Strong Vibration at 3000 RPM

[tranmkp]

dont think so - if it was slipping it would make a noise - beside it would slip all the time not just a a certain rpm

[lindy8_man]

So your belt comes off the crank pully and then goes over the ac pump. Since the vibration comes both with AC on and off, I would look elsewhere. I would also think the balancer would take chop out of the pulley there. I assume you don't have that awesome squeel from a loose belt or a failing idler bearing. what is directly after the ac? If I had to guess the next accessory would be Power Steering. Any issue in steering the car? The power steering is pumping regardless of rpm, but it is isolated from the harmonic balancer. How does the fluid look? I have seen people check power steering pumps by resting a screw driver on the pump and hold the handle to your ear. Can you feel or hear any odd vibration there?

[tranmkp]

no real issues with the car - I had the same issue with my old 164 Volvo - for the ac compressor - it had a long length of belt. It would vibrate like hell at a certain rpm - that York compressor was horrible.

This is the same thing - its to long - I solved the problem on the 164 with an idler pulley - went away completely.

[tranmkp]

BUMP - still buzzing -

[93Regina]

94, 940 wagon....question is to all 700/900 owners who have switched over to r134.

FYI: VOLVO 1993 TECH & SPEC

CFC-Free Air Conditioning -- All 1993 Volvos will feature air conditioning or electronic climate control as standard equipment and all of these systems will use a non-chlorofluorocarbon refrigerant. The new refrigerant, R134A, is a chlorine-free material which is believed to have virtually no ozone depleting potential. The introduction of R134A places Volvo among the first car companies to totally eliminate the use of R12 (freon) as a refrigerant.

[93Regina]

only at 3000 rpm -

1993-944: Quite frankly, I don't experience 3,000 RPM since I drive for fuel economy. Of course, I rebuilt a 1984-B23F engine, and placed it in this 944, which PO blew a rod on OEM engine.

Is your lockup torque converter working? 3,000 RPM must be what 70 mph or faster?

[FREEBUSINESSES]

Curious, I know this is an old thread, but on an 09 XC90 3.2 at 3200 to 4000 rpm range I have a buzz like resonance from engine, not chassis or while in gear, so it is in engine, but runs great, no codes? Not a miss, a balance issue for sure, mechanical as I see it. Any ideas?

Thanks,