STILL overheating, never been so frustrated in my life :(

hahaha we'll see, i'm after as many opinions I can get at this stage.

 

Reckon you are on the money Beaver, My ZX has just been transported down to Adelaide Z Cars for major surgery because the thing overheated and blew the bottom Rad hose in the process. They checked the compression and it was down on one cylindar, when they checked the liquid in the rad, they found exhaust gases in it, so it is engine out, head off time this week!

 

I'm a bit iffy on the first paragraph ( Beavers) but wholeheartedly support the rest ( or un-cool)

 

The more I think about it the more it makes sence to me. Add in a few rpm's and an incline loading up the engine and some boost and that could explain the temperature spikes while the car is in motion, but it declining while there is no or little load on the engine and not nearly as much combustion gas under pressure finding it's way into the cooling system.

I'll see what i can do about getting a coolant analysis later today.

I thank everyone profusely who has made suggestions or comments to try to help. Frankly i'm sick of the sight of my engine bay for the moment and I just want this thing fixed so I can truly enjoy the awesome experience of driving my zed without the justified paranoia of my engine going ka-blammo on me.

Thanks again and i'll post some results when I have them.

Kind regards
Ben

 

Good luck!

:zlove:

 

I had a similar problem for quite a while. It turned out to be caused by wear on the radiator filler neck. The cap didn't seat properly so when it got hot water would leak past the cap and into the filler bottle. Sometimes it would suck the water back into the radiator when cool so I didn't always lose water. A new cap didn't solve it because the neck was the problem. It was easily solved by bending the cap lugs in slightly so that it seats firmly.

Good luck.

 

Another crazy thing to check -- blockage of the AC condensor fins. These cars can be vacuum cleaners in the front end -- folks have reported backwashing the AC condensor coil and finding a lot of debris in there -- especially for early year cars (with more road time). Blockage there hurts air flow to the radiator...

2nd thing to look at -- the lower radiator hose. Sometimes as they get old they collapse a bit and block coolant flow, especially under higher demand situations.

 

2nded on the lower rad hose idea

Eliminate all simple/cheap to fix possible causes first before you pull the head(s)...

 

Thanks guys, I think I mentioned at the start that I already have a lower hard pipe but I may have forgotten to list it. I actually had a look at the a/c condenser yesterday afternoon and yeah it looks a little crudded up but I don't think enough to be causing this extreme a problem, regardless i'll flush it out.

I'm going to try to get a coolant test done now so i'll know pretty soon what might be going on.

Regards
Ben

 

Well......

Stick a fork in me cos i'm done with this POS

Gas test on the coolant was fine so all I've got left to try is take of the front mount and see what happens with the smics back on. This should make some difference but I don't think it's the cause of the problem considering there are like 60 GB fmics running around, some in much hotter climates than mine.

Any further conjecture on possible causes will be appreciated as i'm not sure what my next move will be. Probly after new years i'll just try tog et some cash together and give it to a reputable workshop to see what they can find.

Thanks again for everyones input, hopefully I can get to the bottom of this sometime soon.

Ben

 

This may work

Try this
take the bonnet off and see if temp rises when driving.

 

What will this achieve?

???

 

Same problem with the filler cap

Malc I have the same problem. The radiator filler neck I am told is plastic and these wear. The solution is to fit a new tank. On mine my new service guys picked up that a tab was missing when you turn the cap completely shut. The solution is to back the cap off very, very slightly. If the cap fully closed is 1pm turn it back to about 12 noon.

Long term I'll get the tank replaced. But for now this will do the job. I've had a couple of boilovers with the cap fully closed.

Been out today in Melb traffic. At one point a GReddy gauge showed about 95deg so experimenting I turned off the a/c. Stuck in bumper to bumper traffic the car was happy at around 90 deg. On something like a freeway the temperature will drop down in the middle to low 80s. Mine has a separate cooler for the auto trans.

Perhaps too JSpec cars radiators are smaller than the ones built for Aussie or the USA?

I'm not sure if these cars are super complicated but it does seem if you get a lot of work done at once that nailing down a problem that crops up afterwards can be problematic. That's when you need a mechanic with good intuition and reasonable rates. Not someone who will turn your car into a money pit.

HTH.

 

Id say it was a head gasket. The situation you describe sounds like what happened to me, temp rising rapidly at moderate + speed. If this is the case unfortunately it could mean a rebuild

 

Probably a defect notice

n/m

 

You had

a hydrocarbon test done? and the result was negative. If that is the case your head gasket would seem to be in good shape.What boost psi do you normally run, and is your egr connected and opperating properly.

 

the radiator cap .. i think that baron had a similar issue

even with a new oem cap .. was the neck/locking mechanism as described above .....

 

He has a

custom radiator baz, still worth a look see!

 

Thanks fellas,

I'll check out the neck and cap, i've got another cap here anyway so i'll give that a run for a few days and see if there is any difference.

As bad as it sounds I was actually really hoping it was the head gasket, atleast that was something that could have been identified and fixed to solve this ongoing drama.

Could it be possible that the head gasket might only leak while the engine is under load or at speed?

Ben

 

I normally run around 14 psi but up to 18 on occasion. Not sure about the egr stuff, it's still all there but not sure if it's working correctly.

The last few times it's overheated on me I was driving VERY gingerly and would have been only barely coming onto boost if it all. Most would have been 3 or 4 psi tops. Just enough throttle to maintain around 90 - 100 kph on the freeway.