Bought a non-running 420sel and found a surprise in the records. How screwed am I? - Page 2 - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #11 of 37 (permalink) Old 12-01-2018, 09:51 AM Thread Starter
BenzWorld Junior Member
 
flynscot96's Avatar
 
Date registered: Nov 2018
Vehicle: 1991 300D 2.5 - 1989 420SEL -2015 GLK350
Location: Dallas, Texas
Posts: 23
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
Garage
(Thread Starter)
Quote:
Originally Posted by 281lxm View Post
If you are part of the mb club in dallas reach out to Alabasi, he has engines in his shop. If you want to pm me your name and contact info and I can have him reach out
Oh, yes. I致e seen some of his posts, I think. Seems like a cool person.

I知 out flying right now (pilot), but will PM maybe this evening when I get to the overnight.
flynscot96 is offline  
Sponsored Links
Advertisement
 
post #12 of 37 (permalink) Old 12-01-2018, 10:28 AM
Outstanding Contributor
 
John350's Avatar
 
Date registered: Nov 2014
Vehicle: 1990 350SDL, "Grandpa's Roadster" Project Car
Location: New Hampshire
Posts: 2,827
Mentioned: 9 Post(s)
Quoted: 799 Post(s)
If the valves got bent slightly, it might have taken 25,000 miles for them to finally burn to the point where they cause the engine to stall at idle. I'd suggest a boroscope inspection. If the valves are burnt to the point where they are not round, don't run it any more; pieces can start falling off next.
flynscot96 likes this.

John
"Real engines don't have spark plugs!"
John350 is offline  
post #13 of 37 (permalink) Old 12-01-2018, 01:13 PM Thread Starter
BenzWorld Junior Member
 
flynscot96's Avatar
 
Date registered: Nov 2018
Vehicle: 1991 300D 2.5 - 1989 420SEL -2015 GLK350
Location: Dallas, Texas
Posts: 23
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
Garage
(Thread Starter)
Quote:
Originally Posted by John350 View Post
If the valves got bent slightly, it might have taken 25,000 miles for them to finally burn to the point where they cause the engine to stall at idle. I'd suggest a boroscope inspection. If the valves are burnt to the point where they are not round, don't run it any more; pieces can start falling off next.
‘scoping was something I was contemplating. Thanks for confirming. Is there an at-home scope that’s of decent quality?
flynscot96 is offline  
Sponsored Links
Advertisement
 
post #14 of 37 (permalink) Old 12-02-2018, 12:41 AM
BenzWorld Veteran
 
Richter Rox's Avatar
 
Date registered: Aug 2016
Vehicle: 1988 560 sec
Location: Boston Ma
Posts: 665
Mentioned: 6 Post(s)
Quoted: 184 Post(s)
If it comes to it i would rather swap in a 560 motor than do a top end job , if you are doing the work yourself the cost and time involved would be similar .
flynscot96 likes this.
Richter Rox is offline  
post #15 of 37 (permalink) Old 12-04-2018, 09:18 AM Thread Starter
BenzWorld Junior Member
 
flynscot96's Avatar
 
Date registered: Nov 2018
Vehicle: 1991 300D 2.5 - 1989 420SEL -2015 GLK350
Location: Dallas, Texas
Posts: 23
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
Garage
(Thread Starter)
John350 got me thinking seriously about borescoping this thing before proceeding further.

全cope arrived last night. I値l turn it trough by hand and hopefully have a decent look at the pistons and valves sometime today or tomorrow. If all looks decent, I値l follow up with a compression and leak test.

At that point, we値l hopefully know what direction to start looking.
luckymike and Eddieba like this.
flynscot96 is offline  
post #16 of 37 (permalink) Old 12-05-2018, 03:16 AM
Lifetime Premium Member
 
Tom Kaiser's Avatar
 
Date registered: Jul 2010
Vehicle: 1989 SEL 560
Location: Council Bluffs, Iowa
Posts: 499
Mentioned: 1 Post(s)
Quoted: 134 Post(s)
Lifetime Premium Member
Quote:
Originally Posted by flynscot96 View Post
John350 got me thinking seriously about borescoping this thing before proceeding further.

