Thread: Head Gasket

Going to be tackling this job in a couple of weeks when my car is back from t-case rebuild. Whilst i have the head off i was going to tap a hole into the inlet manifold so that i can install a boost gauge and redirect the waste gate pipe here too.

I have a tpiece which came with my ems2 which is 1/8npt size like all the vdo senders. It's a funny size and tapping a tapered thread like npt scares me a bit. So i was thinking to put an adaptor in and then screwing the tpiece into that.

I can only find M14x1.5 male with a 1/8-27 npt inside to it.

Now my question.

Would this be ok to use? Is the thread too coarse and cause leaks or will it be ok?

I had something like this in mind:

http://pages.ebay.com/link/?nav=item...obalID=EBAY-AU

Or

http://pages.ebay.com/link/?nav=item...obalID=EBAY-AU

Close to same thing.

Would anyone here have any objections?

DO NOT trust the expansion tank low level sensors for a tdi, its possible for 2 undetected faults to combine and leave you with a full expansion tank, a half empty radiator and a mostly empty head. If you're lucky You'll work this one out because the heater will be quick to provide some heat but wont provide as much heat as it used to because its being starved of coolant. IF it happens in summer its most likely going to take out the head over time. But a low level sensor in the tank wont tell you a thing.

fitting one that fits into the bung for the thermostat will give you an intermittant indication early on

for the boost connection, there should be a bung in the back of the manifold up against the firewall.
I think it is m12 x 1.75/1.5

Originally Posted by jboot51

for the boost connection, there should be a bung in the back of the manifold up against the firewall.
I think it is m12 x 1.75/1.5

yea that is where i wanted to initially but after a bit of research it is hard to find an adapter that size which converts to 1/8npt. without needing various adapters, which i dont want and have limited space between the back of the manifold and the firewall.

also, from what ive read i believe the size of the bung is m10x1.5

i could be wrong but all good sources pointed to this size. i guess i can pull it out once i have the manifold out and see, but i wanted the bits before i do it so i have the car off the road for the minimal amount of time.

Originally Posted by Blknight.aus

DO NOT trust the expansion tank low level sensors for a tdi, its possible for 2 undetected faults to combine and leave you with a full expansion tank, a half empty radiator and a mostly empty head. If you're lucky You'll work this one out because the heater will be quick to provide some heat but wont provide as much heat as it used to because its being starved of coolant. IF it happens in summer its most likely going to take out the head over time. But a low level sensor in the tank wont tell you a thing.

fitting one that fits into the bung for the thermostat will give you an intermittant indication early on

man! just when i thoguht it was all figured out you throw this curveball at me.

are you suggesting an engine saver instead of using the ems2 coolant alarm? i thought they plug into the radiator and not the thermo housing?

i already have a water temp sender at the thermo housing so i cant put one here. if i have the ems2 hooked up to expansion tank and an engine saver in the radiator bung would this rule out the possible various reading errors? i already have the float switch installed and an ems2 waiting to go in, so i may as well use it anyway but i could add another water level sensor as mentioned above.

the other issue i have with engine saver is that the cap you screw into the radiator is plastic. i have two brass ones which i thought were the way to go.

FWIW, My Tdi had done about 260K, never been overheated (I was told) and the gasket blew out the back. I paid $68 for head and manifold gasket and did the job myself for the first time. The vehicle has been well maintained so there was need to change anything else...all in good nick. I guess it took about 8 hours max to do. Head was flat with some fine cracks and block flat. About 3K since and fingers crossed still going well. Its a relatively easy job to do, figuring out how to get the centre manifold bolt out took me the longest....and then the stupid bolt in the back of the head that holds the breathers.

If you have overheated the head it's a throw away I understand, no point in putting it back and definitely no point in resurface. The alloy goes soft once overheated so Ive read here and been told by Tdi specialist. Buy a brand new one for around 1K and do it yourself. The fun part is doing all the head bolts up in the correct sequence and at the correct angles.

Drain the block first...I made the mistake of not doing that....

looks good man. thanks for info and pics. i had the gauge on mine go up a couple of times last year on a trip. but has been running pretty good. i dont have much $ left so might get the head checked first see if ok. ill check block myself.

Originally Posted by Fausto79

yea that is where i wanted to initially but after a bit of research it is hard to find an adapter that size which converts to 1/8npt. without needing various adapters, which i dont want and have limited space between the back of the manifold and the firewall.

also, from what ive read i believe the size of the bung is m10x1.5

i could be wrong but all good sources pointed to this size. i guess i can pull it out once i have the manifold out and see, but i wanted the bits before i do it so i have the car off the road for the minimal amount of time.

Next to the bung there is a round flat spot on the manifold, you can drill into it and cut a 1/8th thread. Then a 1/8th 90 degree bent fitting screws in nicely. something like this is what I used, clears the firewall easily.