Leak between exhaust manifold & turbo

[SVOJames]

On the Grey car, I have blown two of the gaskets between the exhaust manifold & the turbo in the past 2 years. I'm almost certain one of those two surfaces needs a milling, I have a person I trust to do the milling.

My question is, if it's the turbo that needs a milling, can I stuff something into the turbo to catch the pieces, or will some disassemble of the turbo be needed?

[in2fords]

I would remove the turbine housing, I was lucky and didnt break any of the bolts there, even if you do, a person that can mill it flat can remove a broken bolt in the housing.
There may be some that will say it would be fine to rinse and blow it out after, Id rather be safe then sorry.

[MikeFleming]

It takes less than an hour to remove the turbine housing from the outlet elbow and CHRA, even if the bolts are mostly frozen. So take it off.

[SVOJames]

Ok. I wasn't worried about how long it will take, only about messing with the turbo. Anything special I should watch-for/do while removing the outlet elbow & CHRA?

[MikeFleming]

The outlet elbow comes off with five bolts, the downpipe connection (2 nuts) and the wastegate arm Jesus clip. Mark the turbine housing-to-chra alignment so you can bolt it back on in the same clocking. Then remove the oil feed line at the top, oil drain at the bottom. Next take off the PCV tube that enters the front inlet elbow of the turbo assy, air hose from VAM, ground wire on top front stud, assorted boost control hoses.

Once the six chra-to-turbine housing bolts are removed (will need to rotate the CHRA to get them out) with the two clamp plates, you can pull the CHRA/compressor straight out the front - try to pull it out straight so the turbine wheel does not contact the housing. Now you can get a socket onto the four nuts that mount the turbine housing to the manifold.

Alternately take the turbo assy off the manifold and disassemble the turbine housing on the bench (held in vice). If it's been together for a long while there may be some rust/heat binding that needs a strong, gentle touch and some penetrating oil.

Before reassembly: Sand the pieces to get the corrosion off and lube them with high-temp anti-seize goop and test fit.

[SVOJames]

I've pulled the exhaust manifold and turbo assembly as one piece, working on the bench I've removed the outlet elbow from the turbo, and removed the rest of the turbo assembly from the exhaust manifold.

I've loosened the 6 bolts that hold the 2 clamps that hold the center housing to the turbine housing, and removed 2 of those bolts. The center housing is blocking removal of the other 4 bolts. I'm confused when you speak of rotating the CHRA at this point, I think I need to rotate the center housing but I can't. Do I need to loosen the 6 bolts that hold the clamps that hold the center housing to the compressor housing? Can I use PB blaster or some such around these areas, or light heat?

Also, any hints on removing the 4 studs from the exhaust to turbo? We put two nuts on the stud, I held top one with a wrench, mechanic turned the bottom on but no luck. Before we bring in heat and breaker bars, these aren't reversed threaded are they?

[MikeFleming]

I've loosened the 6 bolts that hold the 2 clamps that hold the center housing to the turbine housing, and removed 2 of those bolts. The center housing is blocking removal of the other 4 bolts. I'm confused when you speak of rotating the CHRA at this point, I think I need to rotate the center housing but I can't. You may want to soak the CHRA-to-turbine hsg with penetrating/rust deprecating fluids for a wee bit.

Usually the housing and chra lip will kinda rust/fuse together due to the extreme temps they see together and the method I use is to loosen all the six turbine housing bolts a turn or so (until they run into the CHRA casting) and then find a way to gently, slowly, evenly lever the chra away form the turbine housing. Once it starts moving, it will get easier. Get another turn on each bolt as it moves away.

When it comes free, it will want to fall out - so be sure to hold it so it does not - it might damage the turbine wheel. Eventually you will be able to remove the remaining bolts and plates then take the CHRA/comp housing assy off and store safely.

For re-assembly lightly sand the inside area of hte turbine housing and outside mating surg=face of the CHRA and lube them up (more high-temp anti-seize goop). Then you can insert the CHRA into the housing recess easily and rotate it around to get all the bolts in. Once the bolts are all in place, align the CHRA to the turbine housing in the desired clocking and tighten the bolts (12-14 Ft-Lbs with lube). I recommend replacing all of the high-temp bolts (six 8x1.25mm x 15mm and five 8x1.25mm x 20mm).


Also, any hints on removing the 4 studs from the exhaust to turbo? We put two nuts on the stud, I held top one with a wrench, mechanic turned the bottom on but no luck. Before we bring in heat and breaker bars, these aren't reversed threaded are they? Depending on how long (and how many years/heat cycles it's seen), double-nutting usually works - with lots of muscle. The stud portion into the manifold uses locking threads so it's a pita at best. Good shoulder muscle workout.

