello all,

Recently I have noticed a very slow loss of coolant after taking a few short drives around town. Any ideas what might be common causes? I don't seem to have creamy oil so I think I can rule out head gasket or cracked head (Thankfully). Currently the temp gauge stays in the normal range (middle) - I just lose a bit of coolant every time I drive it. For the life of me I can't see any visual leaks in any of the hoses /fittings - am I overlooking something?

 

Clack, normally something like this is common to a cracked nipple on the over flow bottle. If you look at the over flow bottle, you have a large hose that comes out the bottom and then there is one that comes in the back, parallel to the firewall. This back nipple is known for getting brittle, developing a crack in it and leaking out a little bit of coolant over time.

Otherwise, talk with your local auto parts places and find one that rents tools. They should have a coolant system tester. This will allow you to remove your overflow bottle cap and install one from the kit. From there, you can attach the gauge and pump. You can press the whole coolant system up to around 10 psig and see if you can spot any water dripping.

One last check you can try is to get a bright black light. At night (or in a dark room), open the hood of your car and shine the bright black light around the engine bay. Modern day coolants normally have a flourescent dye in them. So, where the water/coolant is leaking out, it should leave a glowing streak under the black light. Granted, you may want to carefully (ie, avoiding the very top of the engine) wash the engine bay say 20 miles/30 KM before doing this so you can wash away most of the dye that has accumulated over the years for various reasons.

 

Thanks for the advice Thermo - Can the back coolant overflow bottle nipple be inspected properly without removing anything?

 

I have ordered a UV blacklight from ebay. Once I get it I'll look for leaks with it.

 

I would also check the O-Ring on the coolant outlet pipe on the left side (as you're looking at it) of the engine bay. If it's leaking, you can usually sneak your finger in under it and feel moisture, or if you look directly down into the valley of the engine on that side, there's usually a little pool next to the cylinder 2 inlet on the head.