Broken Down in N. California..north of Eureka

Any update to this topic? Wondering if the OP got his rig fixed and what the diagnosis was.

Dale

after numerous attempts at restarting, it would barely run rough and not at idle

This has me thinking 'valves' . Sudden high revs caused relatively weak valve springs to jump the cam lobe ? just my guess .

Also check to see it there's any plastic shrapnel on top of the motor. It's also possible you blew up the intake plenum. This would also cause very poor running because the throttle would be bypassed to atmosphere. This would be a far less expensive repair, although also much less likely. But police officers had this happen occasionally during pursuits in their Crown Vic's, whose 4.6L is the same basic architecture as the V10.

It is very possible you locked em up when that happened. Also very possible is you jumped some teeth on the timing chain, hence the very poor running. If it doesn't sound like a blender full of rocks and there's no lake of oil on the ground, you probably escaped catastrophic engine failure.

The timing chain can jump in this situation because at cruise RPM the timing chain tensioner isn't holdings very much pressure (it's hydraulic from the engine oil). Under high RPMs the chain needs much more pressure to hold it tight, especially with normal wear on the chain guides. A sudden extreme change in RPMs means the chain is flailing outward but the chain tensioner needs a second or so to build more pressure (especially on an older motor with oil deposits making all the teeny passages even smaller).

Re-timing the motor isn't hard, but it's a lot of labor to pull everything off the front of the motor to get to the chain. And you'll want to have a leak down test first to make sure no valves were damaged. A compression test might give a false fail result if the timing is too far off. It also requires a special balance-shaft removal tool which few shops have, since v10s rarely have to be opened up. (I had my timing chain replaced preventativey around 400,000 miles because it had some cold start chain slap from loosening up with age)

That's terrible to hear. Hope all works out well for you guys. Let us know what happens.

Can also try https://www.yelp.com/biz/century-service-center-eureka-2

Thanks for the shop's name in Fortuna and we Will call them.
Also the date of mfg is a 1998 like the poster above indicated. Speed was around 50mph. It happened fast and do remember smelling rubber so that would have been due to rear wheels locking I think? Yes or no? We were very lucky no one was following us.

Unfortunately your '99 may have been built on a ''98 chassis, which would mean it has an E4OD transmission which had a conventional valve-body, so over-revving on a manual downshift is possible (not so with the 4r100 which came out in '99.

How fast were you goon when 1st gear was entered? Was it still warming up, or had you been driving a while?

I checked with a friend that lives in Eureka and he says that Fortuna Automotive might be what you need they work on trucks and RVs and are highly regarded in the area,you might give them a call.

He also says that they do roadside repair.

Fortuna is about 15 miles south of Eureka.

The transmission is supposed to lockout low gear shift if it will damage the engine.
Sounds like that system failed.