Quote:
Originally Posted by Effduration
Updating this... Unfortunately, 6 months and 5,000 miles later, I have discovered a coolant leak in cylinder 6...I am going in again !! 
I have been chasing a coolant leak the last week.. I did a pressure test on the cooling system, no luck. I then did a compression test on all cylinders and it passed (ea cyl w/in 10 psi of each other), with spark plugs looking normal. I then put UV dye in the system and still couldn't find it. Today, I swabbed all cylinders with a q-tip taped to a piece of ethernet cable. Cyl 1-5 looked great, and my hopes were high..Then I found it in Cyl 6. The swab was covered in coolant.
Not sure what happened, might be a crack in head I missed, or I might have gouged the head on install, I'll report back if I find something. I also didn't know much about the reconditioned head I bought. I have another one.
Since I believe the block is good, have already time-serted the block, have a different, known-good head, have good access in the 3.0 engine bay, and have done it before, I am going to attempt another head gasket instead of an engine replacement. I'll use an engine hoist for head removal installation with exhaust manifolds attached. |
Finished up the 2nd in-car head gasket on this X5. So far so good...I have driven it 5 miles trips to get it up to operating temps. Smooth running, no smoke, the only error codes were 2 codes related to Bank 1
front and Bank 1
rear 02 sensors heater insufficient. Turns out I plugged the rear bank 1 sensor directly
into the front bank 1 O2 sensor - what a
Dumbass .Anyway, I corrected that and we seem good to go...
Problem is, I am not sure what previously caused coolant to leak into cyl 6.
I looked hard for a crack or gouge in the head or block couldn't see one. I do see a small spot in the head gasket where the fire ring around cyl 6 failed, but not sure it failed or just came off when I removed the gasket. Disappointing.
Well, I used a new gasket (the thicker, 1.0mm Elring gasket), new bolts, and a different, newly machined cylinder head. I mounted the exhaust manifold to the head and lowered the hole head assembly with an engine hoist. Had my son help as I needed to swing the manifold clear during the lowering process.. Torquing the head, installing cams, timing the engine all went reasonably smoothly. I had previously time-serted this block, so threads were not a problem.
Let's hope this is the last time I have to go into this engine. If it leaks coolant again into a cylinder, I'll probably just do an engine swap by lowering the subframe..