2004 Mercruiser 4.3L Oil Leak

[Maverick7]

I started noticing sandy brown water in my bilge about a month ago. The water isn’t an issue, I constantly have people getting in and out from tubing. But the fact that it looked like oily water was an issue.

I then began to notice that over the course of a few weeks the oil on my dipstick began getting less and less, to the point where it’s now at the “add” level.

I started investigating the engine compartment to try and find a leak and eventually found one. The leak is a steady drip coming from behind one of the pulleys, is believe this is the timing pulley that goes into the crankshaft?? I could be wrong though. It’s right where the assembly from that pulley connects to the engine.

I have included some pictures and a video of what’s going on. Looking for help on what this could be, repairs, and costs associated. Thanks!


https://youtu.be/vure9Tqulk4

 

[Lou C]

Ping achris I think he dealt with a similar issue related to the plastic timing cover and the alu oil pan.

 

[Bondo]

Ayuh,..... Welcome Aboard,...... That's where the crankshaft passes through the timin' cover, 'n has been known to be abit of a problem,.....

My fellow moderator, Achris is our resident expert on that particular issue,....

 

[achris]

Only one reliable fix. Replace the oil pan and the timing cover. Engine out, flip it upside down and fit the new parts.

Known issue with these engines, but Mercruiser won't acknowledge it (don't want to deal with the warranty claims :facepalm

DON'T BUY THE PARTS FROM MERCURY! They are standard GM parts, and available for about 1/4 the price from a GM parts supplier (I used the online suppliers, and including shipping to sheepshagistan, they were still less than 1/4 the price of the local Merc stealership).

Here are my threads. Read and enjoy.

https://forums.iboats.com/forum/engi...k-timing-cover

https://forums.iboats.com/forum/engi...oil-leak-fixed

https://forums.iboats.com/forum/engi...-bilge-finally

https://forums.iboats.com/forum/engi...pdate?t=373060

Useful part numbers.
Timing cover - GM 93445880
Oil pan - GM 12597153
Oil pan gasket - GM 10220906

Chris.........

Here's the comparison.. (Merc list the oil pan as NLA, but the last time I looked, it was over $700)

 

[nola mike]

Again Chris, wondering if this was limited to a couple of years. Seems mostly 03/04. Same design on all the vortecs but don't hear much with the older ones?

 

[Lou C]

Never had that problem with my old pre Vortec 88 4.3...

 

[nola mike]

Never had that problem with my old pre Vortec 88 4.3...

It was the vortecs and the composite timing cover/aluminum pan

 

[achris]

Never had that problem with my old pre Vortec 88 4.3...

Yours had a tin cover and tin oil pan. No problems with those.

It was the vortecs and the composite timing cover/aluminum pan

Yep. I have seen enough of the problem. (Several locally and they keep trickling in on forums) I believe GM may have had a defective mold for the oil pan. Probably just one of many molds. They seem to have allowed quite a few through the system before QA/QC caught it and found (and I suspect destroyed) the offending mold.

I even suspect GM saw the composite covers as a weakness, because from 2008, the front covers are machined aluminium. And not backwards compatible with the earlier blocks. :facepalm:

Chris......

 

[Maverick7]

So the shop is having a hell of a time getting parts, due to everything going on in the world. We were able
to find an oil pan, but can’t seem to find a timing cover. OEM cover from Merc is backordered.

So I started shopping online. Turns out that the part number we are looking for is 8m0069799. However, that is a superseded part number, the original part number is 888777001.

Does anybody no if there is a difference between these two parts? Was the part number superseded because Merc (GM) changed something about that part due to an issue? I can find the original 888777001 for immediate purchase, but can’t find the superseded 8m0069799 anyplace.

 

[nola mike]

The newer part has a cutout for a crank position sensor. If you have a carb engine either part will work (as will the gm part for ½ the price). Not sure if/when efi engines incorporated a cps. Chris, I had assumed that you replaced your pan with an upgraded/newer design. Did you just use the same part # that they had presumably fixed the casting issue?

 

[achris]

The original cover used guide pins secured in the cover that located in drillings in the block. The new cover requires the (supplied) pins to be driven into the holes in the block, and the cover located on those...

Chris...

Edit: both covers have the hole for a CPS...

 

[Maverick7]

So on that same note, do you recall which part number you replaced yours with that ended up fixing the issue?

I found the GM listed part number online and available. The only issue I see is that it’s made by Dorman, which is a company that doesn’t seem to always invest in their quality assurance.

 

[Maverick7]

Finally got the new pan and timing cover in the mail. Engines out, old pan off and old timing cover off. Will keep this updated!

 

[achris]

Oh, that's a familiar sight. :facepalm:

 

[nola mike]

So again, is it the same part number for the oil pan, but with a presumably new casting?

 

[Maverick7]

So again, is it the same part number for the oil pan, but with a presumably new casting?

I’m not sure if this question is directed at me or Chris. But for me, yes it’s the same part number with a presumably newer casting.

There is an interactive engine diagram on the Mercury website. You basically just enter your serial number and the engine pops up and has all the parts listed. For the timing cover, it has the original number listed with an asterisk next to it, and then shows the superseded (new) part number. As for the oil pan, there is no asterisk and assumably no superseded part number. In other words, like Chris said, I’m guessing they just junked the bad mold and it was business as usual, as if nothing ever happened.

 

[Maverick7]

The boat is back and so far, so good! Put about 4-5 hours on it this week and didn’t have any oil in the bilge and no evidence of leaks. Will keep this thread updated if anything comes up.

 

[Lou C]

congrats and nice follow up! always good to hear what the solution was!

 

[achris]

Was the old cover broken? They usually crack where the pan pushes on it on the left (I think)...

Chris

 

[Maverick7]

Was the old cover broken? They usually crack where the pan pushes on it on the left (I think)...

Chris

It was cracked, but on the right. And by on the right, I’m saying if you are looking at the front of the engine, as if you were standing in the boat. But anyways, bottom right corner. Seeing as the cover is black, it’s incredibly hard to see it and I couldn’t get a decent picture. If you look at the video in my original post, you can better make out the crack.

Just got off the water.......cruised around for a couple hours, and once again, no oil in the bilge.