Hello All,

Vehicle: 2000 Excursion w/ 163k miles.

Recently flushed coolant because the previous owner had spotty maintenance records and there was some sediment in the overflow tank.

Coolant looked decent when I flushed it. I warmed the vehicle up and maxed front and rear HVAC before I flushed it. (Did this 3 times with distilled water before filling with the proper mix of Zerex G-05).

Installed a new overflow tank after flushing. Topped off the coolant to the line on the tank the next day and thought there were no issues.

Noticed a few days later (Ex isn't my daily) that the level was quite low. Drove to the store and came back and found the level had risen to be in spec. However, the coolant looks to have some oil in it. And the reservoir is already creating some new "lines" on it where the level settles and shows up (kind of difficult to explain, please see image below of my old coolant reservoir).




I have changed the oil twice in my ownership (3k mile intervals) and not noticed anything but oil in the changes. Tried to do some googling and searching on these forums and am thinking the culprit could be the oil cooler. Closest thread I found on these forums was here: https://www.ford-trucks.com/forums/1...-oil-leak.html.

I should probably note that I do burn a bit of oil (quart every 1.5k or so). Never really thought too much about it since the truck runs so well.

Recently changed all 10 plugs and boots and 3 of the COP's and aside from this concerning coolant issue, the truck runs phenomenally.

Any ideas?

Thanks,
-Russell

 

Finding some more good information, but this thread wasn't updated to say if it was actually fixed.

https://www.ford-trucks.com/forums/3...container.html

At this point I'm thinking of just replacing the oil cooler and seeing if that works for me. If it was the headgasket, wouldn't I find coolant in my oil? Plus, oil cooler would be cheaper and easier to replace as first possibility, anyways. Just thinking out loud here.



*Edit*

Found a recall for the V10, but it does not state the Excursion was included, which doesn't make sense, because I believe the oil cooler is the exact same on the Excursion's V10 as the other programs listed...

 

Nice find on the recall, I gotta remember that one.

But yeah, it sounds like your cooler, or just the gasket(!) is bad.

Oil pressure is higher than coolant pressure, and oil goes to coolant, but not vice-versa.

 

Here is the full Field Service Action PDF.

http://ww2.justanswer.com/uploads/he...oil_cooler.pdf

My oil cooler does not fall into the date range of affected parts:




That being said, I still think either my oil cooler or oil cooler gasket is bad. Does anyone know if this part comes with the gasket as well:

Oil Cooler Assembly for 2000 Ford Excursion|4C3Z-6A642-A : AutoNation Ford White Bear Lake | Parts & Accessories


Also, from a few threads I've found, it seems people have said they need to unbolt the engine mount to service the oil cooler. I poked around under my truck yesterday and that doesn't seem to be the case. Furthermore, the field service action doesn't seem to show that step, either. Anyone have experience swapping one of these on an Excursion?

Thanks,
-Russell

 

Just talking out loud here because there is some misinformation floating around and people calling different parts the incorrect names.

My issue is oil getting into the coolant. From my research, this leads me to believe the oil cooler itself is bad. Some threads on here state that there is an "oil cooler issue" or "oil cooler gasket issue" and I wanted to point a few things out if anyone comes across this thread:

1. The oil cooler itself is what the two coolants lines run to and is the piece that your filter threads onto. Removal of this item requires a 14 mm hex inside of the oil cooler itself (part 6A642 below). It does not appear to necessitate the removal or loosening of the engine mount.

2. The "oil cooler gasket" is actually a gasket (part 6840 below) that mates a part (not sure what it is called... part 6881 below) that receives the oil from the oil cooler to the engine itself. This gasket replacement does seem to require the engine mount being loosened/removed.





Since my issue is oil contaminating my coolant, I believe my oil cooler itself is bad. This gasket wouldn't cause issues other than a leak. I will move forward with installing a new oil cooler and re-flushing my coolant system (again... 100 dollars literally dumped out of the engine).

Like I said, just talking out loud here for anyone who may google or search some of these key words.

 

Most likely small leak in oil cooler

 

OEM cooler arrived. Also grabbed a new OEM thermostat since I was already paying shipping and am flushing the coolant again (didn't replace the t-stat last time).

Cooler, engine side:



Cooler, engine side, w/ center bolt:



Cooler, filter side:



Cooler, filter side, w/ center bolt:



P/N for those curious:




Replacing this weekend and flushing coolant as well.

 

Oil cooler replaced. Put the old one in a sink and ran clean water through one coolant pipe and it exited dirtier than it entered. This leads me to believe it did have a leak (didn't actually hook it up to a pressure tester).

It was a bit of a bitch to ensure it was clocked properly upon re installation. For anyone attempting this, I recommend placing the new cooler on (without threading the bolt through) a few times before hooking the coolant lines up and torquing it down. The oil passageway on the cooler is relatively small and needs to mate/clock properly to the engine for proper flow.

Drained and flushed the coolant. Went to fill it up with coolant and accidentally snapped the radiator petcock... and it was late and local stores were closed. Next morning advance auto claimed they didn't have any, and neither did my Ford dealership. Eventually found a local auto parts store who had a perfect fit aftermarket part on the shelf. Threw it on and I was good to go.

I am noticing a bit of oil at the top of my overflow tank. I believe this is because the lines are still going to have a bit of oil coating them. Does anyone have any recommendations on how to really flush/clean the system? Maybe dishwasher low suds mix run through a bunch of times?

I'm going to drive it as is for a while and try to take a turkey baster to the top of my overflow tank for now to try and skim some oil out.

 

You need to thoroughly wash the system to remove the oil film. The oil will eat the hoses over time. Trust me on this one. I just had a top radiator hose blow on our 2003 Church Bus (23 passenger E-450, 6.8L V10 Motor is actually 2001) because of a leaking oil cooler.
I used Cascade dishwasher detergent and normal tap water up to operating temperature, with the heater turned up to clear the heater. Run it up to 3k to really circulate the fluid. Drain and repeat 2 times. Rinse with clear water 3 times .
Fill with antifreeze mixed with distilled water for final fill.

 

Interesting. I wouldn't think that a film of motor oil would be that detrimental than the rubber that Ford uses for the coolant system.

 

Oil will ruin most coolant hoses, they're just not designed for it.

You already bought a cooler, but for the next guy reading this and wondering if his cooler is bad: Get a hose barb fitting the right size, remove the hoses from the cooler and connect them to each other bypassing the cooler. Run the engine and see if oil starts coming out where the hoses were connected. No worries about overheating the oil without the cooler as long as you're not hauling heavy during your test time. Not testing the cooler will leave you wondering for some time since residue will remain in the system and keep coming up for a while if you don't find a way to completely clean it out.

If you still have your old cooler you could test it to know, just gotta figure out a way to connect and pressurize it.

As far as indexing/clocking the cooler, probably not needed. The couple I've done on different motors were similar in design and the area between the cooler and mounting surface have a large gap much like between the filter and cooler so alignment isn't at all critical. The oil will fill that entire space and flow where it needs to go even if the ports are 180 degrees apart.

I had a Jaguar S-type R for a short while, fun car BTW. The trans cooler in the radiator had gone bad on the previous owner, fairly common on that car. The trans and radiator were replaced, the system was flushed, and some hoses were replaced, but traces of oil continued to surface in the reservoir. A few days into my ownership one of the coolant hoses failed, the fun one that's under the friggin supercharger. Altho it's a common failure hose, the car only had 50k so it shouldn't have failed, pretty sure it was the ATF that cut its life short. They were afraid of its power and drove like grannies, I used all the power it had and that extra heat & pressure is probably what finished it off so quickly into me having it. After replacing that hose and a few others and flushing the crap out of it, no more oil in the reservoir.

 

Understood.

It is just frustrating to have to flush the system once more, considering I have already flushed it twice with OEM coolant, which isn't cheap. I wish I would have done the dishwasher detergent cleaning method the last time... 20/20 hindsight.

If I have come this far, I may as well do it right, though.

 

One question did changing the cooler fix the mixing of Oil and Antifreeze? Thanks John

 

 

How much did it help with oil consumption if at all?