全cope arrived last night. I値l turn it trough by hand and hopefully have a decent look at the pistons and valves sometime today or tomorrow. If all looks decent, I値l follow up with a compression and leak test.

At that point, we値l hopefully know what direction to start looking.
What brand scope did you purchase and a relative price if you don't mind? Thanks - Tom
Tom Kaiser is offline  
post #17 of 37 (permalink) Old 12-05-2018, 09:11 AM Thread Starter
BenzWorld Junior Member
 
flynscot96's Avatar
 
Date registered: Nov 2018
Vehicle: 1991 300D 2.5 - 1989 420SEL -2015 GLK350
Location: Dallas, Texas
Posts: 23
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
Garage
(Thread Starter)
Quote:
Originally Posted by Tom Kaiser View Post
What brand scope did you purchase and a relative price if you don't mind? Thanks - Tom
I did some digging around and found this one reviewed by a guy on YouTube who was inspecting his own heads. Seemed decent, and at ~$35USD, pretty inexpensive. Many uses.

This is an updated version from the one in the video I watched-- it has a stiffer cord that is more easily twisted/manipulated inside the bore without having to add reinforcement/stiffness, has an adjustable light source, and is rechargeable, so you can use it cordlessly. It transmits wirelessly to iPhone or Android via WiFi. Comes with a mirror attachment to look up towards the valves, or there are a couple of different ways to get the camera to bend back on itself for a direct look up at the valves.

Pretty cool. I played around with it yesterday and it gives really good detail. Hopefully will be able to get it into my engine today. I'll post pics of the bores/pistons/valves if it works out OK.
Eddieba likes this.
flynscot96 is offline  
post #18 of 37 (permalink) Old 12-05-2018, 10:35 AM
BenzWorld Elite
 
Date registered: Feb 2008
Vehicle: Too many to list
Location: USA
Posts: 8,186
Mentioned: 61 Post(s)
Quoted: 1508 Post(s)
If you can take some screenshots on your phone and post them
tusabes is online now  
post #19 of 37 (permalink) Old 12-05-2018, 05:20 PM Thread Starter
BenzWorld Junior Member
 
flynscot96's Avatar
 
Date registered: Nov 2018
Vehicle: 1991 300D 2.5 - 1989 420SEL -2015 GLK350
Location: Dallas, Texas
Posts: 23
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
Garage
(Thread Starter)
Uploaded some video of the car (walkaround and under-valve-cover inspection).

Haven't had a chance to 'scope the engine yet, but I did put manage to clean up under the hood, scrape off the old hoodliner (it was baaaad), pull the valve covers, and do an initial visual inspection of the valvetrain.

Timing chain and guides look good, no slop or looseness. You can definitely tell something was up with the left bank at one time, though-- there is evidence of the chain eroding the edge of the valve-cover gasket seat slightly on the inboard side above the chain guide. Cam lobes look good (maybe even great). Oiler tubes are intact and the plastic clips holding them in are tight. Clean under the valve covers. So far so good. Pulled the fan, but ran out of daylight before I could pull the plugs and turn over the engine for a borescoping. Hopefully tomorrow if the rain isn't too bad.
flynscot96 is offline  
post #20 of 37 (permalink) Old 12-05-2018, 06:32 PM
BenzWorld Junior Member
 
Date registered: Jun 2018
Vehicle: 1991 350SD
Location: Long Island,NY
Posts: 16
Mentioned: 1 Post(s)
Quoted: 5 Post(s)
Chain jumped over

What you have is bent valves on driver side. It is common problem with 116 and 117 engines. Chain rail on driver side (most likely lower rail) broke and part of it got between chain and crankshaft gear, the chain got on the top of the camshaft gear on driver side, cracked the valve cover and jumped over the gear. The valve timing got out of sync, pistons and valves hit each other and now you have bent valves. that is why you have problem with compression on driver side and car runs rough. They should have pulled the driver side head and replace bent valves. Most likely only the driver side has problem. When the chain nylon rails are new they are flexible, but over the years from heat and age they became fragile like glass and when the stretched chain flaps around (usually in the morning) it cracks the rail before the chain tensioner puts enough tension on it. I saw it way too many times over my 40 years working on Benzes, even on low mileage cars (70-80K).
pepaglobal is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W126 S,SE,SEC,SEL,SD,SDL Class

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome