Like they've said, best to do it yourself and save you some dough €$£$¥$₤₣ ...

Research these chain store you mention. Some of them are not so honest.

Use a shop that knows LoLVos if you can spend the €$£$¥$₤₣.

Find them through these links:
- https://www.brickboard.com/SHOPS/
- http://www.cartalk.com/mechanics-files
- http://www.volvomechanics.com/

Cross-reference with the BBB.

Else, you have right here on the brickboard the FAQ for 700/900
https://www.brickboard.com/FAQ/700-900/

Look for the sections on preventative maintenance and also performing the OBD check, if an 1988-89 or newer with the black OBD check box in the engine bay, to see what needs service immediately. You can post back with fault codes here if you need help understanding what may be at fault in your 700-series OvLov.

Thing like:
- Check for OBD fault codes. See https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm and perform the check.
- Timing belt replacement (every 50k miles, T-belt tensioner every 100k)
- The other thread posters already mention spark plug gap or replace with new and gap, rotor, cap, air filter.
- Sensors like the Oxygen (O2) sensor check and replace.
- Leaking oil? Clean that positive crankcase ventilation (PCV) flame trap!
- Inspection of vacuum lines, engine compartment wire harness (condition, connectors, connection to ground).

And so on. Read the 700/900 FAQ. Get a Volvo factory OEM green manual or a Haynes manual (used at the book store or on eBay). Older Volvo ownership value is maximized when you care for the wee Swedish steel beasties yourself.

Quetions?

Hope that helps.

Buttermilk.
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