Just bought a 1993 850 GLT non-turbo. Has a few issues but I like it. Temperature gage was at half way on my first drive to work and all of the sudden was dropped to the floor. noticed it when I hit the highway about 20 minutes into my 50 minute drive. No overheating and no engine change. What causes this. I browsed some forums and determined that she probably needs thermostat/Temp sensor/and the mucky colored coolant replaced. I've got parts ordered from Rock Auto. The car feels a bit under-powered and the previous owner said the Flame Trap needs to be replaced. I also noticed gas smell when sitting at a stop sign. Just had a tune up right before I purchased

any ideas, as I've always owned 240's in the past
thanks a bunch
S.A.M

 

check Youtube for Robert DIY's video on testing for crankcase pressure (ie do the rubber glove test) to see if the PCV system is clogged. If you smell fuel try looking around the fuel rail/pressure regulator and injectors and trace back to the tank for any signs of leaking.

When you do the tstat/temp sensor you should also inspect the connector/wires. Did you measure the resistance of the temp sensor in the car? when cold it should have a high resistance (on the order of 3000+ ohms) and when warm should be under 300 ohms. If the sensor in the car is good you'll need to check other things - relays/fuses, wires, connectors. There's also the "master clear" (remove the battery cable for 30 minutes) that sometimes fixes issues with the dash cluster (dunno why).

Also consider replacing the coolant reservoir cap (they do pop from time to time). When you change the coolant out, consider using distilled water for the flush versus tap water and a commercial product. Make sure you refill using Volvo friendly coolant (for cars with aluminum heads).

 

I have checked that out, and I was told that I would need to replace that when I purchased the car. I have the parts on order. I have not measured anything as of yet. good to know about the reservoir cap and the "master clear". The gauge actually started working again. It seems to work every other time i start the ignition, although yesterday it worked all day. Coolant wise I always use distilled if I can help it.

Today was spent mostly buffing the red so its red again... turned out quite well actually for a first time hack job

 

Hi and welcome to the forum.