Engine Overheating

**Callifo** · 12-11-2006, 01:16 AM

Had a bit of a search but nothing much specific came up in regards to my situation. Anyway, the other day the old 4ac overheated on the way home from Adelaide. Basically since then it hasn't been right, it runs way too hot. I had it checked and initially the thermostat was replaced but the problem persisted; the mechanic then suggested it could be the head which I'm not keen on spending the money getting a 4ac fixed (4age would be great, but I don't have the time to do one right at the moment).

Anyway have a bit of a check over:

No oil in water
No water in oil or milkshake under the cap
Blows no smoke at all when running or revving.
Running the engine, the water slowly flows out of the radiator into the overflow bottle (or out if the caps off)
Within 5 minutes the engine is at least 1/2 heat, and before 10 she's pushing the top end of the gauge.
Tonight had a check after coming home from work (2.5km drive taking it very slowly and it was 2/3 heat), and it sounded like air bubbling in the top hose.

Before I spend more money getting it checked by another mechanic for a second opinion, is there something reasonably easy that can confirm its the head and not a cooling system problem?

**EldarO** · 12-11-2006, 01:54 AM

headgasket/cracked head.

if waters constantly flowing out of your overflow, its one of the mentioned things.

i am a former 7M owner. listen to me.

Eldar.O.

**Vios-GT_07** · 12-11-2006, 02:11 AM

water pump... no mention of the water pump!!!

i bet u the water pump has seized... and u're bordering onto a BHG now..

of course if this was a 7M, it'd have BHG already

(sorry eldar hehehe)

edit : ur mechanic is a rip off coz who jumps from thermostat straight to the head?? there's many other things first

1. no BHG? okay cool..
2. Check water.. if water keeps getting missing or boiling u might have a leak.. sooo
3. check hoses.. heater hoses, top and bottom radiator hoses.. if no leak.. then
4. check thermostat.. thermostat can't open? or seizing up, change thermostat. if problem persists..
5. check water pump.. remove belt and see if it spins okay.. and for your problem i'm going to bet elevety gazillion yen it's not spinning smoothly, bearings have screwed or just doesn't turn properly or not at all.. (take it off wouldn't be that hard anyway)
6. and if the water pump is spinning right and water is travelling around ur engine...

7. get a second-hand 4A-C or someone might be giving theirs away somewhere.. either way the engines are dirt cheap (cost of a HG replacement = second hand engine with some warranty)..

8. profit ??????????????

**Jorrs** · 12-11-2006, 02:14 AM

dont they come stock with BHG ?

but yeh id be looking at HG, and water pump and see if its still functioning.

**Callifo** · 12-11-2006, 09:26 AM

Ok so tonight when I get some time, Ill try taking out the thermostat and water pump. Does the pump need to come out to check it properly or can you just tell by spinning it?

Could it be a blocked radiator doing it or would that not cause it to continuously flow out like that?

I know someone giving away their 4ac in a few weeks, so that would be an option, though the fact it has more km's on it then mine doesn't inspire confidence.

**Vios-GT_07** · 12-11-2006, 01:46 PM

blocked radiator? highly unlikely.. restricted flow maybe, but to test this just take radiator top and bottom hose off, and use a garden hose, pump water into the top and if it comes out at the bottom it flows alright..

and yea u should be able to tell if the water pump is spinning alright by hand... i can't remember now if the water pump is connected to the timing belt or to the crank pulley.. (i'm leaning more toward crank pulley).

i wouldn't worry about mileage on a 4A-C mate.. they either work or they don't..eheh

**EldarO** · 12-11-2006, 02:06 PM

im 90% sure the water pump is serpentine, and not timing belt.

do yourself a favour mate, get a Tee-Kay test done at your friendly neighbourhood dickheads Autobahn, and you'll know for sure.

this is before you do anything at all.

also, if the TK test still shows nothing, fill your radiator up, when the engine is dead cold.

and idle it untilit warms up, when the thermostat opens, you'll be able to see water flow from the top hose through the cap, even if the top outlet isnt directly there (which i think it is....?) you'll be able to see the water getting disturbed.

but, by the sounds of it, having it overheat once and hasnt run right since then.

you've overheated it because of one reason, and now its caused BHG/cracked head.

Eldar.O.

**SL666** · 12-11-2006, 03:54 PM

way to check the water pump.. idle the car.. feel the radiator, see if it gets hot.. (by that i mean the core) if the rad is getting hot its not a water pump..

do you have thermo fans? if so check they run when they should and run the right way..

you could probably flush out the coolant system anyway.. always helps.. and you could try the old bottle upside down in the rad neck and see if any crud floats out..