Whats up guys, havn't been active much on this forum been working on my new project. So where to get started. My car started making a weird noise a few secs after mivec engages lasts about 2 secs and stops. Sounds like metal rattling I had just hit my 5000km since my last oil change so I decided to check how it was doing. It was missing 2L OF OIL. The dipstick was dry when I was checking the oil. I went added the missing oil. So now I'm scared that I might of messed something up. Its still performing just as good. Just makes a weird rattling noise that last a second or 2. I know that mivec is controlled by oil pressure so could it have fked up since there was not enough oil for it to function properly?

 

So, either you didn't put the proper amount of oil, or your leaking it out someplace, or the engine is burning it up. Car smoking lots of blue? Drip stains after its parked? Is the drain plug or oil filter torqued properly?

 

No correct amount of oil was put. Everything is properly torqued down. There is no oil dripping. Car doesn't smoke blue at all..

 

Well then that's the problem.
Do an oil and filter change but this time make sure you do use the proper amount. Then take it for a drive and see if things sound OK.. Then try mivec. 4500-5000 RPM should be plenty.
Then check the oil every time you fuel up to see if the car is eating it.

 

I'm pretty sure MIVEC would not engage if oil pressure dropped below normal.

At least I know VTEC monitors oil pressure and does not engage if abnormal, so I'm assuming Mitsu did the same with MIVEC.

What brand/viscosity oil do you use???

I used to run cheap Castrol GTX in my RA and went through almost 2 pints between oil changes. Since then I run Kendall GT1 and barely go through half a pint. Not all oils were created equal...

For that last half-pint, I saw a correlation with high revs, so I'm assuming a fair bit of that consumption is blow-by, the rest is probably due to rings/valve seals being worn out to some extent, as my car is approaching 200 000kms (120 000miles for you excentric americans).

If you aren't already running 5W30 in your car, I suggest you do that. Switch back to dyno oil if you are running full synthetic. Steer clear of crappy oils like most of the stuff they sell at Canadian Tire. PCV valves are cheap, change yours.

If all of that fails, piston rings or valve seals could be the culprit.

 

Oh and last thing. Kendall oils have free oil analyzing, so I'd look into that also

 

I meant yes.. The oil level was checked after the oil change. I only run mobile 1 full synthetic been running 10w-30

 

Perhaps its not an engine problem.

Does the noise only occur within a certain RPM range? I had a similar problem that was due to a cracked front crossmember (the one that holds the front engine roll-stopper/engine mount).

During acceleration, every time my revs would rise above 3000 or so, i'd get a nasty metal rattling noise that lasted until around 5k RPMs, after which the noise would disappear until I changed gears and fell between the 3000-5000 RPM range again.

Replaced the cracked crossmember and my problem was solved.

Just a suggestion, maybe get a good look at your crossmember or add it to the list of possible causes.

EDIT* I also noticed you have an EVO front engine mount which I believe is a bit stiffer than the stock OEM. I have a stiff PU BLOX front engine mount that I believe contributed to the crossmember damage (coupled with my stiff coilovers and one nasty pothole).

 

I had the same happen to me.

I have a Blox, don't have any stiff suspension but also had the nasty pothole thing. Steering rack had to be replaced, along with a few tie-rods, a wheel bearing and a rim/tire.

Corrosion from road salt is to blame here mainly. Justin lives ~2h from here so his car must go pretty much through the same conditions.

I don't remember hearing any noises though except some creaking when putting torsion force on the car. Car felt loose all the time, mechanic saw it while doing a clutch change. Pretty nasty stuff.

Pics of the damage :

 

Well, if you have no drips, and the engine doesn't burn any oil, then it really comes down to not checking oil level often enough. The user manual specifies to check engine oil level at every refuel.

Mivec does depend on oil pressure. If the level was that low that it couldn't make enough pressure to engage mivec then, imo, that would cause your noise.

To rule out any other issues, change the oil and test mivec for noise.

 

I don't think it's crossmember related only happens between 4.5k-5k rpm. When mivec engages. Sounds like a metal plate rattling.. Still with the correct amount of oil it's doing it so doing and oil change shouldn't change much...

 

Hmmm...doesn't MIVEC engage @ 3.5k rpm? I'm thinking it's a loose mechanical connection. Are you sure it's coming from the engine?

Try revving it up while on neutral and see if you get the same rattling noise. Better yet, get someone to rev the engine to MIVEC then listen for the noise. I'm thinking maybe it's a transmission issue just because I've been having transmission problems since the day I got mine...

Let us know your findings!

Take care.

 

Thats exactly what my issue sounded like as well. Just saying...

Regardless, let us know when you find the problem. Im curious!

 

Mivec only engages at 3.5krpm on the 2004 models if I remember properly. With the hackish tune it goes up to 4500 which I find kind of sucks because you loose bottom end and I'm not sure if you can change it with the UVTune software. Hmm so I cant hear the noise in neutral. Also seems like if I very slowly ease into it until 5k and floor it it doesn't happen. I checked under the car as much as I could and it doesn't seem like the crossmember is cracked. If I remember correctly it had been changed already. Ill try to get it up on the lift tomorrow and check to make sure. Any other possibilities?

 

Check your heat shield where it covers the Y pipe under the engine. If that weld breaks, it will rattle to all hell, like mine. Had it rewelded but I can still hear it rattle around 2-2.5K rpms.