Blown Head Gasket possible????

[Tims450SL]

I have a funny odor I notice on my 78 450 SL. It has that like hot water smell that associates with over heating. My car runs a little weird at temp., and I just had a thought...could I have a start of a blown head gasket without water leakage, or really a bad noticeable engine? It hesitates alittle at idle to start, and has this feeling like it is not getting positive fuel pressure while at speed. Could someone please take a monment and let me know of your opinion? I really honestly appreciate this.

Tim

[Pili380SL]

You can do a chemical test, testing the antifreeze to see if combustion chamber gases have been mixed in. Check the oil for a milky appearance, especially on the dipstick right at the top of the oil line or on the bootom of oil filler cap. Another way is a cooling sysytem pressure check, escpecially if the leak is outside.

[nobby]

What do the spark plugs say?

[t walgamuth]

Could be just a seepy hose under the hood or even in the passenger compartment that is hard to spot.

Tom W

[300sdToronto]

I had the same smell issue on my diesel - and slight coolant loss. Thought the same as you about the head gasket and sent an oil sample to the lab. Tested perfect - no coolant in the oil.

Solution - new filler cap on the expansion tank. Solved the problem for me. Could well be a small leak somewhere that only manifests itself under pressure, and that your performance hesitation is unrelated.

[Tims450SL]

I replaced the tank cap and problem solved! Thanks! You guys are the best!