2003 7.3, was replacing my oil cooler o rings today as a preventative maintenance type of deal. I needed my coolant changed in a bad way so I decided to do the cooler o rings at the same time.

I drained coolant, engine oil, removed oil cooler and replaced the o rings.

Reinstalled, refilled oil, and was flushing radiator. Ran engine for 2 minutes, shut down, noticed the water coming out of my overflow bottle looked oily. I checked drip stick and it is light brown, water definitely contaminated $85 bucks worth of rotella synthetic and a brand new oil filter.

What could I have possibly done wrong? The o rings were reinstalled in the same way they came off. I used a pipe clamp to push them back together and it doesn't leak.

So i suppose i'll tear it back down but how do i flush the water out of my engine now???

Help! I'm doing all this in a napa parking lot since I live in an apartment.

 

Ok I just have to check as it may have been overlooked. You stated you replaced the o-rings but you didn't mention anything about removing the 2 old gaskets and replacing them.

 

I did remove and replace both gaskets

 

Just wanted to rule out the potentially obvious first. also did you lube the o rings and the cooler caps where the o rings sit with Vaseline or equivalent before reassembly?

 

When you pull the oil cooler off the engine, some coolant gets down into the pan. You should have pulled oil drain plug to empty this stray coolant out before re-filling. Did you? Also, did you drain the coolant from the block via the plugs on either side of the engine? This would minimize the drainback into the pan I'm talking about.

 

I didnt drain the pan after pulling the cooler. But there was quite bit of water in the oil. It was milkshake brown.

I have pulled the cooler back off and one of the o rings looks like it may not have been seated in the right place although i dont know how that would be possible when it's all pressed back together.

My plan is to leave the truck here overnight and take the cooler into the dealer tomorrow morning and ask them to assemble it for me. Then reinstall into the truck. Think the oil cooler gaskets will still be good?

What's the best way to flush out the oil/water mix from the block? Just change the oil a couple times?

 

Also i couldnt get the passenger side drain plug to come out, so i just drained the coolant from the port where the engine block heater goes in.

 

I've done literally (not figuratively) a few dozen of these this way and have ALWAYS done them this way. No worries using this method.

 

Is it possible to have the oil cooler reassembled and the o rings not seated correctly?

 

Absolutely. But it's more common to crack an aluminum attachment piece or front cover.

 

If you can't see anywhere on the gasket where it is cut, pinched or deformed it should be fine. I would use a cheap oil to flush the system. Put in cheap oil, drive 100 miles, flush, repeat. Leave that filter on till you are done with the flush process. Then fill it back up with the good stuff that is on sale!

 

I remember when I did my oil cooler I was told to mark the front and rear header to the original oil cooler position so it could be reassembled in the same orientation.

I made a mark with paint on a spot on the oil cooler/headers to mark the front and back header position.

I'm not sure how important this is. Is it possible to get oil in the coolant or coolant in the oil if the oil cooler and headers are not orientated correctly?

 

I had the oil cooler professionally reassembled today. I reinstalled.

STILL GETTING WATER IN MY OIL....

What is happening????

 

The internals of the main body could have been compromised during the disassembly process... or maybe when it was put back together? Maybe one of the cooler/block gaskets are not in the correct orientation(front one) .

If it were mine, i would pull it apart again and look for nicks in the new orings... and then try to cap off one side of the water jacket connection and maybe pressure up each tube with water and see if it leaks out the oil side... or mity vac each water tube and see if it leaks down... then you could either prove its good, or find your culprit.

 

I pulled the cooler back off and had a shop pressure test it. The oil cooler held 40lbs of pressure just fine. I don't think it's the problem... and the oil pressure is much higher than the coolant pressure so if anything I should be getting oil in my coolant if that were the problem, but it's reversed. Water is getting into my oil.

I had the truck towed to a mechanic for repair. The owner drives a 7.3 as well so hopefully he can get it fixed quickly.

He is thinking there may be a gasket around the water pump that broke loose when I did the coolant flush. Probably something expensive.

The coolant I pulled out was very brown/orange. Looked liked red ELC mixed with orange dexcool and left a thin layer of sludge.