So I've been having some trouble with rough idle, and some difficulty starting, but no sign that I was burning much oil. No blue or white clouds coming out of the exhaust. In the process of pulling the spark plugs I noticed that they all had carbon fowling (I've had some difficulty with my carburetor recently) but there were no signs of oil fowling. I did a compression test and cylinder 1 was low, like 125 while the others were 150-160. (I just did a dry test, I didn't do a compression test with oil because my symptoms didn't seem to fit with a bad piston ring) Got a leak down tester and did a leak down test on 1 (engine is cold, and hasn't been started for a couple days) no bubbles in the coolant, no air coming out of the carb, no air going down the exhaust I could hear but I had moderate leaking, could hear a little air when I pulled the oil cap, but could really hear when I pulled the dipstick. My guess is a bad piston ring, but I'm a little surprised that I didn't see any oil fowling, or really any smoke when I run the car. My acceleration was good too. Am I looking at bad piston rings, or is it something else I'm missing?
Sounds to me this could easily turn into the Granada a friend bought with disassembled 250 in trunk. Was told motor was bad, wouldn't run over 25 mph. No obvious problems but since he knew someone with a good 250, bought that. Replacement engine did not have a carburetor, used the original Granada carb. On first test drive, found it would not run over 25 mph.
Sounds like a bad ring to me, just starting to go bad . Why else would you hear it with dipstick pulled, did you try it on any other cylinders to see if you could hear it . Where was the piston in the hole when you tried the test ?
The engine has at least 70,000 miles, when I bought the car the odometer read 45K but I don't know if the odometer rolled over, or if actually had 45K miles. Car was in a bit of a rough condition so I suspected it was closer to 145K, but I really don't know. Car has sat for maybe a couple months at most, I parked it because I had to do interior work (replace the seatbelt webbing, replace the carpet, deal with floor pan rust, and replace the insulation) but I ran it multiple times while it was down. Most recently I drove it a couple days before the compression test, and ran it the day before or the day of the compression test, but about a little over a week before I was able to do the leak down test. I The engine problems existed before I parked it, just didn't get around to the leak down and compression test till recently.
I did the leak down only on cylinder 1 and with it at top dead center (hooked the leak down tester hose up and turned the engine over by hand with a latex glove secured to the end of the hose [didn't have a balloon available] and when the glove inflated I removed the leak down tester's hose, and put a screw driver in the hole [the piston was already near TDC] and rand rotated the engine until the screw driver stopped moving out of the spark plug hole). I had done compression tests on all 6 cylinders and got 125, 145, 160, 155, 150, 155. The rest of the cylinders were within 15psi of each other (10%), so I focused on the odd man out.
If it were me doing it I would also do it with the piston at bottom just to see if it gets worse or better just out of curiosity , does not look like you have a blown head gasket.
