oil leak

I had my car up on the lift today and was able to inspect everything, theres a slight oil leak right on the bottom of the timing chain cover right behind the harmonic balancer. i was told this is a common area for oil leaks. whats involved in fixing this?

I had my car up on the lift today and was able to inspect everything, theres a slight oil leak right on the bottom of the timing chain cover right behind the harmonic balancer. i was told this is a common area for oil leaks. whats involved in fixing this?

It's probably the front crank seal. The fix for this is usually reconditioning (by sleeving) or replacing the harmonic balancer, and replacing the seal. The reason the balancer has to be reconditioned/replaced, is because the seal will harden over time - and when it does, it will groove the hub on the balancer. The groove will in turn lead to a rapid destruction of the new seal, if it has not been repaired. The repair is a thin sleeve that is placed over the hub, thus providing a new sealing surface.

The reason the balancer has to be reconditioned/replaced, is because the seal will harden over time - and when it does, it will groove the hub on the balancer.

Another reason for this wear is dirt. Remember, this is exposed to all outsode elements and since that is the case dirt can and always does work it's way into the seal. It doesn't get into the engine because of the grooves on the seal push the dirt outward as the crankshaft spins, but it's enough to contribute to the harmonic balancer wear. The sleeving Silicon is talking about is actually fairly simple, but does require a proper harmonic balancer puller (I will emphasize PROPER. I've seen many people ruin a good balancer because they try using a pully puller on the balancer) and some time. For a beginner I'd recommend setting a day aside for it. You must remove all the belts first. Then remove the center bolt along with the three bolts that hold the main pulley to the harmonic balancer. Then using a harmoic balancer puller (Some steering wheel pullers can also work) remove the harmonic balancer. Inspect the area that the seal rides on. If you feel a groove (you probably will) it needs to be sleeved. A kit can be found at any auto parts store that comes with a new seal, sleeve, proper adheisive sealant and directions. Using a flat screw driver from the inside remove the original seal. (The rubber seal is attached to a metal ring that seats in the timing chain cover. The entire thing can be discarded.) NOTE: Be sure to not bend or dent that area of the timing chain cover as it could interfere with proper sealing. Now, technically you should have removed the timing chain cover for this next part, but to save a ton of time it can and has been done while still on the engine. You must evenly tap the new seal into the timing chain cover using a small, preferably balpine hammer to gently and evenly tap it in. If the timing chain cover was off the engine you would set the cover with the back of the seal seat on a piece of wood and use a large socket to match the size of the seal and pound it in evenly that way. With the timing chain cover on the engine, hold the new seal over the hole it seats in on the timing chain cover. Start it in by gently tapping it into the hole with the hammer going from side to side to side to make sure the seal doesn't get cocked. Also be sure not to tap it too hard or force it as this can dent or mis-shape the timing chain cover, causing an even worse leak. Once thats in and your harmonic balancer is sleeved, put it back on. Pound the harmonic balancer back onto the crankshaft a little using only a rawhide hammer or rubber mallet, making sure it's even, then using an impact gun let the center bolt from before do the rest of the work pulling it in. Wipe up any oil, finish putting it back together and run the engine for a bit, take it for a drive and see if it leaks. If it doesn't leak, guess what? You fixed it!

I've done this 3 times on 3 different vehicles... once with the timing chain off the engine and twice with it on the engine. It's really not that bad at all, I just included a bunch of do's and don'ts so sort of "idiot proof" the instructions if thats even possible. You can do it yourself, just don't cut corners. I learned that easy and hard way that cutting corners does nothing but make more work in the long run almost every time.

Thanks for the good instructions Pete. im actually going to school right now for automotive tech so like i said before i have access to a lift now, HUGE shop and all kinds of great and probably right tools for these type of things. i do plan on bringing it in there again because i need to do an alignment there too. ill get back to you as well

Hey Tony,

Of course there's always the "Cat litter on the driveway" free fix.

If it's the COVER, not the CRANK, did you confirm all fastenerrs there are torqued properly? One loose bolt can cause a drip.
How much of a leak - some Gumout and a bit of RTV there can fix the couple-o-day drips.

Hey Tony,

Of course there's always the "Cat litter on the driveway" free fix.

If it's the COVER, not the CRANK, did you confirm all fastenerrs there are torqued properly? One loose bolt can cause a drip.
How much of a leak - some Gumout and a bit of RTV there can fix the couple-o-day drips.

As having 20+ years engine building experience, there's not much to leak there other than the crank seal. The timing cover/oil pan seal isn't likely to leak unless the seals have been disturbed. The only possible exception to this, would be the rubber lip seal at the front of the pan - but I've seen 40-year-old engines where this seal is rock solid and brittle - and not leaking.

now that i think of it, i did take it to this shop when i first got it and they did disturb the timing chain cover so that could be possible. i havent been taking it to that shop for other reasons too