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Blown head gasket? Video


Techspy

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I agree. With the block not mounted that valve was a perfect .007 with a 113 shim. There was definitely something else amiss here. I just don't know what it was. I set each shim on the valve tower, and had each cup in the cam tower and attached it. I had a shim that was kinda tight but it wasn't this one. Maybe some carbon etc was between the valve and head and not until it was turned over and fired in the car did it come out?

John
94 S4

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Posted (edited)

Pretty sure it was. I went with the best of everything. I am running the high torque chip so more than stock boost. It was nice and cool this morning and when I had a good WOT 3rd gear pull which is probably when it let go.

Oh and thank GOD I made videos of the whole process. Watching them now so I know what mistakes not to make again!

Edited by Techspy

John
94 S4

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 Could you have some head lift? Maybe the bolts are stretching with the increased boost levels? :) 

It's getting there......

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A few questions 
Was the liner nip in spec? 
what level of boost are you running?
was the head checked for flatness?
what head gasket brand was used?
Is the cooling system working properly?

all of these are important factors - it’s unusual for a 4 pot to have repeated head gasket failures.

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Posted (edited)

Was the liner nip in spec? Can't recall the specifics but pretty sure I checked it during the last gasket change and it was good.
what level of boost are you running? High Torque #3 chip that states "Max. boost 0.9 bar (1.0 bar only for very short periods under very special conditions)"
was the head checked for flatness? With a metal straight edge but not on a mill etc.

what head gasket brand was used? Goetz
Is the cooling system working properly? Yes, never overheats. Rarely gets warm enough to have the fans come on.

Edited by Techspy

John
94 S4

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Are you sure it’s not overboosting ? It’s just not a common thing to have another gasket fail if the above is true.

mine blew the fire ring out of a gasket that was non goetze that a specialist sold the PO. It was simply not fit for purpose - however most folks would never know that and many don’t drive the cars hard enough for it to become an issue. It’s a well documented fact stateside though.

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Well, with the stock boost gauge it is tough to tell the exact boost pressure so not certain.

However, I found this while disassembling. Seems the "Non-Return Valve, crankcase breather hose" has come apart. Not sure what the consequences of that is but I imagine it could screw with the fuel pressure or boost. Also found one of the spark plug wires has been damaged. Ordering parts tomorrow and then pulling the cam towers and head.

PXL_20211003_185513385-1 - Copy.jpg

John
94 S4

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My sympathies;

Been there, blown that thrice. I had a serial gasket failures from under torque and higher boost, but in the end it will come together. Don't forget the magnets on the cam buckets to keep your shims in the cam housing when you pull it off!

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Posted (edited)

Tear down complete, parts will be here in 3 days. Doing all belts, timing belt tensioner bearing, thermostat, plug wires etc.

Anyway, looking at the gasket it was definitely not as bad as last time. Perhaps because I identified the issue immediately and took it off the road. I did notice that the head bolts (nuts actually) around the left 2 cylinders in the pict were not as tight when I removed them. I know I torqued them all the same last time. Not sure the cause but will be sure to pay extra attention this time. I may have the head checked for flatness as well. Any thoughts?

 

Oh one other questions. Seems the crank rotated a bit removing the belts so it isn't at TDC now. I have hear horror stories about the liners coming undone rotating the crank with the head removed. I assume I can use a couple cross members held down by the studs to allow me to rotate it back to TDC or just wait until I put the head back on and before the cam towers etc. Any advice either way?

PXL_20211004_212903537-1 - Copy.jpg

Edited by Techspy

John
94 S4

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I had one gasket torqued to 80-85 ftlbs on assembly, that took less than 50 ftlbs to disassemble. I can only imagine that heat cycles allow some further compression of the gasket?

I've had a liner lift out from just the ring friction so don't turn the crank until the clamps are on! If you use the liner clamps you should be able to rotate the crank. My memory was having the crank at something like 30* BTDC while doing the assembly for extra valve clearance and bring it to TDC for the belt install.

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That's the best condition failed gasket I've seen....   It's not an original  Goetze item, as it has a copper seal on the oil gallery (genuine uses Viton and the outer sealing ring is black if I recall).  So that's the first change I would make.   Would also suggest new studs if you have had unpredictable results with the old ones.

NB I work on interference fit engines with the crank rotated back 90 degrees  (All pistons halfway down the bore), then rotate forward back into TDC position when cams are set for TDC.   

