1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

1.9 TDi AJM Unexplained coolant loss

Discussion in 'A4/S4 forum(B5 Chassis)' started by B5NUT, Jul 1, 2011.

  1. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 1, 2011]
    Over the last week I’m getting an unexplained coolant loss,which is being chucked out of the expansion tank. The cars has had the following work done on it, new water pump, thermostat, temperature sensor, new expansion tank and cap, new G12 coolant.

    I only start to see the loss when the car is sitting ataround 70-80MPH, any higher and it will chuck the stuff out quickly. Since Sunday I would have lost around 5-6 liters (could be more)
    Also notice that when you release the pressure, the expansion tank can go from being almost empty to around half full.

    What I’m NOT getting is the following, no oil in the wateror water in the oil, no mayo oil cap. No trouble starting the car, no faultcodes on the engine, no smoke coming out the exhaust.

    Questions! Could this the exhaust gasses going into the coolant?What sort of pressure should be in the coolant system? As the pipes are justabout solid when the car has been run.
    Last edited: Jul 1, 2011
    #1
  2. Ads

    Ads

    [Sep 30, 2014]

  3. yendall24
    Offline

    yendall24 Member

    Joined:
    Mar 6, 2007
    Messages:
    569
    Likes Received:
    7
    [Jul 1, 2011]
    the best thing to do would be to get the coolant in the header tank checked for hydrocarbons if your coolant is contaminated with hydrocarbons your head gasket as gone any half decent garage can do this test for you
    #2
  4. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 1, 2011]
    it could be the HG, one thing have noticed is I only get this under load conditions, if I just rev the car to get the engine up to temp it all appears fine.

    Just drove the car 2 miles at around 40 mhp, the engine would have been a little warm when I started the journey say around 30deg. After the 2 miles the system was at full pressure and the temp was only 75deg, this must be a HG failure.
    Last edited: Jul 1, 2011
    #3
  5. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Joined:
    Jan 30, 2008
    Messages:
    15,612
    Likes Received:
    317
    [Jul 1, 2011]
    Sounds like it, not much else can generate enough pressure to pop the caps relief valve.
    #4
  6. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 1, 2011]
    FFS Etka is showing 3 possible gaskets 1 hole, 2 hole & 3 hole. Anyway of telling what the hell is fitted to the car without taking the head off first..
    #5
  7. adamss24
    Offline

    adamss24 Well-Known Member

    Joined:
    Jul 3, 2007
    Messages:
    3,379
    Likes Received:
    181
    [Jul 1, 2011]
    The AJM PD 115 is known for porous heads... I would check very carefully the head and block for cracks on removal and if in doubt have it skimmed and pressure tested. It's just a ****ty engine and every one i've seen does it sooner or later ! If you decide that you want an engine i have a good working one of a passat i am breaking (140k), it's the better ATJ engine with the 310nm torque... The car is crashed on the passenger side and i am just using the gearbox/pedals and shifter to convert a CVT auto audi a6 to manual gearbox as the auto box is broken...Drop me a PM if interested.
    #6
  8. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Joined:
    Jan 30, 2008
    Messages:
    15,612
    Likes Received:
    317
    [Jul 1, 2011]
    Sometimes the "punched" bit sticks out the side so can be seen with the head fitted.

    Otherwise, no, you need to pull the head.
    #7
  9. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 1, 2011]
    Once I get the head off then I'll see what is what, don't want to buy a new engine just yet.
    #8
  10. adamss24
    Offline

    adamss24 Well-Known Member

    Joined:
    Jul 3, 2007
    Messages:
    3,379
    Likes Received:
    181
    [Jul 2, 2011]
    It might be cheaper a new engine than the expense of a engine rebuild... If the head is cracked the only lasting solution is a new cast- don't bother with rebuilt heads, they are welded and will crack again after the 2-3 months warranty period has expired ! I've seen it countless times hence if i were to do it properly i would only buy a known good engine or a new cast. Cast on it's own is £600 + VAT from dealer, good garages fit only a new head witch has injectors/seals/valves all in for £1600 witch- in my opinion- is good value for money considering the injectors are the best part of a grand on their own ! The pd 115 was only fitted to the audi for just 1 year wich shows how bad the design was- it's basically a reinforced 110bhp engine but without the reliability of the VE lump ! Take my advice, if you want reliable motoring, buy a older 110Bhp AFN/AVG engine, much, much better !
    #9
    jbh likes this.
  11. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 2, 2011]
    I can do all the work myself (apart from any head skim & pressure testing) There is not much cost is hecking out the HG first, just not willing to chuck an engine in the bin without even looking at it.
    #10
  12. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Joined:
    Jan 30, 2008
    Messages:
    15,612
    Likes Received:
    317
    [Jul 2, 2011]
    If it is the head, i'd imagine you can simply fit a used head from a later PD130 engine that doesnt suffer this problem?
    #11
  13. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 2, 2011]
    After reading dozens of threads on the AJM engine the most comon failure is the HG, I'm not getting any steam for the exhaust no trouble with starting the engine no oil in coolant & vice versa. Ordered all the parts I need from my local VW garage as this engine was used in the passat from 1997 - 2000 was also used in the A6 from 1998 to 2001. All I need now is a pot of coffee and some good weather next week:icon_thumright:
    #12
  14. adamss24
    Offline

    adamss24 Well-Known Member

    Joined:
    Jul 3, 2007
    Messages:
    3,379
    Likes Received:
    181
    [Jul 2, 2011]
    ^^^ If it was the headgasket then the engine will overheat, it's either a cracked head, cracked liner, or porous head. Cylinder heads on diesel don't usualy warp unless severely overheated... Throw a new head gasket and take-it from there, remember to use new head bolts,pd 150 ARL are higher tensile than the other pd engines...
    #13
  15. tonya4
    Online

    tonya4 TDi Powerrrr

    Joined:
    Aug 9, 2010
    Messages:
    405
    Likes Received:
    5
    [Jul 2, 2011]
    I read a thread somewhere which said that pd diesels lose power if thehead is skimmed,the thinking is that the injectors are no longer in the optimum position,so I wouldn't have the head skimmed.

