halogen25
1985 F250 6.9l
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.
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.