Hi! I've searched the forum but not sure which answer actually is right for me. I drive a 1994 940GL (NA) with an AW71L box and about 127,000 miles on the clock.

There is a small oil leak under the car which gives about 1-2 drops every couple of days on the floor of the driveway. So far, the mech has changed the flywheel oil seal, oil sump gasket and breather but it's still there. Been back to them 5 times, sometimes with 4 guys looking into the engine bay and under the jacked-up car with light in hand and still it looks dry as a whistle. Suspected it was power steering fluid but it doesn't seem so. Anybody with any more suggestions on where else to look?

What's worse, the lambda light is now on. Pulled a 1-1-3 on the OBDI, injectors checked out fine, throttle body and idle valve cleaned and gaskets changed, reset the light but it reappears after a day. Seems to be running rich, noticed the light appears only after cold early morning starts and not at any other time. Cold starts result in the idle hunting between 400-1500 for about 10-15 seconds before stabilising. After that, all's fine - the car runs like a dream rest of the time and all other start-stops are perfect. The mech says there are no vacuum leaks, TB works great and injectors are good.

Asked the mech to check for loose or clipped wires or connections but he says if that was the case, the problem wouldn't only be during cold starts, make sense? Before I go changing the O2 sensor, would changing the timing temperature sensor help? I've had my share of changing many parts and finding out they were not at fault in the first place ... just like a lot of guys out there

Phew ... sorry about the long post. Just wanted to be clear as possible.

Thanks.

 

Curious, what would cause the car to run rich?

Thks

 

as o2 sensors get old they tend to go rich. volvo o2 sensor is expensive. You can hook up digital voltmeter to signal wire and it should vary from .1 to .9v if it is "stuck' or "lazy" then it is time to replace. Your gas milage will improve. The two wires that are colored the same are for the heater circuit the two remainaing wires are ground and signal wire. Do not inject voltage into signal wire in other words use digital meter not analog (needle)

 

Thanks, wojeepster.

I'll try an get hold of a digital voltmeter and test it out this weekend.