Hi all,

I apologize if this is a redundant thread, but I haven't found anything yet that quite describes what I'm hearing.

I have a 2003 Disco II, 111k miles and yesterday I noticed a noise that I've not heard before that has me a little concerned. When idling, everything sounds normal and as I begin to accelerate, the engine revs as usual. But a second or two after I begin accelerating, in addition to the normal noise of the engine, there's a louder rumble noise and I can feel the engine shaking through the pedal and the floor. It continues as I accelerate and tapers off the longer I accelerate, but then begins again a few seconds after I accelerate again. Rumble isn't quite the right word, but I can't think of another way to describe it. Hopefully that combined with the fact that it's vibrating the engine block is enough to trigger someone's knowledge.

(I should also mention that it's not the same noise that happens at cold startup for 30 seconds, I'm familiar with that sound)

I thought maybe at first that it was tied to a certain RPM, but it seems to have less to do with the RPM and more to do with how much pressure I'm putting on the gas pedal regardless of speed.

I checked the primary air filter and everything seems alright. A coworker suggested that perhaps it's the secondary air intake, since the noise/vibration only kicks in after I've started accelerating and then tapers off. Beyond that, since it doesn't do it while idling, I can't really hear it. Though when I put my ear up to the area where the SAI is, I can hear what sounds like a faint version of the noise I hear from inside when accelerating. Not sure if its actually the same noise or just a similar, normal engine noise.

Also, it seems to be consuming more gas than usual, but I'm not sure whether that's just me over analyzing.

Full disclaimer: I'm not a mechanic and have a very limited knowledge of engines, so forgive any ignorance. I can provide more information or clarity if anyone thinks they may have an idea what it could be.

Thanks!

 

any dash lights? have you gone to an auto parts store and had the codes read?

 

To my knowledge, the SAi 'only' kicks in at startup, although mine sometimes does at stop lights, hasn't for a while. It isn't related to engine revs at all. And wouldn't make your foot wells rumble. Even one about to explode from worn bearings doesn't do that. That just sounds like a very angry vacuum cleaner.

As above, any codes? That's the first thing to do, see what the car is trying to tell you.

Be a bit cautious that it 'could' be your front drive shaft, which you really don't want going wrong.