Oil Leak from Crankshaft Position Sensor Plug - 5.0 GL PWTR

[diceybrew]

I’ve been skimming through the forum and found LiquidC’s post from a few years ago that seems closely related to my issue (https://forums.iboats.com/forum/eng...rives/564064-5-7-oil-leak-at-the-timing-cover)

I’m wondering if I have a similar issue. I’ve installed a remanufactured GM long block (initial engine is a 2000 VP 5.0 GL PWTR). As part of the initial startup, I noticed oil leaking from the front of the engine, dripping from somewhere behind the harmonic balancer. It’s a steady, quick drip.

My old engine did not have a crankshaft position sensor, and while the timing cover had the port for the sensor it had no cap or plug covering it. So I assume that the port was sealed.

The new engine has the same port in the timing cover, but came with a plastic cap covering the port. I didn’t think too much of it and installed the engine without removing the cap to explore what was behind it.

Now I suspect my oil leak is coming from the port. When I tried to remove the cap to better investigate, I found that the brass collar that fits inside the timing cover and receives the bolt that holds the cap (or presumably the sensor) in place, simply spun with the bolt. The bolt won’t loosen or tighten...it just spins in place. I’ve dug around a fair bit trying to find a part number or diagram for this cap, but no joy.

So I’m left with a few questions:
1. Is it possible that the timing cover is designed to be used with both those engines that do have a crankshaft sensor, and with those that don’t? And that this cap is intended to be left in place for applications without the crank sensor? (Seems to align with achris’s comments in the thread I referenced.)

2. Would it make sense that this port is where the leak is coming from?

3. If it is the source of the leak, what could I do to improve the seal between the cap and the timing cover? As the port isn’t going to be used, is there a simple solution to get me through the season? Or is there no other option than pulling the motor and replacing the timing cover, which requires removing the oil pan, etc.?

Very grateful for the generous help of this forum!

 

[diceybrew]

Digging around some more led me to this post: https://forums.iboats.com/forum/eng...ives/326133-volvo-penta-timing-cover-oil-leak

Sounds like I might need to go find a cheap position sensor as Don S suggests.

Still have to solve the problem with the brass insert that is spinning in place...

 

[Fun Times]

Correct that pretty much the best, quickest, most affordable way to plug the hole in the timing cover is to run out to an local, known lowest cost auto parts store in your area and buy a crank shaft sensor that fits say a 1998 5.7L GM truck engine...The HP should be 255-HP if the computer asks you for it.
If that's not an option then you can find them on online, EBay, etc. by doing a quick search using 5.7l GM crankshaft position sensor for pretty reasonable low costs such as this for example, https://www.tomtop.com/p-k6924.html?...76029957284830

In the following link below is a place that you could by a plug for the timing cover where the sensor goes if desired though I'm using it more as a place that will give you a visual of what the sensor or plug would generally look like...You'll have to look at the 3 Associated Items below to see the plugs that are aftermarket from GM https://www.eficonnection.com/home/p...-early-engines

Some places while buying a new marine-engine such as https://www.perfprotech.com/gm-1996-...product/242778 gives you notice type details of what you may have to do to make it all work for your engine model such as the following 2 notes quoted below as one of them would of related to your issue....

NOTE: There is a provision for mechanical fuel pump on this engine. Therefore if you are currently using an electrical fuel pump you must get the fuel pump block off plate to cover this feature.
NOTE: It should be noted that the Vortec 5.7L longblocks are supplied WITHOUT a crank position sensor in the front timing chain cover. Therefore you must remove your existing crank position sensor and re-install it in the timing chain cover of the new longblock, otherwise the engine will leak oil out of this open hole. If your old engine did not utilize a crank position sensor you must purchase one to plug this hole as it requires this special o-ring type seal.

As for the brass insert that is spinning in place which would be the threads for the sensor bolt....Not completely sure in your case but maybe the insert may set-up into a tighter position once you start to install the sensor using the sensor bracket as a load to help hold the threads into place until tightened....Just a thought to consider checking out.

In the image below it appears you can see the brass insert at a rest position...Yours look like that or does it go further inwards?

 

[Scott Danforth]

or, remove the plastic plug

using brake cleaner, clean the sensor port. using a rag, make sure the whole inside of the bore is clean

go get some JB steel epoxy putty, cut off a piece, roll it in your hands to kneed it/ mix it,

make a round plug, just a bit bigger than the hole and smush it in there. in 24 yours, use the boat as normal.

if you want to remove it, you will need a drill press or a new cover.

 

[diceybrew]

Fun Times, Scott — Thank you both for your guidance. Good to have some confidence about what my next steps look like.

Fun Times — Thanks for the info on the plugs and the truck model equivalents. The brass insert looks like it matches the one you can just see in the picture you.

I’ll see what I can find locally, and may well go down the JB Weld path Scott mentioned.

Thanks guys. I’ll share an update when I get through this next step.

 

[diceybrew]

First, the good...definitely no more oil leaking from the crank position sensor. Thanks for the help!

The bad...there are other leaks to figure out. After running the boat on the water (gently, as per the break-in guidelines I was given), I still have a leak dripping from the bottom of the front cover. I'll have to pull the balancer off and see whether this is coming from the seal or somewhere else on the front cover.

Adding to the annoyances, it also looks like I have some oil spraying on the right side of the engine. I noticed oil residue and some obvious spray on the right side of the engine well, on the raw water hose leading from the drive to pump at the front of the engine, and on the starter. I thought maybe this was being slung from the balancer, but the balancer (on initial inspection anyway), actually feels oil free.

There also appears to be oil in a spot I'm struggling to even come up with a theory to explain...on the right side of the crank case, just forward of the front, right engine mount is a recessed area that has a machined flat rim, almost like it would be used to attach some other part in another application...there appears to be oil inside that recessed area, and I don't have a good theory yet for how it's getting there.

I'm going to pull things apart again and see if I can track down the source of this/these leak(s). Would happily entertain suggestions or ideas of what to check. Either way, will get an update out once I get a chance to dig in.

 

[diceybrew]

Got a chance to get a good look at things today with the engine running. Oil is spraying from a couple of spots, at least:

1 (red arrow in stock pic below) - Above the starter is a passageway/port. Oil is spitting out. There's a metal plug sealing this hole in the old motor.
2 (green arrow) - forward of the front engine mount is a recess with a couple of ports. Again, oil is pitting out of the lower hole. No obvious plug in the old motor for this one.

Are there plugs for these ports? Could I make another JB Weld plug? Is there a chance that the shop that remanufactured this should have used different gaskets to or internal plugs to seal these passages?

I still need to pull the accessories on the front off to see what's leaking at the front of the engine. I'm guessing the front cover will have to be replaced too.

Thanks guys!

 

[diceybrew]

Here's that pic...

 

[Fun Times]

The red arrow is one of the holes for the oil dip stick tube that's usually covered up if not used on that side.

https://forums.iboats.com/forum/eng...as-engines-outdrives/10540484-mystery-jb-weld

https://www.summitracing.com/oh/sea...cending&keyword=NAL-9421743&retaillocation=oh

https://www.summitracing.com/oh/par...21356724165&utm_content=Chevrolet Performance

The green area is where a mechanical fuel pump would go. Search online GM mechanical fuel pump small block off plates.
https://www.summitracing.com/oh/sea...f-plates/make/chevrolet/engine-size/5-7l-350/

 

[Maclin]

I am not sure if SBC's have an extension rod that rides on the cam to actuate the pump lever, but on big block MoPars there is a plug on the bottom of the fuel pump mount area that is removed when the pump actuator rod (rides on the cam and actuates the fuel pump lever) needs to come out.