# New leak source for the Diesel drivers



## revjpeterson (Oct 2, 2013)

Looks like I've been lucky enough to discover a source of problems on the Diesel that I can't recall being mentioned here on CruzeTalk yet. I am not completely confident on my ID of the part at fault yet, so anyone who can confirm or correct that would be much appreciated:

I actually have 2 leaks right now. The first is the transmission cooler lines, which will be an easy fix. The other is pictured in the photo below. 









The photo is taken from below the oil pan. The leak originates from the sensor with the yellow tab on its plug, located at the top of the oil pan, on the rear side, above the drain plug. The plug to the sensor is a 2 wire plug. I considered, based on placement, that this might be a crankshaft position sensor or an oil temperature sensor, but the only sensor that seems even slightly related to that part of the engine, and has a 2-wire plug, is the oil level sensor (Part# 55575097). The exposed portion of the sensor appears to be installed from the inside of the oil pan, and held in place with some kind of snap ring, which would also appears to be true of the oil level sensor based on the parts diagrams, although they aren't extremely clear on that. 

So, can anyone verify if this is, in fact, the oil level sensor I'm seeing the leak from, and that the repair, as I suspect, is going to involve dropping the oil pan to replace the sensor (since its o-ring is integrated into the plug)?


----------



## Snipesy (Dec 7, 2015)

Yes it is the oil level sensor.

Yes you will need to take the oil pan out.

The O Ring is probably the same size as the drain plug seal (big emphasis on the probably), if you want to try that.

The connector I am guessing is a part of the ECM harness.

It's not a snap ring. Its an E ring, E clip, mickey mouse ring, whatever. I guess you can call it a snap ring if you want but you wont be needing any fancy pliers. That ring is on the outside, not inside.


----------



## IndyDiesel (May 24, 2015)

Thanks for the post rev. How many miles do you have on your ctd?


----------



## revjpeterson (Oct 2, 2013)

IndyDiesel said:


> Thanks for the post rev. How many miles do you have on your ctd?


Just over 73,000 now. I'm putting on less than half the miles now since I moved from rural Iowa to Michigan a year ago. Otherwise, I would be staring down the barrel of a timing belt change in a couple months.


----------



## revjpeterson (Oct 2, 2013)

Anybody have a confident part number for an oil pan gasket? Rock auto doesn't seem to carry it.


----------



## revjpeterson (Oct 2, 2013)

In fact, I can't seem to locate an oil pan gasket on any GM parts diagram or any parts website. That seems to lead to the conclusion that the gasket is either a part of the baffle (and hopefully therefore a re-usable rubber gasket) or that there is no gasket and I'll have to make my own out of RTV. Chrysler/Jeep/Dodge like to use RTV instead of gaskets on a lot of their transmissions and axles, but I've been able to convert them over using parts from LubeLocker (Lube Locker | Premium Differential & Transmission Gaskets - Lube Locker), but they don't do engine gaskets at this point, so out of luck there. Guess I'll just have to pull the pan, have a tube of RTV on hand, and see what I find. Worst case is I find out it's part of the baffle and not reusable, and I have to wait a couple days for one to come from Amazon.


----------



## Snipesy (Dec 7, 2015)

12378521 is what they use. I'm sure you can find equivalents.


----------



## revjpeterson (Oct 2, 2013)

Snipesy said:


> 12378521 is what they use. I'm sure you can find equivalents.


Looks like the Permatex Ultra Black or Optimum Black that I usually use should be equivalent or better than this at 20% of the cost (and won't require a caulking gun to use). Thanks for the part number for reference.


----------



## revjpeterson (Oct 2, 2013)

Wow... So, now that I've looked under there more closely, pulling that oil pan is quite a job. Its not only bolted to the block, but it's got 2 or more bolts through it into the transmission, a couple of other parts bolted to its sides, and I might have to lower part of the exhaust to wiggle it out. Even though I already have the parts here, I'm contemplating just spraying it off with brake cleaner and putting a bead of rtv around it to stop the leak until I absolutely have to take the pan off and change the sensor.


----------



## revjpeterson (Oct 2, 2013)

Then there's the bolts. I'll probably have to buy sockets. It looks like they're an 9 or 10mm internal triple square spline head. Might see if I can make a torx bit catch, bit will have to be really careful not to strip it experimenting.

10pc XZN Triple Square Socket Kit Spline Socket Bit Set Long Drive Metric Bits 4 Inch 1/4 3/8 1/2 Ratchets https://www.amazon.com/dp/B01MY3L0X6/ref=cm_sw_r_cp_apa_phpAzb6W76N9B


----------



## obermd (Mar 3, 2012)

Rev,

Isn't the oil pan part of the power train warranty? I've had pan leaks fixed under power train in the past.


----------



## revjpeterson (Oct 2, 2013)

I'm going to double-check with the dealer, but since all sensors are excluded unless specifically mentioned as included, and the leak is a problem with the sensor's seal, not the pan's, I think I'm on my own, even though the sensor is inside the pan.


----------



## revjpeterson (Oct 2, 2013)

Well, I took the easy way out and just RTVed the area around the sensor to death, hoping I can just hold the oil in without dropping the whole pan and unbolting half the contents of the engine bay from the sides of it. The oil contacting the area where the sensor connector exits the pan shouldn't be under pressure, so as long as I got all the seams filled, it should be all set. 

Of course, it never turns out as easy as you hope it will. I left the car jacked up in the garage overnight, and since I wasn't moving the car yet, didn't close the hood either (the importance of which becomes evident once I find the solution). I got home from work the next day and went to back it out of the garage, and I got 25 engine codes, the "service exhaust fluid system" message, the countdown to death, and it wouldn't start! Knowing I hadn't done anything at all to the fuel rail, intake runners, starter solenoid, or any of the other components referenced in the codes that were set, I figured we were dealing with a wiring harness, plug, etc. So, I went about crawling back under the car and seeing what wiring harness I might have disrupted while dealing with the oil leak and transmission lines. When I couldn't find anything out of place, I disconnected the battery (and since I was going to replace it in 3 months anyway, went ahead and put the new one in now), hoping it would reset the computer and cure the vehicle's confusion about its status. No improvement there either. Then I found the problem while reinstalling the battery hold-down and the box over the positive terminal: One of my 5 kids had unplugged a connector from the glow plug control module (which is mounted on the front plate of the battery box). I plugged that in, and the car started and most of the codes went away. After a 15 mile drive and 3-4 engine starts, the final few codes reset themselves and the countdown to death ceased. 

Next time, I do work under the car and don't need the hood open anymore, I'm going to close the darned hood so the kids (#4 is the prime suspect) don't monkey with the wires and waste half a day of my time trying to chase down the problem.


----------



## Snipesy (Dec 7, 2015)

For all intents and purposes, you can call the glow plug module the ECM.

If you want to update the glow plug module, you don't flash the Glow Plug Module, you flash the ECM.

There is a lot of hand waving involved...

Moral of story unplug one, may as well have unplugged the other.


----------

