OK guys so my new daily driver just started doing some wierd cooling stuff.

So as im driving on the freeway the temp gauge will bounce up and down slowly rising then slowly dropping down to normal temp.
When i pull up to a light at idle it will remain at about 3/4 the way but will not overheat
The heat is also affected too it will get really hot when the motor gets hot but it makes no difference if the heat is on or not

Throw your suggestions my way

 

it sounds like air in the cooling system...have you changed any cooling system components lately?? try bleeding the cooling system

 

i agree, i would check that first.


its the cheapest and easiest thing to do.

 

Well i did change two hoses the one that runs from the block by the therm to the intake manifold, and the one that runs to the fire wall/heater. But the reason i did that is cause the car was overheating so i thought it was that cause it seemed that there was steam coming from there. Before i changed them it was doing this same thing with the up and down of the needle. The bottom hose off the rad was warm then cold today too when i finally go home the bottom rad hose was pretty cold. So ya im stumped

 

any other ideas?

 

still need some help guys

 

have u warmed the car up with the rad cap off. keep topping it up..


it really sounds like your coolant is low.

 

yea, it sounds like your coolant is low....

and as for the temperature change in the lower hose, thats probably because you felt it right before the thermostat opened and then right after so the temperature would have changed....

also, look into the water pump, take off your radiator cap and see if there is a constant flow of coolant coming in

 

Since your lower hose is cold when you reached op temp, i say your thermostat is stuck closed not allowing proper coolant flow. Same thing happened to me, needle would fluctuate between 3/4 and normal, repacing the thermo was the cure. You should change your thermostat, and bleed your cooling system, also make sure your cooling fan is working. Thermostats are only like 10 bucks.

 

ok here is the verdict i must have had a air bubble cause i jacked the car up and burbed the sytem and the car is good to go

 

ok so it wasnt air in the line so im changing the thermostat tomorrow

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spence &raquo;</TD></TR><TR><TD CLASS="quote">ok so it wasnt air in the line so im changing the thermostat tomorrow</TD></TR></TABLE>

Bump for a update.

 

ok so here is the update i replaced the thermostat and test drove it on the same freeway after to see if it seems fixed. Well right now it does so we will assume its the thermostat if not ill update you again

 

my hatch was doing that about 2 months ago so I changed out the thermostat and the temp. sending unit and now it works fine.

 

Thermostat did not fix the problem. It seems that air is getting into the system as the car sits over night. Is this something that is possible????? Also....as the temp starts to rise, I can hear the car starting to make the fizzle noise from the hose to the heater core.

 

Ok so here is the update on things burbed the coolant with the nipple on the neck of the coolant hose. It took 15 min at least until i saw actual coolant. So i would not recomend try to burb the system with the cap off and squeezing the hose. I drove the car all day and no over heating so it must have been a huge air bubble.

 

you should have run the car with the cap off till the fans come on a few times then put the cap back on and used the "nipple"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by janz3n &raquo;</TD></TR><TR><TD CLASS="quote">you should have run the car with the cap off till the fans come on a few times then put the cap back on and used the "nipple" </TD></TR></TABLE>

Ya i did that minus burbing using the nipple

 

you dont actually need to do the rad cap thing.. your just supposed to do the nipple but doing both isalways a good thing