I have 86' 420sel with approx. 250K miles on it and was wondering what mileage I can expect from this engine? The valve job was done at 175K miles. Previous owner took great care of the engine, always used premium gas, scheduled oil changes,... The lower engine end remains untouched.
Also the same question goes to transmission? It was overhauled first time at approx. 150-160K miles.
Your valuable opinions will be appreciated.
Thanks.

I hope you have many more miles in your 420, I have heard that with proper timing chain care the engine should last a long time. I have 156k on my 86 and am wondering about my transmission right now- a question about yours- what symptoms prompted your trans. service at the mileage you refered to?

The transmission was changed by the previous owner and if I remember correctly it was done due to delayed shifting. If you car shifts fine than there is no need for any repair. I think the main indicator that transmission is due for repair is if it delays shifting in reverse.
So you think I can rely on this engine for another 50K or so?

oops- that is what mine does- it delays hitting reverse about 3 seconds, i am hoping that it just is in need of a good fluid change....other than that it runs and shifts flawlessly. anyway- i have seen many 420s on the market with well over 250/300k miles so i expect the same with mine.- my volvo has 98k and the mechanics at the dealer insist it is barely broken in ( what ever that means)

Valve job and chain every 200,000 miles or so, and if the older cast iron engines are any indication, if you don't overheat it the bottom end will go at LEAST 500,000 without work, then only needing rings. The siliconized aluminum block should wear at about 1/5 the rate of the cast iron, so you are looking at 2.5 million miles before the cylinder walls wear out!

Should last indefinitely, I've never heard of one wearing out that wasn't badly mistreated (severe overheating being the worst possible thing to do to it).

Use synthetic oil and you may even lengthen the time between valve jobs!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Many thanks. Your comments are exactly what I was looking for. For a long time I needed an expert's opinion and couldn't get one.

Alex