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Well that gasket sure isn’t showing classic cheap gasket giving way syndrome.

please see below for what’s probably the same Cheapo gasket as you have and how they fail. Alongside is a gasket off a Nissan Figaro - showing more traditional issues - but extreme.

I would say the nip is wrong - or your block or head isn’t flat.

EC8B64DB-8846-4261-87A4-696357C9FD22.thumb.jpeg.f8e95738f9d1d7498fa2a5365002923c.jpeg

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I've killed a couple of the copper ring / red sealant gaskets. Only once did the fire ring move, usually pressure just gets past and erodes the gasket behind, strangely it's typically where I have the most nip.

Current Goetze gasket is holding up so far to my abuse. 100+ ftlbs on ARP head studs.

I wonder how the wet liner motor would like a multi layer metal gasket, should one be offered?

 

IMG_0034.JPG

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Posted (edited)

Thanks Guys. A bit of an update.

I do not recall the nip measurements from last time. I will measure and report back.

I confirmed that JAE did ship me the Goetze THIS time but said they didn't last time and that they don't believe they even stocked it in 2018. Not sure what happened here. I vaguely recall having a discussion on it but don't recall the outcome. Suffice to say this is whatever OEM replacement they sold in 2018. They are providing the proper arp stud lube with the proper torque settings as well this time.

A bit more on the symptoms. Driving along after a 3rd gear WOT pull (nothing crazy or near reline etc). Few minutes later under moderate load it started to stumble badly. Immediately turned around and went home. Total drive time about 20min. Pulled the plugs and they were pretty sad so got a new set, installed went for a ride. Seemed ok at first but as it warmed up (like 5 min later) had white smoke/vapor under any decent throttle with the stumble. Went home, pulled coolant cap and the water was full of oil. No milky substance to note in oil. Same symptoms I had previously without overheating but attribute that to very short drives when I noticed the issue.

Anyway, if it isn't the head gasket I am at a loss. Turbo seals blown out? I have the chargecooler blanking plug and running an electric pump. Possibly a bad water or oil pump? I suppose I will pull both to check.

More picts of the gasket, pistons, and head. I Figured combustion escaped between the head and gasket where the discoloration is (red arrows in pict). I looks like there is a trail right to the coolant journals. Nice indentation from the liner nip on the other side that doesn't seem to be breached at all.

1.jpg

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PXL_20211005_222538081.jpg

PXL_20211005_222541377.jpg

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Edited by Techspy

John
94 S4

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Is this a Goetze  gasket? Being it is unmarked, want to make sure.

Still trying to decide what else I should check. Thinking of pulling the turbo apart to check all seals (WCE turbo)

Anyway, checked valve clearances on intake and re-shimmed 2 of them to get back in spec. Doing exhaust today, measuring nip and may get the head back on.

gasket-1 - Copy.jpg

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John
94 S4

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All valves adjusted (4 total were slightly out of spec but are good now). Belts installed (PITA). New tensioner bearing installed (definitely needed it) Thermostat replaced. And NIP checked. From back to front 0.00, 0.00 : +0.01 , -001 : -0.01, 0 : 0.00,0.00 so according to the manual all good. Cleaning head and block surfaces and installing head next.

Still a bit perplexed being the gasket failure location is not ridiculously evident. For clarity it is probably more accurate to describe the coolant as "smokey" as opposed to oily. Like exhaust gas was in it. When I removed the coolant cap after returning home it has lots of small bubbles in it that lasted quite awhile and smelled "oily/gassy". Anyway, once I am at the point to reinstall the turbo I will pull it apart to see if any seals etc are obviously bad. I still have my stock turbo that was in good condition I can install for awhile if needed. Any other advice on failure places I am all ears.

John
94 S4

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Ok so JAE sent me the angle method with the gasket even though they knew I was using the ARP studs. Do I use the 110lb per nut as recommended by ARP or the angle method as recommended by Goetze? I have found discussions about this but no definitive answer. I am guessing due to the different thread pitch, the arp method is correct. Thanks!

torque-1 - Copy.jpg

Edited by Techspy

John
94 S4

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Thanks. Done. It just seems wrong putting that much torque on something that size. Re-assembly to continue. Waiting on rebuild parts for the turbo s well.

John
94 S4

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