another overheating post

[wifes micra]

I'm really sorry guys I know this has been beaten to death. The wife's car is over heating I'll explain the best I can.
So last nite it over heated within a 5 mile drive from cold it went into the red. To dark to find any problems.
This morning I went out first checked the oil cap seems fine started the engine no blue smoke little rev a bit of white smoke. I let it warm up. Still no smoke on idle still a little white smoke on revving. Rechecked the oil cap and the radiator cap still no sludge and the rad cap hissed.
So after 10-15 mminutes of revving and idle no over heating so I took it around the block in less than a mile the needle was in the red.
On the way back to my house I put the heaters on full put the windows down but the heaters only blown out cold air I believe that last part to be quite important. Any help would be great thanks guys

 

[frank]

any bubbles if you brim the rad and idle it ?

 

[wifes micra]

I'll check that now thanks.

 

[wifes micra]

Ok so turned it on then brimmed the rad. It was a couple bubbles then pulsating the water pushing it out. Then more bubbles then more pulsating not alot was pushed out though.

 

[frank]

you will get a bit of surging, but as long as there is,nt a constant trail of bubbles then ok
is the waterpump belt ok ? both rad hoses warm ?

 

[wifes micra]

Thanks for this frank your a star.
So the rad hose at the top of the rad is warmer than the one from the bottom and I have 2 belts on the left (from the front) both in tack and looking clean and ok. When I turn the engine on all the cogs on those belts move freely.

 

[frank]

if the top hose is hot then the thermostat cant be stuck shut, maybe the gauge ? is the fan cutting in ?

 

[wifes micra]

Ok where is the thermostat and yeah the fan is kicking in when the dial gets over half way up.

 

[frank]

the stat is in the head mate, where the top hose connects, paul (pollyp) has posted loads of stat info on his blog

 

[wifes micra]

so from what's been said so far does it sound like it could be the head gasket at all with the white smoke or the heaters only blowing cold

 

[frank]

a blown h/g wont affect the heater, lack of flow will tho

 

[wifes micra]

Right this is annoying. I've just checked the tank, I didn't spot it sooner cos it's stained on the inside but it is empty. The oil on the dipstick has gone like chocolate milkshake compare to the oil in my corsa with the white smoke it's pointing at the headgasket please tell me I'm wrong

 

[frank]

its rare for a cg h/g to mix the coolant with the oil, all of mine blew the fire ring (combustion-to-coolant) tho that was with boosted cg,s

 

[wifes micra]

I've checked all the pipes and rad. There is no sign of leaks so I'm guessing it's got to be internal. Thanks again frank

 

[alfantasti]

I've checked all the pipes and rad. There is no sign of leaks so I'm guessing it's got to be internal. Thanks again frank

Have a good check of the coolant expansion tank. Original ones fitted at the factory, are prone to going brittle and cracking. If it's cracked underneath, it may be losing coolant without being obvious.
I literally poked a hole in mine with little effort

 

[TonySLX]

I wouldnt suspect internal quite yet ... far more likely to be failed thermostat / low level of water........ and because you havent driven it miles your likely to have got away with it .... fingers crossed.........
Obviously find out where all the water has gone ..... may well be a cracked resevoir ... mines repaired with glass fibre lol...... any drips from water pump side .... any hoses split ..... any water on the floor wells ? (sign of this is condensation inside the car)

Little bit of white condensation from exhaust is normal.

Heater blowing cold air is likely to be because there is no water in it .... low water level.......

Get the system filled .... and check for leaks

 

[wifes micra]

Thanks guys mega help that'll be the next place then the expansion tank I'll do that now
I've topped it up with just water and the wife did the work run. Again about 5 miles and she said it was fine didn't over heat atall. I know I shouldn't use just water but it's such a short distance.
The fan never kicked in though but it was working yesterday and I've noticed this morning both pipes now get warm top slightly warmer than the other. If it's not the expansion tank it's going in for a pressure test

 

[wifes micra]

Next update how prone to failure are the rad caps cos the system is cold now I squeezed one of the pipes and heard bubbling peeled back the sticker on the cap and I have small bubbles coming from the top of it

 

[frank]

they have a little rubber flap that allows the coolant to flow back from the spill tank as it cools down, i ran mine with no tank at all for years (so i doubt if its the tank tbh)

 

[SuperUno]

I have had caps fail before, try a new one - they are cheap enough.

 

[wifes micra]

Yeah I did a Google search on them I think it's that I'm gonna get the head pressure tested in case I did damage but got a new rad cap on the way now

 

[TonySLX]

It could well be that the rad caps been bypassng a little water over time ......( never seen water come out of mine in 7 years ) ... you havent noticed the water gradually declining and its just got very low on water .. hence overheating......... fingers crossed its all okay and the leaky rad cap would explain where the water has gone