Crank No Start, Coolant Dripping From Oil Pan

[AlekAuto]

Please for the love of God let someone know what's going on here
I just finished doing valve cover gaskets, getting new spark plugs, new ignition coils, new radiator, suspension rebuild, I really treated her right. I even turned the crankshaft by hand before trying to start it.
I go to start her up, she'll crank for a moment like she has a low battery, then suddenly start clicking. When I check the battery voltage, it's around 11.5v. I tried again with a battery that was around 12.5, and it cranks longer, but still goes into the clicking thing.
The fuel gauge drops to the minimum whenever I'm cranking, then goes back to a quarter tank. Mind you, that quarter tank is probably half a year old, and it wasn't very high quality gas to begin with.
All the lights flash as you'd expect from a dead battery, but once again, battery isn't dead.
My initial thoughts were either a security lockout, since I plugged the battery in with the key in the ignition, or the crankshaft position sensor, since I had a code for that and I had the replacement lying around but hadn't actually installed it yet.

When I crawled under to double check where the crankshaft position sensor is, because I had an existing code for that, I noticed there was something dripping from the oil pan. I thought "Oh, guess the valve covers weren't the only leak", but to my shock, it was coolant dripping from the oil pan, not oil.
I immediately grabbed a wrench and undid the oil pan bolt, only to find nice, clean oil. Which unfortunately doesn't ease my mind much, since the coolant is also completely clean and fresh looking, so that doesn't exactly sate the part of my brain that worries there's a layer of coolant just sitting on top of the oil in the pan. But why would that literally ever be the case? Every time I've seen oil and coolant separated in the oil pan, the coolant is the bottom layer.
Dipstick is just clean oil, too.

The car hasn't even actually started yet. How could cranking it for a couple minutes tops possibly dump coolant into the oil pan? Why would it be so clean and not milkshaked at all if the motor spun while it was cranking? Is it a cracked block, or is the coolant coming from somewhere else, like the heater core hoses or something, and it's just dripping in the scariest possible place?
This thing was completely fine when I parked it, I parked it over a wheel bearing and decided to give it the full treatment before putting it back in service. What could possibly be causing this problem?

I have my own list of troubleshooting steps I'm gonna go through.
I'm gonna have to bite the bullet and drain all that fresh oil out to see if there's a layer of coolant on top, or, y'know, if coolant settles to the bottom of the pan overnight.
If it's not the absolute disaster my brain won't stop circling around, then I'll install a new crankshaft position sensor and go grab some 91 non-ethanol gas to dilute the stale gas with. Disconnect the battery for a few minutes, make sure the truck is closed and locked up, then reconnect the battery and unlock it with the key to minimize the chance of a security lockout
After that, uhhhhh kind of out of ideas other than "Time to start tearing it apart and looking for anything that might be keeping it from starting".

Yes, I probably should have done those things before posting, but I've been working for like 12 straight hours just to get to the finish line and have a panic attack. I just spent my last like 4 paychecks on this thing and was really relying on it during a move. If it's the worst case scenario, I have absolutely no idea what I'm gonna do. So, if anyone has any ideas other than what's already been listed, reassurance that I'm on the right track, or ESPECIALLY if anyone knows where the hell that coolant could possibly be coming from, please let me know.

Thanks for reading my memoir. Here's some pics of the coolant dripping and the clean oil. Yes, I'm aware the oil pan should be replaced because of the rust, but I mean, c'mon, that's not gonna magically make coolant appear.

[AlekAuto]

Update: I decided it'd be better not to have this looming over my head while I'm trying to sleep, so I undid the oil pan bolt and the oil was clean the whole way down. The oil pan is completely empty, with the bolt removed, and 5qts of the most lightly used oil ever sitting in a jug in my garage, and the coolant is still dripping from the oil pan the same way it was before. This is not the oil pan gasket leaking coolant that's somehow defying physics by sitting on top of the oil.
So, wherever this coolant is coming from, it doesn't seem to be the worst-case-scenario.
Tomorrow, I'm gonna try the other troubleshooting steps I mentioned; making sure it's not the security system, replacing the crankshaft position sensor, and putting a few gallons of 91 in it to dilute the fuel.
Once again, if anyone else has ideas, especially about where the hell this coolant is coming from (this seems like a mighty large leak if I can watch it drip in real-time like this), then that'd really make my day a whole lot easier. Thank you.

I love that you can tell my moods from these images.

[mdmellott]

There is a small coolant hose, connected between the throttle body and the coolant pipe at the rear of the engine and it is attached with a clamp to the upper plenum, which you would have had to disconnect when you did that valve cover gasket job. I would check to be sure that hose is connected to the coolant pipe and that it was not cracked when you removed the upper plenum.

