illinoisboy
Full Access Member
hey guys, i bought a 94 turbo idi. it has a weak cylinder and oil or soot in the antifreeze. any thoughts. i think i want to put a new engine in it but wanted to explore other options first. thanks!
OIL OR SOOT IN COOLANT
- Thread starter illinoisboy
- Start date
icanfixall
Official GMM hand model
How do you know you have a "weak cylinder"? That reason will tell you what you need to do before you start throwing money at it.
illinoisboy
Full Access Member
when it turns over you can hear a weak cylinder in the cycle. also a mechanic tested it and said one cylinder didnt have much compression. thanks.
Diesel JD
Full Access Member
I'm supposing he did a compression test then? FWIW, compression specs are 195-440 but in reality we see anything in the 350-550 range on a healthy motor. What you really are hoping for is all cylinders above 350 and the the lowest reading to be within 25% of the highest. A "weak cylinder" might well mean low compression which could come from rings, a blown headgasket or a valve problem. Black stuff in the oil could be a headgasket blown internally(not extremely common), cavitation pinholes in the block(fairly common on 7.3), or oil cooler o-rings(common on 7.3s). If you have cavitation or a really worn out motor a longblock might be your best option. Other members have used Dealer's Diesel, Promar, and Diesel Auto Services. Good luck,
JD
JD
There's a good chance the oil is just the oil cooler orings.
As far as a weak cylinder, on any old diesel you stand a very good chance of having stuck rings from sludge/carbon buildup. Before condemning anything, try running a couple of treatments of Auto RX and see if you can loosen things up a bit. It's not snake oil, I've revived a number of old diesels with that stuff and seen compression numbers go up as much as 200 psi in holes with sticky rings. The stuff aint cheap, but it's a heck of a lot cheaper than a rebuild, and the worst thing that it will do is leave you with a nice clean engine inside , so if you do still have to tear into it, you won't have as big a chore cleaning parts
-----Robert
As far as a weak cylinder, on any old diesel you stand a very good chance of having stuck rings from sludge/carbon buildup. Before condemning anything, try running a couple of treatments of Auto RX and see if you can loosen things up a bit. It's not snake oil, I've revived a number of old diesels with that stuff and seen compression numbers go up as much as 200 psi in holes with sticky rings. The stuff aint cheap, but it's a heck of a lot cheaper than a rebuild, and the worst thing that it will do is leave you with a nice clean engine inside , so if you do still have to tear into it, you won't have as big a chore cleaning parts
-----Robert
illinoisboy
Full Access Member
thanks for all the feedback guys.
