Oil leak?

[MechanicMommy]

Alright so I've got an 04 trailblazer ext with the 4.2L. I redid all the engine gaskets last June 2017 due to a small oil leak. Now it seems like I'm loosing oil slowly again as well as pressure yet can't find ant source. I'm stuck on my crankshaft seal or simply the crankshaft itself with the slow oil leakage. But its all on the passenger side of my engine as well as the quarter size oil spots I'm finding on the garage floor. I've looked in every place I cld think of and watched videos as well as read threads online... I'm stuck to do this myself at the moment instead of being able to take it into a repair shop but I'm unable to afford that possible expense right now.

 

[Sparky]

Might have to clean the engine really well so that you can see any fresh oil traces.

You're sure it is engine oil and not another fluid right?

 

[Reprise]

As Sparky said - step 1, confirm leak as oil. Place some white paper under area on garage floor (even notebook is ok)

Step 2 - assuming the area is tan to black in color, determine source of leak. Check vehicle before cleaning to see if you can determine leakage point(s). If not, use engine cleaner (one example is Gunk's foamy engine bright; there are others). Another alternative is brake parts cleaner (which is sold as an aerosol; spray liberally & let dry, wiping areas where needed.)

Step 3 - get some dye (30ml bottle) listed as safe / effective for gas engines, and pour it into a running engine after topping off beforehand, if needed. You may need to drive as many as 500 mi ( doesn't have to be all in one sitting) before the leak is visible. If you notice you get a full qt low, before the 500mi elapses, top off and get ready for step 4 a little sooner. Keeping a spare quart in the truck for when you're away from home is a good idea. If the leak is bad enough where you have to put a qt in sooner than every week or so, use whatever is the cheapest 5w-30 you trust until cause is determined.

Step 4 - Get a black light bulb (party city stores carry them for $3, among other places like Home Depot - no need to purchase an expensive one at the auto parts store). Get one that fits your droplight, and examine top / bottom of engine. You may need to reduce lighting in garage while doing this. Don't try in bright daylight.

Step 5 - take some pics of the area and post back. If you can find a description of the area(s) in whatever repair manuals you might have, that's ok, too.

You mentioned replacing gaskets last summer - which ones, specifically? Normally, a new gasket will last longer than 6mo, unless it was installed incorrectly or defective (rear main seals are notorious for this on GM V6 / V8s, especially through the period where our motors were built - while replacement parts are generally good, even the smallest amount of crooked / misalignment of the seal will produce (hard to find) leaks.

Since you mention the crank seal yourself, note that it generally will present the leak in the rear center. A quick way to check is to remove the small transmission inspection cover and look inside where the torque converter joins to the flexplate (flywheel, if you prefer, although a/t vehicles are termed flexplates). If you have a smartphone, a cheap usb cam is great for checking this.

If you do see oil there, in the flexplate area, then you can pretty much figure you have a main seal leak. It can be fixed w/ engine in-car, but you have to disconnect the trans and move it back a bit (you have 3 bolts connecting to flexplate, and approx 10-12 around the outer circumference of the bellhousing, depending on engine / trans model. The top two bolts tend to be the most troublesome to reach.

If you have 4wd, then you'll probably want to disconnect / remove the transfer case *before* disconnecting the trans, as the 4l60e weighs approx 200lbs by itself, and will give you more working space to boot. Drain the fluid from the trans as well (into a clean 5qt pan; you can reuse it, unless it needs a change either from mileage or condition.)

You dont need to fully remove the trans from the vehicle, but you do need to move it back enough to give yourself room to work ( 12-18", as you need to drive that seal in)

There's a second crank seal at the front end of the engine, but those tend to install easier and remain leak-free, compared to the rear.

If you get to this point and still no evidence of a leak, then consumption comes into play. GM considers 1qt per 1000mi 'acceptable'. Most of us don't, but to be honest, most GM engines aren't known for exemplary oil control. If it burns oil significantly faster than that, you may want to (have an observer / helper) check your exhaust for excess smoke during revving / acceleration. Blue-tinged smoke indicates oil is getting past the oil rings and being sent out the exhaust valves. If you see that, and especially a lot of it, the engine will need rebuild or replacement.

Sorry so long; I try to be thorough.

 

[Mooseman]

You also mention issues with your pressure. Have you checked the oil pressure switch just above the oil filter? It is notorious for going bad and leaking through the connector.

Just an FYI, the oil pressure gauge is fake, readings are fabricated by the PCM. All these have is an on/off pressure switch, like the dummy lights of old. If the pressure is too low and closes the switch, the PCM drops the gauge to 0 and gives a low oil pressure light/message.

