'97 Disco I - Crankshaft Pulley Coming Loose
 

Greetings Everyone,

Brand new to the LR Forums and I became a proud owner of a '97 Disco I in January of this year. Below is a list of repairs I have made, followed by the major issue I'm having...

1) Resealed the oil pan with a formed gasket + RTV Red
2) Replaced the oil pressure switch
3) Resealed the passenger side valve cover gasket
4) Replaced the fuel filter
5) PVC tuneup including new oil separator
6) Switched to Rotella 15/40 Diesel Oil
7) Added 1 quart of LucasOil Engine Seal

Results so far: Oil has still been leaking at the rear of the pan and the inspection cover/bell housing (?), and there has also been a leak at or near the engine front cover. Oil light has been coming on when the vehicle is stopped and/or idling after reaching normal operating temperature, but goes off once the vehicle is underway again.

About a week ago, the idle was fluctuating and dipping to the point where the engine was stalling, although once underway again there wasn't an issue. Thinking it was a fuel or vacuum issue, I reinspected the PCV hoses and oil separator, cleaned the separator tube on the valve cover with carb cleaner, and also inspected and cleaned the idle air control valve (all of this after reading related posts on the LR Forums, thank you). That seemed to "fix" the idling issue, but the oil light has still been coming on as described above.

Other than that, the Disco was running fine until today (except for some loudness from the passenger side of the engine which sounds like an exhaust leak).

Now for the major issue: I was driving to my local Home Depot this afternoon when I noticed the smell of burning oil. After I pulled into the parking lot and stopped the vehicle, I took a look under the front and noticed a fair amount of oil had leaked from the crankshaft where it meets the front seal, and had sprayed back to the oil pan. I ran in and got the items I needed, and came back, popped the hood and checked the oil to make sure it wasn't too low to get it home. The oil level was still full. Then I started the vehicle, and as I was backing out of the parking space, I heard a weird slipping noise from the engine and suddenly my power steering was gone. I drove it back into the parking space and shut the engine down immediately. I popped the hood to see that the serpentine belt had slipped off the crankshaft pulley, and some of the power steering fluid had leaked inside the engine bay. What I also saw was that the pulley has moved forward by about 1.5"... and the front of the pulley is less than 1/4" from the fan (!)... so it clearly wasn't a simple matter of loosening the tensioner and refitting the belt.

Needless to say, I called Roadside Assistance and had the Disco towed back to my driveway where it's sitting now. I'm afraid this might be outside of my technical abilities to diagnose and/or repair? I have posted photos of the area showing the crankshaft and the slipped belt, and I patiently await your expert guidance.

One final note: One thing that's been bothering me about the oil pan resealing I did is whether I may have used too much RTV, and perhaps that may be related to the issue, i.e., sealant in the engine? You'll notice in one of the photos that I used quite a bit of it... "If a little bit's good, a whole lot's better"... a typical shade-tree mechanic's mistake!

Thanks in advance!

The crank pulley has a bolt with dished washer behind it, make sure both are still there. Also check the crank snouts half moon key and the condition of the pulley, check for cracks at pulley's neck.

The rear of the pan is difficult to seal because there isn't much lip but you'll want to be sure it's the oil pan and not the cranks rear seal leaking......

You'll have to drop the pan to check for RTV clogging the oil pump screen which is one problem the other is just baked oil on the screen, check and clean. Did you have a valve cover off? Notice the condition of the valve gear, was oil sludge covering everything? These engines make pudding that over time hardens into carbon and can foul oil porting throughout. The oil light comes on at 8psi and below, your hardly running any pressure to keep things from touching when it's that low, shortens bearing life, wrist pins, rings, cylinder walls.......blah, blah, blah. Get that figured out soon!

Oil leak at front cover is the cover's crank seal. Not hard to remove/replace with engine still in bay, front cover installed. Pulley must be removed obviously which doesn't seem like a problem at this point.

