In need of new caps!

[bing]

The all common issue with our cars has been happening to me lately , and that is - MISFIRE !!! As usual, and as from other members experience, it would only tend to misfire when it's been sitting in the garage for days or weeks and once it hits normal temp. it misses for a while then goes away for days with constant use.

Have checked previous service records and it showed at 162km (now on 169km) plugs, leads and rotor were changed but no mentioned of caps.. Hard to believe i know - why caps not changed.. Anyway, while at my mechanic today we checked these and found them to be old and had carbon traces..

Now need to source new caps and seals. However, I seem to remember reading somewhere that there are better caps available rather than the OEM/Bosch ones?? Or am I mistaken?? My Motto is always OEM unless it's proven. Any advise and Part numbers would be appreciated. Also, mechanic says rotors are fine but i'm thinking that these should be replaced at the same time??

Cheers
Bing


P.S now switched to summer wheels (EVO's) ! But boy, I forgot how the ride can be stiff when on 17'' - definitely more comfy with stock 16''.. Looks damm handsome though!

 

[gsxr]

Nah, Bosch is the good stuff. Believe it or not, Amazon.com may have the best price around... second lowest is probably Autohaus. Both have free shipping.

MB # 119-158-01-02, Bosch # 03367 - M119 distributor caps
MB # 119-158-03-31, Bosch # 04271 - M119 rotors
MB # 119-158-01-88, Bosch # 1230500240 - M119 insulators behind the rotor


2016 EDIT: I experienced a defective M119 Bosch (aftermarket) cap out of the box in early 2014. It took many hours of troubleshooting to pinpoint the root cause. The only symptom was a misfire at hot idle. Replacing the cap with another new Bosch cured the problem permanently. That experience soured me on Bosch caps, although it was probably a fluke. I now prefer to get Beru caps if possible; however Bosch rotors must still be used as Beru rotors are unavailable from USA vendors. I'm not a fan of Bremi as their parts are visibly different in design than Bosch or Beru. For the record, the only OE parts are Bosch or Doduco; and the Doduco items are NLA (supercedes to Bosch).

 

[gerryvz]

You also may want to check out the round plastic caps that sit on top of the distributor BELOW the caps. Those are often the culprit of the occasional misfires that most all of us with E500Es have experienced over the years, particularly at idle. Very overlooked item and one that should be replaced.

Cheers,
Gerry

 

[bing]

Thanks guys!

Gerry -will replace the plastic caps also, do u have the part # for this please?

bing..

 

[bing]

Dave, would you change the rotors also at this point, since they've effectively only covered 4000miles??

 

[gsxr]

Normally, caps & rotors are replaced at the same time. But if the rotors only have 4000 miles on 'em... no, I would clean them and re-use them. I normally clean & re-use the caps as well until there is significant pitting on the brass contacts, or damage to the plastic, or other issues which can't be wiped/scraped off. In many cases, a good cleaning/scraping fixes the problem.

If the rear insulators (post #2 updated with part numbers) are bad, those cannot be cleaned; they would need to be replaced. There's not really any test for that but if you have new caps, rotors, CORRECT wires & plugs (non-resistor type), and still have a misfire... those insulators are highly suspect. At ~$100/ea they're a bit spendy to just replace for the fun of it.

2016 EDIT: Check the back side of the insulators for presence of liquid - this requires removing the rotor bracket; make sure the rotor goes back in the same position (it's keyed). If there is liquid on the back side of the insulators, clean them completely dry before re-installing. If installing new caps/rotors, and the existing insulators don't look great, consider installing new insulators at the same time. New insulators should last for another 20+ years.

 

[bing]

Normally, caps & rotors are replaced at the same time. But if the rotors only have 4000 miles on 'em... no, I would clean them and re-use them. I normally clean & re-use the caps as well until there is significant pitting on the brass contacts, or damage to the plastic, or other issues which can't be wiped/scraped off. In many cases, a good cleaning/scraping fixes the problem.

If the rear insulators (post #2 updated with part numbers) are bad, those cannot be cleaned; they would need to be replaced. There's not really any test for that but if you have new caps, rotors, CORRECT wires & plugs (non-resistor type), and still have a misfire... those insulators are highly suspect. At ~$100/ea they're a bit spendy to just replace for the fun of it.

Dave, rotors (also caps) are on sale from 'autohausaz' at the moment for $31.14ea, so I think I may as well take advantage of their offer since I will be ordering other related bits and to go in one shipment.
My only question is do i need the updated rotor brackets (#1191580640) or are 94 onwards updated already? My vin # 1240361C098302

Also, i'm ordering a 'transmission cooling line/hose' ( left side single elbow spring surround) brand being 'CRP', is this OEM??


thanks for the usual advise
Bing