I wanted to thank everyone for their help with this problem. I had to take to a Volvo car repair and they discovered that the engine mounts had sunk in half and especially when it was cold out side the frame of the car was picking up the vibrations of the engine. Now it drives great with new engine mounts......it cost a pretty penny $$$$

Thanks for everyone's help, it is greatly appreciated,

Michael

My 960 was having a surge in idle when very cold. Replacing the temp sensor solve this problem. Did you used OEM sensor for your replacement???

Check fuel pressure regulator and you might also want to clean the idle motor!!

Too bad many folks never see a dealer.

The last time I was at mine, they were offering one hour's troubleshooting for free with a written report of what was wrong with your car.

Check with yours, maybe the offer is still on - beats suffering fir two winters.

Dear VolvoWorryWart,

Hope you're well. This likely has nothing to do with exhaust manifold gaskets. The reason: a leaky (failed) exhaust manifold gasket deteriorates with time - creating an ever-larger gap - and so makes more noise. The noise is akin to that of someone spitting.

I suspect a faulty - dirty/corroded/loose - fuel pump ground. If the pump's ground contact is weak - and improves with running - then warmth causes metal to expand, and to make a better contact. The faulty fuel pump ground wire connection could be at the fuel send unit's connector. This is in a sedan's trunk or in a wagon's storage space, to the left of the load space's center floor panel.

As I do not operate 960s, I do not have a wiring diagram, that shows where the black wire - the fuel pump's ground wire - goes, once it leaves the above-mentioned connector. One of the Board's bonafide 960 specialists should have a wiring diagram for a '96 960.

Another way to circumvent a faulty ground wire connection, is to install a secondary fuel pump ground wire. This wire should go from the black wire's terminal on the fuel pump connector, to any screw, that is in the body work. On the fuel pump send unit's connector, there are small "doors", which - when lifted - expose the point where the wire enters the metal terminal.

Use fine sandpaper (or an aerosol electrical contact cleaner) to clean the exposed metal of the black wire's terminal, where it wraps around the wire. Use an alligator clip to attach a length of wire to this cleaned area of the black wire's terminal. Secure the other end of the extra wire to any screw that goes into the body work.

If this supplementary ground wire cures the problem, then track the black wire from the connector to its ultimate ground point. Clean every connection, including that the ground point. Do not rely on visual inspection: sometimes a layer of oxidation only a few atoms thick - and so invisible - suffices to disrupt the flow of electrons. If a faulty ground is the problem, careful cleaning of the contacts will provide relief.

Hope this helps.

Yours faithfully,

Spook

Sorry to hear about your long going trouble.
You might be on to something with the intake gasket leaking when cold.
I am kind throwing this out, if you can get a propane torch, try this, it might work, never did it my self. While your engine is running badly, try introducing some propane into the air intake. You might have to unsnap the ducting after the air filter and before the MAF. If you introduce a little gas into the intake, if the intake gasket is leaking, then it should even out the idle, the idle speed may change but richening the fuel mixture might cause it to even out. I imagine that if you introduce propane into a correctly idling engine it would start to stumble and possible stall. So maybe the inverse it true? Just a guess.

You also might try unplugging the MAF, do this only with the ignition switched off. Without any signals from the MAF, the computer will go into limp home mode, which is barely noticable. See if that does anything.
Get back to this board. There are some really fantastic people here to help.

Are there any codes? The check engine light does not illuminate for every code. So checking for stored codes might need to be done. Also, the dealer has a scan tool that will allow live information of key sensors. Might be time to bite the bullet. Codes though are only clues and need to be proceeded with caution, if you don't want to spend money needlessly. Most of the sensors under the hood are well built and last. \The connectors on the other hand are weather resistant at best.

DanR '94 964 388,000 miles (154,000 on the new engine)
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DanR