Oil in my coolant 99 EXP 4.0 OHV 4wd

[Jaimec]

I've only had this truck for about 6 weeks, and have noticed oil in my radiator coolant reservoir The oil on the dip stick looks good, so it looks like there's no water there. I'm not losing coolant, and there is no tell-tale white/blue smoke (no smoke at all, actually), and the motor runs great. Mileage is normal, and power is great.

I'm assuming that it's a head gasket, and I will run a compression test on all cylinders. I've read that the original heads were notorious for cracking, but the lack of white smoke, and the fact that the oil is clean and I'm not losing coolant lead me to think it's just gasket related.

Any thoughts? Any other possibilities?

If it is gasket related, and I'd need to have the heads resurfaced, would it not be wise to simply go with new heads? I found them (new castings, not rebuilt) from National Heads for $204.00 each add in shipping and gaskets, etc., and it's roughly $550.00. Are these less likely to crack/cause problems than the original? Vehicle has 145,000 miles, incidentally.

Thanks!

Jaime

 

[deweyville65]

Have you checked the transmission fluid level? I am assuming you have an automatic transmission.

 

[Jaimec]

The tranny fluid looks fine, no foam. The level seems fine (a bit high, actually), but the trucks hot right now, so I'll check it after I get home from work tomorrow. In fact, neither the oil nor tranny fluid seems to have changed since I bought the truck two months/1200 miles ago, but there is definitely *something* in my coolant, and it's making me nervous....

Any help would be greatly appreciated!


Jaime

 

[Runnin'OnEmpty]

Does the coolant reservoir have a gasoline odor?
I believe you have either a blown head gasket or
a cracked head. No way to tell which it is until you
tear it down. I'd pull the plugs and see if one looks
different than the others; that'll confirm the specific
cylinder and make the problem easier to spot.

 

[deweyville65]

Very well could be previous owner added stop leak into the coolant. Some like Bars Leaks have an oil base. You can try draining the system and using a cleaner (Dawn is a good cleaner) to rid the system of oil residue.

 

[IAmTodd]

Retorque the lower intake manifold. Although if that were the issue I'd almost expect the coolant to be in the oil. Worth a shot and it's free.

 

[jremington59]

I have seen coolant that was so old that it looked like it had oil in it and it was discolored. If I'm not mistaken it has some type of oil in it to keep things from rusting. If it were me I'd flush the system and add new and see what it looks like.

 

[svt4cam]

Another poster kind of touched on this but bear in mind there is an antifreeze cooled trans cooler on your Explorer so there may be some co-mingling going on if something has gone bad there.

 

[Hurbold]

About two weeks ago, I found oil in my coolant reservoir and radiator in my 2000 Explorer Sport OHV with 132k miles. Like you, I also had clean oil. In my case, this was immediately after a long road trip at the end of which the engine ran very poorly. Based on some research, I decided to pull it apart and noticed both heads were cracked in the usual places.

Using a few threads on the forum and my Haynes manual, I replaced the heads, thermostat, water pump, plugs and upper engine gaskets.

I bought the heads off of J&C Enterprises on eBay. New heads, with free shipping and return shipping on the cores, for $498. Came with a gasket kit and new bolts. I simply called the guys over there up, gave them my card number and shipping address last Wednesday and had the heads on Monday. The castings were great and obviously better than the factory castings. The gasket kit was fine and had everything I needed. Bought the rest of the stuff on RockAuto, except for a few bolts I picked up at Ace for the exhaust flanges and manifolds (to replace the crappy studs) and the oil filter and oil I bought at Walmart. All told, right at $600.

Took a couple days to get everything back together. It runs like a totally different vehicle. A lot more power, really noticeable with my manual trans. The job wasn't too bad. Believe it or not, in my case, the fan clutch nut was the hardest part. :thumbdwn: If I had it to do again, though, I would have pulled the engine since there's not a lot of room in there and the lower back starts killing after a while. Also, I wasn't really sure what state the lower engine was in, so I made sure to rotate the assembly by hand a bunch to make sure everything was in order and I wasn't wasting my time. If I had more money, I would've have replaced the lifters, rockers, and pushrods, but I was satisfied all of that stuff was in good enough shape to last for a long time to come.

In short, if it is the heads, I hope the above gives you a bit of encouragement. There's plenty of info on the forums to guide you through the process, pics and all. I can certainly answer any questions, too, if you go that route.

Good luck.

ps - special thanks to Dono, Abbondazza, travsbengals, and Betsy98Sport (in no particular order) for info in a couple of the more helpful threads I read for replacement guidance:

http://www.explorerforum.com/forums/showthread.php?t=289847&page=3
http://www.explorerforum.com/forums/showthread.php?t=357323

Bill

 

[Flash]

Do a compression test and a leakdown test. That will tell you for sure if you have any sealing problems in the heads.
Then you can go to a radiator shop and have them test the radiator for the presence of exhaust gas. I believe you can also buy a kit for this at Pep Boys and the like.

It's likely to be a trans fluid leak from the built in cooler in the radiator, in which case you can replace the radiator or bypass the cooler with an accessory external cooler.

It would only take a few drops of oil to show up in the reservoir.

 

[Jaimec]

Thanks, everybody! I feel a bit like a fool, but......it's just dirty coolant!!! To be fair, the truck had been sitting for several months when I bought it, so all of the sediment had settled out. After driving for the last 2 months, it stirred it up pretty good, and the green coolant looked like the Mississippi river I figure I'll pay someone to do a proper flush, then I'll maintain it on a yearly basis.

Like I said, I feel like a fool, but I've been driving air-cooled Volkswagens for the last 15 years, so coolant was never on my radar. Glad it's not the heads, but I have been mentally preparing myself for the inevitable....

Are the after market heads better than stock??? I mean, do they still crack like the originals, or did they get it right for a change???


Thanks again,
Jaime

 

[Hurbold]

Glad you got it worked out.

Like I said in my post, this is a totally different vehicle; so much so, in fact, that I'm glad the heads cracked. It was an experience to replace them but it was entirely worth it in every possible way.

I was too busy to take a pic of the underside of the heads, but it was clear that these were a much better design, with more "meat" between the intake and exhaust valves. I couldn't be happier, all around.

Bill