4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

[paperklip]

Volvo AQ125B Raw-water cooled, Penta 270

Took the boat out this past weekend and immediately noticed low RPMs and slow speeds. RPMs were fluctuating between 2400 and 3200 at full throttle (spending 20 or so seconds at each). Also the boat didn't want to idle. Turned around, motored back in, and trailered home. I then opened the engine compartment and there's milky oil sprayed about. Pulled the dip stick, yep, milky and high. ACK! Water in the engine oil!

It looks like it came from the port side of the valve cover, hit the air filter, and inside of the engine cover and reflected all over the place. I can't yet be sure of the exact source.

I did several searches on here and found a variety of information. I plan to spend some time on it this evening, hopefully getting more information. I'm looking for advice on what to check/test/try. I'd like to get it narrowed down as best as I can before calling on a mechanic.

EDIT:

I should add, the boat is in Florida and has NOT been subjected to freezing temperatures. It was running decent prior to this run, though it was running about 5 to 8 mph slower than normal.

 

[captmello]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Can you tell if it is antifreeze or water in the oil? It should be antifreeze. You should be able to pressure test the cooling system fairly easily with the right pump to fit the coolant container.

Did it overheat recently?

 

[Don S]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Oil cooler next to the oil filter defective.

http://www.volvopentastore.com/Cool...*****.348420804--store_id.366--view_id.784503

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

I don't think this engine has an oil cooler. FYI, it's a 1983.

I just went out and snapped a few pics. Here's the starboard side where the oil filter is:

Starboard top:

Port-side:

Milky puddle on the port side just below the valve cover:

And for good measure here's a picture of the front of the engine and the oily mess that was made:

 

[Don S]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Nope, your engine doesn't have a cooler. Some did, some didn't.

Next step would be to drain the antifreeze side of the cooling system and pressure test it and see if it hold pressure. I doubt it will, but if you take the oil fill cap off while pumping you may hear air leaking into the crankcase.

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

So I'm guessing I could have one of a few different problems, not the least of which would be a cracked block. Seems crazy though, as the motor hasn't been overheated or exposed to any extreme temperatures at all. :-/

This is a raw-water cooling system, no antifreeze (and no tank). The advice still holds though... I guess I'll need to get some fittings to block off both the exhaust and pick-up sides. Then something to hook my compressor up to with a pressure guage. That sound about right?

 

[Don S]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Your engine has a closed cooling system. That is what you have to drain a pressure check. Just like pressurizing a radiator on a car, only you will be pressurizing the block and heat exchanger, not the exhaust. The exhaust is the seawater side.
NOW, if the heat exchanger went bad and the block is filled with raw water, and you boat in salt water ................. well, the game may change.

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Is there any time sensitive issue with the milky oil sitting in the engine? I'm wondering if I shouldn't focus on a drain/refill first and then focus on the pressure test. :facepalm:

 

[sqbtr]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Do you run in salt water?

If so I would be pulling the head. Aluminum and salt don't go well together.

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Do you run in salt water?

If so I would be pulling the head. Aluminum and salt don't go well together.

Yes, I do run in salt water. I'm planning to drain the oil, and flush with some cheapo 10W-30. I was also thinking that once I have it full, I might run it for 60 seconds or so to see if I can pinpoint the external oil leak. Any reason not to?

 

[Don S]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Take the oil fill cap off and look in the valve cover, is it full of milky oil?

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Take the oil fill cap off and look in the valve cover, is it full of milky oil?

Yes. I went ahead and drained it at the plug and refilled with fresh oil. Just couldn't stand having the milk sitting in there for long. I'm thinking i want to run it for 60 seconds or so tomorrow to see what's cracked externally.

 

[sqbtr]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

I'm pretty sure you will find the oil blowing out the breather.

Thats a pretty ingenious bypass of the heat exchanger, but, I wonder about exhaust cooling especially when the engine is cold. Are you still running a thermostat?

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

I'm pretty sure you will find the oil blowing out the breather.

Thats a pretty ingenious bypass of the heat exchanger, but, I wonder about exhaust cooling especially when the engine is cold. Are you still running a thermostat?

Heat exchanger bypass? Can you explain what you mean? I'm not familiar with this engine at all (stock or otherwise) and certainly don't know what the PO changed.

As for the thermostat, the PO said he removed it. I bought a new one but haven't put it in yet.

 

[sqbtr]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

That engine originally had a heat exchanger mounted to front of engine. Looks like a junk yard auto engine in there now, oil press switch instead of a sender, hacked timing belt cover, auto t stat housing, and the yellow marking on the crank pulley. I would suspect the cam is auto also.

By putting a thermostat in it would severely reduce your water flow to the exhaust especially at idle. These engines had heat exchangers becuase of the aluminum head. The ex manifold is severely discolored and may already be running too hot.

Look up the parts diagram for your engine and you will see the original configuration.

Marine Parts Express has good diagrams to go by.

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Looks like a junk yard auto engine in there now

Hmm, good to know. I guess this calls into question whether it's even an AQ125a, as the PO told me.

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

I went to Lowe's today and picked up some fittings to do the pressure test. Couldn't find a finer gauge there or the auto store so I settled for this one. Here's what it looks like:

I did a quick soap test to make sure it's all sealed:

It's on the engine now at 15 lbs and I'll check it in an hour or so. The engine is at ambient temp (around 88F). I marked the gauge with some tape, and the first 10 minutes looked good. I removed the oil cap and listened carefully but heard nothing.

For now, the exhaust manifold is obviously not being pressure tested. Here are some sanity-check pictures:

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

Erghhh.. The pressure test seems to have failed. I checked it after an hour and it was at 7ish lbs. After another 30 mins it was at zero.

What are my next steps? Any advice?

 

[paperklip]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

This morning I'm planning to do two different pressure tests, in hopes of isolating the leak to one of the two cooling sides. I'm still looking for additional advice anyone may have.

 

[bruceb58]

Re: 4 cyl Volvo AQ 125a Milky Engine Oil Sprayed all over

If you are running raw water through an engine originally designed for a closed cooling system, that caused your problem. Could be a head gasket or just the head rotting away. Your engine has an aluminum head and a steel block and was never designed to run without a closed cooling system.