I have a Vauxhall 1999 5 door 1.2 16V Corsa, blows cold air, temperature gauge on red, whats the problem?

A garage has told me it is either the thermostat, water pump or heater unit, if none of these it could be the head gasket....? I have taken the oil cap off on the engine and their is a light brown 'gunk' on the cap...does this mean the head gasket has blown? is there anyway I can test or find out what the exact problem is without spending a fortune?

8 Answers

  • 1 decade ago
    Favorite Answer

    Yes , first buy a haynes manual for your car !

    That will show you how to remove and test your thermostat by removing it and boiling it in a pan.When up to temperature it should open the valve at 90 degrees c. If not then you need a new thermostat , easy to replace and the money you save on a garage will pay for your book.

    If its not the thermostat check your coolant level, if ok listen to water pump for a whining noise or feel for vibration from the water pump.

    Ignore the gunk on the filler cap for oil - ive had that on my vauxhall corsa for years now and have the same gunk on filler cap and its still going strong.

    Probably caused by condensation from the air , a tiny bit is common - if you have a cracked engine you will know about it as the oil will look like foam and you will have white steam from the exhaust and you also will run out of water every ten minutes of driving.

    I would bet on it being the thermostat - easy to replace, or a cheap job at a garage, if not then the water pump which will be a bit more expensive for labour.

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    The thermostat sticking or low coolant will cause an overheated engine and cause the heater to blow cold air. The light brown "gunk" usually indicates a blown head gasket or cracked head, coolant getting into the crankcase. You can check it by either doing a compression test on the cylinders, or a pressure test on the cooling system.

    Hope this helps and good luck

    Source(s): 35+ years fixing my own stuff
    • Commenter avatarLogin to reply the answers
  • Erika
    Lv 4
    4 years ago

    The thermostat sticking or low coolant will reason an overheated engine and reason the heater to blow chilly air. the sunshine brown "gunk" frequently shows a blown head gasket or cracked head, coolant stepping into the crankcase. you are able to examine it by way of the two doing a compression attempt on the cylinders, or a tension attempt on the cooling device. desire this permits and stable good fortune

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    can replace thermostat at home easy hour work maybe cheapest to replace or try

    follow top radiator hos eback to motor remove hose and two bolts scarpe off old gasket replace with new gasket and new thermostat might cost you 30 bucks

    can pressure test radiator to know if it has a leak which might tel you head gasket is bad gunk in th eoil a sign that it is blown but you can stil pressure check it

    water pumps leak when bad 90% of time cant miss that

    type into search box

    how to check head gasket

    how to check over heating car

    how to pressure test radiator

    how to check

    how to remove

    how to replace

    how to install

    name of part

    year and model


    can find most car repairs by typing these word


    how to check head gasket

    how to check head gasket 1999 Vauxhall Corsa

    how to check head gasket video

    • Commenter avatarLogin to reply the answers
  • How do you think about the answers? You can sign in to vote the answer.
  • Anonymous
    1 decade ago

    Brown gunk on oil filler cap help urgent please...



    Got a MK4 99 1.6SE Golf, I regularly change the oil on the car and have noticed brown gunky stuff on the inside of the oil filler cap! [img]/ubbthreads/images/graemlins/frown.gif[/img] Also noticed there is a little bit more of this gunk inside the hole!

    Does it mean there is water in the system?

    What else should I be looking for/doing?

    Thanks in advance

    31-01-2005, 12:14 AM #2 (permalink)


    Mini Cooper S

    Join Date: Jun 2004

    Location: mid wales

    Posts: 557 Re: Brown gunk on oil filler cap help urgent pleas


    How do you use the car ? ....every day

    How long are the trips ? 5 miles...60 miles

    Is the cooling system using water..what colour is the water in the expansion/header tank ?

    cheers [img]/ubbthreads/images/graemlins/169144-ok.gif[/img]

    31-01-2005, 12:30 AM #3 (permalink)


    Fiat 500

    Join Date: Oct 2004

    Posts: 46 Re: Brown gunk on oil filler cap help urgent pleas



    The car is used everyday short trip 10miles there 10miles back all motorway. Its not booted either.

    The expansion tank water is due a change its brownish too [img]/ubbthreads/images/graemlins/frown.gif[/img]

    Im thinking and hoping not headgasket, how much is it to do on one of these?

    31-01-2005, 01:09 AM #4 (permalink)


    Mini Cooper S

    Join Date: Jun 2004

    Location: mid wales

    Posts: 557 Re: Brown gunk on oil filler cap help urgent pleas


    What is it like after a good run..say 50 miles plus ?

