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Old 03-04-2011, 06:48 AM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
To the team:
Please tell me what I missed in this attempt at a quality response?
And, why aren't there more head gasket DIYs?
Please improve the "typical scenario" below as I don't have the technical expertise to write this important paragraph!

To the OP:
We're very sorry to hear about this issue. The main problem is that the BMW cooling system is a time bomb. If not periodically overhauled (about every 6 years or 60,000 miles), the cooling system "will" leak in multiple places ... (see pictorial reference here). If you drive for even a few minutes with an overheated engine, the aluminum heads warp & crack, often causing bolts to pull out of the aluminum block E39s (some E39 blocks are, thankfully, cast iron and are less susceptible to this common problem), and other internal damage to the engine (valves, cylinder walls, piston rings, etc.). This is bad. Very bad. The cost for parts is nothing compared to the labor rates involved. Half the engine needs to be removed. If you "suspect" this problem, you really need professional advice with the engine being TESTED! Your options are to replace the parts (expensive), replace the engine (expensive), or buy a new vehicle (expensive). Plus the car will be out of service a minimum of a couple of weeks realistically. Did I mention you really must get professional advice from someone who has the engine to test in front of them? Good luck. And, please keep us informed as to your progress, if for no other reason, so that we may advise the next person who follows in your footsteps.

We get this question about once a week:
- 525i BIG problems!
- Major Decision - replace head or buy "new" engine
- E39 528i Engine removal/replacement
- Overheating and water loss
- Replace head gasket or replace engine
- E39 528i Engine removal/replacement

The problem is this is like asking a forum "I think I'm having a heart attack ... what should I do?". You may be in serious trouble; so you need professional help. Up 'till now, this was my standard response (1).

o 1997-1998 6-cyl M52 engine: iron block, ferrous-liners?, aluminum head
o 1999-2003 6-cyl M54 engine: aluminum block, non-ferrous liners, aluminum head
o 1994-2005 8-cyl M62/S62 engine, aluminum block, non-ferrous liners, aluminum heads

However, I'll try to consolidate the questions from those last few threads to come up with a more standard (i.e., artificial intelligence) approach for improved efficiency.

For quality control, I would ask subsequent posters to help us hone this questionnaire below...

To the OP:
  1. What happened?
    • Who was driving (i.e., reporting what happened)?
    • Did the car overheat?
    • How long did you drive it overheated?
  2. What is the vehicle?
    • What vehicle (i.e., engine) do you have?
    • What is the age, miles, condition?
    • Do you (really) want to keep the car?
  3. What is your situation?
    • Can you afford the few thousand dollars to spend on the fix?
    • Do you have (or want to have) the appreciable skills to DIY?
    • Can you allocate the weeks-long downtime while it's being repaired?
  4. What symptoms do you have now?
    • Do you have white smoke in your exhaust?
    • Is your engine running rough or not at all?
    • Are you losing coolant?
      • Is it visibly leaking?
      • Is your dipstick oil somewhat milky?
      • Does your oil or exhaust smell somewhat sweet?
  5. What tests have you run?
    • What are your wet/dry compression pressures? (1)
    • What is your cylinder leak down results? (1)
    • What is the cooling system pressure test result?
  6. Have you had a professional price out your options?
    • Comparison cost of a replacement vehicle = ?
    • Installed cost of a replacement engine = ?
    • Labor rates for a replaced head gasket = ?
      • Warning: "Head gasket" costs often escalate due to unseen issues like the bolts ripped out of the aluminum heads or damaged rings, cylinder walls, or valves, etc. Pad accordingly!
  7. If you decide to fix the engine yourself
  8. While you're at it, replace a few other maintenance items
    • Vanos seals
    • CCV, ICV, & DISA valves
    • All cooling system & belt-drive system parts
If the OP is a newbie, which often is the case, then these links below should help with pricing:
- BMW phantom diagrams (1) & nominal prices by part number (1) labor rates by zip code (1) (2) (3) where to find a good mechanic (1) (2) & finding a specialty BMW indy in your area (1)

Also, see this summary:
- Summary advice to provide users who suspect a major engine repair due to overheating (1) & how to test an engine for blown head gasket, cracked heads, a warped block, cam seizures, contaminated bearings, coolant hydrolock, or piston, ring, or valve damage (1) (2) & a well researched reusable response to a particular user with a blown engine (1) & what questions to ask when severe heating-related damage is initially suspected (1) & what E39 engine swaps are most recommended (1) (2) (3) & how to lift & remove the engine (1) & where to obtain a new or rebuilt replacement short block or long block (1) (2) & why the E39 engines are so prone to heat-related damage in the first place (1) & real-world results from 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).

Last edited by bluebee; 04-15-2011 at 12:10 AM.
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