Opinions Needed After Compression and Leakdown Tests

[Rot 911]

My 3.2 has 133,000 miles and is burning about 1 qt of oil every 400-500 miles although I never see any smoke come out of the exhaust even when I try the decelleration test for valve guide wear. Today I did a compression and leak down test after I drove the car. Here are the results:

#1: Compression 145, leakdown 80%
#2: Compression 180, leakdown 8%
#3: Compression 180, leakdown 6%
#4: Compression 190, leakdown 2%
#5: Compression 60, leakdown 100%
#6: Compression 205, leakdown 8%

As you can see I have some real problems with cylinders 1 and 5. However #1 sparkplug is clean, but #5 sparkplug is oil covered. I drove the car again and retested with the same results. On the leakdown I could hear air escaping into the exhaust system on both 1 and 5. I squirted oil in cylinder 5 and there was no increase in compression. I am hoping there is a possiblilty that the exhaust valves on 1 and 5 are adjusted too tight and my plan is to pull the lower valve covers on both sides and adjust 1 and 5 exhaust valves. Any opinions or suggestions out there?

[Rot 911]

BTT

[Early_S_Man]

Kurt,

Your oil consumption rate may not be related to the problems below ... may just be worn valve guides, at that mileage! Intake valve guides are often bad on 3.2 engines, so oil will be burnt in combustion chamber and can show up on the spark plugs! And, at that consumption rate ... I don't believe you would necessarily see it in the exhaust! Your oil on #5 may be due to that particular worn guide, and the compression may be too low for complete ignition/combustion.

Sounds like some definite issues with #1 & #5 exhaust valves ... and maybe valve guide wear as well.

Some possibilities, in no particular order or likelihood:

1. Too tight valve clearance -- open always, or just too tight, as your initial thoughts!

2. Burnt exhaust valves ... maybe due to extended runtime in either above or below condition.

3. Carbon caked under exhaust valve ... seems like a fairly remote possibility with a DME engine, unless O2 sensor failed or disconnected.

If no change in compression or leakdown after valve adjustment, then I suggest the Berryman B-12 Chemtool treatment on the bad cylinders ... fuel rail & #1, #5 injectors need to come out so B-12 can be poured or sprayed down the port. Never done it on a DME engine, personally, but it has worked on MFI & carbed engines with very low compression ... spray or pour an ounce or two of B-12 down each port with intake valve open, then let engine sit overnight ... then crank engine over with coil primary +12 Volt supply disconnected and spray/pour another ounce or two down each cylinder, let sit for an hour, and repeat. Do cold compression test with all spark plugs out ... if compression improves but not fully back to normal, repeat entire treatment process, and retest!

If B-12,improves the compression significantly, I suggest a 1-2 hour test drive with heavy dose (2 - 3 cans in one half tank of gas) of B-12 or Techron in the tank ... then do another compression & leakdown test while engine is hot.

If compression doesn't come up ... engine drop and teardown is the only option I see. Good luck!

[AFJuvat]

Would also pull your lower valve covers and see if you had a rocker shaft slide out from the arm - sticking the valve open.

AFJuvat

[724doorE]

Good luck Kurt, and thanks for the 72E sticker! It got here yesterday and will go well with my newly polished fan and housing.