1992 Mitsubishi Montero Antifreeze Leak

Reader Question: Hello,

I have completed my survey for insurance quotes and Travelers seems to be the front-runner. Thanks!

I have a 1992 Mitsubishi Montero 3.O Liter V6. I have developed a slight leak of antifreeze coolant coming from the around the driver side exhaust manifold.

I cannot see if it is coming from the intake, from the manifold, or from the head. When parked I see a few droplets dripping from the back of the engine on the driver side. It uses about a quart of antifreeze every week or so.

It steams a little from the driver side exhaust manifold after a trip. Heating gauges are running normal 180 to 200 degrees unless I start to run low on antifreeze.

I had the water pump replaced (was leaking) 2 years ago. Engine has never overheated. No antifreeze in oil or transmission fluid.

Do you think it is a head gasket problem, a cracked head, or an intake manifold gasket? Is this a common problem with this 3.0-liter engine? Do you think I should try a stop leak (Bart) product?

I am hoping that it is a frost plug or an intake manifold gasket because the engine has 178,000 miles.

My Dad was a master mechanic and known as “The Doctor of Motors”. Since he passed away, I need someone to help me diagnose this problem. I have enough mechanical background on engine repair to make me dangerous without your help and guidance.

Please let me know what you think.

Thanks in advance!

Gary

Howdy Gary,

Thanks for your e-mail.

I would HIGHLY recommend you take the vehicle to your regular mechanic or even one of the fast lube places and get a cooling system pressure test to locate the leak. This is a simple and cheap test they can do while you wait.

This leak could be from something as simple as a thermostat housing gasket, or a heater hose that is leaking coolant and running down the side of the intake manifold.

Since you did not mention any of the common head gasket symptoms, I would assume this is an external coolant leak and not something drastic like a manifold or head gasket leak.

I would NOT use a stop leak additive until you get a proper diagnosis of the problem. If you get bad news, e-mail me back and we can talk about options then.

Blessings,
Austin Davis