E55 M113K Misfire Cylinder #8 P0308

SL03WLY · Dec 11, 2020

Hello,

I recently got an E55, all was well and after a steady cruise for around half n hour or so, I started to notice what sounded like a misfire when I would press the accelerator from around 10-20mph. So, when revs were low. Thewn I approached a set of lights and felt the car shaking and a bit of vibration and then the Engine Management light appears. Scanned with OBD2 and it showed me P0308 misfire on cylinder number 8. I am looking to replace all 16 spark plugs and the coil pack for number 8 for now.

I have read possibly the valve cover may be leaking onto the ignition leads?

I wanted to ask, if anyone else with an M113K engined vehicle has experienced similar misfire situations and what course of actions you took to get the matter resolved please?

Many Thanks

Gbrowncls55 · Dec 11, 2020

Mine occasionally has a slightly uneven idle but a good blast with a couple of pulls up to 6k usually seems to clear it. Most of the time these cars dont get much above 2k revs so the occasional blast is probably in order. What you are thinking of doing if the Italian tune up doesnt work seems the correct route in response to that error code

SL03WLY · Dec 11, 2020

Gbrowncls55 said:
Mine occasionally has a slightly uneven idle but a good blast with a couple of pulls up to 6k usually seems to clear it. Most of the time these cars dont get much above 2k revs so the occasional blast is probably in order. What you are thinking of doing if the Italian tune up doesnt work seems the correct route in response to that error code

Yeah, I umm meant Italian tune-up when I said "steady cruise". I will report back after changing the spark plug and coil pack.

Will · Dec 11, 2020

Possibly a coil pack or lead. Is it worse in damp weather?

You could swap the coil over (and/or leads) to see if the fault transposes?

IanW · Dec 11, 2020

Mine is an M113 - no compressor. A similar problem; changing the leads & coil packs around didn't help isolate the problem, I suspect more than one lead had failed, but the 2 plugs per cylinder hid the fact. In the end I changed all the leads. Then the faulty coil pack (#5) was easily identified as the problem.
I was helped by the OBD reader I was using showed live data for 'engine smoothness' per cylinder.
I was surprised by how obvious a misfire was on an 8 cylinder engine.
Ian.

SL03WLY · Dec 11, 2020

IanW said:
Mine is an M113 - no compressor. A similar problem; changing the leads & coil packs around didn't help isolate the problem, I suspect more than one lead had failed, but the 2 plugs per cylinder hid the fact. In the end I changed all the leads. Then the faulty coil pack (#5) was easily identified as the problem.
I was helped by the OBD reader I was using showed live data for 'engine smoothness' per cylinder.
I was surprised by how obvious a misfire was on an 8 cylinder engine.
Ian.

I have come across a few forum threads that mentioned low compression in cylinder 8. I hope I am not a victim of that....

I managed to get hold of the bosch coil pack for £50 off Amazon. Part No. 0221503035 (0 221 503 035). Will also be checking the VCG, but not sure if all the plug wires are the same. Can these be swapped around?

Will · Dec 11, 2020

If you suspect a compression issue, grab a compression tester and whip one of the plugs out. Only a couple of minutes work if you’ve already taken off the coil pack and lead.

The M113K is pretty tough - I’ve seen the odd mention of this issue, but can’t recall an issue like that with standard cars. Has yours been modded?

The leads come in a few different lengths, but there’s only a few mm difference one some of them. You should be able to find a pair that can be swapped around

merc85 · Dec 11, 2020

I had miss fires when the old fuel pumps were getting tired, BUT she never through a Engine light on or code.

Rocker cover gaskets do leak quite common but it would have tobe bad to cause a miss fire.

Leads and plugs worth changing if you dont know when they were last done.

I did all 8 coils, Plugs, Leads on mine but only out of preventative maintenance.

I do still have the coils which tbh are all good if you'd like to try them? I'm in Great Ormond Street This Monday if you met me there id be happy for you to try them see if it cures your problem.

I take it your car is a m113k?

SL03WLY · Dec 12, 2020

Will said:
If you suspect a compression issue, grab a compression tester and whip one of the plugs out. Only a couple of minutes work if you’ve already taken off the coil pack and lead.

The M113K is pretty tough - I’ve seen the odd mention of this issue, but can’t recall an issue like that with standard cars. Has yours been modded?

The leads come in a few different lengths, but there’s only a few mm difference one some of them. You should be able to find a pair that can be swapped around

Ah ok, yeah I have noticed its mostly in US where these issues are occuring. As far as I'm aware it is a standard car. I started her up the other day and noticed a rich burning smell? Not sure if I can describer it any better. Will try compression test if spark plug doesnt do justice.

SL03WLY · Dec 12, 2020

merc85 said:
I had miss fires when the old fuel pumps were getting tired, BUT she never through a Engine light on or code.

Rocker cover gaskets do leak quite common but it would have tobe bad to cause a miss fire.

Leads and plugs worth changing if you dont know when they were last done.

I did all 8 coils, Plugs, Leads on mine but only out of preventative maintenance.

I do still have the coils which tbh are all good if you'd like to try them? I'm in Great Ormond Street This Monday if you met me there id be happy for you to try them see if it cures your problem.

I take it your car is a m113k?

Ahhh thats interesting, I have read around the fuel filter being within the pump housing unit and needs to be changed around 60k mark. Im on 143k and have no history of it being changed. Also, yes its an M113K E55. Let me see how changing the one coil goes, and I will ping you a message if anything. I much appreciate your help though. Thanks!

