Engine runs bad. cylinder 6 doesn't work (?)

[emi]

I took off from the light and at around 3k rpm, I felt the engine loosing power, then as i cruised away, the engine was shaking when accelerating... So, I pulled over and after looking around the engine. i pulled out the spark plug wires, one by one... cylinder 6 made no difference... all the other ones made the engine run worse... so.


there is current going into the spark plug. the thing arcs audibly.
replaced all spark plugs, it didn't help.
replace all ignition wires, distributor cap& rotor - no good.

I checked the injectors, they were EXTREMELY dirty, so I just replaced those. Still no good. What the heck is wrong with it. this car has been nothing but trouble, sucks too... it's only got 76k miles on it. The timing belt was replaced 500 miles ago.

[Jordan]

broken rocker arm

[emi]

that sounds bad... what's involved in fixing that? rebuild the head?

[A_325i]

rocker arms are cheap and fairly easy to replace..get a bently manual or a haynes manual ..but while your at it if your replacing 1 rocker then you might as well replace all of them...that will cost you a decent penny but its worth it

oh and also to tell if you have a broken rocker arm just take off your valve cover...

unbolt the brack that is attached to the intake manifold and the valve cover then remove the breather hose that is attached to the valve cover...then remove all the nuts on the valve cover and it should pop right off....you might want to get a new valve cover gasket when you do this and clean off all the old gasket material once you remove the valve cover you can clearly see all the rockers and will easily be able to tell if one is broken or not

[emi]

yeah, did that yesterday. the rocker arms are all fine. I'm thinking of other possibilities... Is it possible that low fuel pressure causes the last fuel injector to not get any gas?

I checked continuity on the harness, also. Seems good. there's no cuts or anything like that.

[kowalski]

is it getting fuel? is the injector clogged? could be fuel presure change your fuel filter as well. also check to see that the number 6 injector plug is getting power.

[emi]

yes, it's getting power. the spark plugs and wires are new, and I can hear the arc on the plug when I get the connector close enough. Fuel filter is my next bet... I shoulda thought about that earlier... Oh well, it needed all those parts anyway.

[modifiede30]

Let me get this straight. You have a problem with cylinder 6 where there is spark and the injector has power but you're not getting any combustion? I can't see how a filter is going to impact only one cylinder, it feeds a single fuel rail. I would pull the fuel rail to make sure something isn't clogging the rail near or at injector 6. Also, rather than listening to the arc, I'd make sure that's what's actually happening via visual inspection, and run a compression test to see if you have a major leak on 6 somewhere that's preventing combustion all together.

[emi]

Let me get this straight. You have a problem with cylinder 6 where there is spark and the injector has power but you're not getting any combustion? I can't see how a filter is going to impact only one cylinder, it feeds a single fuel rail. I would pull the fuel rail to make sure something isn't clogging the rail near or at injector 6. Also, rather than listening to the arc, I'd make sure that's what's actually happening via visual inspection, and run a compression test to see if you have a major leak on 6 somewhere that's preventing combustion all together.

yes, correct. As you suggested, the fuel filter made no difference. I check fuel delivery, as described in the bentley manual.. it's good. Compression test revealed no compression, tho. I'm not sure i did it right, but the pressure gauge should have indicated something. I plugged the gauge on a different cylinder, turned the engine by hand, and the gauge showed some 30psi. However, on cylinder #6 it was 0. my dad was funny, he kept turning and turning, maybe it'll come back to life, lol... he was attempting CPR or something, hehe..

I also plugged an air hose to it, turned it again, and listened for air escaping. I was expecting to hear ait coming out of the valves, through the exhaust, and the intake, alternatively, as well as moments of silence... but there's always air coming out from somewhere... don't know where... nor do i care. I'll tow it to the shop. i'm done screwing with it.

[modifiede30]

yes, correct. As you suggested, the fuel filter made no difference. I check fuel delivery, as described in the bentley manual.. it's good. Compression test revealed no compression, tho. I'm not sure i did it right, but the pressure gauge should have indicated something. I plugged the gauge on a different cylinder, turned the engine by hand, and the gauge showed some 30psi. However, on cylinder #6 it was 0. my dad was funny, he kept turning and turning, maybe it'll come back to life, lol... he was attempting CPR or something, hehe..

I also plugged an air hose to it, turned it again, and listened for air escaping. I was expecting to hear ait coming out of the valves, through the exhaust, and the intake, alternatively, as well as moments of silence... but there's always air coming out from somewhere... don't know where... nor do i care. I'll tow it to the shop. i'm done screwing with it.

Based on what you described, it sounds as though you've blown a ring or put a hole in your piston (at least a crack). If there are no metalic sounds from the engine, than I suspect there's nothing wrong with the head, and would bet on the bottom end. One last thing you might want to do is put a flashlight in the 6th cylinder and see if you can see anything strange when its at TDC. Otherwise, I'd have a shop look at it unless you want to pull the head.

[kowalski]

i doubt it would put ahole in a cylinder just from driving down the road, could be rings, or head problems too, cracked head, could be a blown head gasket if you only cranked it once over, usualy you crank it a few times to see what it maxes out at. hopfuly its nothing major tho. anyways good luck!

ps: you should be getting a hell of a lot more then 30 psi.

[emi]

i doubt it would put ahole in a cylinder just from driving down the road, could be rings, or head problems too, cracked head, could be a blown head gasket if you only cranked it once over, usualy you crank it a few times to see what it maxes out at. hopfuly its nothing major tho. anyways good luck!

ps: you should be getting a hell of a lot more then 30 psi.

yeah, thanks.. and i wasn't trying to measure it acurately.. I just saw the neadle move on cylinder 3 and that was good enough of a test for me. the 6th cylinder showed nothing.

[emi]

the shop has it, and they confirmed that there is no compression on cylinder 6... they are blaming the intake valve, but won't know for sure what's going on until they pull the head off.

[modifiede30]

Hopefully it didn't get stuck open while it was running.

[emi]

it got stuck open alright. i'm so @#$%@#$%@#$%@#$%@#$% off. a metal clip got suck in, and got jammed on the intake valve. no damage done, except my pocket and my ego. That metal clip got in when I cleaned the AFM. What else am I gonna break? oh, I already broke a bolt. I hate it when this happens... 10 times in a row.