 

[Reprise]

Good idea to heed Mooseman's advice before mine; he's owned these with the 4.2 and is way familiar with them. Mine has the 5.3 V8. Not to mention that his advice is way easier / shorter to follow

 

[Redbeard]

What kind of oil are you using? I only ask because my 04 with the 4.2 will regularly leave one or two drops of oil on the floor when I used Mobile one. When I started using the extended performance Mobile one the slight drip stopped completely. I believe it was coming from the rear main. No other changes had been made. So for the couple of extra bucks during the oil change my dripped stopped. Are you able to see the loss of oil on the dip stick? I ask because if you aren't using enough oil to "show" might it be better, at least for now, just to place an aluminum pan on the floor to catch the dripping? I am saying that because if you need to add a quart of oil occasionally to keep it topped off it would be much cheaper than having to run it to a mechanic for big bucks. Not an optimum solution, but when one doesn't have the funds or the time we do what needs to be done.
just my 2¢

 

[mrrsm]

Two Cents of a Suggestion from @Redbeard is worth a King's Ransom if heeded. I'd also like to recommend parking overnight atop a large piece of Cardboard so the Oil Traces will leave their nocturnal prints... just run a Black Magic Marker around the Tire Contact Pads so you can orient where the leaks emanate from after backing off of the Cardboard Mat.

With the Oil Leak making its presence known on The Passenger Side of the Engine Block... take a close look at your CPAS ...slightly to the rear of the Power Steering hardware and observe whether or not the Electrical Connector at the top-front of the CPAS and see if the area under the Hold Down Claw Clamp are not streaking oil that is leaking out and down the block due to a failing CPAS "O" Ring as well.

 

[MechanicMommy]

The fluid smelled and looked like oil underneath my truck on the white cardboard box I have placed under were its parked. I've cleaned the engine and haven't seen anything yet.
The gaskets that's were changed was the head gasket and valve cover because that's where the leakhad started so I redid all that and tightened down to specs. Ran great with nothing till this past DEC. Now I did move from ky to Illinois and as far as I know this truck hasn't been thru the extreme cold that we have had here. I don't know if that truly has anything to do or any affect on it but I'm sure in some way it does. Now I have a slow oil leak going somewhere and only finding a drop here n there.
I know I mentioned the crankshaft n seal but there's no oil on my belt or anywhere along that area.
I've driven it the past few days and haven't seen anything but it started to misfire. So I checked my coil packs n low and behold I have oil sitting in the bottom of my first plug. Second one nothing maybe a drop as well as there on forth...(I'm going from front to back with the plugs on a straight six. I know firing order is different) the only other spot I've seen oil is when I removed my air casing from atop the engine it leaked out what seemed to be some water and oil from the inside. I dont know why oil wld be there at all. I know I need an oil change but don't want to do it until I know for sure I won't lose it lol. I've got all that on hand. Anyhow going over thirty miles ypou do start to get a faint oil burning smell but nothing more. I use valvoline syn 5w30 always have except once cus I didn't do it myself and someone else did thinking they would do me a favor... As for adding oil maybe a quart in the past two months but I haven't been driving it much cus I normally have my children and don't want to take the chance unless needed if it was to break down in the cold with them inside.....

My oil looks as if its being mixed hopfulky just water cus its kinda gunking up. Idk how else to explain it except it looks kinda yellow on the top of my oil cap, nothing on dipstick except oil when checking it

 

[Reprise]

If it needs the oil change, go ahead and do it. A replacement qt of oil is way cheaper The other thing is that you'll be starting from a baseline, knowing that you put the 7qts in.

Regardless of your mileage, switching over to a 'high mileage' oil can be helpful, as the additive packs have seal swellers that may help slow / stop your leak, at least for a bit. Since you like Valvoline, their 'MaxLife' blend is considered a good high-mileage oil (I use it in my own, right now.) And it's a semi-synth. They also make a full-syn version of it now. @MRRSM makes a good point about checking out the area around the CPAS / connector - it's a known 'leak' area on the 4.2L

Re: what you found on your oil cap - a good chance it's water condensation, and not a big concern. Most ppl report it as 'white'. You'll see it more in the winter months. Clean the cap well, and note how long it takes to reappear; other than that, I think you're OK, there.

Since you mention the water issue...It's a good idea to keep an eye on the coolant reservoir, to see if you're losing any. A small leak is hard to detect, unless you've been keeping an eye on it. If it's low, fill it to the 'full cold' mark (when cold, of course), and start tracking from there. If it's bone-dry, also check the level in the radiator (overnight cold) - it should be just coming up the fill neck, w/ no air gap between the bottom of the fill neck and top of the rad. Hopefully, you'll see orange-colored fluid in the reservoir, which should indicate DexCool was being used (the 'right' stuff).

Finally, I should not comment on what you found in the spark plug wells; I'll let 4.2 owners address that. And you did fine in your numbering sequence; that's how most members describe it. Kudos to you for knowing the actual firing order was different, too.

 

[Mooseman]

Oil in the plug well is a common issue but usually due to old gaskets. Yours are new. Maybe the bolts need re-torquing? Another thing you could do is add a washer under the long bolts that hold the coils as they do add some clamping force to the gasket around the well. This however would not account for the oil spots.

Did you check the oil pressure switch?