Newbie here - 740- Vacuum Leak? Please Help

[MyVolvo740]

Hi-
Newbie here!

Beloved 1991 740 Wagon with 381,000 miles. Kept in great condition - I take it for oil changes, all parts work, etc. etc. I'm the second owner, first one was a mechanic and the car has always been treated well.

Lately I'm hearing a noise that sounds like there's a loose vacuum hose. It gets louder when I accelerate, and the car almost seems to hesitate before it shifts. Just for a second. When I took it to the dealer they were beyond rude, took 5 seconds to listen to it, and said I needed a new engine. While there is definitely a bit of a valve noise sometimes, it doesn't seem like a pressing issue, and it certainly isn't the noise that I hear at idle (the loose vacuum hose noise).

I'm taking it to someone else tomorrow to have them look at it - but in the meantime - is there a vacuum hose that goes to the transmission? I'm really clueless about parts, so sorry if this is an absurd question. Are there any other parts I should be considering? It idles ok, except for the noise mentioned above, and runs well overall. Has fresh oil, and all the fluids are where they should be.

I know it's a bit of a broad question without actually hearing the car - but any thoughts??
I get the impression this is a fairly easy fix and the dealer's just trying to get more money out of me!

Thank you!!

[billofdurham]

Welcome to Matthew's Volvo Site.

There are no vacuum lines to the gearbox. However, if any of the engine vacuum lines are leaking that can cause hesitation of the engine which could be occurring just as the gear change is due.

A good mechanic should be able to find a leaking vacuum pipe.

Bill.

[rgk]

Bill, is there a way to check the vacuum hoses at home? Say, with the soapy water in a spray bottle trick?

Of course, you can always check the soft rubber hoses for cracks, especially at their connections.

Anyone with a screwdriver can unscrew a clamp, that's how I started working on Volvos.

It's fun!

[Enginer]

You didn't mention whether your vehicle was turbocharged or not, but I recently noticed a noise on accelerationin my '92 740T. Oddly enough, at the same time, the boost gauge stopped working.

I'm now struggling with those poorly designed catches that hold the dash gauge panel in place to get to the (likely) failed air pressure coupling behind the dash.