GX460 Not Starting (On Trail)

[mdtwyne]

Hey Folks, just back home to Denver from a great trip through Moab. Full write up to come, but unfortunately my 2011 GX460 is still on the trail. Everyone is ok and local law enforcement has been notified. I'm hoping that the community here could provide troubleshooting suggestions given the following situation:

Sunday afternoon I was driving slowly in 4low with center diff locked, up a steep incline approaching some stair steps. The engine skid hit the first stair, and the engine immediately shut off. Only noticeable damage is an oreo sized dent in the passenger side of the front slanted potion of the OE engine skid. There is nothing meaningful behind that point except metal support bars that tie back into the front diff mounts.

I attempted to restart the engine. The starter turned the engine over quickly and easily, but no sign of it catching. A "low oil pressure" warning message came up on the center dash. I could see no evidence of oil leaking anywhere. I should have checked the dipstick for actual oil level but forgot to given I didn't see or smell any leaks and was pretty stressed out. The oil was last changed 4k miles ago at a trusted Denver shop, Tru Automotive. I am not aware of the engine burning oil so I don't check it regularly but that is a small possibility. Truck has 90k miles and runs very well prior to this.

Based on web research and speaking to @Inukshuk and Dan Kunz of GXOR, we suspect the following possibilities:

1. Loose or damaged oil pressure sensor sending a false (or no) reading, causing the ecu to deny fueling. This sensor is located just above the fuel filter.
2. An impact related safety system cutting fuel.
3. Slightly low engine oil exacerbated by the incline and impact.
4. Damaged oil filter restricting flow.
5. Loose fuse

My goal is to return to the truck, get it running, and drive out. Aside from extra gas and tools, I am currently planning to bring the following:

1. Several quarts of oil
2. Scan tool that can read and clear codes for ecu and safety (SRS) computer
3. New oil pressure sensor
4. Spare fuses

Has anyone encountered this sort of issue before? Any recommendations for what to check or how to check it?

I am also looking for assistance to get back to the truck, ideally sometime this week or coming weekend March 25-26. I am happy to pay the right person for their time and assistance. Thanks!

 

[HDavis]

You should get a laptop with Techstream on it. This will tell you a lot more information about what's going on with various sensor in real time.

 

[Romer]

When the starter was cranking did it sound like at full power? Wondering if you knocked a ground loose that was attached to the skid plate

 

[Romer]

This is for an 80 series, but should be able to give you some other things to check https://forum.ih8mud.com/threads/em...-item-recommend-keeping-copy-in-truck.115816/

 

[CardinalFJ60]

You have the 4.7 in that right?

I had a weird thing happen that @Inukshuk help me with once. It was like an over pressured fuel line. It was a matter of putting a bunch rags over it and remove/replace, squirted gas, cleaned it up and waited for it to dry up. Started right up after that. Daniel can prolly explain it better.

DS soft fuel line, weird little clip on it. I think it was green.

 

[Inukshuk]

You have the 4.7 in that right?

I had a weird thing happen that @Inukshuk help me with once. It was like an over pressured fuel line. It was a matter of putting a bunch rags over it and remove/replace, squirted gas, cleaned it up and waited for it to dry up. Started right up after that. Daniel can prolly explain it better.

DS soft fuel line, weird little clip on it. I think it was green.

I had that situation in my mind when I brought up checking for fuel on the call with Matt and Dan this morning. Offhand Dan did not know 1) where and easy disconnect was like on the 100, and 2) whether an old brittle clip would break if tried.

 

[mdtwyne]

Thanks for all the fast replies folks! Few answers and clarifications:

1. Techstream seems like a great option @HDavis. I'll try to source the software and a cable before heading back to Moab.
2. The starter was definitely at full power. Very fast, no hesitation. Thanks for the Troubleshooting FAQ @Romer !
3. GX460 is a 1UR-FE, 4.6 V8

 

[nakman]

Matt, not sure where it's parked but is it possible to get strapped off the trail? You can still operate the steering and brakes, right?

I'm not much help tech-wise, I do think the oil pressure sender is a long shot and pulling a pan out in the desert just to rule that out sounds awful.. if at all possible to do that work back in town, or better yet back in Denver, that would be my plan A.

