My 1988 Volvo GLT recently developed two faults at once which I thought might be connected: (1) I was constantly having to fill up the coolant reservoir and (2) the temperature gauge needle was constantly below the usual half-way mark (more like one third of the way up the dial). I found that the heater hoses were leaking so I replaced them, which solved problem (1). But the temperature gauge was still reading low, so I replaced the thermostat with a new Volvo thermostat of the same heat rating. I was surprised to find that the temperature gauge is now reading HIGH though still some way from the red zone (about two thirds of the way up the dial). I'd be grateful for any ideas about what I might try next.
Happy New Year everybody, Eric

 

You need to make sure you have good flow.

Also sometimes installing a new thermostat will make the temp go up some from the other. They are funny about that.

 

Many thanks for your comments, Tech.
Making sure I "have a good flow" sounds sensible. How do I do it, though?

And when you say that fitting a new thermostat sometimes does result in a higher temperature than previously, are you saying that it's really nothing to worry about?

All the best,
Eric

 

Just keep and eye on it. Also the Temp compasation board on the back of the speedo cluster may be going bad,

If it runs a little higher no big deal as long as you know it isn't overheating.

 

Please explain a little further, Tech, to help an ignoramus, i.e. HOW do I keep an eye on it ("good flow")? What am I looking for and where do I look for it!

Thanks,
Eric

 

I meant keep an eye on the Temp. If it starts rising or stays higher then you will need to look further.

If you really wanted to you can remove the Radiator and have a radiator shop do a flow test on it.