Hello all -

I have an '01 Disco named Matilda that I've babied for years that has about 120k miles. I've got a significant misfire situation and I basically am looking for some feedback on my hypothesis and my intended course of action.

I only drive it about 4,000 miles a year or so for off-roading, mountain adventures, etc. From 2018-2021 I was outside of the country most of the time and she sat in storage and was only driven intermittently every 6 months or so. Unfortunately, there was a period where it was left without sta-bil in the fuel and the tank was left at only 1/4.About 6 months ago it developed a bit of a rough idle. I ran some sea-foam through the tank, and it got really bad, flashing engine light, knock sensor code, lean condition, misfires (I believe it was for multiple cylinders, but I don't recall now, I assumed it was an injector issue after having sat the way it did for the periods of time that it did).

I did run some BG 44K through it, but as it was running so poorly by that time I didn't want to cause any damage by continuing to drive it to run a full tank through (I got about 25% through the tank). Oddly, all of the issues went away for about 4 days and I was happy as a clam, thinking that the BG 44K helped knock something loose. Unfortunately, though, the misfire came back and has remained persistent since then.

My hypothesis is that the injectors probably didn't fare too well as a result of the vehicle sitting for extended periods, and potentially compounded by the additive breaking even more varnish or other gunk free, and of course by the improper storage and stabilization of the fuel for a period. My plan is to 1.) Replace the injectors and seals, etc., 2.) Replace the coil packs while I have the intake manifold off.

I'll also note the condition of the plugs and wires (I don't have a place to work on/further diagnose it here in the city, I've gotta have it hauled out to my garage), etc.

About 15k miles ago in 2018, I did the head gaskets, new plugs & wires, valve cover gaskets, belt, all new hoses, thermostat, K&N air filter, etc., and I've tried to keep ahead of most other maintenance.

I'm pretty confident I'll resolve the issues with these repairs, as the symptoms (to me) seem to reconcile well, but I wanted to throw it out there to see if any veterans have further suggestions or insight, or anything else they recommend doing while I'm at it.

Also, should I do the valve cover gaskets again? Open to any suggestions.

Thanks for reading, and happy Rovering.

P

 

Your theory sounds reasonable to me.
I wouldn’t replace my valve cover gasket’s unless they were quite bad.
You should move this post over to the Disco 2 part of this forum.

 

scan for codes before spending money on parts