My zed is overheating when you flooring hard mainly when you get over 70 mph.....it looses coolant from the bottle as well....

I have reciently flushed the cooling system as there was brown sludge in the water and no antifreeze as the previous owner couldnt be bothered to use it!!!.

Refilled with 40% antifreeze / coolant still overheating......Radiator cap seems to be hissing and letting coolant back into bottle when very hot.....Auxillery fan on all the time after driving down motorway even while stationary.....

Viscous fan locked on also after driving down motorway...

No air bubbles in radiator while cap off and engine idleing.....No while smoke or drops of water coming from tailpipes....No leaking pipes.....

I have only two conclusions 1>faulty radiator cap,2>clogged radiator?????

 

Any other common ideas that these zeds suffer from.....Zed is fine when sat in traffic or driving lightly..... :shock: :shock: :shock:

Brown slugde in water could be head gasket gone? Oil getting into water?

A hot radiator is usually needed to make the viscous fan hot enough to lock up whereas a blocked up radiator would actually be cold when the engine is hot. Maybe your rad cap isnt holding pressure or you have a coolant leak. Is the top hose getting hard when hot to indicate proper pressurising? If not the water boils off easier and once you loose a little water it will overheat. If the aux fan is on then the engine is really hot for sure. Are you aircon on or off / econ? Aircon on will add even more heat to the front of the radiator via the condenser. So with the heat from the engine the rad could still be suspect. Hope the brown sludge wasnt a radweld overdose as that stuff is excellent for closing up fine matrix alloy radiators.

spot on willie o, rad cap is as cheap as chips and this sounds to be your prob from what you say, the system is pressurising, it reaches the breakpoint of the cap which releases pressure,

Brown sludge is not necessarilly oil, that would tend to be white sludge, the brown stuff is usually accumulated crap, needs flushing though to avoid other overheat probs, re flush if necessary, new rad cap, bet your probs are over.

Incidentally, when you add antifreeze it reduces the water density and therefore will find more leaks, thats what looks 2 have happened here! bit of boring tech stuff for you!!

If you read my post i did say id flushed the cooling system and the top pipe is hard when its hot and releasing pressure.....and as i said theres no leaks other than the coolant reservior spillling out onto the road.......

could be (in order of expense):

 

air lock where youve drained & filled the cooling system

thermostat stuck

water pump impellor broken off (never seen it on a zed, but seen it on other cars)

head gaskets :( (a cyl leakage test, or a chemical "head check" test kit may help to confirm this)

May have been an airlock......But drove today and not overheating gauge staying at halfway but still throwing out coolant out of expansion reservior.???

Rad cap.... oh yeah someone already said that :rolleyes: LOL

Run the engine for a few minutes to get her warm then try to squeeze the water pipes with your fingers. If difficult then you have pressure and the rad cap is probably OK

 

When my head cracked the sludge was sure as hell brown. More like a chocolate milkshake. There was more oil than water in the coolant, but in practice this doesn't directly lead to overheating (mine didn't) since oil has a reasonable specific heat capacity.

yes ok but the cap could still be week by only a pound or two causing early pressure leakage....

does sound like the rad cap TBH ........ Replace it

i have a similar problem in that Baggins and i bypassed the plenum pipes as it kept blowing pipes one by one. Now i have another problem in that when she gets hot it now seems to be leaking from back of engine bay again? did it friday after we sorted problem out by doing the bypass, Ryan came to look at it tonight, not a thing, he goes i drive her about 16 miles and she has started pissing like a bitch? anyone shed some light on the matter? :confused: :cry: :confused:

i have a similar problem in that Baggins and i bypassed the plenum pipes as it kept blowing pipes one by one. Now i have another problem in that when she gets hot it now seems to be leaking from back of engine bay again? did it friday after we sorted problem out by doing the bypass, Ryan came to look at it tonight, not a thing, he goes i drive her about 16 miles and she has started pissing like a bitch? anyone shed some light on the matter? :confused: :cry: :confused:

 

Dave just got your PM will call you later mate , sods law that we can not get it to leak while I am there :confused:

Was gonna start a new thread til i saw this one.

