OK, I have cured my coolant leak by replacing the water pump.

Now instead of 230-260 degrees the car runs at 150 degrees open road and 190 degrees city. Granted its cold out there but I think after 25 miles running I should have more than 150* especially when not driving gentle... I suspect thermostat is jammed open, or missing. However I go to remove the t'stat cover and I can get on the rear bolt OK but the front bolt is obscured by the fuel feeds to the rails. (I have the L98 5.7 in my '88 GTA) I have tried every tool I have to get on it and I can't. I don't want to disturb the fuel lines unless I have too as they look like the sort where the lines will kink or snap as you try break off the stuck nuts! Is there any way of getting the stat out on these cars without doing that or am I just going to have to pull those hard lines?

Next up: how hot should the motor get before I get heat? I have the heater on HOT and blowing but I am getting cold air still at 150* on the gauge. I'm off to investigate the pipework to see that its connected up right but assuming it is can I easily trouble shoot the heater mixer control?

Thanks chaps.

 

150° won't give you decent heat output at all.

I'm not sure why the fuel rails are bothering you. Most people take the throttle body off (4 bolts and the shifter/throttle cable)

 

Ah, the main problem I have is the heater core is bypassed. Which I guess means it leaks.

Fuel pipes bothered me because they look like the sort of thing which will gall up and snap as soon as I try unfasten them. Over the years I have learnt to recognise the stuff which will twist and bust up. Brake lines are a favourite.

Throttle body would be easier to get off. Cool.

 

Always spray PB Blaster on those bad looking things and wait a day, if they still are stiff, spray again and wait another day - the PB Blaster is great at penetrating and loosens pesky bolts great, just spray and wait, respray and wait if needed - even the worst stuff can be easily wrenched in a few days.