T

touchwood777

Member
Suddenly my pet develop vibration and rotten egg smell from the pipe. after checking and replacing the spark and HT wire on the cylinder 1, nothing change... I keep the roughness
in cylinder 1 and NO FAULT CODE. do not know what to do..

here is the diagnostic screenshot
rougness1.jpg

air-fuelling1.jpg

o2-1.jpg

general.jpg


please advice.

Thanks
 
Do all the plugs look the same colour?
It could still be a bad plug or lead.
You never get 100% firing on every cylinder every time, that's normal. There's a rolling threshold before it trips a misfire code. 5 isn't ideal but it's not really bad.
Have you done a compression test?
 
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kermit_rr said:
Do all the plugs look the same colour?
It could still be a bad plug or lead.
You never get 100% firing on every cylinder every time, that's normal. There's a rolling threshold before it trips a misfire code. 5 isn't ideal but it's not really bad.
Have you done a compression test?
Click to expand...
level 5 for roughness on cylinder 1 is at idle. the engine vibration and rotten egg smell is strongly felt in the cabin when driving.

I have no fault regarding the injectors?..., and the plug (picture attached) removed from the cylinder 1 was corroded on the wire side but not wet despite the rotten egg smell...

4 month ago, I got rotten egg smell as well when my cylinder 4 misfired, at this time, the plug has full of crap and misfire FAULT appeared. after I changed the plug, everything was fine and no more rotten egg smell.in fact when there is a misfire, unburnt fuel goes in the catalyzer and produce the rotten egg smell.

BUT THIS TIME, even after replacing the spark and HT wire on the cylinder 1, the violent vibration and the roughness do not disappear at all .NO FAULT or misfire is detected by the ecu....
it is like a misfire behavior undetected by the ecu....

the cylinder 1 seems to be the most affected by the roughness according to the diagnostic test.
by the way is it possible that the problem is not from the cylinder 1 but from an other one??
on the first diagnostic screenshot the cylinder 8 have a some roughness as well..., I am wondering if the cylinder 1 and 8 are synchronized or related together?.
 

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no, 1 and 8 are not on the same coil.
roughness is a rolling misfire count. each increase is an actual misfire, but this doesnt count as an actual misfire event until you have a certain number per minute. i think roughness has to reach ~10, if i recall correctly
however, the firing order is 1-8-4-3-6-5-7-2 so if 1 and 8 have more misfires than the rest then this might be something you feel.
you can measure the resistance of your plug leads, make sure it doesnt spike as you wiggle each end.
from the manual;
This (roughness) value will increase the more unevenly the engine is running. Engine roughness is not displayed if idle.
When the ECU detects a possible misfire, this count value is increased by one. If the value increases to more than
a preset limit within 1000 engine revolutions, a misfire fault is set. If not, the misfire count value will be cleared to 0 and a new count begins. It is normal to expect a certain number of 'false' misfire detections during each count.

that said, if the coil, leads and plug are good then you're left with either a valve problem or cam wear

the coil is good because you dont have corresponding roughness on #5 or #6 - wasted spark system
 
kermit_rr said:
no, 1 and 8 are not on the same coil.
roughness is a rolling misfire count. each increase is an actual misfire, but this doesnt count as an actual misfire event until you have a certain number per minute. i think roughness has to reach ~10, if i recall correctly
however, the firing order is 1-8-4-3-6-5-7-2 so if 1 and 8 have more misfires than the rest then this might be something you feel.
you can measure the resistance of your plug leads, make sure it doesnt spike as you wiggle each end.
from the manual;
This (roughness) value will increase the more unevenly the engine is running. Engine roughness is not displayed if idle.
When the ECU detects a possible misfire, this count value is increased by one. If the value increases to more than
a preset limit within 1000 engine revolutions, a misfire fault is set. If not, the misfire count value will be cleared to 0 and a new count begins. It is normal to expect a certain number of 'false' misfire detections during each count.

that said, if the coil, leads and plug are good then you're left with either a valve problem or cam wear

the coil is good because you dont have corresponding roughness on #5 or #6 - wasted spark system
Click to expand...
right now i'd be checking and rechecking the plugs and the leads because its occasional
 
It needs old fashioned engine basics rather the repeated diagnostics, i.e.
  1. Clean or better still replace spark plugs
  2. Test injector spray pattern & clean them. It's easy DIY using a kit like this https://ebay.us/m/cNgk6I
  3. Compression check all cylinders (with spark plugs removed)
  4. Fuel rail pressure (just need a tyre gauge on the test valve)
None of these will log specific faults in the ECU, but just symptoms like you are seeing.

