RM European Auto Parts
Page 1 of 2 12 LastLast
Results 1 to 25 of 28

Thread: Can't find coolant leak

  1. #1
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54

    Can't find coolant leak

    I did HG job over the last couple months.

    Had heads surfaced and pressure tested.
    Replaced radiator with cheap aftermarket.
    New t stat
    New coolant pipes
    1 new heater core hose
    New hose that goes from coolant pipe to expansion tank
    New (cheap) water pump
    --------
    Have not replaced expansion tank
    Just got new cap, but car hasn't been started since.
    Only things left to replace on cooling system is

    the hose that goes from coolant pipe to heater valve
    Lower radiator hose+sensor
    Heater return hose
    Expansion tank
    Isn't there a coolant sensor on the block or head?

    So when I drive I lose coolant. No steam from exhaust. No oil or combustion smell in coolant. Just changed oil, no coolant in there either... I drove about 4 miles the other day after filling and bleeding the system twice, it did not begin to overheat but when I got out, I noticed about a cup of coolant running out from under the car. I looked under there and it was dripping off of the (subframe?) bar that sits between the engine and transmission.

    I lost enough coolant to think that it would at least be a visible leak... I removed the intake manifold and did a pressure test on the system. I turned the key on and put the heater on to open the system, and I pumped it to 25psi. After about 10 min it dropped down to 19 and stayed there. Wasn't going below 19...

    No visible leaks no drips or anything.... Wtf. I figured if it was leaking bad enough to pour a cup out on the ground after engine is off then I should be able to see something with 25psi on it, but no...

    Any suggestions? I really thought because of the location that it would be the hose that connects the rear heater pipe to the heater valve, but it seems dry...

    Gonna get a leak down tester today too so I'll post results of that soon

  2. #2
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    Could be boiling off hot parts before enough collects to drip. Look for staining from the coolant at all the connections, cap, gaskets, etc.
    If it's going into the combustion chambers the spark plugs will show, the effected cylinders will have abnormally clean plugs. Fingers crossed for you.

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

  3. #3
    Join Date
    Jul 2005
    Location
    Indianapolis, USA
    Posts
    307
    My Cars
    1993 318i Touring
    The easiest DIY way to find a coolant leak is go drive the car and get it good and warmed up.

    Shut the engine off. LEAVE THE HOOD DOWN.

    Wait 5 minutes.

    Lift hood and look for the leak. 5 minutes after shutdown is the time when the engine is hottest and the pressures are also the highest. That's when the leaks show up.

  4. #4
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    After a quick drive, I can see the drip coming right below the exhaust. There is even steam coming off the exhaust pipes. I put uv dye in the system and directly below that subframe bar there is a baseball sized puddle of green dye. I looked at the heater core hoses with the UV light and they are clean.... Gonna take the intake manifold off again tomorrow morning and see if there is dye anywhere

    But I do believe it's an external leak because it is puddling on the ground below the car.

    I pulled plugs a couple days ago and they were all blackish. Not really clean
    Last edited by Shawnk111; 06-18-2018 at 11:48 AM.

  5. #5
    Join Date
    Jan 2007
    Location
    .
    Posts
    7,708
    My Cars
    .
    There's nothing on the far right side of the engine that can leak onto or around the exhaust except the head gasket. There's no hoses over there.
    ASE and BMW Master Certified Technician

  6. #6
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    So is it possible that the water jacket part in the hg blew and is leaking outside of the engine and not leaking internally?

  7. #7
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    Quote Originally Posted by Shawnk111 View Post
    So is it possible that the water jacket part in the hg blew and is leaking outside of the engine and not leaking internally?
    Yep. Corrosion or overly aggressive cleaning of the block surface(whiz wheel leaves a divot) on the block or head.
    Dare I say it: this might be helped with something in a bottle
    ducking for cover now..............
    Last edited by ross1; 06-18-2018 at 04:00 PM.

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

  8. #8
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    Dang... I'll pull the intake off again tomorrow and see if I can see any dye. If not I guess I'll put a bottle of stop leak in

  9. #9
    Join Date
    Jun 2002
    Location
    Aberdeen, NC (yes, again)
    Posts
    23,672
    My Cars
    E39M5, E500 4WD
    WAIT.
    Don't disassemble until you find the leak.

