General: 70: mpg-where's it gone

[friedfrog]

Here.....

Whats the temp gauge doing? Should be at 3 o'clock. If not could be thermostat, that really knocks the mpg.

[trojan]

temp ok. Always at 3o clock when warmed up

I rang bodyshop this morning and told them that I had been to main stealer (lies I know) and was told that they hadnt replaced parts correctly and that air pipes etc need sorting before they can diagnose.

Am taking her in on Wednesday to bodyshop for them to look at!

[trojan]

Just read codes...... none to read! Help, I now think it's thermostat as I had to top up coolant the day I got car back and it isn't going down so no leak!
It just seems funny how it happened while car was in bodyshop!

[friedfrog]

Hello,
It can be a pain in the R's when summat like this occurs. I'd try a few cheap/free options first and see how it goes.
I'd start by removing the Idle air control valve (IACV) and giving it a good clean with carb cleaner, within the IACV there is a "flap" which needs to be "floppy" and completly free in its movement. Strips of rag soaked in carb cleaner and fed thru will help clear any gunk thats stopping completly free movement of the "flap".
Whilst in that area of the engine whilst the IACV is off i'd also give the throttle body a good clean, again with carb cleaner & rags and maybe a soft toothbrush for any stubborn bits, being careful not to scratch any of the throttle body surface.
Also whilst there, locate and throw away the flame-trap I've run my S70 2.5 for 50k+ without flame trap with no adverse affects. If you can get a compressed air supply from anywhere, blow some of that thru the associated "pipes" too, clean out any "sludge".
Then i'd have a good check for any air leaks.
I'd then have the plugs out, clean and check/reset the gaps or replace if heavily "mucked up"
HT leads are a slight possibility and cost £30 something, so that one is up to you.
I'd also get some redex or similar next time you fill up and get heavy on the right foot for a few miles, red-lining it thru the gears.....but then i'm a boy racer at heart..lol seriously tho that can sometimes "blow" any carp thru the system.

I think i'm right in saying that if the temp gauge is at 3 0'clock when warm (or as near as dunt matter) then no thermostat problems are likely, having said that thermostats are quite cheap £10 -£15 and dead quick and easy to fit.
Hope you get it sorted, best of luck.

Ant.

[trojan]

Update for those who want to read it

I am pretty sure thermostat is dodgy as I've noticed no '3 o clock' on temp gauge.
When it eventually does warm up the mpg gets to acceptable standards, but as I'm doing mainly runs of 3-5 miles its not getting a chance.

Anyways I ordered my thermostat from Rufe (thanks simon) and after letting the engine cool from dropping little un off at school yesterday, got my torx kit and went to change the stat. AAAAAAAAGGGGGHHHHHH, the bonnet catch is stuck shut.
Rapid drive to bodyshop to shout at them and to moan about probs I'm experiencing. The donut there said ,'how can the thermostat be shut open , that never happens' I just let him know he wasnt an expert in Volvo mechanics and said I had taken advice from a Volvo specialist ( all of you out there) and I would be swaping thermostat to see if that was the issue. If not then I will be back.

Oh and he adjusted the bonnet release so hopefully it wont happen again.