i have an 89 5.0 mustang that starts to over heat and lacks a lot of power when driving so what could it be?

there's only one thing that comes to mind on that one,and that the timing is set too high on it,that and the car may be running way to rich on fuel ,that will make the headers glow on it,i ran my timing up on my truck once to see how it would run,and it did this,the headers got really red on it,right after that i also had to replace the head gaskets on it,try checking the timing,that's the most common cause of one doing that ,good luck on it.

When the header glow bright red hot either:

1.) too much fuel is being burned in the exhaust

or more likely 2.) the exhaust valves are not closing

(A very dark red glow only seen in the darkest of night can be normal.)

If the heads have been milled, you may need shorter pushrods or adjustable rockers.

Old Ford Racer

enable me see if i'm able to bottle each and every of the solutions. a brilliant form of them had sturdy factors. The loud clicking sound is a susceptible battery. it might desire to be that the alternator replaced into undesirable and you drained the battery using it. you will probable in basic terms want one and not the two. even if often times you do might desire to interchange the two because of fact the alternator did circulate undesirable and the battery replaced into on that is final legs too and draining might have finished it off. there is another area of shock. The tension belt might have broken even if you need to have felt that for the duration of the steerage first. If it broke and each little thing went lifeless without warning that could desire to factor to the battery first. All that being stated, i could anticipate the alternator first. you have got had a substantial short too even nonetheless that is doubtful. Corrosion on the battery or a unfastened cord on the alternator additionally might desire to be the perpetrator. The alternator itself might have been the quick. it may be inner on the alternator and it might desire to empty the battery in a rely of seconds. you have got additionally had an inner short in the battery besides yet i do no longer think of you may get the click sounds if that befell.

Thermostat could be upside down, Should be a small hole in the part, that gos on the top half... lets air get out of the system

Did you bleed the air out of the coolant after doing the T-stat swap ??

Could have a bad "air pocket" build up in the coolant system.

Seen it happen many of times.

Still EFI or swaped to Carb ???

I was going to say the thermostat but you've fixed that. If it is giving like it's going to stall and then going again it is probably the fuel line like the injectors, fuel filter, or the fuel pump. If it's an automatic and it's giving up hill when you hold the gas steady and it gives it could be your transmission.

I hope this helps,

Tess :)

Sounds like it's either running way too lean from a weak fuel pump/clogged fuel filter or the cat converters are clogged up.

if I was you, I would take it back, and demand for them to recheck it again but this time ask that someone from the shop to drive it while you are with that person so you explain what you notice when you drive it.

don't let them give you an answer just by looking at it

I am sorry I couldnt help more

if the headers are glowing red, it is running too lean. if it is carburated then the jets are wrong, not giving it enough fuel the amount of air it is getting. check and see you can get that looked at.

sounds like you have clogged catalytic converters, if that's the case check you fuel system or the type ( kind, brand ) fuel you are using.

now i am not too sure about this but did you change your cam shaft when you bored out. or regap your spark plugs, made sure you rad can handle that kind of new presure it is now introduced too.