imseksy

well guys, happened about 2 weeks ago, i was driving home and i noticed nothing was wrong. and then when i was about 10 seconds away from my house i find my engine temp almost at H. i pull over and check to see if theres any smoke. couldnt see anything, so i start the car again and the engine temp is back to normal, i drive it around for a little bit, never hitting above 2500 rpm and notice the engine temp is going up again, so i park it and turn it off. i dont see any fluid dripping so i figure i would just leave it overnight and see what happens in the morning. i look at my car the next day and see coolant all over the floor. i assumed it was a cracked radiator because i tried adding water to the radiator and saw that it was leaking fluid. so i went and bought a new radiator. we installed the new radiator today and i still have the same problem. temperature will go to normal in idle and then the fans would blow pretty hard in idle. no heat coming out of the heater either. i take it for a test drive and the same thing happens, temp is normal in idle and once the car goes forward the temperature rises again. no fluid leak from the new radiator however...


so we try bleeding the system, making sure no air is in the system, see if that helped... no luck still overheating once the car is in motion. we are starting to think that it is the thermostat. so were buying one tomorrow and see if that helps. but does anyone else have any more suggestions on what this can be? temp is normal in idle and rises once in motion and the fans turn on loud while in idle but temp never goes up. any input or suggestions would be appreciated. thanks.

Rotary

If you dont have any heat you probably have a problem with the heater core. Heat is generated by the coolant circulating through the heater core. If no heat, no coolant circulation, which means the coolant is not circulating to the radiator.

That would be my guess. Check hoses and the heater core.

imseksy

would that have something to do with the engine overheating though? i checked hoses and everything seems good.

TreeFiddyZee

iTrader: (19)

If you swapped the radiator, I'd make it a rule-of-thumb to change the thermostat at the same time. Pretty cheap insurance.

Z1 Performance

iTrader: (564)

I've not seen one of these cars go through a heater core yet

What does the overflow look like? When the car is cold, and you remove the rad cap, is the radiator full?

edit - you have air in the system. There is a bleed valve on the back of the engine, passenger side, on a coolant pipe. Follow the factory service manual instructions and you'll be good. A fullel (any kind works) will help, but the bleed procedure is essential

06Track

Since you replaced the radiator, you have air in your cooling system. When refilling the
radiator air pockets form and while the radiator appears full there is still air somewhere.
Search for a post from Sharif at Forged Performance. This is always a problem in
a situation like yours and it can be easily corrected. He uses a special funnel to fill
the radiator while the engine is running or you might be able to purge the air a couple
of different ways. Just search overheating and you should see the post recommending
a solution. No hot air from heater means air!!!!

SpoilsofWar

iTrader: (39)

95% of all overheating issues with this car are directly due to air pockets in the cooling system. For some reason we are especially prone to it.

Buy a spill free funnel, bleed the system, problem solved.

Category5

It's probably the water pump. That would explain the sudden rise in temperature, and leakage on floor.

SpoilsofWar

iTrader: (39)

That is the absolute last thing I would suspect.

Category5

You're not flattering yourself. What do expect will happen when your water pump fails? Angels start to sing? Hmmm, do you think maybe water leakage and immediate temp-rise??? Note: If it wasn't for the water leakage, I would have suggested fan belt broke. I guess you would have been stunned by that one too.

Z1 Performance

iTrader: (564)

It would surprise me, since Z's don't have fan belts. Water pump failures in this car are immediately noticeable since its driven off the timing chain. I've seen 1 go bad, ever...and it's a dead give away. - similar to the sound you would make if your hand accidentally fell into the blender (the bearings (or bushings...whatever it uses) scream like mad

I suspect my the OP's posts, that the water leak is gone as a result of the radiator change, and as such, air is the most likely candidate - its proven time and time again in the vast majority of instances

SpoilsofWar

iTrader: (39)

LOL, please go take a picture of where the "fan belt" is on your Z/G.

The water pump in this engine is timing chain driven. If its not spinning, you've got lots of other issues. So unless all the impeller fins broke off a la Volkswagen, I am going to have to disagree with you.

imseksy

we tried bleeding the system for air as well too, still the same problem... i think it may be the thermostat.... what do u guys think?

ADMAN

iTrader: (9)

That might explain the rise in temp once the car is moving. But, it wouldn't explain the loss of fluid.

Did you replace the hoses too???

SpoilsofWar

iTrader: (39)

The thermostat could certainly be a suspect... When the car is warmed up, touch the upper radiator hose. If its cold, your Tstat is stuck shut.

However, how long did you try bleeding the coolant system for? Are you certain you were using the correct method? Air pockets can be very stubborn in these engines and can take a bit to work out. And if you aren't using a spill free funnel, you are making the job a lot harder then it has to be. I suggest you go read some of the overheating and coolant purge threads in the FI section, there is lots of good info in there - to include tips and tricks on getting the air out of your cooling system.

Z1 Performance

iTrader: (564)

I had this on my car when we first built the engine. It took us literally hours to burp it! Originally though it was the t stat, but turned out to just be gas

absolutely ^

9.9 times out of 10, it's an air issue

superchargedg

iTrader: (4)

A big +1 on that as it took me an hour and a half to get what i thought was the last air pocket out.I had heat and everything seemed normal until i drove it the next day.Driving to work it was fine but on the way home in a traffic jam.......quess what the temp gauge started creeping up.

As soon as i parked i got some more antifreeze and burped her 2 more times and since then all is good.

citymunky

iTrader: (50)

I had the same think happen to me, when I replace the coolant at 30K miles. You have air in your coolant system. You just need to purge it.

iStan

iTrader: (29)

Snow-G

iTrader: (1)

+100, same problem to the "T". Search the forum for the procedure. I believe you warm to normal opp temp, turn heat on full, and open purge valve SLOWLY while someone else blips the throttle.