Overheating problems

[marode]

In the last few days I had some overheating issues one even short trips (up to max.3 miles). All started with the engine overheated to about 120?C on a short hill climb just before my house. Temperature was climbing from 50 to 120 within 5 minutes. From 90 to 120 took about 1min, I switched off the engine then, because fortunately I reached my house in the same minute.
The next morning I determined the loss of approx. 1.2L cooling water.
Filled it up again and carefully started with the next test drive. All seemed to be fine for a 15min drive, even it had taken place in heavy traffic on a summer day. Then: different day, same problem. Starting with a cold engine, when driving up the road to my home (ascending for approx. 1mile) I reached 110? again very fast. Turned engine off. Could not determine water leaks in the dark. Again there was 1 liter missing. Next test was running the engine at idle speed in front of my house, watching the engine for water leaks. Seen water dripping out of the radiator cap after 2 minutes (engine still cold). Changed the cap and did a short test drive (predominant downhill). Engine reached 85? after 5 minutes and kept this temperature when I reached my destination and kept it running for another few minutes. No water leaks visible, blower started his work, all fine.
Next day: again overheating on the same short route uphill. Heard some fizzling noise coming from the heater area, also some steam was coming up through the front air inlets just in front of the windscreen. My thought was "air bubble in the cooling system". I the absence of a propper car jack at home I decided to use the neighbors drive to ensure the radiator cap is the highest point in the cooling system when filling it up. Then filled up approx. 0.5 liter. Drove the car back to my house (max. 100 yards), engine still cold (I guess temperature was raising from 20? to 23?), but now car parked slightly with the nose down. Opened the radiator cap to check the water level and got a splush of (cold) water with pretty hight pressure in the engine bay. The water level was now above the level which I had just filled up, even after a pint of flush.

Do I have a head gasket problem? Cracked head? What are your thoughts?

Here are some facts:
Elan +2S / Twincam (Weber)
Compression when engine hot (measured last week): 12 - 12,5 BAR on all 4 Cyl.
No white or blue smoke visible
No oil in the water, no water in the oil visible.
When I run the engine now with an open radiator cap, the water level in the radiator goes up within seconds. Some bubbles came up after 30sek, then no bubbles. Engine Off --> level lowers again.

cheers
Matthias

[elanmac]

I would check the thermostat. Although when they fail they should 'failsafe' ie open but I have known them fail closed, stopping the water circulation.
elanmac

[Tonyw]

Matthias,

Sounds to me like a blown head gasket and you are getting exhaust gas in the water system causing the extra pressure and hence water displacement, exhaust gas being a higher pressure that the radiator cap.

If you run the engine with the radiator cap off and full of water you can sometimes see the bubbles of gas often very large, large enough to push out quite a bit of water, always assuming you have not got a sticking thermostat and or other leaks.

Tonyw

[marode]

Ok, I?ll check running the engine without the thermostat. I can?t see any other water leaks, but the heater system is not that much accessible. The thermostat could also fail if it?s surrounded by an air bubble of exhaust gas. So, depending on where the bubble actually is, engine heats up when thermostat fails or does not when it opens correctly. The question is: what causes the pressure? I?m afraid tonyw might be right.

[Bob]

Hi,
If its not all the seriouse things like gaskets etc, do this in any case make sure you have a seal in the radiator cap. Make cut a piece of neoprene or something link that butmake sure the cap seals to the radiator. That way you wont loose water under normal circumstances.
It work beleive me and cost nothing.
Bob