Have not posted anything in the Help section for months now two problems in two days :(

 

Car overheated big time today 107c , steam pooring out the rad cap and all over the floor. and it went from 80c to 107c in about a 1.5 miles

 

Last time the car overheated about 6 weeks ago the expansion tank was full to the top, emptied it out and all has been fine since , it now seems its full up again

 

Anybody have any ideas why the expansion tank would fill up completely and not go down , and why the sudden overheat ??

I had this the other day. All was fine for ages, then it started bubbling and then overheated.

 

So i filled it up, and went for a little drive. ALl was OK, but had to put in another litre.

 

Did the same again, went for a drive then put another litre in. Seems like it could have been air locks.

 

Temperature is now rock solid.

Originally posted by Bigbscan

I had this the other day. All was fine for ages, then it started bubbling and then overheated.

 

So i filled it up, and went for a little drive. ALl was OK, but had to put in another litre.

 

Did the same again, went for a drive then put another litre in. Seems like it could have been air locks.

 

Temperature is now rock solid.

 

What I don't understand is why its been ok for weeks and I have done approx 500 miles with no problem , even today I did about thirty miles , then bang the temp just rockets

Dont suppose it could be a faulty thermostat sticking?

 

What about a faulty rad cap letting air in?

 

If mine stays OK now, Im blaming it on air locks. If it goes again, Ill try a new rad cap.

 

I know what you mean though, it just seems to happen out of the blue.

A simple thing like a rad cap can cause this problem.

 

When my car was over heating, I could open the rad cap and nothing would happen. It was just very hot water but no shoot out.

 

I think in the end it was a faulty thermostat, as 3 weeks later the car would not warm up at all.

 

How ever I must say that according to other people 107ºC is not over heating. The fan will come on at 105ºC and on hi-speed at 110ºC and I cant see Nissan making the fan come on when it is a few degrees away from over heating.

 

I wonder if the thermostat has gone completely balls up, and once it gets so hot, starts to close again?

After changing mine the temperature never goes over 80ºC.

 

Stuart

Originally posted by SRRAE

A simple thing like a rad cap can cause this problem.

 

When my car was over heating, I could open the rad cap and nothing would happen. It was just very hot water but no shoot out.

 

I think in the end it was a faulty thermostat, as 3 weeks later the car would not warm up at all.

 

How ever I must say that according to other people 107ºC is not over heating. The fan will come on at 105ºC and on hi-speed at 110ºC and I cant see Nissan making the fan come on when it is a few degrees away from over heating.

 

I wonder if the thermostat has gone completely balls up, and once it gets so hot, starts to close again?

After changing mine the temperature never goes over 80ºC.

 

Stuart

 

Cheers Stu

 

The Thermostat is only a year old as is the rad cap and they have only done 4.5k in total since new

 

As regards 107C not over heating . it left me with hardly any water in the whole system it just dumped the whole lot

 

Normally mine stays steady at 80c as does yours

 

Ryan

Mine stays steady at 65ºC and goes upto 80ºC on a hard drive.

 

Do you have your old rad cap? Was there anything wrong with it in the first place? If not try putting that back on and lets hope that clears the problem.

 

Does the radiator have any leaks in it at all?

Originally posted by SRRAE

Mine stays steady at 65ºC and goes upto 80ºC on a hard drive.

 

Do you have your old rad cap? Was there anything wrong with it in the first place? If not try putting that back on and lets hope that clears the problem.

 

Does the radiator have any leaks in it at all?

 

All I know is that when they did the 60K service before I bought the car that was listed on the invoice as being replaced

 

I think I will invest in a new Rad as I am going to do the additional external oil box cooler anyway , so will go for the manwell rad

 

Thanks

 

Ryan

Strangely I had a 1 or 2 year old OEM Nissan rad cap go with a big whoosh - it actually blew off the rad (found it elsewhere on the engine). Luckily I was only doing about 40 mph (had done a couple of 80mph motorway hours, then turned off to bimble home and let everything cool down slowly). After about 5 miles "whoosh" water all over the road :eek: stop.

 

RAC man filled up radiator system - needed about loads and loads - not just a top up.

 

Pressure test on warm engine at Nelson - no fault found.

 

Maybe there is a bad batch of radcaps out there?

Originally posted by Gio

Strangely I had a 1 or 2 year old OEM Nissan rad cap go with a big whoosh - it actually blew off the rad (found it elsewhere on the engine). Luckily I was only doing about 40 mph (had done a couple of 80mph motorway hours, then turned off to bimble home and let everything cool down slowly). After about 5 miles "whoosh" water all over the road :eek: stop.

 

RAC man filled up radiator system - needed about loads and loads - not just a top up.

 

Pressure test on warm engine at Nelson - no fault found.

 

Maybe there is a bad batch of radcaps out there?

 

Possible I suppose , weird how they just let go though

There is a thread on here from a few years ago when some one went to Nissan with their car over heating and was told they needed a new head gasket or something. Basically it was a few grands worth of work.

 

They then went to Hiteq further down the road in Wigan to see what they said. After 30 seconds of a mechanic looking at the engine, he walked to the back of the garage and came out with a rad cap, replaced it and said it was free of charge. The car worked OK from then on.

Stuart.

Well Bagins' problem obviously lies with the expansion tank, sounds to me like the water has no problem getting there but doesn't find it's way back to the rad. This will obviously lower your coolant levels, giving air pockets and cause your car to overheat, giving big problems if not careful IMO.

 

I dont see how a rad cap causes the overflow to fill up and not come back :confused:

Originally posted by Robtor

Well Bagins' problem obviously lies with the expansion tank, sounds to me like the water has no problem getting there but doesn't find it's way back to the rad. This will obviously lower your coolant levels, giving air pockets and cause your car to overheat, giving big problems if not careful IMO.

 

I dont see how a rad cap causes the overflow to fill up and not come back :confused:

 

Robtor

 

Sounds about right , So if I remember correctly there is a pipe at the bottom of the expansion tank where does that feed to ??

 

Cheers

 

Ryan

The expansion pipe is the small diameter one just above the rad cap. Try pullin it off an blowin in it - the water in the expansion tank should bubble, then suck and you know its free to come back if you get a mouth full.

If that works ok surely prob has to be faulty rad cap not opening under vacuum?

Can also be a small leak on a hose. Just enough to hold pressure when running but suck air in when cooling down instead of sucking back extra water from the expansion tank.

 

Or worse gas creation - head gasket

 

Or air locks from rushed anti freeze adding.

A faulty rad cap *could* cause the water not to return, as the pressure drop in the water system normally pulls more in from the expansion tank - the "vacuum" pulls the inner piece of the rad cap down to expose the exp tank hose, letting it flow in.

 

If your expansion tank is filling up gradually, it's obviously taking it from the system and not returning it.

 

Is it an OEM one?

 

Pete

Pete,

 

I think so but ahve just ordered one from Nissan so will see how I go

 

Cheers

 

Ryan