Testing a 4-Tec Oil Exchanger for a leak

[RX951]

Did some troubleshooting to determine where I was losing oil on my GPRXP.
After narrowing down the component that was the culprit, I decided to pressure test it with residential city water pressure to see if it leaked.

Some troubleshooting steps I took

1. Looked for oil in hull
2. Looked for oil residue exiting a water outlet in the ski
3. Looked for smokey exhaust from oil burning.

Mine was #2 ^. I had oil exiting the water outlet from the oil exchanger.
I then examined/swabbed the water line to and from the oil exchanger. The water line leaving the exchanger was milky. The water supply to the exchanger was clean and clear. This then led me to determine it was the oil exchanger.
On a closed loop ski, it has been documented that oil will pressure up the coolant system (first noticed in coolant bottle) and this can be a huge mess.

Parts:

• 3 hose clamps
• 1 Garden Hose Adapter
• 6"-1' piece of 5/8" hose
• 1 rubber heater hose cap

Steps

1. Cap one end of the exchanger coolant outlet and clamp.
2. Attach the 5/8" hose and clamp both ends of the hose.
3. Connect the hose attachment to a residential water supply.
4. Open the valve slowly, maybe 1-2 rounds until you feel the hose begin to pressure up. It won't take much so don't open the valve all the way.
5. Examine the oil inlet or outlet opening for the next 30 seconds to 1 minute to see is oil/water begin to exit.
6. If it does, there is a leak. The oil pressure is higher than the water pressure or coolant pressure so oil will typically leak into the coolant system, or on an open loop ski, oil will exit the water outlet.

Possible culprits of oil exchanger leak:

• Age of part; anything can fail due to age.
• Old oil that hasn't been changed and has become corrosive due to the internal combustion process.
• Electrolysis eating components e.g. exchanger. Examine all your zinc anodes for wear over time.

There can be more causes, these are just a couple above ^

Video below of pressure test. Click on link below

http://s2.photobucket.com/albums/y32/dandbesales/GPRXP%20Conversion/?action=view&current=b850b79f.mp4

[RX951]

Here are some articles for read. Just a bit of information to think about on these oil exchangers in our marine applications.
Not only do we have pressure to be concerned over, its corrosion as well.

Corrosion Analysis

http://met-tech.com/oil-cooler-analysis.html

Cooling and heat exchanger problems in marine applications

http://www.boatfix.com/how/cooling2.html

[RX951]

oh, and something to think about on these open loop skis, the oil exchanger is at the bottom of the motor, after we flush, do we truly get all the moisture/water out of the cooler especially when it sits up for months during the off season? This can be a recipe for corrosion to sit in and eat away at the exchanger and over time, the metal gets thin and weakens, then causing a leak.

Also, the internal combustion process deteriorates motor oil, and if oil is not changed regularly (to remove particulates & contamination), the oil can be corrosive as well on internal components.

and at the same token, closed loop skis have experienced failed oil exchangers as well

[elmatta]

Hey rx951, very nice write up. I have the same/similar problem with a 2002 4-tec n/a ski that has oil in coolant. Ive got symptoms 1,2,3. Except that the hull oil/coolant milkyness may be from coolant tank resevoir spitting out. My coolant tank also looks like its bulging. As for the water outlet, the two small outlets right above the exit nozzle of jetpump are slowly leaking milkyness, not sure if those are bilge line outlets since ive got a mess from disconnecting hoses. Ive got no coolant on oil stick or cap and no milkyness on mag side. I managed to take off the t-stat housing and didnt find much. If oil is smoking from exhaust, what does that mean? And after the oil exchanger pressure test, what other steps can i do to narrow down the oil leak? Do i have a busted head gasket? And is there a special tool for those star bolts and the female star bolts? Ive been using 6.5mm sockets for the male star bolts but im stripping the head bolts with a 6.5

[brotu123]

I cannot find that part for sale anywhere? I am going to pull mine and test it, but what it the part number for the exchanger?

[RX951]

I cannot find that part for sale anywhere? I am going to pull mine and test it, but what it the part number for the exchanger?

Place a WTB ad in the classifieds, somebody will reply with one for sale.
Located under engine block accessories

Part #33 is called an oil radiator for a 2004 4-TEC
420888850 OIL RADIATOR $223.49 $223.49





Part number 34 oil radiator for a 2008 4-TEC
420888852 OIL RADIATOR $222.49 $222.49

[kartracer]

2013 gti its pushing milky chit out the water bottle,i put a new oil cooler on thinking it was the problem,but i was wrong, now i have no clue what to check.any help would be great