    I think I asked you this on another of your threads: Did you replace the two plastic coolant pipes from the front of the head to the back and side of the motor?

    Don't take it apart until you know what you're replacing.

    EDIT: STOP LEAK ??? GTF outa here. If you put that crap in your cooling system, don't come looking for help here! You will have officially crossed over to an entirely different forum, the title of which is not flattering.
    Last edited by bmwdirtracer; 06-18-2018 at 09:32 PM.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  10. #10
    Join Date
    Jun 2007
    Location
    Northern VA
    Posts
    718
    My Cars
    97 M3/4/5; 04 M3 6M
    I agree with Chris, but after a while I think you will need to redo the head gasket. I chased a leak for over 6 mos. Finally just bit the bullet and brought the head to a machine shop. 8-9 thou got shaved, warped at the corners enough to leak overboard (as you suspect), would see drips hanging from the subframe, absolutely no other sign of the leaking fluid.

    The other curious thing about my condition, which I documented elsewhere in this forum, was that the expansion tank would always show the fluid at the "kalt" line when...even the morning after it overheated!...once when it was 20° out.

  11. #11
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    Yes coolant pipes were replaced. I removed the intake again this morning and found the leak coming from the rear intake side corner of the heads. I paid a shop to machine them to a flat surface when I did the job. And I used a reputable brand gasket. Should I contact the shop and see if they will surface it again? They took of 0.015 the first time.

  12. #12
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    Quote Originally Posted by bmwdirtracer View Post
    WAIT.
    Don't disassemble until you find the leak.

    I think I asked you this on another of your threads: Did you replace the two plastic coolant pipes from the front of the head to the back and side of the motor?

    Don't take it apart until you know what you're replacing.

    EDIT: STOP LEAK ??? GTF outa here. If you put that crap in your cooling system, don't come looking for help here! You will have officially crossed over to an entirely different forum, the title of which is not flattering.
    Yeah, that's what I meant if the HG is weeping externally. OP says the head was decked, so that leaves the block or a shite gasket. Either way another big job.
    A million Cadillacs can't be wrong

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

  13. #13
    Join Date
    Jun 2002
    Location
    Aberdeen, NC (yes, again)
    Posts
    23,672
    My Cars
    E39M5, E500 4WD
    I'm not going to argue with you Ross. It really pains me that you've said this, on this forum. I'm leaving it at that, because I like you.

    The cylinder head of an M54 can't be machined 15 thousandths of an inch. It's garbage. and the block is probably garbage too. And that's why you just don't mess with it, you buy a damned used replacement engine for five hundred bucks.


    2002 BMW 325i Sedan (E46)
    L6-2.5L (M54)

    Milling Tolerance
    Cylinder Head Height Standard

    Cylinder Head Height Standard mm 140.0
    Machining limit
    mm 139.7
    Max. warpage allowed 0.05mm
    Last edited by bmwdirtracer; 06-19-2018 at 10:44 PM.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  14. #14
    Join Date
    Jun 2007
    Location
    Northern VA
    Posts
    718
    My Cars
    97 M3/4/5; 04 M3 6M
    I think you know all you need to about your "reputable" machinist who shaved 0.015 from a BMW head without asking you first. On the other hand, and I'm not casting aspersions (I've made some colossal mistakes with my DIYs, well chronicled here ), but your description makes it sound like an installation error or defective head. If it isn't something like you dropped it on that corner when reinstalling or transporting it, it could be the prep work you did (as already mentioned). Maybe you'll find the gasket is screwed up.

    In any case, it does sound like you should at least take the head off and investigate before going all-in on a replacement engine...you think a head gasket job is a pain...! And, afterall, you haven't noticed any die leaking from the block, right? Chris would know way better than most whether there is risk from the now super-high compression and low clearance, which, by the way, can be fixed with a thicker gasket with the blessings of BMW (they list using a thicker gasket in the TIS).

    Also, leaking overboard from the corner...OMG does that bring back some bad times. Sorry to hear it. Best of luck. Keep us posted, if you would.

  15. #15
    Join Date
    Jun 2007
    Location
    Northern VA
    Posts
    718
    My Cars
    97 M3/4/5; 04 M3 6M
    I just noticed that you applied the "reputable" adjective to the gasket. My sentiment is unchanged...stay away from that shop except to try to get some money back.

