How do u tell when head gasket has blown off

[shizhab]

After traveling for 15km only, I realized my temperature gauge wasn't working then I stopped but the engine was really hot...five minutes later I tried to start the engine and the reading went up to about 90 degrees Celsius what does this mean?. It is a 1996 C200 v-boot 111 engine

 

[Dieselman]

It is probably short of water and/or the thermostat has jammed closed.

 

[shizhab]

Both coolent and oil levels are ok

 

[markjay]

The reason that engines with failed head gasket overheat is coolant loss, because the coolant escapes by entering the oil supply system or the cylinder chambers.

If the car overheated and there is no coolant loss then the reason should be something else (e.g. thermostat stuck in closed position).

 

[Dinizulu]

When water enters the oil supply it emulsifies giving they oil a grey appearance.

 

[grober]

90 degrees is not that hot for an engine. Especially if you drove it for a while first to build up some heat in the engine block. What would probably happen is if you drove it further on the open road the temperature would then come down slightly as coolant was passed through the radiator [ assuming the cooling system is working OK] It sounds as if your temperature gauge--sensor or readout failed for a time and then started working again. Zero readout on the temp gauge is a temp gauge problem not a CHG problem. But if you are concerned do the checks the other posters suggest- check the coolant level for starters--- but NEVER top up a hot engine with cold coolant!
ps check the wiring loom+ connections to the temperature gauge sensor at the front of the cylinder head---- you are just at the edge of the dodgy degradable wiring loom period.

 

[shizhab]

Thanks guys you are so helpful. It looks like the thermostat got stuck and temperature failed to read. Now the temperature is normal around 40-50 degrees.No coolant loses seen so far. I was scared thot I blew my head gasket set.

 

[spike60]

90c is a fairly normal working temperature, 40-50 would usually mean thermostat failed in the open position.

 

[Will]

Thanks guys you are so helpful. It looks like the thermostat got stuck and temperature failed to read. Now the temperature is normal around 40-50 degrees.No coolant loses seen so far. I was scared thot I blew my head gasket set.

40-50c is far too cold, 80-90 is correct. The thermostat is designed to restrict coolant flow through the radiator until the engine is full warmed up - around 87/88c or thereabouts.

 

[230K]

Hi

How I determine whether gasket is gone is by whether the expansion tank is pressurising or not.

With car at operating temperature, slacken the cap to let off any pressure (be careful not to get scalded). Tighten cap and rev engine a few times, on subsequent re-release of the cap there should be little or no pressure.

Another way is to watch for air bubbles with the lid off.

Lots of people have different ways of determining apart from a pressure test, those are mine.

Hope this helps.

230k

 

[tonyc280]

Had identical problem on my 1996 C200. was the thermostat. Real easy job to replace.

 

[shizhab]

Thanks guys, my tempeature has since stabilized between 80 & 88 degrees. Like most of the responses I got it was purely a thermostat failure.

 

[deian]

Just to add: another way for a headgasket to fail is for it leak exhaust gases into the coolant channels, I had pug 106d once and it stopped warming up, the water would mix with the exhaust pipe and the pressure building up in the coolant resevoir was exhaust gases. So they can fail in different ways, I think if you get mayo (mayonaise in your oil filler cap), that emulsifiying that then you have some time to plan your repair.

A good way of visualising it is, the headgasket seals not only the top half of the engine to the bottom (which are not mechanically connected except for the beltor chain), but it also seals the holes in between where there are oil channels, water channels, air channels, and exhaust channels. A gasket can fail and any combination of these channels can fail and give differnt symptoms.

Best way forward is to do a compression test. But I know yours isn't this issue.

 

[Grahamcol]

... you are just at the edge of the dodgy degradable wiring loom period.

I didn't think this applied to the C Class nor to this year ?? I have a 1996 C200 registered in August 1996. It's one of the first with the 5 speed 722.6 autoboxes, 1997 model year I think. Would the degradeable loom apply to mine ?