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Garage => Mechanicals => Topic started by: rosenfe on 31 October 2020, 11:55 AM

Title: Looking at 77 6.9 with 169k
Post by: rosenfe on 31 October 2020, 11:55 AM
I have a 450sel and familiar with 116. Seller has replaced accumulators ,alternator,warm regulator,fuel tank cleaned new accumulators. Car is distant. Pics show no rust. New servo. Cclimate control all works .int good. Dash no cracks.
Video of engine start cold after a week sound very good.
No leaks.
What else should I ask
Title: Re: Looking at 77 6.9 with 169k
Post by: daantjie on 31 October 2020, 12:22 PM
Compression test
Detailed pics of wheel wells, rocker panels, underneath all the loose carpets etc
Check if front/rear glass rubber gasket has been done, that's a huge job
Suspension rubber been done?
Brakes, that too can be a big ticket item
Exhaust still nice?
Windows up and down easy?
Rear seat padding good?
Title: Re: Looking at 77 6.9 with 169k
Post by: rosenfe on 31 October 2020, 12:43 PM
I am also concerned about passing smog in ca. This car is out of state. He wants 11500$.
Title: Re: Looking at 77 6.9 with 169k
Post by: daantjie on 31 October 2020, 01:35 PM
That's a lot unless it's in really good shape I would say.  We all know there is usually 5 - 10K in deferred maintenance waiting in the wings, so that needs to be factored in as well.  Miles are not too bad, but again if those miles were under marginal maintenance and general neglect then I would say this is a hard pass.
Title: Re: Looking at 77 6.9 with 169k
Post by: rumb on 31 October 2020, 02:10 PM
A 40 year old car need to be looked at carefully, but a well kept car could well be worth that price. An independent inspection and in this case a fresh emissions test report would bode well. Since you know W116 already, the 6.9 components are important and it seem that has been serviced. I assume the car has been cleaned, but look for leaks from the hoses and hydro struts. the 6.9 engine is robust.  I would 2nd a compression test.
Title: Re: Looking at 77 6.9 with 169k
Post by: rosenfe on 31 October 2020, 05:25 PM
Wouldn’t timing chain ,guides and cam oilers need to be inspected as well?
Title: Re: Looking at 77 6.9 with 169k
Post by: John Moore Sr on 31 October 2020, 08:51 PM
Wouldn’t timing chain ,guides and cam oilers need to be inspected as well?
Definitely. Also the Oil Pump Chain.  JMSr.
Title: Re: Looking at 77 6.9 with 169k
Post by: daantjie on 31 October 2020, 10:55 PM
The 6.9 engine generally does not suffer the same fate of the 117 motor with regards oiler tubes and such.  It is a much more robust design as well with ratcheting tensioner thus even with a stretched chain jumping a tooth is pretty much unheard of on the M100 engine.
Don't get me wrong an inspection of these items is of course prudent but to note this is one extremely overbuilt and reliable mill.
Title: Re: Looking at 77 6.9 with 169k
Post by: rumb on 01 November 2020, 06:48 AM
Wouldn’t timing chain ,guides and cam oilers need to be inspected as well?
Definitely. Also the Oil Pump Chain.  JMSr.

On a 6.9 you would have to remove the engine to inspect the oil pump chain.   :o

Pre inspection I'm not sure a seller would be willing to pull the valve covers because of the cost of gaskets. @$200 for an Elring set. However upon purchase it would be wise to do so and inspect/replace chain/guides. One could also use offset cam keys to correct a bit. The guides require the front of engine disassembled to reach the lower one, though the upper ones are the ones that exhibit the most wear and one could reasonably not change the lower ones. The tensioner guide by far takes most of the abuse and heat deterioration.

File this job under deferred maintenance list to be taken care of by new owner.
Title: Re: Looking at 77 6.9 with 169k
Post by: rosenfe on 01 November 2020, 04:01 PM
How different is it to drive a 450sel vs 6.9
Title: Re: Looking at 77 6.9 with 169k
Post by: daantjie on 01 November 2020, 09:27 PM
How different is it to drive a 450sel vs 6.9

More power, and much thirstier of course  ;) 
You can rev it out in first gear floored to about 100 km/h if that gives you any idea.  3 speed vs 4 speed trans which can feel a bit sedate around town.  Putting your foot in it on the highway is where the real magic of the 6.9 is, it pulls way harder than a regular 450 but if you drive them both with a light foot the feel is very similar  except of course the feel of the hydro suspension.
A well sorted one truly is the magic carpet ride 8)