I own a 1989 300se with 60,000 miles which drives fine, but recently the "check engine" light is coming on intermittently. Any ideas of what to look for without going to the shop? I do not have a diagnostic tool for the codes.
Thanks.

O2 sensor is usually what causes the check engine light, but you really need to read the codes and/or check the mixture and duty cycle for the feedback loop to be sure.

Peter

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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!

Do your back-up lights work...climate control? The CEL is on the same fuse. When the fuse fails the CEL is activated. At least on a federal '90.

Codes are real time only, unless you are in california. This is why you need to provide you LOCATION.

CA cars are different.

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'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

I believe that the CEL is supposed to come on at 60,000 miles, and again at 120,000 miles. This is the O2 sensor replacement interval.

Well, you can see if your o2 sensor is working pretty easily, in that case.

Don't see to many 60k mile 126 cars anymore.

Curious...how does the odo know to trip that light?

Your diagnostic tool is a multimeter, and this site, of course.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

I can't remember. A lot of similar era volkswagens have the same thing. Like a secondary odemeter. Honestly, I have completely blanked out. I may have dreamed this up.