Coolant in Oil

[halogen25]

After several weeks of lurking here and thedieselstop, it is time to ask for some advice.

I purchased an '85 6.9L several months ago that looked outstanding. Less than 100k miles, no visible leaks, and everything functional. After a few weeks I noticed that it was losing coolant, about 1 quart a week (200 miles or so). I sent an oil sample off to Blackstone when I changed the oil. Their tests confirmed my fears, at 2.5% coolant and high copper and lead levels in the oil. From advice on this site, I attempted a coolant pressure test, but saw no leaks when cold, and no pressure spikes within a few minutes of running.

So I am guessing that it is a head gasket leak that occurs after the engine is hot. That is probably not a surprise from this motor at this age. Are there any other tests I should do before concluding this, or should just I start planning to pull the heads? I also assume that I shouldn't be driving it much until this gets resolved.

I've read Warden's excellent page on head gasket replacement, as well as Mel Agne's page. Thanks you guys for providing such detailed and helpful advice. A job that big still scares the hell out of me, but I didn't buy this truck thinking it would be a cake walk. I am hoping that I can find someone in the San Diego area who would be willing to advise me when I reseat the heads.

Finally, assuming that I'll be doing this job, what else should I go ahead and replace while I have the engine apart? I am already assuming the thermostat, water pump, and injector return lines.

 

[Fordman75]

I'm a diesel newbie but my guess would be head gasket or possibly the oil cooler?

 

[international]

do the oil cooler first, it's easier than heads.

 

[halogen25]

Hi Folks. Now 4 months later, I have bad news to report and a request for suggestions.

I solicited the help of a friend who is a mechanic, and together we replaced the head gaskets and oil cooler o-rings. We used ARP head studs also added many new parts (thermostat, water pump, hoses, added a coolant filter, etc). Took the heads to be magnafluxed, and they checked out fine. Everything was done right (or at least following the advice from this site.)

Unfortunately, however, the problem still persists. Right after the job, I took a 300 mile trip with the truck over Thanksgiving and ended up adding about 1-2 gallons to the radiator every 100 miles. (I changed the oil before the return trip!)

So I am at a loss about what to do. There is not white smoke coming out the tail pipe, so it seems that the water is getting into the oil only, and it seems to be a slow leak that happens only after the engine is hot. It could be as simple as a leaky oil cooler (I did not get it tested) or as disturbing as a cracked block. I don't have much more cash to throw at this thing...
http://www.oilburners.net/forums/images/smilies/cussing.gif

Any suggestions?

 

[mabc926]

EDIT: Wow this is an old thread, guess I should have read all the post


Anyways first thing you should do is pressure test all the cylinders, that will tell you what is going on, either it be a cracked head, or pin holes in the cylinder walls.

 

[Diesel Max]

Can't help but wonder if its cativation.................

 

[Fordman75]

I thought that was only an issue on the 7.3L's?

 

[GOOSE]

;pMy problem was relatively easy to find once I lifted the head off. I'm guessing you inspected the bores thoroughly.

http://www.oilburners.net/forums/showthread.php?t=39283

 

[typ4]

Very unlikely cavitation, get the oil cooler tested or make the plate to do it yourself, it also could be the water pump plate seal to block. I dont remember if the intake gasket seals out water , some heads have plugs some use the gasket, these checks cost much money, if you get in a real jam one of my best friends lives down there and may be able to lend a diagnostic hand. DONT be afraid to ask.

 

[yARIC008]

I thought that was only an issue on the 7.3L's?

Nah, can happen on 6.9s. It can actually happen on any high compression engine, even gassers.

 

[halogen25]

Problem solved!

Hi Folks,

Now almost a year later, the problem of lost coolant has finally been solved.

I had been driving the truck intermittently and checking the coolant level carefully when I did. Nothing happened for months. Then one day I took it on the highway for a 45 minute trip, and I decided to push it a little by driving at 80 mph. Suddenly the temperature started rising quickly, so I pulled over. Just as I got to the side, the truck stalled and steam billowed out from under the hood.

The passenger side freeze plug had corroded through. Apparently it had been leaking slowly for months (years?) whenever long trips were made, spraying coolant on the exhaust manifold such that it was never noticed. $20 later, and the problem was fixed. Apparently the previous owner noticed coolant loss and put Radiator Stop Leak in the coolant, which pretty much ruined the radiator. So add $400 to the cost to fix it.

A final note. Given that this was all found because of coolant in the oil in a Blackstone oil analysis, I can only conclude that my head gasket / head bolt replacement was justified. So in the end all the right things were done. I've only really lost some hair in the process.

Thankfully it wasn't a cracked block or cavitation, and hopefully the overheating won't cause any additional problems. I'll be sure to use SCA's in the future, and I've already installed a coolant filter.

Thanks for all the advice along the way.

-Mike

 

[papastruck]

Thanks for posting back. I noticed a tiny drop of anti-freeze on a line while crawling around underneath the truck a while back, but as I'm not losing any coolant I didn't worry too much. I've got a coast to coast move this summer, so I'll make sure to check more thoroughly for weepage down there.

 

[icanfixall]

Sometimes its the overlooked easy things that is the fix... But all the parts and upgrades are a better thing. Glad your running well now... enjoy the ride.

 

[Clayton]

So did you ever figure out how the oil got contaminated with Anti-Freeze?

 

[halogen25]

Yes, I think this really was a bad head gasket and/or head bolts. There was tons of watery snot up in the valve covers (worse on one side), indicative of the leak. The heads checked out fine under magnaflux.

So really I had two problems (head gasket/bolts and corroded freeze plug), and luckily both got fixed.