So in order to determine whether or not the head gasket is a problem, I performed a compression test on each cylinder among a few other checks as advised in my other thread.
I bought a compression tester, an oil can and rubber hose to attach to drop oil down into the cylinders along with a wrench, extension bar and socket. I'll add that being someone having never bought wrench or sockets before, determining what size socket I needed and how to make everything work with an extension bar was confusing for even after googling and when trying to pick what I needed in the store as I didn't understand why some sockets were in mm, some in fractions, what 'drive' was, what SAE is and still don't but eventually I had what I needed!
On my other thread 94RollaDad asked if I was having high coolant and oil consumption. The coolant I can't speak to as while I reported above how full it currently is, I'm not sure when it was last full. So if someone can let me know if I can and should buy and fill my coolant all the way, I can check this going forward.
The oil consumption part, I know I have a rear main seal leak, but this isn't leaving tracks of oil up the driveway and If I top my oil up every say 12 weeks this seems to be enough to manage it.
However, as far as I can see there is no sign of mixing of oil and coolant, the colour of my oil dipstick seems to look ok and like any other oil dipstick I've seen? (attachment 1)
Koko4 advised dipping the coolant overflow rubber stick into a glass of water. Result - No bubbling.
I also checked the oil-filler cap on DannoXYZ's advice looking for chocolate milkshake like sludge. Seems ok (attachment 2) and nothing like the example he posted.
Lastly, while watching for white smoke, if I turn it on and idle, white smoke does come out of the exhaust, however if I drive off I can't see any evidence of this in my rear view mirror trailing behind me and certainly isn't a thick ploom. It's also cold here, 1 degree and snowing right now which may effect this? I can't say if the smoke I'm seeing has always been there though as I've never looked for it before now.
So onto the compression test. The only step I couldn't follow was to disconnect the distributor connector. I think I know where it is but couldn't get it off and was worried about breaking it. If you see attachment 3, is this it circled in red? Is this a problem I didn't do this step with regard to the results?
I took my spark plugs out. Now according to the service history these were last changed at 254k, over 50k ago. Taking this into account and what they look like (attachment 4) should I be looking to change these? The 2nd one looks particularly rusted/stained I noticed, does this tell me anything?
Anyway, in goes my compression tester, I floored the accelerator and turned the car on letting the engine turn over 5 times. I then added some oil to the same cylinder and tested again and recorded my results. The results are below:
- 150 (dry) / 160 (wet)
- 150 / 160
- 150 / 160
- 160 / 170
While these are pretty consistent, is the compression too low? What exactly does this tell me?
So with the above taken into consideration, does this give me enough to suggest that the head gasket is not on the verge of going and to proceed with other fixes? Is there anything else this tells me that I should take note of?
The only other thing I didn't do as advised was to clean the engine block and to put UV dye into my oil. Is it still worth doing this and if so how do I clean the engine block exactly? Power wash? Cloth and soapy water?
Any input onto all of this is greatly appreciated!