About 2 weeks ago our white B4 showed definitive blown head gasket signs. Finishing up the job right now with a bunch of downtime for fixing things while I’m there. Not the least of which is removing the 1/8-1/4” slot crap from the intake ports. I uses a hybrid cleaning method of propane fire and soaking in solvent. They aren’t perfect, but they won’t be indistinguishable from brand new. Had to use a water hose to flush free chunks out. For the record, I have the EGR cooler.
While I was there, I refurbed my MityVac handpump with new lube. I can build 30 PSI again, now. This GT1544 also cracks at 8-9 psi and moves at 10 psi, just like my old one. Looks like the thread pitch on the actuator is ~1 psi/revolution and I upped the pressure to 10.5 just because. Others have reported a much lower fracking pressure, but I’m
Confident that no one has done anything to this turbo. Btw, minimal radial play and no discernible axial play. Blades on the compressor look wonderful.
The head had light scoring from the old HG. The block had *none* whatsoever. I’m going to adjust the tune to drastically reduce/turn off the EGR along the normal driving conditions so I don’t have to burn out the intake manifold again. Speaking of which, burn plus pressure washer *up* the intake ports does clean it fully, unlike the cutaway I posted many years back. Still need to tap the weep hole for a drain. What’s the threading others have used?
Anyhow, fully lubbed 12.9 bolts were used with a thick washer + hardened washer setup as before. Reduced friction for torquing me as greater clamping force at the same torque level, thus the 12.9’s yield a benefit. Along with the sticky Permatex copper gasket stuff. I used a bit of twine to secure the new HG to the head & EM, which worked well since I couldn’t find my 3/8” aluminum rods I’ve previously used for alignment.
Since we have updated nozzles, 520’s I think but I’ll have to check notes, and a cleaned head, and a tad higher opening pressure on the turbo, I’ll probably tweak the boost & N75 maps too while adjusting EGR, after flushing fluids. Don’t want to clean that intake manifold again if I don’t have too and I want this car to have a bit more oommf like mine when it was stock.