The more I learn the more confused I get.
This is a 2006 X30 MCX. I bought it in the spring of 2012 with 93 hours on it. I did test drive it before the purchase - it ran great - but didn't do any other investigative work on it. I have been a bit surprised at the amount of fuel It consumes - especially compared to my neighbor's 24' 2007 Tige' (same 5.7 GM block but not Indmar).
As I said, it runs great. It now has 212 hours on it - 60 last year and 60 this year. The only thing that started me down this path was that I only got 3.5 quarts of oil out of it when I winterized it last week.
So after thinking that my leak down and compression numbers weren't making a lot of sense, I retested the leak down on several of the cylinders this morning - same results. I tried to remove the raw water pump so that I could crank the engine manually but that proved to be more work than it was worth - that thing was't wanting to come off. So I once again used the remote start to bump the engine until I could feel pressure in the tester hose. I am confident I was indeed testing @ TDC on each cylinder. I'm confident in the results I reported earlier in this thread. The cylinders that I said were leaking into the intake (3 & 5) I re-confirmed by holding my hand over the throttle intake (where the K&N filter attaches) and pressure was definitely building in the intake. The cylinders I said were leaking into the exhaust (4 & 6) were definitely creating a lot of noise in the muffler and exhaust hoses.
But shouldn't leakage thru the valves make it not run well? There is no question that cylinder 5 is burning oil and some in 3 as well.
Again, I'm no professional mechanic, but things just aren't adding up. I know I have never abused this engine. Could the original owner have not broken it in properly and caused these kinds of issues? Could the fact that the original owner only put 93 hours on it in the first 6 years (which means it sat a lot! - I don't know when it was last used prior to my purchasing it) have caused things to gum up to where I am having these kinds of leakage issues. Or am I just totally off base with my tests? I'm going to check with the dealer for service records - I think the previous owner had them do all the service.
I have a neighbor who is the local distributor for BG Products. He wants to run a couple of BG products through the oil and fuel systems to clean things up and claims that I will be amazed at the results. He thinks my problems are from the fact that it sat so much during the first 6 years. Could the answer be that simple? Have any of you had any experience with BG products? What do I stand to lose by letting him try it?
Another thought - what could I learn by running an analysis on the oil I drained last week?
Again, thanks for all of the valuable input.
Last edited by Skyskiguy; 10-28-2013 at 02:57 PM.