Rough Idle after driving up 5 floor parking garage - any thoughts?

[agsiress]

Greetings,

I had a very strange event happen yesterday and I thought I would ask you all. I had 1/2 tank of gas and drove the car up to the top of a garage (6 levels) to take some photos after a ceramic coating. Once I was done, I started the car and it had a really rough idle. I drove down the parking garage and the rough environment continued. Some have said to use seafoam, others maybe it's bad gas. I started it this morning and it started and idled fine.

before I do anything I figured I would ask. Car has 89K miles, I got it at auction a few weeks back. haven't driven it much.

thank you all in advance.

 

[gsxr]

It's not fuel, if it started this morning and ran fine. Don't bother with Seafoam or any other fuel additives. It's almost certainly ignition, related to caps/rotors/insulators. How old are these items, and what brand was installed if they are recent?

Search the forum for more info, this topic has been covered repeatedly, and some new information has surfaced in the past year on how to possibly cure the issue permanently.

 

[nocfn]

And to cut to the chase, if you replace any of the components: cap / rotors / insulators, if you have ANY oil evidence leaking out of the cam seals, just REPLACE them and the CAM MAGNETS or you will fight that issue until you do.

 

[gsxr]

And to cut to the chase, if you replace any of the components cap rotors insulators, if you have ANY oil evidence leaking out of the cam seals, just REPLACE them and the CAM MAGNETS or you will fight that issue until you do.

Yup.... that too: ^^^

 

[szvook]

I was gonna say check the ignition coils as well, but I think you would have some misfires and difficulty starting the engine if they were bad.

 

[Duh_Vinci]

And another question for @agsiress how long did you drive the car that day before shutting it off and parking it for the photoshoot?

 

[agsiress]

And another question for @agsiress how long did you drive the car that day before shutting it off and parking it for the photoshoot?

maybe 5-10 minutes max.

 

[agsiress]

I was gonna say check the ignition coils as well, but I think you would have some misfires and difficulty starting the engine if they were bad.

no misfires and it starts clean every time.

 

[nocfn]

10 minute drive then the hesitation is indicative of how this issue with the insulators (oil blow by on cam shaft seals) presents itself. Especially the right side directly behind the fan.

 

[gsxr]

no misfires and it starts clean every time.

See what I already wrote in post #2. If you read the old threads discussing this issue, you'll find it always starts perfectly. The misfiring occurs after 5-20 minutes of running, or if shut off and then attempt to re-start 5-20 minutes (approximately) after shutdown.

You also never answered my questions...

 

[smilecenterlab]

exactly what happened to me,my car left me stranded in the middle of the street because i could not get it to started after a20 min drive.changed caps,rotors and insulators ,have not had a problem since.

 

[agsiress]

See what I already wrote in post #2. If you read the old threads discussing this issue, you'll find it always starts perfectly. The misfiring occurs after 5-20 minutes of running, or if shut off and then attempt to re-start 5-20 minutes (approximately) after shutdown.

You also never answered my questions...

Sorry I actually don’t know when or if they have been changed I am a new owner and am awaiting the prior records from the old owner.

 

[gsxr]

Sorry I actually don’t know when or if they have been changed I am a new owner and am awaiting the prior records from the old owner.

Ah, got it. If you can't confirm recent replacement, I'd plan on all 3 items: Bosch or Beru caps, Genuine MB rotors, and Bosch insulators. About $500 total in parts and 1-2 hours DIY labor. If paying a shop they'll nail you for $1k or more. And as Louis said, while it's apart look for any sign of oil leaking from the seals behind the insulators. If so, the seals must be replaced (this isn't super common).

Also, based on recent findings, I'd also consider adding the additional slots on the new caps to help the problem from recurring. This is mentioned in post #17 at this link. Also see photos at post #63 and #81 in the same thread.

 

[agsiress]

Ah, got it. If you can't confirm recent replacement, I'd plan on all 3 items: Bosch or Beru caps, Genuine MB rotors, and Bosch insulators. About $500 total in parts and 1-2 hours DIY labor. If paying a shop they'll nail you for $1k or more. And as Louis said, while it's apart look for any sign of oil leaking from the seals behind the insulators. If so, the seals must be replaced (this isn't super common).

Also, based on recent findings, I'd also consider adding the additional slots on the new caps to help the problem from recurring. This is mentioned in post #17 at this link. Also see photos at post #63 and #81 in the same thread.

Thank you! -- I gave up my garage and tools (to my brother) when I moved into a high-rise downtown Austin. So as much as I would love to DIY I am going to have to find a local shop. There is one here that is 3rd party and highly recommended. - I am reaching out to get a quote. Thank you all for the diagnosis and remedy.

Tony

 

[nocfn]

If you are going to have the work done, insist on the certain brands. The cam seals are incremental for the shop and they can be pressed in on the car, no need to remove the cover. You should be able to get the rotors and caps from Napa BERU, and that will help you avoid worldpac pricing plus upcharge by the shop. This is clearly a DIY and a set of metric sockets, wrench and male Hex should be kept in the car anyway. All you can get cheap at lowes or Napa.

 

[smilecenterlab]

i ordered caps,rotors and insulators from fcp for around $450 (beru) then had them installed at an independant MBZ shop where he charged me $400 and that was with new spark plugs i also provided.

 

[Duh_Vinci]

maybe 5-10 minutes max.

Also, based on recent findings, I'd also consider adding the additional slots on the new caps to help the problem from recurring. This is mentioned in post #17 at this link. Also see photos at post #63 and #81 in the same thread...

Based on the details you provide, I too would likely point to the moisture collection. My symptoms were very similar. After a short drive, then parking the car at the store, very rough idle for few min... Re-starting next morning no issues, and no issues after long drive. Only as you said, short drive>park for short time>restart.

Additional slots in the caps as @gsxr linked post above - took care of the moisture build, no issues for 11 weeks now.

Regards,
D

 

[kegmankipp]

If you are going to have the work done, insist on the certain brands. The cam seals are incremental for the shop and they can be pressed in on the car, no need to remove the cover. You should be able to get the rotors and caps from Napa BERU, and that will help you avoid worldpac pricing plus upcharge by the shop. This is clearly a DIY and a set of metric sockets, wrench and male Hex should be kept in the car anyway. All you can get cheap at lowes or Napa.

Worldpac doesn’t seem to have any legit parts for M119 anymore after the new owners took over I pretty much only see Chinese made parts listed

 

[nic520]

Hi,
please consider buying some tools - no garage, no tools and a („new“) 30 year old Merc sounds like future missed opportunities of DIY and saving money.
Cheers