Head Gaskets, Victor reinz, turbo Zentrum etc

[Shoppinit]

What torque wrench do you use? A good one?

[Puggie]

What torque wrench do you use? A good one?

Big stuff 1/2"
Teng Tools for wheel bolts
Halfords Pro for everything I'm bothered about

Medium 3/8"
Draper Expert for general stuff
TorqueLeader Dial indicator for small stuff

And they get looked after, slackened off when not in use etc.

[Shoppinit]

You sure it's coming from the head gasket? What's the compression doing? Seems crazy that the head gasket could fail to the extent that it would leak oil to the outside of the engine without major running issues.

[Puggie]

Threads would have yielded during the torque down process if they were going to go (IMO). Bolts could be duff e.g manufacturing fault, could be torqued too high and yielded, but I'm not sure that this would be possible before the block threads give way.

That is my thought process, they felt fine though while tightening. I would have though I would have felt the block threads going if that was the case

Have you checked the torque on the bolts in the vicinity of the leak? Otherwise, warped head, foreign object, failed gaskets. Either way that head has to come off, so very close inspection would be required e.g. head and block mating surfaces, thread conditions, possibly helicoil threads as a precaution etc.

Not checked anything yet, and wont get a chance to for a few months (lack of access to ramp and I would rather leave it in a moveable state until I go in to sort it). My first check will be that bolt and probably see if its still up to whatever the torque should be before the last turn of degrees. Head was skimmed and pressure tested before fitting, block surface was cleaned with brake cleaner and fine scotch, and checked for flatness with a ground bar (it was visibly low between the cylinders but still within spec). Threads were cleaned out with an old head bolt with a quarter ground out the length and some grease to catch any bits then the holes thoroughly cleaned with de-greaser and blown out with air.

I'm thinking when I strip it to check flatness again hoping i can get away without another skim and the block is still flat, helicoil the block for all head bolts and slap a new head gasket in.

Looking at the car, I reckon this engine had been driven enthusiastically before my ownership (extra oil coolers, phaeton brake ducts etc). When the headgasket originally failed, the gasket was still complete but showed visual signs of very slight leakage round most cylinders (3 of 4 on this bank) and a more significant (but still not huge) leak to the coolant jacket on this end. Compression was down a bit on most cylinders but it still ran fine, just pressurising the coolant. I had a second engine with a broken valve. I actually fitted these heads, with a new valve and cleaned up the couple of marks in the combusion chamber, so the heads are from an engine without the overheating history. The headgaskets in that one looked happier despite a few more miles. All bits come from TPS so quality should be ok.

Thanks for your thoughts because this is doing my head (and wallet) in at the moment.

[Puggie]

You sure it's coming from the head gasket? What's the compression doing? Seems crazy that the head gasket could fail to the extent that it would leak oil to the outside of the engine without major running issues.

Yep, I've had a little endoscope camera in there while its running and I get a trickle of oil from that corner down the block and over the back of the alternator. I thought it was the oil/water heat exchanger first, but its coming from above that and the cam cover/exhaust manifold area is totally dry (I thought it could be the rocker rail first assuming they are a pressurised oil feed for the rockers and it coming down the back of the timing covers). I'm also pressurising the cooling system with exhaust gas again (checked with a bubble manometer homebrew widget and the blue fluid that turn yellow with CO present). I've not done an actual compression test on that cylinder as I was too pissied off with it at the time. I did remove that cylinder injector plug and spark plug and that reduced the rate of the oil leak and bubbles coming through the coolant very significantly. That kinda said enough to me that it was headgasket at the time.

The ability of this engine to run sweet and sound lovely while having these issues is amazing, the first time the headgasket went the garage that did the MOT could not believe it as it just seemed spot on for the way it ran the emission etc. The issues just appeared under load once I was driving it.

The state of the gas leaking to the coolant is worse now than before I did the headgasket (bubbles are more frequent when idling). Also worth noting when I cleaned everything out when doing the headgaskets there was definitely radweld residue in there!

And again I appreciate any input as this thing is driving me insane. I get very little time to work on it and I feel I've wasted the last 8 months doing these head gaskets

[Shoppinit]

Yeah, I feel your pain. I would be extremely upset, especially after having taken the care to do the job properly once.

Could there be a blocked coolant channel causing localised warping? Doesn't seem likely, but neither do any of the other scenarios. Having said that, if there's a bunch of rad weld in there, could be a clot.

Possibly a duff head gasket, but it's not an ECP special you put in there.

I think you would have felt it if you'd stripped a thread / pulled a stud out. You always know. It's a horrible sensation.

[Puggie]

Yeah, DPO means I'm well versed in the 'righty tighty tighty loosey bollocks' sensation, I think I've helicoiled half the M6s in the block during the rebuild. saying that for the head bolts I was concentrating much more on getting the final angles right than what they felt like when putting them in, so I know the feeling but was not really paying attention to it when I put them in.

All I can think is the block threads were stretched when the head lifted on the previous gasket, and when I torqued them up they were on their absolute limit, a good wodge of boost was just a bit much for that corner.

I just don't want another failure and guess i'm wondering if I should source a new block to start again. for this rebuild I have refurbed the turbos (Owen Developments) intercooler cores, starter motor, torque convertor, engine mounts and loads of other bits, so that lot will be better than any second hand engine I find! Might poke my inspection camera down the other block and see what the waterways look like and if I can see enough to inspect the block when I take the head off.

[Lander91]

Post some pictures of the area or as much as you can to show where the leak is. Who knows, maybe there is something else leading to the trickle - forest for the trees and all that.

[Puggie]

Will get some pictures later this week.

[steve2003rs6]

Sorry you are having a major problem. Especially as you have already repaired it once. Nightmare.
I really hope I am never in a similar position.
Hope you get it sorted mate.