M113K cold start rough idle

[SL03WLY]

Hi,

I wanted to ask if other M113K owners, see their car engine stumble and possibly misfire on cold start?

Mines has been doing this for a while now, despite having new
- Plugs
- Leads
- Coil packs
- New Injectors

within the last years/4,000 miles. Its also been 4,000 miles since it had a full rebuild.

Once warmed up, the idle hunts 100+/- rpms in Drive or reverse only. The hunting started after getting a stage 1+ remap from MSL. Went back there twice and they can't find anything wrong with the map so. They checked spark plugs to see if they are seated well, map sensor and throttle body changed too with used but working units.

Any suggestions on this please?

Bear in mind that no codes are being thrown up, this was confirmed by merc specialist rather then my own conduct.

I recorded a video this morning of it on cold start, you can hear a ticking noise which is coming from under the rocker cover which goes once I blip the throttle a bit and once warmed up. If you hear the oil pump whine, you can hear it somewhat misfiring and about to cut of for that second.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[mbzclk]

Have you resolved this? I don’t think it’s a misfire.

 

[Matt58]

Hi there, my 2003 E55 with 108k does exactly the same minus the ticking, I like you have in the last 18 months changed plugs leads coil packs, injectors surge tank and throttle body gaskets. On initial startup winter or summer fast idle choke is rock solid, but when Revs decrease the engine never seams that happy, more consistent once drive is selected, and solid again after a few miles, I’m frustrated by this but learned to live with it, no codes by the way, no smoke on start up, nothing when accelerating hard and on deceleration, but I’m using around 1.5-2 lts of 5w40 liqui moly in between 5k mile services, which is a mystery to me, but I’m monitoring this very closely, and when I changed plugs they were all in good condition.

 

[mbzclk]

I think it’s a vacuum fault / EGR fault maybe.
If it seems fine when the Secondary air injection pump is running but gets worse once that stops.

This is demonstrated on the M112 V6 but wonder if it’s similar / same for M113 V8?

Maybe worth investigating. Also look for any split / leaky hoses given they will be 15+ years at this time.

 

[merc85]

have you checked the fuel pumps ? raise the rear seat and the steel inspection hatches, maybe leaking also worth checking the fuel pump pressure they maybe getting weak.

I changed both pumps on my last e55k similar issue

 

[Alps]

doesn't sound like a misfire, fuel pumps were a culprit in mine, the surging could be a loose vacuum pump located behind the rhs surge tank

 

[Matt58]

I think it’s a vacuum fault / EGR fault maybe.
If it seems fine when the Secondary air injection pump is running but gets worse once that stops.

This is demonstrated on the M112 V6 but wonder if it’s similar / same for M113 V8?

Maybe worth investigating. Also look for any split / leaky hoses given they will be 15+ years at this time.

Yes mine is spot on when sec air running, I haven’t ruled out fuel pump, but I’ve checked under seat and all is well in regards to leaking or condition of electrical connectors, and my thinking is that if it was fuel related it would idle rough when warm as well as cold, but I’m no expert. I think I’m going to have smoke test at some point to rule out or pin point vacuum leak, which my gut tells me is the problem?

 

[Matt58]

doesn't sound like a misfire, fuel pumps were a culprit in mine, the surging could be a loose vacuum pump located behind the rhs surge tank

Is that passenger side? (Uk)

 

[mbzclk]

Check the pipework for vac.
Also a stuck EGR valve won’t throw codes so certainly look there.

 

[Matt58]

Check the pipework for vac.
Also a stuck EGR valve won’t throw codes so certainly look there.

Thanks for reply, so it’s the Y80 and Y81 that are the shut off valves? I’m slightly confused as to when they should be on or off as I’ve used my icarsoft and I’m pretty sure sometimes they are both off on cold start then on a few miles down the road, but looking back at some vid I kept one time one was off and one was on on cold start, I must admit I’m a bit confused, would be good to switch SAI off to see if idle improved, really annoying as solid when warm, but I suppose it’s better this way than the other.

 

[Matt58]

Sorry, I think I may have hyjacked

 

[Matt58]

Sorry I think I may have hyjacked some of this thread, apologies to all.

 

[SL03WLY]

Sorry I think I may have hyjacked some of this thread, apologies to all.

I insist you hijack it lol. Its still a problem I have today. No codes, drives fine, pulls hard, no smoke nor have I noticed any oil usage yet.

 

[Matt58]

I insist you hijack it lol. Its still a problem I have today. No codes, drives fine, pulls hard, no smoke nor have I noticed any oil usage yet.

Stand and deliver, yeah bit of a mystery really. If you don’t mind me asking, what exactly was involved with your rebuild? From what I’ve read, you had work done by PCS who have also worked on my car (money pit) several times in the past, and who I would prob have major works undertaken if it came to that.

 

[SL03WLY]

Stand and deliver, yeah bit of a mystery really. If you don’t mind me asking, what exactly was involved with your rebuild? From what I’ve read, you had work done by PCS who have also worked on my car (money pit) several times in the past, and who I would prob have major works undertaken if it came to that.

Sure, it was a full rebuild, so
- Head gasket
- Oil Pump Seals
- Timing Chain and Guides. Believe one of the guides were cracked. Think its the top right guide in the pic below. Looks like its broken there
- Bottom end bearing
- Piston Rings
- Valve Stem Seals

All the pulleys and tensioners have been changed.
Cooling system refreshed too
Throttle Body
Map Sensor
Intake Temp Sensor
Vaccum hoses

I did a break in service too so didn't drive too hard for first 800 odd miles then changed oil. No metal bits and now is stronger I guess, coolant is blue and not seen any oil being used yet.

The heads weren't skimmed though but this problem was present before the rebuild as the piston rings on 3 and 8 were gone and was burning a litre of oil every 50 -100 miles.

However, since then the cars had more problems with airmatic shock bursting and th primary Cats disintegrating. Absolute money pit, but still brings in the smiles though just not as often at the moment.

 

[Matt58]

Sure, it was a full rebuild, so
- Head gasket
- Oil Pump Seals
- Timing Chain and Guides. Believe one of the guides were cracked. Think its the top right guide in the pic below. Looks like its broken there
- Bottom end bearing
- Piston Rings
- Valve Stem Seals

All the pulleys and tensioners have been changed.
Cooling system refreshed too
Throttle Body
Map Sensor
Intake Temp Sensor
Vaccum hoses

I did a break in service too so didn't drive too hard for first 800 odd miles then changed oil. No metal bits and now is stronger I guess, coolant is blue and not seen any oil being used yet.

The heads weren't skimmed though but this problem was present before the rebuild as the piston rings on 3 and 8 were gone and was burning a litre of oil every 50 -100 miles.

However, since then the cars had more problems with airmatic shock bursting and th primary Cats disintegrating. Absolute money pit, but still brings in the smiles though just not as often at the moment.

View attachment 130914View attachment 130915View attachment 130916View attachment 130917View attachment 130918View attachment 130919View attachment 130920View attachment 130921

Wow, great pics, and defo the full works, out of interest what state were the valve stem seals? I suppose the only good thing was the fact the bores were ok, as they are not easy to come by used, and not sure weather your able to adapt another M113 N/S block. I’ve just replaced both front airmatic struts as well, im still having counciling for for that gem, think I’ll have to sell a kidney if I have to pull the motor, still like you when I give it the beans it really puts a smile on my face, and surely has to be one of the best understated sleepers out there.

 

[SL03WLY]

Thanks Matt. The Valve Stem, I can't recall what PCS said about them as they got it done elsewhere at a specialists but on start up I did get a puff of white smoke which no longer occurs so must have been bad.

The bores, unfortunately didnt get any pics, but yes as you said seems to be fine now as its not burning much oil. Probably could use an NA block but not sure if the oil or coolant galleries are the same though both are M113 so could be. as I read someone who turbo charged their E55, they used the E500 intake manifold after removing the supercharger.

With regards to your Airmatic strut change. Did yours level out fine after changing them? When I replaced my one it was lower on one corner then after replacing it the left corner it blew after a month but was lower then the right side despite airmatic calibration.

 

[Mackhack]

M113ML doesn’t have an EGR valve.

 

[Matt58]

Thanks Matt. The Valve Stem, I can't recall what PCS said about them as they got it done elsewhere at a specialists but on start up I did get a puff of white smoke which no longer occurs so must have been bad.

The bores, unfortunately didnt get any pics, but yes as you said seems to be fine now as its not burning much oil. Probably could use an NA block but not sure if the oil or coolant galleries are the same though both are M113 so could be. as I read someone who turbo charged their E55, they used the E500 intake manifold after removing the supercharger.

With regards to your Airmatic strut change. Did yours level out fine after changing them? When I replaced my one it was lower on one corner then after replacing it the left corner it blew after a month but was lower then the right side despite airmatic calibration.

Mine was fine surprisingly, I had misting in one strut so decided that after 100k and 18yrs to swap both out for oem bilstein. The rear on the other hand is ever so slightly lower on the passenger side, but I can live with that.

 

[alexanderfoti]

They all have a slightly grumbly idle when cold. If yours is particularly bad, I would start with looking at the adaption values. These will give you an indication on too much fuel, or too lean at idle and what its doing to compensate. Air leaks are common and adaption values will tell you this (STFT and LTFT on OBD readers)