Will · Dec 12, 2020

amand said:
Ah ok, yeah I have noticed its mostly in US where these issues are occuring. As far as I'm aware it is a standard car. I started her up the other day and noticed a rich burning smell? Not sure if I can describer it any better. Will try compression test if spark plug doesnt do justice.

Smell from the exhaust or engine bay?

If from the exhaust, maybe the cats have been modded/removed? If from the engine bay - maybe an exhaust leak, or oil burning from a leak (eg cam covers etc)?

SL03WLY · Dec 12, 2020

Will said:
Smell from the exhaust or engine bay?

If from the exhaust, maybe the cats have been modded/removed? If from the engine bay - maybe an exhaust leak, or oil burning from a leak (eg cam covers etc)?

Im not 100%, but I started it and left driver door open and I can't for the love of God pinpoint it. It seems more obvious rom the front and under driver side door, but also from the exhaust area too. I really hope CAT's aren't bashed out, will be well annoyed! Mind you the EML wasn't on when I bought it, though I can hear the V8 exhaust tone a bit but no drone or rasp. Can the EML be programmed out to accomodate decats?

On a side note, I see you have a 190E 2.5 16v. That must be a good hoot to drive.

AMGeed · Dec 12, 2020

amand said:
Can the EML be programmed out to accomodate decats?

Yes it can.
I'd suggest the London branch of MSL in Dagenham seeing your location.

Coming Soon - PPL Tuning

ppl-tuning.com

Will · Dec 12, 2020

amand said:
Im not 100%, but I started it and left driver door open and I can't for the love of God pinpoint it. It seems more obvious rom the front and under driver side door, but also from the exhaust area too. I really hope CAT's aren't bashed out, will be well annoyed! Mind you the EML wasn't on when I bought it, though I can hear the V8 exhaust tone a bit but no drone or rasp. Can the EML be programmed out to accomodate decats?

On a side note, I see you have a 190E 2.5 16v. That must be a good hoot to drive.

Check the clamps between the cats and the downpipes are intact and not broken or loose.

Whilst you’re there you can have a quick look to see that the cats are still there - although I’ve heard of people having them gutted out and welded shut/refitted.

O/T - The 2.5-16 I currently own has been off the road for a few years (family/work/life balance and too many other cars), although I did have it running earlier this summer during the lockdown. I really like these 16-valve 190Es, I’ve run six of them (2.3 and 2.5) since the early 00s. They’re great cars to drive, although I suspect the fond memories I have of them probably wouldn’t cut it as much nowadays since I’ve been spoilt with various other machines since!

SL03WLY · Dec 12, 2020

AMGeed said:
Yes it can.
I'd suggest the London branch of MSL in Dagenham seeing your location.

Coming Soon - PPL Tuning

ppl-tuning.com

B*llocks, I feel mugged off. Thanks for the referral, will call them up.
Btw with decats, I thought it’d have been a rotten egg smell? Am I mistaken?

SL03WLY · Dec 12, 2020

Will said:
Check the clamps between the cats and the downpipes are intact and not broken or loose.

Whilst you’re there you can have a quick look to see that the cats are still there - although I’ve heard of people having them gutted out and welded shut/refitted.

O/T - The 2.5-16 I currently own has been off the road for a few years (family/work/life balance and too many other cars), although I did have it running earlier this summer during the lockdown. I really like these 16-valve 190Es, I’ve run six of them (2.3 and 2.5) since the early 00s. They’re great cars to drive, although I suspect the fond memories I have of them probably wouldn’t cut it as much nowadays since I’ve been spoilt with various other machines since!

Took a peek and cats are they. But can’t tell if its been open welded or gutted.

O/T ah the good old days without 20mph limits and average speed cameras

clk320x · Dec 13, 2020

Are you the guy who bought the 6k E55 for sale near Peterborough?

Sorry to hear you’re having issues with it, I saw it advertised on Facebook and the guy said he took it in PX, guy seemed a bit dodgy seemed to be based in a scrap yard?! Then mysteriously it got deleted overnight and another guy relisted it the next day, he said he bought it from his brother but all of a sudden realised it’s not for him?! Not sure how genuine the story is, seems like a load of lies!

SL03WLY · Dec 13, 2020

clk320x said:
Are you the guy who bought the 6k E55 for sale near Peterborough?

Sorry to hear you’re having issues with it, I saw it advertised on Facebook and the guy said he took it in PX, guy seemed a bit dodgy seemed to be based in a scrap yard?! Then mysteriously it got deleted overnight and another guy relisted it the next day, he said he bought it from his brother but all of a sudden realised it’s not for him?! Not sure how genuine the story is, seems like a load of lies!

Oh that doesn't sound good. Was that the silver one for sale, and looked like it was taken off roading?

SL03WLY · Dec 13, 2020

Right, so misfire seems to have now fixed. Time will tell but thank God its running. Much better now but still bit vibration on idle, interior lights also seem to flicker a bit and it shifts bit hard on downshift at slow speeds. History showed it being changed last in 2011 at around 91k. Don't get why people buy these cars but don't keep on top of the maintenance. Seems that valve cover leak dripped into the #8 ignition coil ground area which might have messed it up.

We replaced #8 and all 16 plugs. The HT leads were a pain in the back side to remove, some have been replaced in the past with Beru ones. Lot of inconsistent parts being replaced.

Broken intake hose too and the plugs the go into the ignition coil have been tied with metal clips as they broke the tabs.

Lot of oil leaks around too, more from from 5-8. Pics below, the spark plugs all appear either full or thick carb soot, oily and smell of unburnt fuel which is expected I guess.

Will appreciate any direction or advise on fixing the oil leaks, broken tabs and intake fix as the cable tie just isn't doing it.

Many Thanks

Cylinder 5-8 plugs: