help analyzing spark plugs
#16
Three Wheelin'
Thread Starter
At 196k, you're overdue for a valve job anyway. But in the meantime, have you checked the reservoir cap to make sure it holds pressure and have you pressure tested the system? If you have an external leak, a pressure test will show it quickly. Any place that coolant comes out, air gets in...
#17
Rennlist Member
I replaced the cap a while back. I have often pressure tested the system, but not lately. Hardly a week or 2 goes by that I don't have to open the cooling system for one thing or another, so there are plenty of opportunities for air to get in, and it's next to impossible to keep track of the coolant level. I have noticed some white antifreeze residue collecting at the edge of some of the rubber hoses so I probably do need to do another test and tighten everything up.
#18
Three Wheelin'
Thread Starter
Ah, well if you are opening the system and letting the air in yourself, that's a different issue. I had the impression you were finding air in the system after multiple attempts to vent. Either way, if you are seeing antifreeze residue, then definitely time to test with pressure.
#19
Rennlist Member
Perhaps V2 rocket can comment on this..If an EGT gauge probes were placed in the exhaust manifold runners, would it be sensitive enough to detect the differences between cylinders in this case? Divil has already tested this with a laser thermometer on the runners and hasn't noticed any appreciable differences..jus wondering..Tiger 03447
#20
Three Wheelin'
Thread Starter
Perhaps V2 rocket can comment on this..If an EGT gauge probes were placed in the exhaust manifold runners, would it be sensitive enough to detect the differences between cylinders in this case? Divil has already tested this with a laser thermometer on the runners and hasn't noticed any appreciable differences..jus wondering..Tiger 03447
#21
Three Wheelin'
Thread Starter
more pics
As requested, here are all the plugs lined up together.
Unfortunately, they are making me look like silly now because they are WAY different from when I took the first set of pics. After a little driving #2 has darkened, while #4 has cleaned up quite a bit, with the result that 2, 3 and 4 all look pretty much the same now. #1 still looks a lot darker than the others but the difference overall looks much less dramatic.
I promise though, 2 was squeaky clean when I took those other pics!
I also noticed that the white/grey stuff on piston #2 is still there, looking identical to yesterday (before I drove) so I don't see how it can possibly be antifreeze residue...maybe ash from burned oil?
(Cylinders 1-4, left to right):
I also pressure tested the cooling system - at first I did hear a little noise from the electric pump but it soon stopped and the system held pressure at about 9psi. I wasn't sure how high I should test it but it got pretty hard to pump at 9 and I didn't want to overdo it.
Unfortunately, they are making me look like silly now because they are WAY different from when I took the first set of pics. After a little driving #2 has darkened, while #4 has cleaned up quite a bit, with the result that 2, 3 and 4 all look pretty much the same now. #1 still looks a lot darker than the others but the difference overall looks much less dramatic.
I promise though, 2 was squeaky clean when I took those other pics!
I also noticed that the white/grey stuff on piston #2 is still there, looking identical to yesterday (before I drove) so I don't see how it can possibly be antifreeze residue...maybe ash from burned oil?
(Cylinders 1-4, left to right):
I also pressure tested the cooling system - at first I did hear a little noise from the electric pump but it soon stopped and the system held pressure at about 9psi. I wasn't sure how high I should test it but it got pretty hard to pump at 9 and I didn't want to overdo it.