Cobra 3.0L oil Milkshake with a twist...

[Bluestream]

A little background:

I bought this boat last fall with a broken engine coupler. At that time I changed the oil and the oil was black, but had no signs of water in the oil or the filter. PO said he was using it up until June when the coupler let go, and then he parked it and put it for sale. I put in new spark plugs and a fuel filter. Engine compression was 135, 130, 140, 140. Ran it on the hose for 15 mins and no water in oil. I then launched the boat and ran it for 25 mins. I then fogged the engine for storage, pulled in out of the water and drained the block and manifold, and stored it for the winter.

This spring I took it out of storage, and spilled a few gallons of water into the boat when taking the cover off, and noticed some milky oil in the bilge. I had cleaned the bilge spotless last fall. Checked dipstick, and the lever was up several inches over full (getting worried now) Bottom of dipstick had rusty film on it. I put the drain plugs back in and started the engine and it ran fine for three mins. Checked dipstick and saw milkshake all over. (Getting very worried now) I noticed there was milky oil running out on to the intake manifold right by the carb. I did not see when it was coming from, so I wiped it up.

I can only assume the water got into the oil when I ran it last fall. It is strange that there was no oil in the engine when I bought it. Possible that the PO had not used the boat last year as he told me, but the year before, then let it sit over winter not properly drained.

Any ideas where to start to trouble shoot this issue?

 

[dubs283]

Re: Cobra 3.0L oil Milkshake with a twist...

drain all oil out of pan

fill with four quarts new oil

run engine until warm - note level on dipstick

let heat soak for 1/2 hour

run engine for 20 mins

check oil level again

if the oil level is increasing, you got a crack somewhere

 

[fishrdan]

Re: Cobra 3.0L oil Milkshake with a twist...

Edit... Did you drain the engine block and manifold, dig around in the drain port and pull the hose off the pump? Sounds like there was still some water left in the engine and cracked it. Change the oil and see if it comes back.

 

[Bondo]

Re: Cobra 3.0L oil Milkshake with a twist...

Checked dipstick, and the lever was up several inches over full (getting worried now) Bottom of dipstick had rusty film on it. I put the drain plugs back in and started the engine and it ran fine for three mins. Checked dipstick and saw milkshake all over. (Getting very worried now) Any ideas where to start to trouble shoot this issue?

Ayuh,.... Ya shoulda Drained the Oil, the very minute you found the oil Level several inches High....
Water is heavier than oil...
Oil Floats on water...
The oil pump pickup is at the Bottom of the oil pan....
You pumped Nothin' but pure rusty Water through the motor, til the oil emulsified inta the Goop ya found later...

When was the Last time ya checked the oil level,..?? Last Fall,..??
It really don't matter who left the water in the block, nor does it matter Which winter it was...
She's an Anchor, or at best some parts can be stripped from it...
Ya need Another 3.0l Long Block, or complete motor at this point....

 

[Bluestream]

Re: Cobra 3.0L oil Milkshake with a twist...

Edit... Did you drain the engine block and manifold, dig around in the drain port and pull the hose off the pump? Sounds like there was still some water left in the engine and cracked it. Change the oil and see if it comes back.

All of the water was drained out of the block and manifold, there is no doubt in my mind about that. A lot came out, and I am familiar with the procedure. that. I don't recall if I checked the oil after the last run of the season or not. If I did check it, I would have seen the water milkshake, so I am assuming that I didn't check it, or checked it and it was fine...

When running on the hose, how long would it take for water to show up in the oil? Is there anything about a lake run, that would increase the rate of water intrusion into the block?

The PO was not very mechanical, but had owned the boat since new. He had always taken it to be stored and serviced by someone else. At this point, I have to assume that it was in this condition when I bought it. I cannot see any way water would have got in over winter other than sabotage...

 

[Bondo]

Re: Cobra 3.0L oil Milkshake with a twist...

When running on the hose, how long would it take for water to show up in the oil?

Ayuh,... It would depend on where, 'n especially, how Big the crack it...

Is there anything about a lake run, that would increase the rate of water intrusion into the block?

It's under Labor...

 

[Bluestream]

Re: Cobra 3.0L oil Milkshake with a twist...

Looking for some more advice..

Trying to find if block is cracked, so I hooked my garden hose direct to the water intake and turned it on. Took out oil drain plug and looked to see if any water came of of the crankcase. None came, but cooling system was not under much pressure. I assume the exhaust needs to be blocked off to test for cracks?

Checked engine compression and it was 140-145 PSI. I drained the old oil/water mix and added fresh oil, engine fired right up and ran smooth. How do I know that I don't have a rusted or cracked intake manifold and not a cracked block? Or a warped head for that matter. When I got the boat, the outdrive impeller had 2 vanes broken off and I found them in the water hose by the thermostat. I would assume this may have caused some overheating?? Maybe a warped head, but compression seems OK

 

[HT32BSX115]

Re: Cobra 3.0L oil Milkshake with a twist...

To determine if you have a crack, you need to make up a simple cooling system pressure check jig from common plumbing fittings, a gage, valve etc.....

Pressure the block and head to about 15 psi, close the valve and observe the gage.

If the gage DOES NOT drop over several minutes, you probably DO NOT have cracked block/head.

If it drops and you hear hissing, the location of the hissing is your leak. If it's internal, water WILL run into the oil sump.



Cheers,


Rick

 

[Bluestream]

Re: Cobra 3.0L oil Milkshake with a twist...

Thanks, presuure the block with air or water???

 

[HT32BSX115]

Re: Cobra 3.0L oil Milkshake with a twist...

Thanks, presuure the block with air or water???

It's VERY hard to hear hissing from using water! So it's best to use compressed air!

 

[buyrum]

Re: Cobra 3.0L oil Milkshake with a twist...

Had the same issue, be sure to check for a cracked exhaust manifold, it will make a "milkshake" every time. It can be internal and best found at the shop, in a water tank pressure test.

My question. Does the 3.0L inline four normally have an exhaust flapper installed to reduce the possibility of backwash into the engine??

 

[Bluestream]

Re: Cobra 3.0L oil Milkshake with a twist...

Had the same issue, be sure to check for a cracked exhaust manifold, it will make a "milkshake" every time. It can be internal and best found at the shop, in a water tank pressure test.

My question. Does the 3.0L inline four normally have an exhaust flapper installed to reduce the possibility of backwash into the engine??

I assume that all 3.0L engine have the flapper valve. This is defiantly not an item that is going to stand up over long time use.

Curious how would a cracked exhaust manifold make water in the oil?