'03 4.6 Coolant in oil

[2000StreetRod]

lower pressure?

If the gasket for the oil filter/thermostat housing casting is bad or if the casting is cracked flow should be in the direction of least pressure. Normally, I think the oil pressure exceeds the radiator pressure. In that case there would be oil in the coolant instead of coolant in the oil. What is your oil pressure vs your radiator pressure? You might try a low pressure radiator cap to see if that makes a difference. If your oil pressure exceeds your radiator pressure then I suspect your coolant leak is where the oil is not pressurized.

 

[wesalexleft]

Oil cooler/filter adapter

Too funny, that's me you quoted. Anyway, I did replace that gasket. All looked fine. That's also a good recommendation about the low pressure cap. I loosened mine, and drove it for a few weeks, but still lost coolant at the same rate. I've been driving long and short distances and coolant loss seems the same. I suspect I'm losing it at warm up or cool down only, but at temp, I don't think I'm losing much coolant. I'm really just looking for some test or sign that would point to either head gasket or block, but not the other, and avoid the tear down to find out.

 

[eeprete]

Not sure if anyone has found the issue(s) associated with this problem. I've had a similar issue for years. First at 69K miles approximately 5 years ago. Wound up rebuilding the whole top end while foolishly keeping the original intake. About six months ago I overfilled the canister, which revealed one of my leak sources, at the passenger side of the intake where the plastic meets the aluminum runner. I've also read a failed o ring inside the oil cooler assembly can also cause this. I'm actually considering bypassing the oil cooler to test. Same here no oil in coolant.

 

[wesalexleft]

I've seen your posts also, and followed them closely. I've replaced both the intake manifold gaskets as well as the oil adapter gasket. At least on my 03 4.6, there is no way to bypass the oil cooler, but it's not a bad job, or expensive. It didn't fix mine though. Eeprete, are you still driving with the coolant leak, I've decided to run mine until it fails and then do a motor swap. No shop can say if it's heads or block, or even find the leak. It's too small to show up on tests. I'm still losing about a pint a month at daily driving.

 

[Joe in NY]

Well it could be one of those pinholes that the oil is too thick to travel through while the water isn't. Also, side note, the cooling system is still under pressure for a long time after you shut the engine off. It's only pressurized while running. It holds pressure till it cools off.

 

[eeprete]

Wesalexleft, recently I've noticed an increased use. Previously thought it was isolated to the intake but now with the increase I wonder if the oil filter adapter gasket is leaking too. If this and the intake are taken care of and its still using coolant it must be the block.

 

[eeprete]

Very good point Joe in NY

 

[wesalexleft]

I have decided that it's either the beginnings of a failing head gasket, or a cracked block. If it were head gaskets, I would have them replaced, but I haven't been able to confirm gaskets or heads. My problem is I don't want to spend 3K on gaskets, then still have the problem because it's the block. There are a few people here that have discovered block problems. I've done every inexpensive repair to try and stop the leak, so only bad scenarios are left. I'm going to shorten oil change intervals, and drive it to failure, then look into a motor swap. Hate it, but it has very little trade value, and I'm not passing it to another (bad karma).

 

[Joe in NY]

For $3,000 you could buy a Jasper Reman motor... Much more cost effective vs spending $3k on head gaskets...

 

[wesalexleft]

That's my thinking. I haven't looked at all options, and a motor swap is above my shop, but 6k gives me a jasper installed with warranty. So, I think I'll just going to drive it till it quits, then swap.

 

[eeprete]

Maybe I shouldn't have read this thread.... I tackled the intake today and while that went well, I then started the car and I now have a rod knock..... Bad.

 

[kalotis]

Hi everyone, I also seem to have coolant leaking into the oil of my 2003 Explorer V8 with 90,000 miles. I have read a lot of posts on this where folks have done some extensive repairs and still have not solved it.

I wondered why no one seems to mention using a sealer in the coolant? Wouldn't that be worth a try if you expect your engine might be eventually gone anyway due a cracked block or head gasket problem? Thanks.

 

[eeprete]

From the factory they do use a bars leak type solution to prevent the minuscule leaks. Have you pressure tested the system? Is there leak down? Also check your oil cooler adapter gasket.

 

[kalotis]

Thanks for responding eeprete. The car has been using coolant for 3-4 years but only began using a lot in the past year. I have to add around 14 ounces per week so it is using a lot. I had two garages perform pressure tests and chemical tests of the coolant and they found no problems. One wanted me to leave it overnight to see if it held pressure overnight but I didn't leave it.

The last time they changed the oil however they said they saw water come out first when they pulled the drain plug. I also see different darknesses of fluid on the dipstick if I check it when it is cold, it is darker on one side and lighter on the other and darker down toward the tip. Strangely the oil level never seems to vary much, it never goes up, it does go down a little over time.

I guess I might try some sealer now. Thanks again.

 

[eeprete]

If you have been using coolant I'd first suspect the intake is bad. Took me four years to find where mine was leaking. Do a compression check of the cylinders. The pressure test the cooling system. If both check out ok change the intake.

 

[Number4]

Resurrecting this thread due to all the info.

I have an ‘03 as well, which seems to be a common factor.

I did all (all) gaskets on the engine and replaced the intake. Engine runs great other than coolant in oil.

Engine had overheated and blew headgaskets when I bought it. So cracked block has always been on my mind. But I thought the computer was programmed to shut off the engine before catastrophic temps were reached.

Why are these all ‘03’s?
Anyone have this issue with an ‘02, ‘04 or ‘05?
This is baffling.

Also, don’t run engine with coolant in oil. Will majorly gum up your engine.

First pic shows what happens to your engine.

http://www.explorerforum.com/forums/index.php?threads/how-would-you-clean-this.456742

 

[boominXplorer]

Before you go looking for another motor I'd take the valve covers and timing cover off and do a pressure test. I've seen 2x coolant in the oil because of an internal freeze plug leaking. Both times were on the 4.0 v6 but BOTH were 2003 models.

 

[Number4]

Before you go looking for another motor I'd take the valve covers and timing cover off and do a pressure test. I've seen 2x coolant in the oil because of an internal freeze plug leaking. Both times were on the 4.0 v6 but BOTH were 2003 models.

Someone had mentioned a plug under the timing cover. I honestly don’t remember looking at it.

 

[boominXplorer]

Someone had mentioned a plug under the timing cover. I honestly don’t remember looking at it.

There's at least big one on each head in the front. I can't think of any more in the timing area.

 

[Supercharged281]

Hey, just wanted to say I've had the exact same problem with this before. Mine always turned out being the oil filter adapter gasket.

I've owned a few 4.6s and all have had that problem.

This guy is right. I'm on my second 4.6 and at 155,000 the first oil adapter failed internally. And now on different engine at 230,000. No oil in the coolant, outer seeping, cracks none of that. Just a sweet weird smell from the tail pipe was my indicator.