As others have said on RR.net, bad egg smell is probably the CAT's. The fuelling figures look about right.
 
As said it's a wasted spark system, it will spark down 2 leads at the same time. Normally when a coil goes it will impact both cylinders not one.
I would suggest the coil is working fine at this point.

It could be a dodgy injector, but i would say not likely. Yet.

Move the plug to a different cylinder.

Move the plug lead or replace with another of the same length

Do a compression test

Does it get better/worse/same under load?
 
thanks, I will make some check.

just in case I am preparing some spare injector
Bosch 0280155787 is the correct part?

is it possible that the cause of the roughness in cylinder 1 detected by the ecu was actually provoked by an other cylinder (cylinder 8 for example)??
 
I already changed the spark and lead with new ones on cylinder 1 , still have exactly same roughness and rotten egg smell. so next step if it not a faulty coil will be compression and injector test, right?

my previous data reading were made at 720RPM
 
I clean the MAF , changed air filter and again change the plug in cylinder 1 , 6, 8 with new lead. same roughness at 720rpm and 3000rpm in parking mod in cylinder 1 and 8.

I inserted a camera in the cylinder 1, I found nothing special apart some slight carbon build-up.
I usually drive at low RPM (less than 2400rpm) with valvoline maxlife high mileage engine oil.
Does it clear the engine cylinders or injector if I drive at more than 3000rpm in sport mode for a while?

cylinder1-piston.jpg

cylinder1-valve-side.jpg
 
What are the fuel trims showing?
Do they have a post cat lambda sensor?
What are the lambda sensors showing on the diag?
Regular wave patterns or flat patterns when the engine is upto temp?
 
kermit_rr said:
Roughness is not measured at idle so ignore those numbers.
Driving at a high load and higher revs can clean things up if you always drive it like granny
Click to expand...
NEW data under load driving in sport mode 2500/3000+rpm,
the misfires are detected!!! in cylinder 1 and FAULT p1300, p0301, p1319 appeared!
strange the misfires were never detected at idle....

rougness-underload.jpg
 
When my P38 went "lumpy" the garage's fix was to change an HT lead on the cylinder concerned.
This went on for a few weeks and by the time they had changed 3 leads I had had enough and I told them to change ALL the leads and both coil packs.
Never had a problem after that.
 
You have already changed plugs & leads, but try the coils flip anyway. Then clean get a DIY injector cleaning kit & clean the injectors. It's quite easy & that way you will know if one is bad.

If you had a location (town name) someone might be nearby - new members never seem to add location anymore.
 
FOUND THE PROBLEM!!!!!!!!!!
I followed my instinct and swapped the leads on the coil side cyl 1 and 6 that suppose to fire at the same time, and the roughness moved to the cyl 6!

the coil is shot!!!!!!!!!!!!!! only at the coil outpout 1
prob-swap!!-1-6.jpg

so yes coil can fail for only 1 cylinder , my case is clear evidence.
no wonder why I found plenty of corrosion on the cylinder 1 lead.... something was wrong on the coil side as well

Now I have a new BRITPART coil under hand , is it wise to use it or should I buy a BOSCH coil ?
can I remove the coil without removing the inlet manifold, what is the type of screw on the coil??

Thanks a lot!
 
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If you took the leads off and swapped them around then that proves the lead is damaged
You can take the coils out while still attached to the backing plate but helps if the foam backing on the firewall is in poor condition or otherwise damaged. It's a tight squeeze
 
kermit_rr said:
If you took the leads off and swapped them around then that proves the lead is damaged
You can take the coils out while still attached to the backing plate but helps if the foam backing on the firewall is in poor condition or otherwise damaged. It's a tight squeeze
Click to expand...

the leads were changed with new ones when I made the data diagnostic , I just swap the leads 1-6 connectors at the coil side not at the plug side. so for me the coil is faulty not the new leads.
I believe that an electric problem occurred on that coil as my old cylinder 1 plug and lead were badly corroded and the plug end was cracked..
plug-cylin1.jpg
 
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