View Single Post
  #30  
Old 01-18-2013, 06:36 AM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
 
Join Date: Mar 2008
Posts: 21,859
Mein Auto: 02 BMW 525i M54 auto 130K
Here is another cracked head, with a successfully welded crack:
> E39 (1997 - 2003) > Another cracked head

Quote:
Originally Posted by H2odiesel View Post
I got the Head off on 12/21, and I was relieved to see no sign of Valve butter as I like to refer to the oil and water emulsion that is formed after running for a time with oil contaminated with coolant. Upon close inspection the typical cylinder three crack from exhaust valve seat to coolant passage is present. I've decided to have a local company do the repair. They said they do them frequently and warranty the repair for two years. There were also two sets of heads on the counter waiting for the local BMW dealer to pick up, which I felt was a good sign. I dropped the head off with cams still installed along with all of the studs still in place. The counter man reassured me they understood the proper cam removal procedure. I'll get it back repaired with a valve job and new valve stem seals, fully assembled for $550. I think that price includes a $50 off locals discount.

There is a steel washer under each head bolt, and after removing the head bolt you can fish the washer out on edge through the Bearing ledge that supports the cam shaft and lifters. Does anyone have a tip on how to best get these washers back in place when reinstalling the head? I was considering running the washers up to the machine shop and have them stick them down with some assembly lube in there recesses.
Quote:
Originally Posted by H2odiesel View Post
Update: I've had the repaired head on for about three weeks now, and once I tracked down a slight coolant leak from an inadequately tightened hose clamp, the engine has preformed well. I also did the vanos repair while I had things apart and I can feel a distinct difference when accelerating. Here is a pic of the repaired area. If you look closely you can make out a little of the welded material in the coolant passage.




See also:
- Summary advice to provide users who suspect a major engine repair due to overheating (1) (2) (3) (4) & how to test an engine for a blown head gasket, cracked heads, a warped block, stripped head bolt threads, cam seizures, contaminated bearings, coolant hydrolock, or piston, ring, or valve damage (1) (2) & what are the major factors in deciding whether to rebuild the engine, replace the engine, or sell the car (1) & a DIY for replacing the I6 M54 head gasket (1) (2) & replacing the V8 M62TU head gasket (1) & why these engines are so prone to heat-related damage in the first place (1) & welding the crack between cylinder #3 and the water jacket on the exhaust side (1) & what engine swaps are most recommended (1) (2) (3) & where to obtain a new or rebuilt head (1) replacement short block or long block (1) (2) & how to lift & remove the engine (1) & the most recent real-world results from the last 50 people faced with similar blown engine problems from which this advice came from (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50)
__________________
Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need
Reply With Quote