 

Over the past 2 weeks the Zed has shown a red warning light twice. I'm assuming it's the overheat light (what looks like a square with 3 whisps coming out of it - sorry about the lack of technical ability).

 

This happened once last week while cruising in 5th at 60mph, and again last night while doing 80mph. Slowed down to around 50mph and the light went off. All dials (temp, etc.) are showing normal. There doesn't seem to be any leaks, smoke or anything visibly wrong.

 

Does this sound like a faulty sensor, or am i about to kill my engine?

 

All help gratefully received :confused:

Sorry, just seen another thread so guess it must be the cats???

Was gonna start a new thread til i saw this one.

 

Over the past 2 weeks the Zed has shown a red warning light twice. I'm assuming it's the overheat light (what looks like a square with 3 whisps coming out of it - sorry about the lack of technical ability).

 

This happened once last week while cruising in 5th at 60mph, and again last night while doing 80mph. Slowed down to around 50mph and the light went off. All dials (temp, etc.) are showing normal. There doesn't seem to be any leaks, smoke or anything visibly wrong.

 

Does this sound like a faulty sensor, or am i about to kill my engine?

 

All help gratefully received :confused:

 

Jester this is the cat warning light , usually indicating unburnt fuel is the car running ok i.e on all cylinders etc

Hi Baggins,

 

Yep she seems to run fine. The past few days I've noticed she hasn't been pulling as well but i think this is due to the weather. Not used to driving her in the wet that much.

 

Everything else seems fine.

 

Apart from decatting, how can i sort this out and is it causing much damage? It's a pain when you have to back off to 50mph all the time...

Hi Baggins,

 

Yep she seems to run fine. The past few days I've noticed she hasn't been pulling as well but i think this is due to the weather. Not used to driving her in the wet that much.

 

Everything else seems fine.

 

Apart from decatting, how can i sort this out and is it causing much damage? It's a pain when you have to back off to 50mph all the time...

 

regarding the damage it depends on what is causing it , your cats could be shot there for overheating or like I said you could be getting unburnt fuel if the car is running fine it would suggest the cats could be up the creak

 

decatting is not without its problems (turbo seals)

Check the coilpack connectors and the PTU connectors!

I'm alright on the decatting then, mine's a non turbo :)

 

Sounds like it will be easier to decat then. Anything in particular i should get checked out? Have a mechanic that looks after all the stuff on the car (I'm still learning) so i can get him to check some stuff out. How do you fix the unburnt fuel problem?

 

As long as I'm not going to do much damage to the car before i can fix the problem...

The cats will be fine. The overheat indicates raw fuel in the exhaust. Get your mech to check the ignition circuit connectors, from the power transistor unit through to the individual coil pack connectors ;)

Thanks guys, will get it checked out on saturday when i see him :)

Just ordered a new rad cap from Nissan....and went home to check level of coolant/water remaning in zed after usage the previous day and had to top it up 2 gallons :( ????

Started engine and saw air bubbles rising in the top of the rad thinking Oh Poo!!! Dreaded head gasket or cracked head(s)......then noticed water level dropping fast right in front of my eyes so continued to fill another gallon or so then decided to have a look underneath my Zed and noticed water/coolant streaming out from underneath very fast!!!! so i turned off Zed and had i quick look but cant see where its coming from .Other than its at the middle back of the engine i havent had a chance to get underneath with all this rain today but any common places these zed can leak at the Back there??????

Cant see anything either side of the block from uptop?????

Either matrix hoses or one of the turbo water feeds.

also, you might want to check your water pump. the same thing happened to my friends car of a different type a month or two ago when his pump went.

Run the engine for a few minutes to get her warm then try to squeeze the water pipes with your fingers.

 

he wants advice not a sex lesson LOL