400E intake manifold rebuild
 

Hello All:

Thought I would post my PDF that illustrates the steps I went through to solve an extreme drivability issue with my 92 400E (260,000 miles)

Symptoms - engine stumbling, limp mode, harsh idle and stalling, horrible gas mileage
Previous corrections - New MAS, tested Throttle Acuator, new dist caps/rotors and plugs - no improvement
Test - confirmed vacuum leak in intake manifold - sprayed starting fliud in various regions of manifold while engine was running. Found engine to stumble/stall when sprayed near the front section of manifold.
Cause - broken manifold connector ring (gasket) on #1 cyl plenum. Remaining 7 gaskets were intact but extremely brittle and likely leaking.
EGR system 100% blocked - not sure that's a cause but was certainly not functional
Solution and additional mntc - remove and rebuild intake manifold assembly. replaced all gaskets, seals, vacuum lines and emission/vapor pipes. Cleaned all parts. Rebuilt fuel injectors while removed (washers, spacers, filters and pintle caps). Replaced small heater hoses at rear of engine while manifold removed. Repalced spark plugs, cleaned dist caps/rotors. oil change and coolant refill.
Result - WOW! my 400E is back! a 300HP sewing machine. no more stumbling or hesitation, no limp mode, smooth idle and mileage appears to be improved (still need to officially check)

Try clicking on the link below. It's a PDF of the photos I took throughout the process. I hope you can access it and I hope it helps.

https://app.box.com/s/qla96ib4yrtofnpnn4jy

Fantastic job. Great resource. question: was harness already replaced beforehand?

Yes.. the car had a replacement harness put in about 10 yrs ago. It was still very flexible and had no problem with brittle insulation

JC, that documentation brings a tear to my eye! So well done and annotated. Great, great stuff. By any chance did you keep a list of all the parts needed with part numbers?

Mods, this should go in the Wiki!

Rgds,
Chris W.

Awesome writeup.

Do you have MB part numbers for the injector rebuild parts (pintle caps, filters, etc)?

:zorro:

Great post. That is interesting about the fuel injector filters. I didn't even know they had filters. Has anyone experienced any clogging of these filters on their M119 engine?

I double-checked the EPC, and don't see the injector filters (or pintle caps) available from MB.

Jeff, if you could please post part numbers and a source for these items, it would be greatly appreciated!

:balloon2:

I will be glad to write the parts like and post. Let me dig up my invoices and I will post the parts with their numbers.
The Fuel Injector parts. The rebuild components are not MB numbers parts. I had to search high and low to find a rebuild shop that would sell the parts. I will post their info when I post the parts list. (the guy sells the stuff on line so I can post the link) As info, the injectors are Bosch model 1 or gen 1 and the pintle caps, washers and spacers are all the same for that model injector regardless of the application.
Look for another post this weekend with the details!

Parts List
 

Here is the list of parts I replaced while rebuilding the intake manifold

Mntc Items: Not directly associated with Manifold job but good to replace
Spark plugs - 8 F8DC4's
new Bosch Dist caps and rotors if current ones are >30K miles
Oil Filter and Oil - in case there is any coolant contamination
Radiator coolant - top off with fresh coolant by the amount you partially bled

Parts changed during manifold rebuild:
8 intake seals Interm Piece M116/M119 117-140-02-65
4 - 5 Meters of new vacuum line 000-158-14-35
1 Air Mass Meter Boot - air Meter to Throttle Actuator 119-141-01-67
1 left intake manifold gasket - 119-141-15-80
1 right intake manifold gasket - 119-141-26-80
1 throttle actuator gasket (manifold to actuator) 119-141-12-80
1 EGR valve gasket - 119-142-08-80
this is the gasket that is in between the EGR and face of the manifold. there are 2 smaller EGR tube gasket that can be replaced. Mine were is good condition and I reused them
3 Meters of black vacuum line 000-987-27-27
1 water pump to pump socket gasket - I don't have the part #
2 - idle air hose connectors 119-094-02-12 (you might need more depending upon how many you can salvage. I was 2 and 2)
Idle Air hoses (I replaced all that broke and reused the ones I could salvage)
replaced air hoses include:

• 119-094-28-82
• 119-094-31-82
• 119-094-40-82
• 119-078-00-81
• 124-830-59-96

1 coolant hose manifold to heater core 124-830-76-96
1 coolant hose rear of block to secondary recirc pump 124-830-59-96
Fuel Injector Rebuild parts
Fuel Injector Service Kit - caps O rings 8 Cyl - Item TF3
includes 16 washers, 8 spacers, 8 pintle caps and 8 filters
(think he throws in 1 extra of each in cash you mess up)
From: Mr Injector http://stores.ebay.com/Mr-Injector
NOTE NOTE NOTE - the Pintle Cap openings are very small. Smaller than the port configuration on the ends of the MB Bosch Injectors. In order to broaden the opening, use a center punch to spread the diameter of the pintle opening. The plastic pintle material is firm but moldable. The opening will remain at the diameter you create. If I can dig up one of the spares, I will post a picture of the procedure for widening the opening.

Of course, cans and cans of carb cleaner, brake cleaner, rags and gloves. Old toothbrushes are great for loosening sludge without damaging surfaces.

Enjoy fellow Benz fans!

Huge help here. I love it when people actually return with the fix for their cars. This is even a step above that. :)