tpotter1100

I have a 2003 A4 1.8T quattro and I overheated the engine bad enough that it blew a head gasket. I had water pouring into the cylinder 2 and 3. So i decided I tackled the big job myself and bought a new head gasket. I tore it all down and removed the head from the block. i did my best to inspect for cracks and did not see any. i did my best to check for any warps with a framing square. ( i know that's probably not ideal, but its what i had) and i was getting around .004 clearances towards the middle of the block and head. i cleaned everything installed new head-gasket and new timing chain and new water pump, etc. when i filled it with water i did not see any leaks. but when i bump started it, with spark plugs removed, i noticed that water came shooting out of cylinder 2 spark plug hole. i didn't notice any water leaking anywhere and didn't take into account that water could be filling up in the cylinder as well. (facepalm). My question is if i take this all back apart, should i take the cylinder head and get it milled down at a machine shop? along with the block? meaning and entire engine removal? or would just the head getting milled be ok? i feel completely defeated with this thing at the moment. any encouragement would be helpful!!

Thanks for your time,
Tpotter

AudiAllTheWay

Overheated 1.8T heads like to crack between valve seats and spark plug hole and leak coolant into one or both of the middle two cylinders. Since your pulling the cyl head again then inspect for combustion chamber cracks.

tpotter1100

Ah man, i checked and rechecked, cleaned it off real good again, and checked again to see if any cracks around valves and plugs or anywhere on the head and block for that matter. I inspected the the block very thoroughly as well for cracks anywhere around the water columns. I used a high output light and checked the intake and exhaust ports all around the valves as well and didnt see any cracks. I have taken this dang thing apart twice now. If i am not seeing crack/s anywhere could that lean more towards a warp type issue? Which leads me to my original questions. If i take the head to get milled by a machine shop, do i need to take the block as well? Which, to me means, Just pull the whole motor and take it apart and have a shop resurface the 2 mating surfaces and put it back together. Would i need a new gasket and bolts even though they have only been tightened down and not exposed to combustion and heat yet?

Cybersombosis

Check the block for flatness with a straight edge. I would buy another head if it were me. We’ve had loads of B6 1.8’s come through with overheating and cracked heads. Some of them come in badly overheated with no signs of cracking. We replace the head because of exactly what you are going through. If the head is cracked internally and you can’t see it, you will be in the exact same spot as you are now.

Hate to ask but did you put the head gasket on upside down? Did you torque the head bolts in sequence in 2 or 3 stages? Did you thoroughly clean both surfaces before putting it all back together?

I’d also do a compression test and see what numbers you get. Then with the head off and on the bench on its side and the cylinder in question with all the valves closed, pour water into the intake/exhaust hole and watch for water to leak out somewhere other than the valves. If you have water leaking out any of the ports, there is an internal leak. If you don’t see any water come out, turn the head over and do the other side.

tpotter1100

i checked the block for flatness and it seemed to check out pretty good. No dips or high spots that i could tell. I used a level, a framing square, and a piece of steel with feeler guages and only found one area that had about .003-.004 gap.

Truth be told i originally put the gasket on upside down and water started leaking straight out of the exhaust and I thought my turbo seals were blown as well. So i tore it back apart and realized it was on upside down. So upon second time I checked and double checked with the old gasket pretty thoroughly to make sure that didnt happen again. 2nd install attempt i Didnt see any more water coming out of the exhaust or anywhere around the block itself. Only inside the cylinder.

both attempts i torqued the bolts down in 4 stages from 40ft-lbs then 60ft-lbs then 2 stages of 90 degree turns.

both mating surfaces were cleaned and cleaned again a second time when i put it all back together.

are you suggesting doing a compression test on the remaining 3 cylinders before i take the head off?

Cybersombosis

Thanks for being honest. You may have compromised the head gasket by torquing it down then removing the head and reusing it. Gaskets seal by being crushed. On top of that it sounds like you ran the car with the new gasket so that is another reason for failure. Sounds like all you need is a new head gasket. Count yourself lucky. Or it may leak again. You won’t know until you try again unfortunately.

tpotter1100

Yea….I was wondering about the gasket and bolts if they were at all reusable after it has been crushed. (And in my case twice now).
And I have actually not ran the car at all yet after replacement. I have only turned the engine over by hand, after getting timing belt on both times. And on the second head gasket install attempt, once i verified no water leaking in the outside of block, i only bumped the starter to make sure it turned over smoothly. Amd thats when i saw water shoot out of the cylinder. So as of now water leaks i to cylinder 2 with no pressure. I sucked it out but You can shine a light down and watch it pool back up.

AudiAllTheWay

Head gasket and head bolts are use once. Head bolts are torque-to-yield and are at risk of breaking if re-used.

Cybersombosis

When you said “water started leaking straight out of the exhaust”, to me that sounds like the engine was started and coolant was leaking out the tail pipe.

If it were me, knowing I installed the gasket upside down, I’d try another head gasket. If the bolts were new for the first time you torqued them down, I’d use them again. If they were the originals and are now torqued three times, I’d get new ones. But that’s just me. Do at your own risk.

tpotter1100

my apologies on the confusion. The first time i put the gasket in upside down, as i filled it with water i saw it leaking out of exhaust and into the turbo. Maybe thats just because of the way the engine is tilted. So yea, i have yet to actually start and run the engine.
Ok, i think you have convinced me enough to try a new gasket before i try to replace the head completely. The gasket i bought came with new bolts, so ill just get the same gasket kit and use new.

thank you for the advice so far! Much appreciated