  16. #16
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    Well I did use the oversized Victor reinz head gasket to compensate for the material being taken off the head. I tried to find low cost engines, but the cheapest thing I can find is $900. I'm in Ohio.

  17. #17
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    @Chris,
    I knew you would cringe.
    The alternatives are all expensive, especially if considered as a proportion of that car's value.
    Do you think it's worth trying to snug up the head bolts?
    Last edited by ross1; 06-21-2018 at 12:03 PM.

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

  18. #18
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    When I did this job, I time serted all of the head bolt holes... When tightening the first time, a couple of the time serts stripped out of the block also. So I used big serts on those and tried again with yet another set of head bolts since I had already stretched a few of them before the rest stripped. During the final install, I followed proper torque procedure. During the second round of 90 degree turns, I felt 2 of them start to become weak. They did not strip, but I knew they were close. I already stretched all the bolts and didn't have another set to use, so I just left it as it was and hoped it would hold. Obviously they did not.

    Today I removed the valve cover and saw that the ones that were becoming weak had actually become completely free and were finger loose.

    I had a total of 3 holes needing repair, and luckily I had 3 more big serts left. And I have another gasket waiting as well.

    Soo.... Yeah I realize that even though they were already beginning to strip when I first reinstalled everything, they probably pulled because the head warped more. However, I assume I can't have any more surface taken off the deck. So I'm not sure what I can do besides to bolt the darn thing back on and hope for the best.

    I know a replacement engine is the best way to go. I fully understand that, however, location is a huge issue for an engine swap, not to mention that I can't find one for a decent price. Found 2 around $900 with 150k miles...

    Planning to put it all back together in the next day or 2 and see how it goes. If this fails, then hopefully I will at least be able to drive it far enough to get to a location where I could actually do the engine swap

  19. #19
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    The writing was on the wall the whole time, why didn't you mention this before?

    "So I'm not sure what I can do besides to bolt the darn thing back on and hope for the best." Might as well, you'll know if it's gonna' work or not once you run the bolts down.
    Good luck

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

  20. #20
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    Well I've had several posts with this issue. Didn't realize this coolant leak was related to the same issue until I found out it was leaking from the head, and took it apart. I'll update you guys once it's back together. Thanks for all the advice

  21. #21
    Join Date
    Jun 2002
    Location
    Aberdeen, NC (yes, again)
    Posts
    23,672
    My Cars
    E39M5, E500 4WD
    I'm sorry that it's ended this way for you. I hope you'll see that this engine is DONE, and not waste any more time and money on it. Nine hundred bucks would be significantly cheaper than what you'll have spent on this trashed motor, before it fails you AGAIN. That said, if you go to Car-Part.com, you can STILL find an M54 for 5 or 600 bucks in or near Ohio. (Ask for a warranty....three months is common.)

    By the way, Time Serting this block needs to be done with a fixture, or the holes are rarely dead straight, or dead center, so they strip out again when you tighten the bolts.

    And, since you have a fluid leak from the block/head....are you absolutely sure that the head bolt holes in the block didn't have ANY coolant or oil in them, before you torqued them, especially since you redid it more than once? (Just a few drops of coolant in a head bolt hole will cause the block to crack when you torque the head)
    Last edited by bmwdirtracer; 06-21-2018 at 10:05 PM.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  22. #22
    Join Date
    Mar 2018
    Location
    Ohio
    Posts
    88
    My Cars
    2001 BMW 325xi, e46, m54
    Yes I'm sure there was zero fluid of any kind in the holes when I torqued them. After time serting them I cleaned them out with rags and wd-40 then let them sit for a day or 2... I'm curious as to why this would cause it to crack though? Is it just because there isn't room for the bolt AND the coolant together in the hole? Not doubting you just curious as to why that would happen.

    And thank you for the website. As I mentioned on previous threads, I am usually not too keen on using different websites online, but I trust the stuff you guys recommend on here. I'll check it out.

