1998 Holden Vectra Overheating

Hi there,

I would go get the head check done, this is an inexpensive chemical test that detect Co in the cooling system, a sure sign of a head or gasket problem, this test take a few min to do .

mark (mhpautos)

[quote:8238943045="ziomarco999"]Engine Cooling problem
1998 Holden Vectra 4 cyl Two Wheel Drive Automatic 147000 miles

Issues:
car overheated for the first time 2 months ago
it went from a normal 80 deg c to over 100 c
loss of most coolant
no heat into heater - not sure if hot water is getting there

actions so far
thermostat replaced
radiator removed and cleaned
radiator pressure tested and OK
maybe head gasket gone - been checked and 50/50
maybe water pump - seems to move coolant through motor
maybe temp sensors - don't know how many and where they are
possible reservoir cap leaking but this would be minor
no sign of water leaks under the car or anywhere inside the engine bay

what tests can be done to eliminate all the minor items before I get to the head?

what could be causing the overheating?[/quote:8238943045]

head has been checked for leaks by 4 mechanics - the answer is inconclusive.
why doesn't the heater work - no heat?
could there be some soft hoses collapsing with different flow rates and water pressures?

[quote:7dc621095c="ziomarco999"][quote:7dc621095c="ziomarco999"]Engine Cooling problem
1998 Holden Vectra 4 cyl Two Wheel Drive Automatic 147000 miles

Issues:
car overheated for the first time 2 months ago
it went from a normal 80 deg c to over 100 c
loss of most coolant
no heat into heater - not sure if hot water is getting there

actions so far
thermostat replaced
radiator removed and cleaned
radiator pressure tested and OK
maybe head gasket gone - been checked and 50/50
maybe water pump - seems to move coolant through motor
maybe temp sensors - don't know how many and where they are
possible reservoir cap leaking but this would be minor
no sign of water leaks under the car or anywhere inside the engine bay

what tests can be done to eliminate all the minor items before I get to the head?

what could be causing the overheating?[/quote:7dc621095c]

the head has been checked for leaks by 4 mechanics the answer is inconclusive.
why doesn't the heater work - no heat?
checked for soft soft hoses collapsing with different flow rates and water pressures?[/quote:7dc621095c]

the head has been checked again - no leaks.
there is no oil in the coolant.
there is no water in the oil.
thermostatic fan kicks in about 100 c which is apparently normal
the cars normal running temp all year round is 85 c
turning the airconditioner on does not cool the engine down with its fans running.
it has the correct coolant mixture in it.

there is a set of heater hoses called the heater matrix, which can get blocked.
I'm going to check the matrix for blockages next.

I'm reading on other forums that there could be airlocks, it seems odd but I'll try bleeding the air out tonight.

Overall, this has got me stumped. It seems many Vectras across the planet have the identical symptoms with inexplicable overheating and there are at least 20 inter-related reasons for this. In modern engines it is quite bizarre that there isn't a simpler diagnostic process other than pull parts off and replace them and hopefully this is it.

Bugger this I'm gonna design a testing system for the coolant system over the weekend.

In the meantime, does anyone know if there is a Opel, Vauxhall or Holden mechanic out in cyberspace willing to tell us if the Vectra has a more serious fault that explains the large number of overheating problems.

Can anyone tell me where and how many temperature sensors are on the engine, radiator, thermostat ?

Does anyone have a wiring diagram and coolant system diagram of the Vectra 1998 JS series ?

How do you test if the water pump is pushing through enough water without have to take it off the car?

Does anyone have a factory workshop manual? Haynes is ordinary and not relevant to the motors in Australia.

Basically, I've run out of money to throw at the Vectra so all the cheap options have to be eliminated before I can possibly think about replacing head gaskets etc.

Hey mate how did u go with your Vectra?

We're having the exact same problem with mine at the moment, we're doing the fuses and relays and seeing if that fixes the problem.

150000kms and it's just started over heating now, not the radiator, not the head, not the water pump.

Hopefully you can tell us what ended up being the prob with yours.

Thanks