Front seal leak or oil pan leak

[GMTJunky]

I just changed the oil pan gasket and put a new oil pan on my 97 k1500 5.7. After changing the oil pan and starting the motor a significant amount of oil is leaking from the front area of the oil pan. Its hard to see if it is leaking from the pan or above/in front of the pan and it only seems to leak while the engine is running. There was oil leaking in this area before changing the oil pan as well. In the process of changing the oil pan I removed the motor mounts and jacked the engine up by placing a 2x6 under the harmonic balancer and using a floor jack to lift the engine enough to get the old oil pan out.

Everything is back together now, so before taking it apart to check the gasket and surface again on the front of the pan I have a few questions becasue Im suspicious that the front seal is leaking and not the pan. Also, that process was a pain in the ass being that the differential is in the way!

Would lifting the motor by the harmonizer like described above damage the crankshaft seal further making it leak more? If it is the oil pan gasket that is leaking at the front of the engine, would it also leak while the engine is not running as the oil appears to only leak while running and it is pouring out?

(I cleaned the surface with a plastic gasket razor and brake cleaner thoroughly before placing the gasket and put permatex in the 4 corners. I tried tightening the bolts more in sequence and it didnt change the behavior of the leak)

 

[HotWheelsBurban]

Did you replace the timing cover? The Vortec engine has a plastic one that is prone to warpage; GM recommends replacement when it's removed ( usually during timing service).
I had to do timing service,water pump and oil pan gasket on my other 99 Burb, and there's not much room on a C1500. What I had to do was pull the motor mount bolts out and raise the engine on the crankshaft snout, with a bottle jack and a block of wood with a curved notch. I worked slowly and carefully, not wanting to damage anything, and the engine only needed to be raised a couple inches for the windage tray in the pan and the baffles on the main caps to not get tangled up in each other. Of course I had the cover and the seal off, since I was changing the timing gears and chain.
It all started out as an oil change and replacing the belt tensioner, and then I saw the orange drips. Truck had around 175-180K on it so it was due.... Just a pita when you thought it was a one afternoon project and it took 3 weeks!

 

[GMTJunky]

Did you replace the timing cover? The Vortec engine has a plastic one that is prone to warpage; GM recommends replacement when it's removed ( usually during timing service).
I had to do timing service,water pump and oil pan gasket on my other 99 Burb, and there's not much room on a C1500. What I had to do was pull the motor mount bolts out and raise the engine on the crankshaft snout, with a bottle jack and a block of wood with a curved notch. I worked slowly and carefully, not wanting to damage anything, and the engine only needed to be raised a couple inches for the windage tray in the pan and the baffles on the main caps to not get tangled up in each other. Of course I had the cover and the seal off, since I was changing the timing gears and chain.
It all started out as an oil change and replacing the belt tensioner, and then I saw the orange drips. Truck had around 175-180K on it so it was due.... Just a pita when you thought it was a one afternoon project and it took 3 weeks!

I didn't get into the timing cover, but that would make sense. I do think it is coming from that area or maybe I damaged the timing cover seal when I was cleaning the surfaces for the oil pan gasket. It makes me more suspicious that the leak is in the timing cover area because of how fast the oil flows out when the vehicle is running, I assume the chain is pushing it out. Feels like I've really opened a can of worms here and this project is going to take longer than expected!

I was reading online that an aluminum replacement cover is recommended so it doesn't warp...

 

[Darkimag22]

I just went through this with my 98 5.7 vortec. Bought it with 417,000km on the clock this summer and when I did my first oil change I had oil leaking from just about everywhere. The timing change cover was where most of the oil was coming from after tearing everything apart. Ended up replacing every seal/gasket from top to bottom: oil pan gasket, head gaskets, intake gaskets, exhaust gaskets (plus had to buy new manifolds since the originals where on their last legs and had numerous broken studs), new timing chain set and cover (original chain was stretched and worn out), new distributor since the original owner thought it a good idea to keep it in place with a couple zip ties. It is a bit of a can of worms but while you are in that far, might as well do it right.

 

[GMTJunky]

Mine has 250k, so I'm sure ripping into the timing chain and replacing it and the cover is probably a good idea. Just trying to gauge if I'm headed in the right direction with fixing the current leak.

I just went through this with my 98 5.7 vortec. Bought it with 417,000km on the clock this summer and when I did my first oil change I had oil leaking from just about everywhere. The timing change cover was where most of the oil was coming from after tearing everything apart. Ended up replacing every seal/gasket from top to bottom: oil pan gasket, head gaskets, intake gaskets, exhaust gaskets (plus had to buy new manifolds since the originals where on their last legs and had numerous broken studs), new timing chain set and cover (original chain was stretched and worn out), new distributor since the original owner thought it a good idea to keep it in place with a couple zip ties. It is a bit of a can of worms but while you are in that far, might as well do it right.

Mine has 250k and I just got to a few months ago and trying to get it up to par. I'm sure ripping into the timing chain and replacing it and the cover is probably a good idea. Just trying to gauge if I'm headed in the right direction with fixing the current leak. And from the feedback sounds like I'm about to dive in deeper.

Thanks for the input!

 

[Hipster]

At 228k I pulled my engine, bought a complete gasket set, rear main seal, timing chain set, and was done in a weekend.

Easy to re-gasket the engine with it sitting on a stand, as opposed to spending days on end under, over, and in the truck.

Sometimes the short cut is the long way if it's leaking from every orifice.

 

[GMTJunky]

Words of wisdom.

 

[JeremyNH]

I replaced my timing cover in Spring with the Dorman plastic cover on my 1998 k1500 and after it leaked when running. I bought the Holley Aluminum cover based on reviews that it doesn't leak and used it to fix the leak which it did though in truth I didn't need to use the Holley version I just needed to install the plastic one properly. When I removed the plastic cover I looked at where it could be leaking and noticed that the rubber inlaid gasket doesn't extend all the way to the cover bottom. It stops about 1/16" before it does and I only applied the RTV to the bottom lip of the cover. What looked to be happening is that with the engine running the oil flicked off the timing gears hit the gasket seal and from there dripped down on the way back to the pan but had another place to go where the gap was. Most of the oil would have gone back to the pan but enough made it through to cause a drop every 5-10 sec. Point is when you apply the RTV to the cover bottom lip bring just a little bead of it up to make contact with the rubber gasket so that it's sealed everywhere, let it set for the required hour or so, then torque the cover down. I did this with the Holley cover and no leak. If I had to guess what your problem is it would be that jacking up by the harmonic balancer bent the cover away from the block to break the seal so you have a large gap where mine was just a small one and that's why the oil is gushing out when running. It may not be visible but the cover gasket is going to get hit with pretty much all the oil making it onto the timing chain as it flicks off. If it was the seal itself it shouldn't leak much because the spinning shaft will flick the oil off keeping it in the cover. But you get a new seal with the cover so replacing the cover will fix either problem. Also, use a lot of RTV to seal the cover bottom lip against the pan because the gap is pretty pronounced there so you need a substantial bead. By a lot I mean practically the whole tube.

 

[GoToGuy]

Leaks while running. What's also operating/ running? Oil pump, constant leak around crank snout Harmonic balancer? Seal worn, wear grooves where seal rides. Did you identify where leak is coming from or " kinda looks like the pan gasket"? Who told you to jack the engine by the balancer?

 

[Hipster]

Who told you to jack the engine by the balancer?

That's a no-no in my book but others will argue it's a good idea. An item bonded by rubber that when it lets loose can create a good bit of carnage.