Passing the Calif. Smog Test (1993)

[karpdiem2]

I looked at a 1993 940 Turbo today. It was very clean, had high miles,
162,000. It handled ok. But I have a couple of concerns.

1. It's a turbo.
2. It failed the last smog (it did pass after some monkeying
around, according to a CarFax report I pulled).
3. Radio (probably factory installed) doesn't work well. I didn't
try the cassette player.

My plan is to take it to a Volvo repair place locally & have them check
it out. But I have this gut feeling about. Asking price is
$3995, which is below book, pp or retail. But that doesn't assauge my
fears about it being a "gross poluter."

Does anyone have any experience with this?

Thanks.
A. Smith

 

[Scott]

162,000 is more or less "average" mileage for a 12-year-old daily driver.
The motor and drive train are good for 250,000+ if the car is well
maintained.

The turbocharger may be nearing the end of its useful service life. One
telltale sign is fore and aft play in the shaft.

You did not state which portion of the emissions test the car failed.
Generally, smog failures on these cars are attributable to fuel injection
components that are out of spec, e.g. the oxygen sensor or air mass meter.
The fuel injection computer uses signals from these sensors (as well as the
coolant temp sensor) to set the A/F mixture. An overly rich mixture can
definitely raise emissions. The air mass meter trim is actually
user-adjustable with a screw driver and a volt meter/dwell meter. This
could have been part of the mechanic's "get the car to pass smog" ritual.
Anyway, the fact that it passed with a little 'tweaking' means that there is
(probably) nothing seriously amiss with the emissions equipment or motor.
Wouldn't be too worried about it.

I would be very interested in the car's service records. Has the oil been
changed regularly? How about filters, plugs, wires and so on? Check under
the oil filler cap and in the coolant expansion tank. If the coolant is
discolored, or the oil cap/dipstick has a frothy white residue, you have
evidence of a previous engine overheat and pending headgasket failure. This
is more common on turbos. Also have your mechanic check compression. This
will give you a good idea of the condition of the engine, and of how well
the car has been maintained in general. Compression should be between
120-160 psi with a maximum variation between cylinders of 10%.

How is the cooling system? The factory radiator has a useful life of 8-10
years. The heater control valve is also a plastic affair that has been
known to fail after about the same period of time, resulting in a massive
loss of coolant and overheating.

Something else to look for is replacement of the rear trailing arm & torque
rod bushings, as well as the conical bushings in the front end. If this
hasn't already been taken care of, they are due in the very near future.