 

[mdtwyne]

@nakman - Steering and brakes are operational, minus mechanical assistance given the engine is off. There are several steep obstacles with off camber and sharp turns that would feel dangerous to me in a towing situation. But beyond that, 90% of the way back would be manageable for towing. My concern is finding an appropriate tow vehicle and a driver that is both willing, available, and cautious / skilled enough to attempt it safely. Those logistical challenges are compounded by me living out of state.

If it came down to it I could rent a Jeep to tow with, so finding the right driver is the primary concern.

Based on troubleshooting feedback here and on GXOR, I am optimistic about being able to get it started on trail. If that doesn't happen, I'm tempted to bite the bullet and hire Rory at Moab Motorsports to tow it in the interest of safety.

 

[KC Masterpiece]

I have a techstream cable if you need to borrow one. Right off the highway in Silverthorne.

 

[mdtwyne]

UPDATE: Truck was recovered this past Saturday. Big thanks again to everyone who chipped in ideas and support. And particular shoutout to my girlfriend McKenna, @Inukshuk (Daniel), Dan Kunz, and the legend Mark Weissinger.

For background, I met Daniel by chance in a grocery store parking lot in Fruita on the way out to Moab first time around. (I used to own an 80 series and naturally pulled up next to his when I saw it.) We talked about meeting up at the next Rising Sun Land Cruiser club meeting in Denver and exchanged numbers.

Fast forward a few days later with my truck stranded on Lockhart Basin and me back in Denver, scratching my head on what to do. Took a chance on calling Daniel, presented the situation, and asked if he had any suggestions. Daniel went out of his way to connect me with Dan Kunz for troubleshooting assistance and Mark Weissinger who lives in Moab.

With help from this community I had a pretty good short list of potential issues, so my girlfriend and I packed up parts and tools and headed back to Moab in a borrowed Jeep. I connected with Mark and we made rough plans to meet up Saturday morning down Kane Creek Rd. That was hard to coordinate though, given the lack of cell service out there. My girlfriend and I started hiking before Mark got there, and luckily were at the exact perfect point on a switchback to look down the canyon and see him approach. We screamed and waved and finally got the message across to come further up the road. Sound dilutes pretty quick in those huge open spaces and apparently he barely heard us. He drove up and we walked back down. Mark masterfully drove 99% up the treacherous part of the canyon in his mildly modified 470, never once getting out to check an obstacle. We stacked lots of rocks in an attempt to get him over the crux boulder at the top, but our rock stacks kept settling and collapsing so we abandoned that idea. In another demonstration of shocking talent, Mark backed down the treacherous hill largely unaided until he could find a spot to pull off trail.

Next, the three of us hiked 3.5 miles south to the truck. Mark hiked in flip flops haha. Upon arrival we checked the oil (full) and disconnected the battery to clear any potential codes. Mark started checking out the aftermarket remote start system, which includes a kill switch down by the e-brake. Once he looked under there, the issue was clear. I have an aftermarket dash switch that allows the KDSS system to be switched on/off. The switch ties into the fuse panel under the driver's dash with a fuse tap. That fuse tap had fallen out, and happened to be tapped into the ignition circuit. Upon replacing the fuse, the truck fired right up!

We had originally planned to drive out the easier but much longer way to the south. With the confidence of Mark's spotting help, we proceeded north. With ample rock stacking and Mark's masterful spotting, we got the 460 down into the canyon bottom with minimal drama.

We paused to celebrate near the bottom and saw a convoy of well modified Land Cruisers coming down behind us. The 80s and 100s walked through everything with ease, including one 100 series towing a camper trailer. Incredible. They stopped to chat and one of the crew turned out to be Kurt Williams. His group was scouting for Cruise Moab. Everyone was very friendly and Kurt spotted us the remainder of the way down.

I can't say enough about Mark's contribution to the recovery. All in, he gave twelve hours of his weekend to help a stranger. I'd like to think we would have figured it out eventually on our own, but his presence contributed to a drastically faster, safer, and more emotionally stable recovery effort. I would not have attempted driving out to the north without him.

I also want to give credit to my girlfriend McKenna. She is afraid of heights and has never driven off-road before, but overcame her fears and smoothly piloted the borrowed Jeep over the remainder of Lockhart Basin and Kane Creek Rd back to Moab. The recovery would have been logistically impossible without the gift of her time and help.

 

[Johnny Utah]

Thanks for the follow up!

 

[FZJ Dave]

It was good to meet you guys @mdtwyne! I was there in the last 80 of the Wasatch Cruisers group. Glad the truck is off the trail and y'all are home safe!

 

[Romer]

Awesome news.