    Is it using water ? ...if not, the h/gasket may be ok [img]/ubbthreads/images/graemlins/confused.gif[/img]

    are you getting steam/'white smoke' from exhaust ?

    it's a 'so-so' job .....cam timing/exhaust front pipe....that type of thing [img]/ubbthreads/images/graemlins/crazy.gif[/img]

    depends what your use to...what you've done in the past ??

    good luck [img]/ubbthreads/images/graemlins/tongue.gif[/img]

    02-02-2005, 06:06 AM #5 (permalink)


    BMW 330d

    Join Date: Apr 2004

    Location: Northants

    Posts: 1,710 Re: Brown gunk on oil filler cap help urgent please...


    The problem is the oil breather unit is the oil cap!

    Take the oil cap off, and there a little hose on the bit the cap goes onto disconnect that, turn the housing with the pipe 90deg and it will come off clean it all out and you will be fine! you will see how it just a add on breather unit fitted to the 1.6 engines!

    just to check that is all for the 1.6 8v? the 16V is different again [img]/ubbthreads/images/graemlins/169144-ok.gif[/img]


    Tobes Flickr account

    Tobes youtube account

    07-02-2005, 11:08 PM #6 (permalink)


    Shank's Pony

    Join Date: Jan 2005

    Location: Dorset

    Posts: 16 Re: Brown gunk on oil filler cap help urgent please...


    If that doesn't fix it (keep a check) ... it could be the first signs of head gasket on its way out. I knew someone who had noticed some brown gunk when he filled up the Oil....a year or so later when he went to change the Air Filter there was brown like mayonaise & he started to lose a more & more cooling water - and yes the head gasket was to blame.

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    Light brown gunk is not thermostat issues.

    Thermostat's only mission is to hold back the flow of coolant from entering the radiator at set temperature.

    If it was removed, engine could overheat from coolant passing through radiator not slow enough to cool off before entering the engine again.

    Thermostat does not block flow to heater.

    Light brown gunk can be, in foam condition,

    head gasket, or

    Excessive moisture, engine never gets to operating temperature to burn it off, causing acid formation.

    But close inspection is necessary of cooling system.


    No Heat Condition.

    Reason= No Coolant in Heater Core.

    Followed by+

    Engine Coolant Level, Extremely Low.

    ***Disregard Coolant expansion/overflow tank.

    Check coolant level at Radiator Only.

    There is hand pump pressure gauge tool put in place of radiator cap that takes cooling system to its max pressure of roughly 16 pounds with engine off.

    Can be forced to 20 pounds to reveal stubborn leaks, but coolant level needs to be at cap level.

    Gauge pressure dropping= Is showing system leak.

    Now to discover the leak.

    If the cooling system has trapped air void of coolant, it could hide the source of leak.

    Re-inspect cooling system level and vent any air out.

    Raise vehicle by any means to help coolant fill any air-bound voids.

    Best method is radiator cap being the highest point.

    Make sure heater position switch or lever is in the high heat mode to allow coolant to fill the heater core complete.


    Radiator only. Do not look at over flow tank.

    Pre-tighten all hose clamps before testing begins.

    Tool pressure applied, any fitting will show signs of leaking.

    Regardless if head gasket was damaged or not, it will be damaged if the radiator is low.

    **Caution on aluminum engine blocks.

    Aluminum will warp at lower temps than steel.

    Re-Check coolant level anytime gauge pressure has dropped.

    It must be to the cap.

    Re- pressurize the system.

    It should stay at this level all day, not five minutes.

    **Tests that do not show external leaks/

    Remove tester.

    Radiator re-filled/ start the engine.

    Leave radiator cap off.

    Is coolant in radiator violent and bubble out?

    If so, end of story, head gasket is indeed blown.

    **Internal coolant leak is direct combustion

    pressure entering cooling system, forcing out the coolant.

    You might get lucky with adding a coolant stop leak if the leak is minor, but it' a rare 50/50 shot.

    The engine needs several heat cycles to make it effective.

    Pre-boil sample of coolant or water with added stop leak mixed, then add to radiator.

    This is important to not have compound settle to bottom of radiator.

    I would advise removing the heater core from the engine's fittings to prevent compound from entering heater core. Simply remove hoses. Use short hose to connect both engine ports.

    Run engine to full temp, blocked added throttle speed above idle.

    If cooling system leak seems repaired, then add heater back to the system.

    Good luck on that one.

    Source(s): Forty Years in Monster Garage, where guessing is not an option.
    • Commenter avatarLogin to reply the answers
  • Anonymous
    1 decade ago

    Is the cooling system full of a 50/50 mix of coolant? Did you check the radiator -NOT the expansion tank?

    Oil caps sometimes get that way in the winter.

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    likely it is the thermostat won't open when the water has warmed, I don't think it is the head gasket but I am concerned your water temp is in the red. Check water levels are sufficient so that it can cool your engine and deliver enough heated water to your heater.

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.