help on over heating

[aidssasin]

kind of in a little slump right now. haven't had time to tackle the problem due to work and transferring schools but here is the issue at hand:

when i first drive my car it'll heat up just fine and run at normal operating temperature (at least according to my gauge) after maybe a half hour of driving my coolant temperature will shoot up but not overheat completely. just about 1/4 away from being fully overheated.

recent changes in my vehicle are the thermostat and the type of coolant. i changed from regular green to GO5 when i changed the water pump not too long ago. from my understanding GO5 has the same mass as regular green coolant and does not affect the drag or its "visciocity"


any help is welcomed and the coolant system is fully burped. maybe i might have misplaced the direction of the jiggle valve on the thermostat? and the thermostat is good as well as it was tested prior to installation

[H1tman]

Possible causes of cooling problems.

1. Coolant level
2. Clog
3. Thermostat
4. radiator
5. headgasket
6. Z hates u

What do you mean by misplaced the direction of the jiggle valve?

[nissanfreak12]

Don't forget to check the fan clutch, if it doesn't engage, it will not pull enough air through the radiator when speed are lower than 35-40.

Easy to check, with the engine off, if it spin freely without resistance, its bad. If you spin it and doesn't make a full revolution, its ok.

Also, when does it show heating up city or highway driving? If city, more than likely the fan clutch. If highway, look more toward the radiator.

The Jiggle valve should be at the 12 o'clock position, if you have it at any other position it just makes it harder to bleed the system, shouldn't cause it to overheat. Most vehicles came without a jiggle valve and have zero issues for the most part.

Have you flushed the radiator? How old is it? How is the radiator cap?<another thing to check

[300ZXttZMAN]

Moved to the Z32 Tech section.

Shadow topic left in place.

[t.mcginley.jr]

Just to make sure... with the radiator cap off and the engine running, do you see a continuous flow of bubbles? And how does the coolant look? Any oily deposits?

[ruslan300]

it might be your radiator. I had the same problem with mine. i changed water pump, by passed thermostat, flushed system. The car would drive ok for a bit until the car would warm up ( like 10 to 15 min) also as soon as i got on the highway and speed increased the gauge would go up a bit over half way but never over heat. installed new radiator and problem was solved.

[aidssasin]

i finally got around to doing a leak test on the cooling system and found out that the top of my radiator is leaking a bit of a coolant. one of my friends who is a lead tech figured that the constant flow of coolant in one direction ended up sucking in air through the small leak as opposed to spitting coolant out and created a nasty air pocket.


the coolant looks just fine, there are no black deposits nor oil deposits, so no carbon is entering the system. I'm going to change the radiator out later this week and bleed the system again! just want my baby back on the road