1964 365 hsp oil pan/timing cover leak

[John R.]

I have read several of the posts regarding 1 piece pan gaskets and the 2 types of pan/gaskets. So was looking for some guidance.

As a starting point, I do not know the maintenance history of the car I am working on. It clearly has had a historical oil leak issue as it already has a blue 1 piece oil pan gasket installed AND has brand new shiny bolts holding the timing cover AND is still leaking! Leak where the pan lip meets the timing cover at the front of the motor.

So, the first thing was to drop the pan to see which type of pan was installed. It is the production/stock type with the rectangular, spot welded, threaded plate for the oil plug, and the front is 2 1/4 depth. I expected to see the service pan with the 2 3/8 front depth and that would mean I need to install a new gasket. Since I had the 2 1/4, I just reinstalled, but still leaks.

I have included some pictures and would like some advice on the next course of action. Could it be possible that the 2 3/8 gasket is currently installed with the 2 1/4 pan? That does not make much sense to me, but..?

[Joe L.]

Re: 1964 365 hsp oil pan/timing cover leak

I have read several of the posts regarding 1 piece pan gaskets and the 2 types of pan/gaskets. So was looking for some guidance.

As a starting point, I do not know the maintenance history of the car I am working on. It clearly has had a historical oil leak issue as it already has a blue 1 piece oil pan gasket installed AND has brand new shiny bolts holding the timing cover AND is still leaking! Leak where the pan lip meets the timing cover at the front of the motor.

So, the first thing was to drop the pan to see which type of pan was installed. It is the production/stock type with the rectangular, spot welded, threaded plate for the oil plug, and the front is 2 1/4 depth. I expected to see the service pan with the 2 3/8 front depth and that would mean I need to install a new gasket. Since I had the 2 1/4, I just reinstalled, but still leaks.

I have included some pictures and would like some advice on the next course of action. Could it be possible that the 2 3/8 gasket is currently installed with the 2 1/4 pan? That does not make much sense to me, but..?

John-------


First of all, are you sure that the leak is coming from the oil pan gasket and not the timing cover gasket, timing cover seal, or, even, the valve cover gaskets?

Second, did you find and/or did you apply RTV at the gasket "corners" (i.e. where the front and rear seal areas meet the side rail areas)? The gasket instructions for the 1 piece gaskets instructs to do this and it is necessary.

Third, I doubt that the installed gasket is for a 2-3/8" radius pan. However, if I were dealing with an oil leak and even though the 1 piece gaskets are technically reusable, I think I'd replace the gasket whether I knew it was correct, or not.

[John R.]

Re: 1964 365 hsp oil pan/timing cover leak

Joe, thanks for the input.

I am not sure if it is coming form the timing cover gasket. How would I determine this? I do not think it is the timing cover seal, since I do not see much oil inside or backside of the balancer. How would one inspect the timing cover seal further? Valve covers are not leaking.

I did not install the current oil pan gasket, but will check the corners out for RTV.

Good advice on not reusing the current oil pan gasket. I am going to check to see if a part number is on the oil pan gasket somewhere or some other identification.

Lastly, the timing cover edges sure seem to be irregular where they meet the block or pan. Just seem to be bent in certain areas. Wondering if that could be a cause of a leak? Photos may show this somewhat.

[Joe L.]

Re: 1964 365 hsp oil pan/timing cover leak

Joe, thanks for the input.

I am not sure if it is coming form the timing cover gasket. How would I determine this? I do not think it is the timing cover seal, since I do not see much oil inside or backside of the balancer. How would one inspect the timing cover seal further? Valve covers are not leaking.

I did not install the current oil pan gasket, but will check the corners out for RTV.

Good advice on not reusing the current oil pan gasket. I am going to check to see if a part number is on the oil pan gasket somewhere or some other identification.

Lastly, the timing cover edges sure seem to be irregular where they meet the block or pan. Just seem to be bent in certain areas. Wondering if that could be a cause of a leak? Photos may show this somewhat.

John-------


Unfortunately, it's often very difficult to discern exactly where an oil leak is emanating from. Fluorescent dye testing with a black lamp is one way that professionals sometimes use but even that is not sure to pin-point a leak.

The main thing that causes a timing cover seal leak is a worn seal surface on the snout of the balancer. You can inspect this if you have the balancer off to further check the timing cover.

As far as the timing cover goes, the gasket is a very thin gasket. This means that the timing cover seal surface has to be near-perfect and/or RTV sealant needs to be applied. In this case, I don't see any sealer "squeeze-out", at all, from the timing cover. So, I suspect that little or no sealer was applied to the gasket surface. This is OK IF the timing cover sealing surface is perfect. A used timing cover is rarely perfect. A used cover can be improved by flattening the area around the bolt holes. Also, I note something troubling on your cover. Note the area around the dowel pin. The cover appears distorted (i.e."pushed up"). In other words, when the cover was installed, the dowel pin did not fit cleanly through the hole in the cover and the cover was "forced on". That could be a source of a problem.

Your gasket appears to be a Fel-Pro. You can inspect it after you have it out for a part number; I don't know if there's one on it, or not. The 2-1/4" gasket is Fel-Pro #OS-34509T or 1802. The 2-3/8" gasket is OS-34510 or 1803. However, another way to tell the gaskets apart is the front seal thickness. The 2-1/4" gasket should be 0.22" thick; the 2-3/8" gasket should be 0.41" thick.

[Mark E.]

Re: 1964 365 hsp oil pan/timing cover leak

John-------

Fluorescent dye testing with a black lamp is one way that professionals sometimes use but even that is not sure to pin-point a leak.

Good advice from Joe. Be open-minded about the location of the leak. With the fan, balancer and air flow blowing stuff everywhere, the leak source and the mess you see can be a distance apart.

One method for finding the source:

1. Clean the engine really well. With the engine's surface comfortably warm to the touch, douse it with Dawn diluted with hot water using a spray bottle. Let it soak for awhile then carefully rinse with water. Repeat as needed until the surface is perfectly clean. A soft bristle brush and paper towels can help loosen the tougher muck. Do this from the valve covers down; you'd be surprised how many leaks seemingly from the oil pan, front cover or seals are really from the valve covers. Avoid engine degreasers; they typically leave a shiny, oily residue that makes finding the oil leak harder. Dawn and water leaves the surface clean and dry with no residue.

2. Add UV dye to the engine oil.

3. Run the engine awhile, then check for leaks using a black light. You can buy an inexpensive UV "flashlight" for this purpose.

An aggressive leak will show almost immediately. Smaller leaks may take minutes to hours of run time to show up. Either way, check regularly; if you wait too long, the oil will blow around making it harder to identify the source.