As for the engine not cranking over, I know replacing the radiator can be a messy job and that any coolant which may have gotten onto the negative battery cable, where it grounds to the engine, could be an issue if there was a bit of corrosion to begin with at the ground connection. The coolant seeping into a bit of a corrode connection may have been all it needed to make that ground connection fail, which would prevent the motor from cranking over.

Just a couple of thoughts that might be possible.

[AZhitman]

^ I like this.

The pan is just the lowest surface on the engine. It's coming from somewhere above, and unfortunately, the grime and rust makes it hard to trace.

I'd drain ALL the coolant, fill with regular water, add some UV dye (kits available at any auto parts store), crank it again, and you'll find the origin of your leak.

[AlekAuto]

There is a small coolant hose, connected between the throttle body and the coolant pipe at the rear of the engine and it is attached with a clamp to the upper plenum, which you would have had to disconnect when you did that valve cover gasket job. I would check to be sure that hose is connected to the coolant pipe and that it was not cracked when you removed the upper plenum.

Just a couple of thoughts that might be possible.

That was actually one of my first thoughts, since I wrestled with that hose for way too long while reinstalling the throttle body (don't ask). I'm not ruling it out entirely, but I did put a shop towel back there to see if it'd get wet and it was completely dry when I took it back, that was my ghetto "Is this the leak?" test lol I'll go back and be more thorough about it either today or tomorrow, maybe removing the air filter box and throttle body so it's easier to get to.

[VStar650CL]

AZ is right, if you can't find the source any other way then UV dye is your best friend. The standard universal dyes are actually miscible with coolant so you don't necessarily need to drain it, but that can make a UV mess once you locate the leak and go to fix it. So a D&R with plain water is usually the best way to employ the stuff.

[AlekAuto]

Well, I got a lot of it figured out.
I checked the coolant lines that run along the back of the engine, nothing. I made sure the battery was charged, replaced the crankshaft position sensor, and put 5 gallons of 91 octane with some fuel system cleaner, then finally reconnected the battery with the car closed so I could unlock it with the key before entering to prevent the security lockout.
So, after all that, it fired RIGHT up like nothing was ever wrong.
However, it ran rough, and I noticed the valve covers I just installed were leaking. Badly. Like, not drip-drip leaking, but almost like they weren't sealing at all leaking. Smoke was coming out and everything.

I torque'd the valve covers to around 40in/ibs 'cause I couldn't get any actual information on what the real torque spec is (the manual says literally nothing on valve covers), and some guy online said it was "literally like 20in/ibs", and another guy said "no more than what you'd do with a screwdriver". Getting info on the torque spec of the valve cover bolts is hard enough, but getting information on the torque spec of SPECIFICALLY the aluminum ones from 2001 is nearly impossible.

I did find, however, that the Nissan Maxima, which doesn't share the same valve covers but is the only vehicle with the same valve cover bolts, does have the valve cover torque spec in the service manual. I wish they'd stop hiding these things.
It says to tighten the valve covers in two stages, once to 26in/ibs, and again to 82in/ibs. That's double what I torque'd it to. So, I'm gonna go in and tighten these down to the Maxima torque spec, see if that helps at all. Is it a bad idea/overkill to get these milled to make sure they're flat while I'm already taking everything off again?
I've already started taking the intake manifold off, so I'm gonna replace that thermostat while I'm down there. God knows I don't need more potential failure points.

Once I've finally finished all this, I'm gonna have stumbled my way into being the Nissan VQ Valve Cover Expert. My video on the subject is gonna include all the potential pitfalls one might fall into doing what would be a simple 30 minute job on any other engine, simply because I fell into every one of them.
If anyone has better information, I'd love to hear it. Thanks.

[mdmellott]

I torque'd the valve covers to around 40in/ibs 'cause I couldn't get any actual information on what the real torque spec is (the manual says literally nothing on valve covers), and some guy online said it was "literally like 20in/ibs", and another guy said "no more than what you'd do with a screwdriver". Getting info on the torque spec of the valve cover bolts is hard enough, but getting information on the torque spec of SPECIFICALLY the aluminum ones from 2001 is nearly impossible.

The Nissan FSM do not differentiate in the illustrations for assembly between aluminum and plastic rocker covers but the assembly and torque specs are the same. Their illustrations show plastic covers, which have the spark plug tube seals already installed and not replaceable, but they also show spark plug tube seal separately, which is a bit confusing. My Haynes manual illustrates the assembly with aluminum covers and confirms the same torque values as the FSM. Haynes also indicates the 2-step torque process. The FSM does not. Nevertheless, the 2-step process is the best practice to follow. Step 1. 9 to 26 in-lbs. Step 2. 61 to 78 in-lbs.

