Loud misfires, loud bangs, stock car, no CEL
 

Hey, I need help.

My 86 has a nasty misfire on nearly every startup and also under load (partial throttle to full throttle), mostly between 2500 and 3300 RPM.
Only when I accelerate really slowly and carefully the car doesnt do it.

It sounds like this : https://www.youtube.com/watch?v=450Pov98STg.

Not my video but same noise and under load its even louder, scarier and very frequent.

Has anyone experienced something similar or knows someting about this issue?

Thx :)

Could be a coilpack. Check the coilpack closest to the passenger's side headlight. And by check, I mean replace.

Hello emerahl86 and welcome to our forum - :clap:

Have you hooked up an OBD reader up to see if it shows and codes?

Does your car have any power mods?

What was the last thing that you did to the engine?


Come back.

:)

If new take it to the dealer.

Even if there is no CEL, the car is still counting the misfires and storing them in a counter somewhere in memory, the CEL will light up when that counter reaches the correct value for a trouble code to set, but you can still read the counter before there is a trouble code.

It's in MODE $6, and you're not going to get to it with a cheapo code reader. So I suggest you bring it to a trusted mechanic.

You CAN throw parts at it like suggested above, but I'll always advocate investigation over playing darts with parts.

Thanks for the replies so far.


I will replace the coilpack as suggested.


I also already opened the engine and found a different Issue:

The long screws which hold the two engine blocks together, (on the left side, besides the cylinders, way down there) are rusted and there is oil sludge around them. Looks like they dont seal properly so oil from the crankcase seeps in. Anyone experienced this issue ? I will take a picture/s next time I'm at the Garage.


To answer some questions: Car is from 2013; just bought the car 2 months ago; only mods are K&N Filter and a catback exhaust, no engine tune afaik, but I'm the 6th owner so - no idea; didn't try a proper OBD reader yet, but will do that.


I will report back if I fix it or break it further.


Anyone have some suggestions on what to look for, now that the engine is out?

Or useful Mods ? Small stuff, like oil cooler maybe?


Thank you :)

sweet, some people pay money for bangs and fire.

I gotta remember that one. Thanks! :thumbsup:

Change the spark plugs.

Possible DI seal failure.

https://www.youtube.com/watch?v=eqrlwMgfqtY

Sweet lord there could be almost anything that was done and then removed.
Probably a reason it has changed hands so often.

Did that already, forgot to mention that.

I'd break it further but that's just the way those things go.

So you did the plugs already, now change the serpentine belt and maybe the idler pulley/tensioner. I'd also change the throwout bearing and clutch fork. Put in a Fumoto valve before you refill the oil.