Yep, way too much dope on the oil pan. Use "Right Stuff" from Permatex to make a perfectly sealed oil pan gasket. Works a bazillion times better, any excess doesn't end up in pan.

Thanks for your quick reply. The pulley bolt and washer are still secure and no cracks or damage to the pulley or neck. It's 11pm here so I'll have to check the half moon key in the morning. Once I get the pulley off to replace the crank seal, will I be able to get it back into its proper position and depth? (Again, this is new territory for me.)

The pickup tube and screen were clear when I (overzealously) resealed the pan last month and replaced the oil pressure switch... which stopped the leak coming from the old switch, but the pressure light issue became worse thereafter. That's what caused me to wonder if there is excess sealant clogging the screen as you've suggested. I'll drop the pan and redo it with the "Right Stuff," however I've also been wondering if the pan is not the only source of the leak. What's the best way to determine if it's the rear crank seal, and if it is, how much of a job is it to replace that? If I add Blue Devil to the new oil and drive the requisite number of miles, will that do the trick? (Just another suggestion I've read in the forums here.)

I did remove the passenger side valve cover when I resealed it (another minor leak stopped), and everything was clean, no sludge or buildup. The previous owner installed a new oil pump and new main and rod bearings and serpentine belt, and the engine runs great except for the oil light and idling issue which was present when he sold it to me. For good measure, I added engine flush to the oil and ran it for about 15 minutes before switching to 15/40 diesel when I resealed the pan and replaced the oil pressure switch.

Thanks again for your quick help!

What he is saying is, your pulley has come out, not your crankshaft. The shaft on your pulley that slides over your crank shaft is what makes contact with the seal. Remove the nut and washer and pull off pulley to make sure the half moon is where it should be, then rent a harmonic balance puller/installer to reinstall the pulley, install the nut and washer and tighten to 59 ft lbs. Chances are your seal is fine, but installing a new one is probably good idea. If you look close on your pic, you can see the slight groove on the pulley that the seal has formed.

http://shop.advanceautoparts.com/p/p...ns_exhaust_eez

Advance Auto and other supply houses will normally rent or lend you this tool. Do not hammer the pulley back in place or use the nut and washer to reinstall.(a lot of people do use the nut and washer, but why take the chance when the right tool for the job is available)

Thanks for your reply. When I looked at the area in detail, I did notice that the seal itself seems to be in good condition with no cracking whatsoever. It makes sense that the damper is coming off the crankshaft, but what would cause that to happen? Just loosening over time? I can borrow a puller/installer kit from AutoZone or O'Reillly here or buy one for as little as $20.00, so that's doable. Of course, per ihscouts I still need to figure out the oil pressure issue and reseal the oil pan... and not be so generous with the goop!

Thanks again!

More than likely whoever put the crank pulley on last forgot to torque it down.

Maybe yes, maybe no. All depends on what they find when they remove the crank pulley. Since the truck is idling poorly what do you think the crank is doing to the pulley.......crack the whip. That will loosen the pulley up and it appears it's not something new, the PO had the same poor idle issue so it's been cracking the whip for some time. I just hope the crank snout isn't bent and keyway is sharp.

Yep, that makes sense as well. I'll know more when I get the pulley off. Heading down to the local AutoZone shortly to borrow the puller/installer kit. It could also be that the PO had the pulley off and didn't torque it correctly per june82000. When I resealed the passenger side valve cover, the rubber gasket was in perfect condition; the PO just hadn't seated it properly and the two rear bolts weren't tightened all the way. I'll post back with my results. Thanks again for all your help, guys! Much appreciated!

Per the Hanes Manual, I need to remove the transmission bell housing cover/inspection plate and jam the flywheel to prevent the crankshaft from turning... Is this correct or can I remove/reinstall the pulley without doing so? (Newbie question, please bear with me!)

I used a strap wrench with a section of old belt wrapped around the pulley and my son torqued the bolt. However you see fit without doing any damage is how to get it done, just need to prevent the crank from rotating.