89 civic hatch DX

So I'm cruisin down the freeway about 80ish for a good 15 min, all of the sudden there's this loud sound I can only describe as a automatic paintball gun going off fast, it was not a metallic noise, more of an air noise. My first thought was severe backfiring, but it was not the usual loud pop or combustion sound of a backfire, it sounded exactly like air blowing in hard fast spurts. (like a paintball gun). I almost thought I blew a hole in my exhaust.

Simultaneously the car held back fast, quick loss of power. BUT as soon as I let off the accelerator the noise stopped instantly. I eased on the accelerator again, and it was fine for about 30 seconds, then same thing, I let off again, instantly stopped, gave it more gas, about 30 seconds later it did it again. I gradually slowed all the way down to 50mph before I could give it throttle again without making the noise/loss of power.

I had my window down, and it really sounded like it was coming from the front of the car, which really made me worry it was something with the motor, but my passenger insists he thought it was coming from the exhaust out back.

I get home and check everywhere and everything I can think of. My oil level was about 3/4 on the dipstick, which I quickly fixed. I thought that was strange since I had just had it fully serviced, and looked everywhere for signs of leakage but there was none. Couldn't really contribute that to the noise though....or should I?...

Since then I have tried re-creating the event several times and run my baby pretty darn hard, with only the result of GREAT performance.

Everything is stock. I've only owned the vehicle for about 8k miles (currently at 285k). about 1k miles ago I had a full service:
timing belt,
valve adjustment,
new spark plugs and wires,
and replaced almost every single hose line
and had all major seals/gaskets replaced.

Up until this event, it runs so great I would feel confident enough to drive it on a cross country tour....but what the heck. My honda specialist says he'd have to hear the noise himself...which we cant' seem to recreate at the moment, which I guess is a good thing...just annoying that I can't figure out a solution without it acting up again

anyone had any similar issues?

 

UPDATE:
took the 'ol girl on a 220 mile road trip, avg. speed 75ish, when I reached my destination 1/2 my oil was gone

the trip home exactly the same, but this time, all my oil stayed where it should be

BUT no weird noises, no hesitations, ran great the whole way.....this is weird

 

what did the oil look like?

 

what do your plugs look like?

 

it was definitely dirty, but not due for an oil change for like another 1500 miles

I didn't check them only because they're brand new (about 1000 miles), but I'll check in the morning.

 

BUT, I'm glad you asked, b/c you just jogged a memory. When my mech did all that service work, he replaced me with standard oil....I HAD been running full synthetic. I've heard rumors once you go synthetic your not supposed to go back. But then I've also heard that's not true as well. So I NOW remember thinking "I'll keep an eye on it and just change my oil at the first sign of any weirdness"....come to think of it, the oil I've been adding to the current standard oil is synthetic, so now they're mixing....wonder what rumors will creep from that lmao

 

Ah, I've also heard not to ever mix them either sooooo ya.

 

lmao, I'll put a label on my oil cap that says "synthetic only please" and change my oil in the morning, check my plugs which should still be ok, and see if I notice anymore "weirdness" going on over the next few days, I'll drop an update then

 

You never mentioned whether or not it's a manual or an automatic transmission.

 

ah, oops, yes, MANUAL

 

is it 285k on the original catalytic converter? It could be getting clogged causing exhaust gas buildup.. Take it off and have a look inside it. if you can't see light through the honeycomb, that might be your problem. The fix is either to get a new cat, or "stage 3 weight reduce" yours with one of these on..