    All in all it's not a huge loss if this engine doesn't work out. Most of the money spent was on parts for the cooling system and a couple other things that should have been replaced even with a new engine. In total, IV spend maybe $300-400 on the actual engine. And most of that is for tools like the time serting kits and the vanos timing tools. If nothing else I gained some tools and a good deal of knowledge thanks to you guys. Overall it's been a positive experience even if it ends poorly

  23. #23
    Join Date
    Jun 2002
    Location
    Aberdeen, NC (yes, again)
    Posts
    23,672
    My Cars
    E39M5, E500 4WD
    Liquid doesn't compress.
    To clean out bolt holes, you need to use brake clean and compressed air, not rags and WD 40.
    That website has listings from hundreds, even thousands of salvage yards. I'm not vouching for any of them, just giving you a resource.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  24. #24
    Join Date
    Feb 2005
    Location
    Joppa, Md
    Posts
    2,553
    My Cars
    99 M Coupe,04 K1200rs
    $900 is about 100 times more than Bar's leak, I've seen it work maybe 30% of the time, so easy, its funny.

  25. #25
    Join Date
    Sep 2006
    Location
    NW suburban Chicago
    Posts
    16,300
    My Cars
    hiss by my window
    Quote Originally Posted by Shawnk111 View Post
    Yes I'm sure there was zero fluid of any kind in the holes when I torqued them. After time serting them I cleaned them out with rags and wd-40 then let them sit for a day or 2... I'm curious as to why this would cause it to crack though? Is it just because there isn't room for the bolt AND the coolant together in the hole? Not doubting you just curious as to why that would happen.

    And thank you for the website. As I mentioned on previous threads, I am usually not too keen on using different websites online, but I trust the stuff you guys recommend on here. I'll check it out.

    All in all it's not a huge loss if this engine doesn't work out. Most of the money spent was on parts for the cooling system and a couple other things that should have been replaced even with a new engine. In total, IV spend maybe $300-400 on the actual engine. And most of that is for tools like the time serting kits and the vanos timing tools. If nothing else I gained some tools and a good deal of knowledge thanks to you guys. Overall it's been a positive experience even if it ends poorly
    Are you going to try to re-do the Time-serts? Those bolts were talking to you, you know.
    You have a great attitude so I'm sure you'll get this done one way or another.
    FWIW, if you replace this engine you've a fair amount of bits from the old one that ought to sell quickly and recoup some of your investment

    - - - Updated - - -

    Quote Originally Posted by Shawnk111 View Post
    Yes I'm sure there was zero fluid of any kind in the holes when I torqued them. After time serting them I cleaned them out with rags and wd-40 then let them sit for a day or 2... I'm curious as to why this would cause it to crack though? Is it just because there isn't room for the bolt AND the coolant together in the hole? Not doubting you just curious as to why that would happen.

    And thank you for the website. As I mentioned on previous threads, I am usually not too keen on using different websites online, but I trust the stuff you guys recommend on here. I'll check it out.

    All in all it's not a huge loss if this engine doesn't work out. Most of the money spent was on parts for the cooling system and a couple other things that should have been replaced even with a new engine. In total, IV spend maybe $300-400 on the actual engine. And most of that is for tools like the time serting kits and the vanos timing tools. If nothing else I gained some tools and a good deal of knowledge thanks to you guys. Overall it's been a positive experience even if it ends poorly
    Are you going to try to re-do the Time-serts? Those bolts were talking to you, you know.
    You have a great attitude so I'm sure you'll get this done one way or another.
    FWIW, if you replace this engine you've a fair amount of bits from the old one that ought to sell quickly and recoup some of your investment

    If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

Page 1 of 2 12 LastLast

Similar Threads

  1. Using UV dye to find coolant leaks?
    By ElleShooTiger in forum 1996 - 2003 (E39)
    Replies: 1
    Last Post: 12-22-2011, 12:17 AM
  2. fixed overheating problem but can find coolant leak
    By mitchelllanier in forum 1991 - 1999 (E36)
    Replies: 4
    Last Post: 01-26-2010, 07:16 PM
  3. Hard to find coolant leak. Bring on the ideas
    By rotaryboots in forum 1988 - 1996 (E34)
    Replies: 4
    Last Post: 12-02-2009, 01:46 PM
  4. Cant find coolant leak, but i did find this PLEASE HELP
    By offsetfactor in forum General BMW Mechanical Help sponsored by RM European Auto Parts
    Replies: 15
    Last Post: 09-29-2007, 02:49 PM
  5. help find coolant leak on a 540
    By Hypr5 in forum 1996 - 2003 (E39)
    Replies: 2
    Last Post: 02-21-2007, 09:41 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •