Just finished my first month with my 97 6.5 TD. Truck is running fine, however noticed a couple oil drops in the snow after it sits over night. These drops are very close to the front of the truck. I have read several threads where a problem of leaks around the oil cooler and lines have been mentioned in passing. It's going to go above freezing here later in the week, I thought I'd run it up on the ramps I have and crawl under and have a look. Could someone comment on where to look and where the leaks usually occur? Is it usually a fitting problem, or do the oil lines rust out? Thanks.

If it's in the front it's either the fittings leaking or the oil cooler lines where they go rubber.

Most likely the lines.. They're one of the only problems i've had with my 6.5, both oil cooler lines had to be replaced as they start to weep where the metal is crimped to the rubber.

Me seems to have sprouted a couple of leaks myself, i haven't tracked them down completely but they appear to be coming from the valve covers, tuna can seal on valve cover, oil return line from turbo. Valve covers can stay the way they are, to much of a PITA with the injection lines sitting on em. Maybe my constant 10-15 psi has helped produce these leaks?

Maybe not. I'm not sure GM even put a gasket in there during production and the fel-pro cork doesn't last.

CR,
it's alot easier taking the 4 lines off the injectors and gently raising them out of the way if you remove the stays on the intake manifold before hand.

I didn't think they'd move enough without bending them too severely, so are there gaskets under there or not?
Oil leaks always look worse than they are, i change my oil around every 5000 km's which is about every 25 days, even with the truck runing about 8 hrs/day during that time i'm still only using 2 ltrs/qts per change.

The fittings at the cooler where the aluminum crimps to the hose weep and have been known to fail, that can be repaired by using a Dremel tool or other device ie hacksaw CAREFULLY cut away the crimp sleeve and using quality hose clamps to secure the hose to the tube, use 2 one in front of the other and wire together so if one tries to move the other will restrict the movement.

IMO though this is a stopgap measure, another problem with the 6.5 cooler lines is the "in block" adapter fittings/quick disconnects are held in place with a spring clip wire, if that fitting fails as has done in the past on some; then oil pressure goes away fast, and does some UGLY things to your engines innards.

Look around several vendors here sell replacement kits IIRC Kennedy does, maybe Heath, Lubespecialist does for sure http://www.dieselplace.com/forum/showthread.php?t=22065, that is where I bought mine, you can make your own but IIRC the block is metric threads, rather than doing the trial & error and wanted to "just be done with it" bought a ready made kit.

The original valve cover gasket is silicone sealant. I use Permatex "Ultra Copper". If you do a good job of cleaning off the residue and oil, this will seal well. The trick is to be sure it's clean. Use "Brake Clean" type stuff for the final wipedown.

Be sure to use a small screwdriver, an awl, or an o-ring pick tool to remove any sealer in the bottom of the bolt hole (threaded bosses) of the cyl. head. Blow out the holes with compressed air after scraping the sealer to break the bond. There is usually a "plug" of old sealant that pops out of each hole. Failure to remove the old sealer causes the bolts to "bottom out" in the holes and can result in broken bolts.

Put a bead of sealer (1/8" thick) all the way around the cover in one, continuous bead. (No "breaks" or open spots) I even put a small bead around each bolt hole in the cover. Install it while the sealer is still wet. Some say to allow it to "skin over", but I've had better luck applying it wet.

It's not a bad job. The worst part is, as you said, the injector lines. Good Luck.

Oil lines are rubber & aluminum



Just finished my first month with my 97 6.5 TD. Truck is running fine, however noticed a couple oil drops in the snow after it sits over night. These drops are very close to the front of the truck. I have read several threads where a problem of leaks around the oil cooler and lines have been mentioned in passing. It's going to go above freezing here later in the week, I thought I'd run it up on the ramps I have and crawl under and have a look. Could someone comment on where to look and where the leaks usually occur? Is it usually a fitting problem, or do the oil lines rust out? Thanks.

Thanks for the replies. Had a quick look after work today and it looks like a line is weeping there it is crimped on as Turbine Doc described. I'll get my dremel out later in the week and apply the two hose clamps as suggested. I'll also look into some of the products suggested for a more permenant fix. Thanks again.