3.3L VGER Compression Test

Hello,

I am new to this forum and excited to have found it. I have a 2004 Desert Runner 5spd (3.3L). I purchased it ~ 2yrs ago with 85K and hoped to keep for a long time as I saw these motors hit the the 200K mark all day long.

I only put ~5k miles per year so my oil change frequency (full synthetic) is twice per year. I drive 7 miles to work each way every day. Temp gauges indicates full operating temp when I get to work (same position if I go on longer drive).

In the first year of ownership I noticed a ticking noise upon start up. After some research I concluded it was the well known "noisy lifter" issue that is common for this motor, and figured it is what it is.

On the last 2 oil changes made two observations: 1) right after the oil change the famous "lifter noise" practically disappeared and 2) the amount of oil I drained (with filter replacement) was just shy of 2 liters. Side note, there is NOT a single oil leak from this motor nor is there any signs (puffs of smoke) of oil being burned and coming out the tail pipe. Tail pipe looks absolutely perfect. Also, I just did an oil change 300 miles ago so I am yet to measure how much oil is being consumed.

My temporary conclusion is that the lifter noise is driven lack of oil (result of being burned). I ran a compression test and the results as follows:

cylinder 1 = 150
cylinder 2 = 148
cylinder 3 = 150
cylinder 4 = 125
cylinder 5 = 145
cylinder 6 = 140

Per the manual, standard is 173 and minimum is 128. My trucks cylinder 4 is at 125 psi. I did NOT add oil to the cylinder to determine if the low reading is indicative of rings vs valves. I do NOT own the tools to perform a leak down test. However, I speculate it is the rings since oil from the crankcase must past the rings to be consumed.

So, here is my question(s):

1) Is this a common problem with this motor? Meaning 5 cylinders have good compression and 1 not?

2) If you have encountered this challenge on the 3.3L (either your own or customer of yours if you are a mechanic), what solutions have you attempted and what were the results?

3) Based on internet readings a plausible notion is that we have carbon deposit build up or a busted ring of some kind. If its the carbon build up what do folks think about treatments such as Sea Foam to break up the "sludge" and carbon build up? I see Sea Foam can be used in the crank case, via the induction system, and also via fuel system.

4) Basically, was recommendations do you offer to potentially solve the low compression on this one cylinder?


Many thanks to all for your time!