    tony
    #14
  16. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 2, 2011]
    I was not going to, also read the same about the HG strange they make 3 different versions mine is a 2 hole version.
    #15
  17. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Joined:
    Jan 30, 2008
    Messages:
    15,612
    Likes Received:
    317
    [Jul 2, 2011]
    The gasket thicknesses are to account for slightly different piston-deck heights.

    Skimming the heads of diesels is generally "not allowed" due to the extremely tight tolerances inside the combustion chamber (the same reason you need 3 different gaskets to account for tiny variations in deck height.

    You might manage to bodge it using the next thicker gasket if you've had to skim it though.
    #16
  18. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Jul 2, 2011]
    I'm not getting the head skimmed, I was just trying to say what I'm able to do without going into great expense. The more and more I read about the AJM engine the more certain I'm suffering HG failure, there are a fair few reports of people suffering the same fault as I have, however they appear to have run the car quite hard even though they know the car has a major fault. Since I found this fault the car never goes over 65mph, and I have the heater on to keep the coolant temp down, and this also helps with the pressure in the system.

    Had a good read up on the gaskets, to thin and your piston & valves meeting together, to thick and combustion is incorrect and you end up killing the engine or time. I've got a 2 hole and I'm replacing it with the same.
    #17
  19. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Aug 7, 2011]
    Figured I would update this thread as it may help other people, thankfully I did not chuck the engine in the bin as it did turn out to be the Head gasket. It was a relieve cheap fix as I did most of the work myself.

    Took a little longer than planned as I figured while I was there I would do some other work on the car, as I the flexi was leaking and the egr valve was on it's way out, some of the stuff I was able to get off ebay at very good price (old dealer stock) Also found that the end glow plug had been put in cross threaded so had the head repaired by a local engineering place for £45 which was not bad.


    So the following has now been done on the car.

    New Head Gasket
    New Shocks Front & Rear
    New Front top & bottom arms (Meyle from ebay.de)
    New Cat with flexi (Was able to get a genuine unit from ebay for £80)
    New Glow Plugs
    New Battery
    New CV Boots
    New Coolant tank
    New egr valve (Was able to get a genuine unit from ebay for £25)
    New water pump
    New Thermostat
    New Cambelt kit
    New Cambelt Tensioner
    New Ribbed belt
    New Ribbed Belt tensioner
    New Viscus fan (Was able to get a genuine unit from ebay for £10)
    Air-con pump
    New Air-con dryer
    New Air-con concondenser
    New air-con belt
    New Padgid disk & pads all round.


    TODO
    Rear bushes
    Replacment front bumper & guides
    New springs all round
    Air-con regass
    Dam good detail.
    #18
  20. Dimokslis
    Offline

    Dimokslis Member

    Joined:
    Oct 1, 2011
    Messages:
    48
    Likes Received:
    2
    [Jan 5, 2014]
    Any list of what engine heads can be used to replace an AJM one? Is 130PD heads straight fit? Or need injectors, turbo to be replaced at the same time? Thanks.
    ATJ;...
    #19
  21. tomyoud
    Offline

    tomyoud New Member

    Joined:
    Dec 17, 2013
    Messages:
    11
    Likes Received:
    2
    [Apr 20, 2014]
    Hi guys, I've recently bought a A4 1.9TDI 115hp 2008 B7.
    I had it serviced about six months ago along with a new thermostat and o-ring for the j plug (I think) because it was leaking. Now had the expansion tank and cap replaced because it is just spitting out a little coolant every time I drive it from the expansion tank. It was at the max line about a month ago and now just over the min line.
    I don't recall it spitting out from the expansion tank before having it serviced.
    Coolant is a nice pink colour and oil is just the usual black colour.
    Could this really be a head gasket failure??

    Many thanks
    #20
  22. B5NUT
    Offline

    B5NUT Well-Known Member VCDS Map User

    Joined:
    Feb 6, 2010
    Messages:
    2,310
    Likes Received:
    260
    [Apr 20, 2014]
    You could get a sniff test done that would confirm if exhaust gasses are in the coolant, but an easy test is the check the coolant hoses if they are rock hard when the car has been driven and is up to temp then something is pressurising the coolant system, which could be a HG or cracked or head.
    #21
  23. tomyoud
    Offline

    tomyoud New Member

    Joined:
    Dec 17, 2013
    Messages:
    11
    Likes Received:
    2
    [Apr 21, 2014]
    Thanks for replying. I took my car for a 20 mile run to get it nicely up to temperature. The hoses are not rock solid but slightly firm and I can squeeze them, but still a little amount of coolant comes out. No steam/white smoke out of the exhaust at all either. So hopefully nothing to do with the head.
    Could it just be the rad with a build up of sludge?

    Many thanks
    Tom
    #22

Share This Page