Engine Refurbished...or not?

leedom

ratrace wrote: »

is the fan working does it cut in and out to control the engine temp check that it maynot be working

been told fans are ok

leedom

ratrace wrote: »

is the fan working does it cut in and out to control the engine temp check that it maynot be working

fan cuts in

Norman_Castle

leedom wrote: »

if it was stuck closed would the heater in my car work - and if so would that be why the heater is very hot ie it isnt being cooled/ regulated?

Yes to both. If the thermostat is stuck shut you are cooling the engine through the heater. Depending on the car they can be very cheap and easy to replace.

arcon5

Thermostat should have been the first port of call not the last.

atrixblue.-MFR-.

could be as simple as a air pocket. You said that the rad was replaced, It could be possible the garage didnt bleed all the air out properly and theres a air pocket trapped in there near the head temp sensor or water temp sensor and causing a overheat issue. Go back and ask them to bleed the system to elimante it.


There are several things that can cause what your describing, but i would start with the simple basics that rads been replaced, could be a possible air pocket. Once this is eliminated, then you know the rad isnt the issue and a stuck thermostat shouldnt cause this issue as there is if memory serves there is a bypass, (unless someone modified the thermostat housing or blanked off the bypass) but for the sake of elimination you could replace it with new one.



You say there is no white cloud of smoke and no milky oil but this does not rule out a faulty headgasket as water could be leaking from a water gally or port and dribbling down the rear front or sides of the engine.
As the engine is unknown at this time, as to what work has been done to it in its lifetime, you never know that a previous garage could have changed a timing belt and water pump caked up the water pump mating surface with sealant (big no no never ever do it) and that sealant has flowed intot the internal passages for the water and blocked one up causing overheat.


Basics first, have it bled again.

foxy-stoat

Thermostat should be changed ASAP - why was the radiator and expansion bottle replaced?

foomanchu

You can check for stuck thermostat; from cold with the engine idling you can often feel the rad hose return to engine does not get hot. If the fans cut in before the return hose gets hot, good chance it's a stuck thermostat. Pretty easy and cheap to change I'd question why it wasn't done at same time as radiator. Bleed worthwhile too.

If that doesn't do it you might have a head gasket failure. This doesn't always lead to mixing of oil/water but can be as simple as high pressure cylinder forces bubble into coolant effectively causing an airlock or forcing coolant out. You can't always see milky oil or bubbles in coolant, but there are chemical kits that will test for exhaust fumes in coolant, which will tell you for sure if this is the issue.

[Deleted User]

I remember running a low mileage Vauxhall Cavalier for around 2 years with water leaking away somewhere unknown making the engine slightly over heat sometimes if I did nt top up constantly . Eventually one day it would nt start, after an 800 mile run to Cornwall and back , so took a plug out and when it was pushed in gear water spurted out of the plug hole.
Surprisingly just replacing the head gasket for £10 cured it. Drain and refilled ( after an engine flush )
the oil/water mix and it ran perfectly well for another couple of years.
There was no signs of any water leaking out at all because it was leaking from the water holes through the head escaping into the engine, but the engine seemed to like having a bit of water in it and sounded good

Geodark

Water Pump? Thermostat? blocked radiator? HGF? (doesn't always show as milky stuff), could me many things. As said though first point of call should be the thermostat.

Robisere

If all the possible faults above have been checked and found to be OK, there may just possibly be a problem with the Heater Matrix, a small radiator which lives under the dash near the floor and provides heating from piping passed through from the cooling system. This is controlled by the heating controls on your instrument clusters: it sometimes blocks with sediment, being the lowest point of coolant flow.