Non-MB coolant disappearing - PeachParts Mercedes-Benz Forum

kerry · #1 02-23-2007, 06:01 PM

I'd ask this over on the Suzuki forum, but the mechanical expertise over there is at the pre-school level compared to this board.
I've got a 1996 Suzuki Sidekick Sport 1.8l. Bought it last March, mainly to pull behind my motorhome. It was leaking coolant at the water pump when I purchased it. Water pump had been replaced about 6 months prior. Replaced the pump and used it this summer. Short infrequent trips mostly, on the hook behind the motorhome much of the time. Sat in the backyard during the fall. When we got hit with repeated snowstorms this winter, the wife started driving it for the 4wd. I drove it one day and heard coolant sloshing around so I knew it was low. Added coolant(almost a gallon) and found the waterpump (Bosch) leaking again. Replaced it. Still losing coolant. No sign of any drips. No smell of coolant in the cabin. Slight smell of coolant at the front of engine after driving. Oil not milky. No evidence of oil in the coolant. No white smoke. BUT it seems to be losing about a pint or more of coolant every 20 miles or so. I thought maybe the overflow tank was leaking invisbly somehow so I let that run out and just drove with the coolant in the radiator. Still lost the same amount of coolant. Checked the engine and radiator with an infrared thermometer. Temperatures seemed fine. Gauge shows normal. Where could it be going?

vstech · #2 02-23-2007, 06:05 PM

it could be leaking near the exhaust, and burning up. go to any garage and have it pressure tested, they will pump up the system and look for water escaping. I work on so many cars, I bought my own set.
John

#3 02-23-2007, 06:07 PM

Strange, I would start by replacing the radiator cap (cheap and easy) just to rule it out. You should be able to see a pint if it's an exterior leak, let it run and look/smell for leaks. I assumed you don't smell any coolant in the exhaust? If it has a tranny cooler in the radiator, I would also take a look at the tranny fluid level.

kerry · #4 02-23-2007, 06:10 PM

I just thought of the transmission and checked it. Not going there. I thought about the radiator cap also. I tested it by removing it when the engine was hot and it was clearly holding pressure. It may not be holding enough so I will probably replace it.
I will try the pressure test. All I need is a cap into which I can pump pressure right?

kerry · #5 02-23-2007, 06:12 PM

Quote:

Originally Posted by vstech

it could be leaking near the exhaust, and burning up.
John

i hadn't considered that. You mean dripping onto the exhaust pipe and evaporating? That might account for the slight smell under the hood but no liquid.

tangofox007 · #6 02-23-2007, 07:00 PM

Quote:

Originally Posted by kerry edwards

I will try the pressure test. All I need is a cap into which I can pump pressure right?

Autozone will lend a pressure test set.

babymog · #7 02-23-2007, 09:20 PM

I had a Suzuki Sidekick / Geo Tracker that I towed behind our Wanderlodge years ago, the aluminum block cracked for no apparent reason, we finally found a small leak through the block I think to the rear of the passenger side behind some accessories. It never left a puddle.
The nice thing is that the engine is light enough to carry around by yourself, I gave my replacement engine a big bear-hug and carried it from the truck into the garage, with manifolds and accessories (including A/C) on the engine. A great replacement task for an afternoon and almost comical in its simplicity.

kerry · #8 02-23-2007, 09:24 PM

Oh lovely! That's not the answer I was looking for. Was yours the 1.6 or 1.8 liter? !.6 has a timing belt, 1.8 has a chain. I also think the 1.8 has 16 valves.
Working on it does remind me of my go-cart days as a teenager.

babymog · #9 02-24-2007, 11:43 AM

Not sure, I hated that thing so have erased the memory of it. A good trailer, but a lousy car. Probably a single-cam if I remember correctly.

DeliveryValve · #10 02-24-2007, 12:03 PM

I don't know if it is the same design but in the case of my wife's Honda, she was loosing one recovery tank of coolant 250-350 miles. I spent months trying to figure out what is going on because there was no puddle or evidence of it leaking at the "usual" spots. Then one day her car was "creaking" after a drive. So I check under the hood, started the car up, and found that one (there are several) of the 3/8 inch coolant hoses that snaked in around the fuel injection and manifold was dripping slowly and never making it to the bottom the car. I think it was hitting the exhaust pipe and disappearing. Looking back, I should of borrowed a pressure tester and could of found the leak earlier. So if you have little hoses, you might want to check those also.

Palangi · #11 02-24-2007, 05:47 PM

At one time I had an old Ford 6.9 which used to lose coolant for no apparent reason. Eventually found a bad freeze plug. It was located directly above an exhaust pipe. Coolant would drip on the hot exhaust and disappear without leaving a trace.