The torque sequence pattern is critical. As well as applying RTV silicone sealant at two crucial locations for each gasket, which is actually easier to apply this to the corner location on the cylinder head. If the torque sequence pattern is not followed, or the torque spec is not met, or the sealant is not applied, the covers will leak. All of this information is in the FSM at https://www.nicoclub.com/service-manual ... 2%2Fem.pdf
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[AlekAuto]

The Nissan FSM do not differentiate in the illustrations for assembly between aluminum and plastic rocker covers but the assembly and torque specs are the same. Their illustrations show plastic covers, which have the spark plug tube seals already installed and not replaceable, but they also show spark plug tube seal separately, which is a bit confusing. My Haynes manual illustrates the assembly with aluminum covers and confirms the same torque values as the FSM. Haynes also indicates the 2-step torque process. The FSM does not. Nevertheless, the 2-step process is the best practice to follow. Step 1. 9 to 26 in-lbs. Step 2. 61 to 78 in-lbs.
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Thanks, mate, that's exactly what I was looking for!
Really nice of them to hide it in the timing service, even nicer of them to have an obvious typo; pretty sure this is supposed to tell you to do it in 2 steps, but accidentally just tells you step 2 twice in a row. So, in my defense, this service manual sucks. Better than Kia's manuals, but still not great.

If you're from the future reading this, here's an important lesson: Don't reuse valve cover bolts on the aluminum valve covers! The used ones have just enough corrosion on them to cause a bit of extra friction, which makes them reach the torque spec early compared to the new ones. I gave one side new bolts, reused the bolts from the donor Pathfinder for the aluminum valve covers on the other side, and guess what? The side with the new bolts is sealing great, and the side with the reused bolts isn't. This is especially apt, since the side that got the new bolts was actually the side that wasn't sitting entirely flat when I first installed it, so if all things were even, that'd be the side you'd expect to leak. The scientific method at work!
See? I'm not just a lunatic doing everything wrong on a valve cover job, I'm offering valuable information to future generations of R50 owners

[mdmellott]

Really nice of them to hide it in the timing service, even nicer of them to have an obvious typo; pretty sure this is supposed to tell you to do it in 2 steps, but accidentally just tells you step 2 twice in a row.

That is odd. Hadn't realized that is a typo. Assumed it was redundant wording for a. (one side) then b. (the other side). I use my Haynes manual for more how to do type of instruction than the FSM which has a boat load of what to do, since it was written for service techs not shade tree mechs like me. Downloading the the entire FSM as a PDF file so you can keyword search the document for things like "rocker cover" makes it easy enough to use when you don't see what you are looking for in the index at the beginning of each manual section. It's a great resource tool to have a soft copy of.

Showing the plastic rocker covers in one section of the manual and aluminum covers in another section is only a little confusing but it did throw me way off when I also saw the shoulder bolts pictured with the aluminum covers in the cylinder head components graphic. I knew my plastic covers had shoulder bolts but I didn't know at the time the aluminum covers do not. I bought the washer/grommets and spark plug tube seals before I replaced the gaskets on my plastic covers, based on that graphic image. Even a search by my VIN incorrectly confirmed I needed those parts. I ended up giving them away because I couldn't return then to PartsNext in the UAE.

[AlekAuto]

I knew my plastic covers had shoulder bolts but I didn't know at the time the aluminum covers do not. I bought the washer/grommets and spark plug tube seals before I replaced the gaskets on my plastic covers, based on that graphic image. Even a search by my VIN incorrectly confirmed I needed those parts. I ended up giving them away because I couldn't return then to PartsNext in the UAE.

Yeah, I actually had another thread asking about the valve cover bolts because I'm swapping from the plastic to the aluminum so I hopefully don't have to go through this again, and I didn't realize the bolts were different until I removed the ones from the plastic valve covers and went "There's no grommets on these.". I then realized that I had made a mistake.

I'm currently editing a video of the whole job so nobody has to go through the trial-and-error that's been common with this job again. Everything'll be in there; the weirdness of the service manual, the correct torque pattern/specs, not reusing the valve cover bolts, which part numbers you need depending on which year you have, doing the thermostat while you already have the intake off, all of it.

When I first started, I figured the only special information was gonna be the part numbers for the ignition coils. Oh how naive I was! It was definitely a good call to be recording all of this.
Hopefully, I'll be the last person to have to go through this specific set of mistakes. I'll make a dedicated thread for the video and link it here when I'm done.

Y'know how long it took me to do the same thing on a Toyota? It took about 30 minutes, and that's because I also double-checked the timing while I was in there. Nissan always finds a way to make everything overly complicated, and then underexplain everything as if we're all just supposed to know all these weird, niche things that literally only apply to this specific engine in this specific vehicle.