1997 Volvo 960 - no power in hills

[ms]

I just purchased a nice 960 volvo wagon with 150kmi. What a great car - I love volvos [my wife has a nice v70xc]!

It has one problem that may be vacuum/transmission related that I need help identifying the cause.

Symptoms:
When I picked the car up yesterday, I followed my father in his 940 wagon. We cruised easily on the highway. I could dust him on the flats, but he could pass me on any and all hills. In the hills, my 960 would start to slow, shift and the rpms could go up but the car would not accelerate up the hill. I could simply maintain position, if I let off the accelerator, the car would upshift and continue to maintain position. It was almost like it was 'searching' for a gear? I don't think it's engine related because I could reach higher rpms (4000 + easily) ...?

Other symptom (may be related/unrelated):
While cruising the car ran good, but accelerating to higher rpms, I could discern a very pronounced whirring sound! It sounded like a child sucking on a straw in a nearly empty slurpee cup.

BTW - I got 24+ mpg on the 200 mile ride home.


Any help would be appreciated!
Best,
Matt

[billofdurham]

Welcome to Matthew's Volvo Site.

I assume that the Check Engine light is not lit and that the gearbox warning light is not flashing.

Bill.

[ms]

Bill,

Thanks! No lights are on.
Ideas?

-Matt

[billofdurham]

So, no lights no fault codes unless somebody has disconnected them - very unlikely.

Back to old fashioned diagnostics for insufficient engine power:

Check fuel injectors; fuel pressure; airflow sensor; restricted exhaust; coolant temperature sensor; air temp sensor; throttle switch and connector; ignition circuits; engine speed sensor and intake system.

They are not in any particular order but are all things which on their own or with others can cause the problem you experienced.

However, because of the nearly 'empty slurpee cup' noise, a great description, first check all of the vacuum lines for splits, bad connections and general condition of the hoses.

Bill.

[ms]

Bill,

Thanks for the help. I don't think the problem is engine related, because I can attain (and maintain) very high engine RPMS w/no misfires/hesitations/etc.

When I purchased it, I checked all fluids, but was perplexed at the time at how to check the transmission fluid.

Two days ago, I changed the fluid. The original fluid has about 153 kmi on it and was smelly and darker than the engine oil = really black and stinky. As an aside - when i changed the fluid, my father walked outside and said, "what stinks". I did a flush (3 gallons) with some valvoline dino-atf fluid (type III/V for high mileage engines). Immediately, I noticed an improvement in shift quality and driveability. After a few spins around the block, I took it to a hill that is very steep & accelerated hard and noticed the slurping noise had ceased (coincidence??).

I noticed another, similar, improvement in shift quality after having let it sit overnight.

Before the transmission flush I was getting about 23.5 mpg and after the flush it's over 26.5 mpg.

I plan to run it for a week with the valvoline and flush with Mobil 1 synthetic.

Oh, Do you know if Mobil 1 Dex/Merc V is a suitable replacement for D/merc III fluid?

Best,
Matt

1966 122s
1997 965
1998 v70xc