Hello Roverers!

Since some days ago I've been feeling my 2002 DISCOVERY SII SE with nearly 162K miles "sputtering" a bit or just "jumpy". Initially it started when pressing the pedal to accelarate trying to overpass another vehicle, but just very mildly; now I've been feeling it when travelling in the 70s MPH, but have also felt it above 30s, again, very mildly, but you can feel it.

Only codes showing are the ones from "Three Amigos" (1520 if I recall well), and 0420, Bank 2 Converter not working properly; these two have been present for a very very long time, the latter comes and goes, so these are nothing new. No other warning light or signals are being shown.

I still can listen to that high pitch turbine-like sound that I wrote in another post, but have ruled out driveshaft failure, and have changed front & rear axel fluids, so the noise coming from these has been ruled out. Still need to check pulleys, AC & Alternator to rule failure in those bearings as well. I tell you this, so you may have the "noise scenario" surrounding this new situation.

I've thought of gas issues too, but have been filling up regularly with Premium gas at my neighborhood Costco; in fact, last fill up I threw in a can of Seafoam, as I try to do every 5K miles or so. BTW, after last oil change, replacement of front main oil seal, and front & rear axels fluids, I've felt the gas consumption to have been better; lately I have been travelling nearly 320 miles or so before each fill up, and MPGs have stayed above 14... seems to be a good sign in that departament! ;-]#

This weekend I'm planning on checking spark plugs "visual conditions", and wires, to try and rule out something disconnected, etc... but I guess this would throw a missfire code if disconnected or faulty.

Any pointers as to where to look to solve this situation, ahead of the weekend, would be greatly appreciated, thanks in advance! ;-]#

 

When was your last tune up. If if is random, SES lights might turn on and disappear. You dont have any codes at the moment just the catalytic code. Might be clogged but often some O2 codes should appear first before the 0420. Any significant codes showing at this time?

 

Thanks LR03NJ for your response.

Last "tune-up" I did, that involved replacing spark plugs and wires, was a bit over 33K miles ago (08/2014).

SES light only appears when 0420 comes back to life, is the only code showing for quite sometime already; any other had been taken care of already, and it has been a very long while for any other to appear -well over a year if I had to guess, just that 0420 that comes and goes randomly. If it gets too annoying I just clear it, but it comes on again eventually, I guess until I replace the darn thing, no need for that now in SoFla.

No other codes appear before showing 0420, I guess I'm passed that scenario with this converter.

Other than that, 1520 -if I recall right- the one that goes on when ABS issues and Three-Amigos is the other code that shows up, but does not turn the SES light on.

Thanks again.

 

Best way is to check the spark plugs, at least you can get some clue on its condition. Some does not last long, theres always 1 out of 8 that fails or even more. With regards to ABS, I never had problems yet with those but once in a while I see amigos but they disappear.

 

Thanks, that was my thinking, since it sure feels the fault to be along that line -or gas realated- so hopefully a spark or wire might faulty, maybe in an early stage that prevents from throwing a code just yet. As per the Three-Amigos, they are my amigos and accompany me since day one, so I see these dudes every day! ;-]#

 

Good you have company. You'll be lonely without them. LOL!

 

Plugs are a good place to start.

My experience with Costco gas is that it's not any better than low octane from any other non discount chain (Exxon, BP, Shell). I have been using non ethanol 93 octane and my truck has never run better. It's costs more but the difference is noticeable in mpg and I no longer have the kind of issues you are describing.

 

x2 on what Frank said about Costco gas. I really think is the bottom of someones tank from 5 years ago/
Have you replaced the coils?
In my experience, what I thought was just a little hesitation quickly spiraled into giving all of the appearances of of my D2 going into a seizure. Replaced the coild and have not looked back.

 

Thanks for the feedback FRANK4, but truth be told I have only experienced a good performance with Costco than what I have used before, which was 83 from whomever was cheaper, until I mistakenly hit the 93 button once while filling up at Costco, and the difference was felt immediately, so have been using 93 ever since, mostly from Costco though... maybe once or twice from Shell or Mobil. In my last 3 to 5 fill ups I've noticed a better mileage per gallon, might be due to all services I've been doing to my truck, is just running better overall... until a week or two ago that it started to feel slightly jumpy and sputtery at times when cruising... but again, your comment on Costco's 93 is welcomed, and it is not the first time I've read it, I guess I should cough-up the difference and start filling up with some other brand and be on the lookout for any improvements. Thanks!

 

Thanks for the feedback MATT3502, and nope, I have not changed the coils, and yes, maybe more than sputtering and jumpy is does feel like it hesitates a bit. Last time I saw the coils they looked pretty old and banged up, but again, mostly anything on these trucks look old and banged up, but I'll keep it in mind, even though it is a PITA to get to it! ;-]#