I have a 93 mazda protege DXL4 - 1.8L 1839cc MFI GAS SOHC with 233,880 miles on it & I recently changed the plugs, wires & rotor then got an oil change. Before the oil change I went to the gas station & they put regular instead of premium in my car like I asked. I went to the store & got some octane boost. Then it started cutting out like it did the last time regular gas was put in my car. I decided to change the air filter & fuel filter thinking it might be clogged up (whitch was not an easy task due to location & very little tools). The check engine light came on briefly a few times so i had diagnostic done & came up with a code 2 (but no crank position sensor found for this car) & 17 (bought new sensor but not installed yet) & i did the oil change the same day. After all that I started to hear a ticking sound coming from the engine compartment. Now I am losing coolant & don't know where. I have a slight bit of white smoke coming out of the tail pipe with a little bit of moisture but looks more like condensation. I also noticed that there is a milky substance on the under side of the oil cap but none on the dipstick (no sign of coolant in oil at oil change either) I am assuming this has to due with short trips while cold out side causing condensation under the cap. I am stumped by the ticking sound because it starts when the car warms up then gets louder, quieter & comes & goes. it gets faster upon acceleration & slower when clutch is pushed in or RPM's go down. Do you know what could be causing the ticking sound?

 

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

If your car requires premium and regular is put in, nothing good can come. Is there a reason why you put premium in? Does your car call for it?

Put more octane booster in or get fuel removed. Put in 94 octane gas to bring it up.

 

I do not think this particular engine requires premium octane fuel, its compression ratio is only 8.9:1 which is rather normal. If it cuts out on low octane fuel that could mean you have a deeper issue with timing control/detonation detection rather than it needing high octane fuel but I cant be sure without looking at the actual car. Does the tick sound high up in the engine or down low? Is it more pronounced under load (up hill for instance) than flat roads? You can put in some UV dye tracer into your coolant bottle and then use a UV light (WITH APPROPRIATE GLASSES) to trace your coolant leak after a while. My parents had a '97 F150 with the standard 4.6 in it, it would ping horribly on 87 octane and ping less so on 91, after some fiddling I removed the "octane bar" otherwise known as a spout connector and the truck ran PERFECT after that, strange how cars are sometimes.

 

UPDATE........
So the tick in my car is an automatic valvue adjuster. But my machanic pulled the o2 censor located on the manifold & sweet smelling steam was coming out (mind you that the car was not fully cooled before changing the o2 censor) & he said probobly a blown head gasket. But here is my delema, My oil is not mixing with any water & the oil levels are staying fine. I have one spark plug that keeps loosening that we have to re-tighten & I thought I saw some water drops right outside of third plug from the left. I am thinking possible cracked head instead of head gasket. Is there anything recomended to put in my radiator that can help stop the leak until I can get a new motor, re-build this motor or a new car? Oh & I am hearing alot of water sloshing sound from passenger side (sounds like it is coming from dash area near firewall) upon accelleration. There is no coolant coming from my heater vents, so I am not thinking the heater core but it does loose water faster when running my heater. I would just park the car & not run it at all but I have to take my daughter back & forth to school every day & I also take care of my mom whitch lives about a mile away. PLEASE HELP.... ANY INPUT THAT WILL HELP WILL BE GREATLY APRCIATED !!!

 

You can try Barrs leak or something else they are about all the same. If you're smelling sweet smell, that is coolent. Regardless if it is a head gasket the head will have to come off, I'd recommend have it checked for cracks.