Re: overheated while running at idle
You dont say what car or model or engine.
However, assuming port fuel injection, first look at dirty idle speed
control.. symptomatic of 'hunting' plus occasional low idle.
If the Ford has the mass air flow (MAF) sensor, warm the car up. Stop
engine, disconnect MAF connector, then start and test drive.
If better, then clean your MAF; If worse, or wont run at all, You probably
have another sensor problem.
Another possibility, bad fuel pressure regulator.
If the car doesnt overheat now, leave the head gaskets and rings to worry
"Peter" <firstname.lastname@example.org> wrote in message
> My car seems to run more difficult at idle when just started. The ecu
> to rev up irregularly and sometimes the rpm gets really low for a while.
> When driving, fuel consumption has gone up when accelerating - which is
> as vivid as before - and even at cruise is slightly higher than before.
> Could this be an indication for head gasket problems ?
> I will have someone check fuel system problems, but this is the story from
> last week.
> One mechanic replaced coolant liquid by just filling up the radiator a bit
> with the engine at idle, and adding more at large intervals of time -
> instead of using the vent plug near the thermostat. The thermostat appears
> to have a vent hole though.
> He did not drain the cabin heater as far as I know, because he added less
> than the total circuit content. He also used some water for flushing
> but I can't tell how much.
> I wonder if a head becomes warped when the engine overheats slowly at idle
> He did not rev up until he had added more coolant and the fan had turned
> Can a head overheat and not warp ?
> Still, compression tests show good values, this time when hot and full
> throttle, 17 bars on all fours. When measured cold and closed throttle a
> while ago, it was 15 bars.
> Since then I read posts about oil control rings, and the above would not
> exclude oil ring problems and better compression values due to oil - which
> is consumed in a more than normal way - I sucked some burned oil out of
> cylinder with a tube and vacuum.
> For the rings, maybe my style of driving - very low throttle - and oil
> consumption could lead to other problems, I read about glazing ? I would
> tempted to step on its
> tail and open the throttly, but the head gasket could fail ?
> How can I ever tell the engine has suffered damage from overheating,
> when the head gasket really blows ?
> Since fuel consumption has risen only a small amount, could it be ring
> damage ?
> Puzzled & looking forward to advice,