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Possible head gasket leak after VNT conversion

Discussion in 'VW Mk3 Jetta, Passat TDI and other/older diesels' started by TDIdude, Apr 9, 2012.

  1. TDIdude

    TDIdude New Member

    Joined:
    Apr 8, 2012
    Messages:
    17
    Car:
    1998 Jetta TDI
    Mods:
    VNT17, Sprint 520s, Malone Chip, EGR delete. Diese
    I have been lurking around this site for a little while and I find it to be very informative. Great write ups! This is my first post.
    I just got a GT1749VA installed on my 1998 Jetta TDI. At first I was having some extreme over boosting issues causing limp mode due to a bad N75 and a vacuum leak. At first I didnt have a boost gauge installed and I was going by my logs to see where my boost was at. The MAP sensor on my 1998 Jetta only reads up to 2.5 bar. So the highest value VCDS was showing me was 2570mbar, which is roughly 22ish psi when subtracting atmospheric pressure.

    After I installed my boost gauge I seen this [​IMG] :confused:
    The highest spike I seen was 32PSI!!!!

    The first couple days I started noticing pools of oil on the ground which looked like it was coming out of the hole in my intake manifold and the intake gasket. So I just assumed that the boost spikes were causing this. Anyway I really got scared when I noticed there was also coolant on the ground. I do know for a fact that my water pump is leaking and the pool of coolant is right where the water pump would leak. My parking spot was spotless before the instal. I also noticed my coolant feels oily but I cant say for sure if it was like this before and caused from my EGR(now gone) or oil cooler.

    Can overboosting cause a water pump to leak more? Would it also cause oil to squirt from the intake? I really want to rule out a head gasket ASAP , so I am thinking about getting an oil analysis done, pressure test(Great write up BTW!!) and actually get under the car for a visual inspection when I get to my dads garage. Is there anything im missing out?
    Are the pressure testers for this expensive? Would I be better off taking it to someone or just using that money and buying one myself? I have thrown a crap load of money at this and id really like to get it sorted as cost efficient as possible.


    Any advise would be great!
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  2. Seatman

    Seatman Active Member

    Joined:
    Jul 9, 2010
    Messages:
    5,139
    Car:
    2000 Mk4 Golf Estate 1.9tdi 174 bhp
    Location:
    Scotland
    Mods:
    PP764's, turbo and mapping
    I expect with the new poke you've probably been giving the car extra foot which will maybe up the temp a bit and may cause the coolant to squeeze out a bit more, if not from pressure then just purely the amount of coolant flowing through it. As for the coolant feeling oily, it does anyway, pour a little bit from a bottle onto your fingers and rub it around, see how that compares. My suspicion is that with it being new that you're maybe a bit over sensitive to the slightest thing which is good but you have to be careful you don't freak yourself out lol.
    The oil from the intake could just be because there's more boost some of the oily residue is escaping out a join in the boost pipes and there could well be a bit more blowby due to the higher pressures.
    Just keep an eye on things and do a bit more investigating and get that water pump sorted.


    welcometomyturbodies
  3. TDIdude

    TDIdude New Member

    Joined:
    Apr 8, 2012
    Messages:
    17
    Car:
    1998 Jetta TDI
    Mods:
    VNT17, Sprint 520s, Malone Chip, EGR delete. Diese
    Coolant always feels oily? That's good. I really never noticed. Thanks!
    I'm sure I'm over analyzing this.. You don't think there's a chance it could be coming from the head gasket?
    I'm going to try and get a better look tonight.
  4. TDIdude

    TDIdude New Member

    Joined:
    Apr 8, 2012
    Messages:
    17
    Car:
    1998 Jetta TDI
    Mods:
    VNT17, Sprint 520s, Malone Chip, EGR delete. Diese
    I just popped off my lower inter cooler hose and was expecting oil to gush out. Nothing came out.
    Is it normal for alot of oil to seep from the intake and the hole under the EGR?
  5. Seatman

    Seatman Active Member

    Joined:
    Jul 9, 2010
    Messages:
    5,139
    Car:
    2000 Mk4 Golf Estate 1.9tdi 174 bhp
    Location:
    Scotland
    Mods:
    PP764's, turbo and mapping
    They can seep from there, if the oil level isn't dropping dramatically it should be fine, if there's a turbo issue for instance you'll notice the oil level going down a bit quick. The egr valves are prone to leaking oil from there too, I think the only real cure is to replace it or do away with it all together.
  6. A_Shifter

    A_Shifter New Member

    Joined:
    Apr 15, 2012
    Messages:
    1
    Car:
    2003 Jetta TDI Wagon
    Boost!

    Even 29 PSI seems really high...but 32? jaw drops
    If you haven't already, I'd be looking at upgrading your exhaust - I wonder what your EGTs are doing?
    I'm only running about 23 PSI, and I had to spend some $$$ to get there and be safe.
    I'll be interested in what others have to say.


  7. TDIdude

    TDIdude New Member

    Joined:
    Apr 8, 2012
    Messages:
    17
    Car:
    1998 Jetta TDI
    Mods:
    VNT17, Sprint 520s, Malone Chip, EGR delete. Diese
    I got it under control. It turns out my N75 was bad. She is running really nice now. Not sure what my EGTs are. I was supposed to get a hole drilled for a probe but the mechanic I had to do the instal obviously had no idea what I was talking about. He welded a 90 degree elbow with a plug in it on my exhaust mani, no idea what he was thinking. EGT probes dont bend do they :dunno

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