If that doesn't work, just get some 10x1.5mm standard nuts and weld them onto the end of the studs. Then get a six point socket with a LONG breaker bar on there to slowly thread them out (long to have LOTS of control as top how fast it turns NOT to use more force). Slow and steady - the way I climb stairs. Clean the female threads with a sharp (new) 10x1.5mm tap, install new studs (without any locking compound.

I may have pics somewhere on assembling the turbo housings and chra. I'd have to look though.

[SVOJames]

Well, got the Turbine housing removed, so that's good, however I'm seeing a few cracks, two of which are visible from the inside as well (the ones at 5:00 & 8:30). Got a call into Charlie at Evergreen Turbo to see if I need to replace it.

7136

Still don't have the studs out of the exhaust manifold, going to have to weld the nuts on them, and don't have access to a welder until Tuesday.

Mike, as always, thanks for all your help even though it took be far longer that the hour you claimed it would take. ;)

[MikeFleming]

Cracks like that are common, and usually nothing to be concerned about (until you can fit a coin in there). That happens from 'time at temperature' conditions - either too high a temp, or too much time at a slightly lower temp. These housings get to 1650 F (as designed) stock. Usually more power means higher temps. (Do not think about your exhaust valves or seats at this point.)

The earlier 0.63 housings were more prone to cracking, possibly due to the lower fuel flow capacity of the smaller injectors. More fuel keeps temps down. The 0.48 housing don't crack as much, but it still happens. And the .48 housings are more plentiful.

As long as the gasket mating surfaces are flat, I personally wouldn't hesitate to ruin that housing.

[SVOJames]

That's good to hear. Not only because I save a few dollars, but my mechanic is relieved because while we were safely storing the expensive part of the turbo, he knocked the turbine housing off the bench and thought he might have caused the damage.

[SVOJames]

.... I recommend replacing all of the high-temp bolts (six 8x1.25mm x 15mm and five 8x1.25mm x 20mm)......

I'm having a doozie of a time finding "high-remp" bolts. Hardware store, specialty fastener shops, speed shops, etc, all look at me funny when I ask for "high temp" studs & bolts, and several of the shops offered grade 8 bolts. Is their a special type of steel I'm lookiing for, or can you supply a link to a place to purchace them? (4 of the 5 8x1.25mm x 20mm bolts had been replaced with 8x1.25mm x 25 mm studs, this is a T3/4 hyrbrid from Evergreen turbo (who I have called, but never got a call back.))

[MikeFleming]

PT&E (precision engine and turbo, might be just precision turbo now, don't know) should have kits available. Most turbo rebuilders and suppliers that deal with Garrett units will also have them. Do a web search for Garrett TO3 hardware kit.

The original ones are an air-hardening tool steel, if you're interested. Nothing in a hardware store will work, although the closest would be some in 304 SS if you can find them. 304 is OK for elevated temps, but it's not very strong.

And get (and use) some high-temp anti-seize moly paste when you assemble the hot side parts and bolts. I use the Loctite stuff rated to 2400 F. Good stuff.

[SVOJames]

And get (and use) some high-temp anti-seize moly paste when you assemble the hot side parts and bolts. I use the Loctite stuff rated to 2400 F. Good stuff.

Ive got some nice anti-seize goop, and red locktite. New hardware (t3/t4 assembly). What Loctite stuff are you recommending?

[brsvo]

I have way more Resbond 907TS blue than I will use. Good to 2100'. If your interested I will sell you 10 bucks worth + shipping. Its $70 for enough to do about a thousand bolts but should be used within 6 months according to the bottle.

[SVOJames]

Brsvo, thanks for the offer, but I've had so many (probably) heat related stuck problems, that I'd rather have the 2400 stuff Mike spoke of.

Mike, I had a brain-fart....when I see Loctite, I think thread locker. Then I noticed the anti-seize I use was also made by Loctite, but it is only good to 1600 f. I see now they also offer a pure nickel based anti-seize good to 2399 f, and a non-metallic one good to 2400 f. From the descriptions I've read, they would both work, but I'm going to be reassembling the turbo housing, mounting it back on the E6 manifold, then installing the manifold.
Does it matter which of those two I use?

[MikeFleming]

Taking a mosey to the shop the label on the bucket of goop I have is titled "Heavy Duty Anti-Seize (by Loctite)", desc:
"Lead and lead-compound free lubrication that protects metal parts from corrosion and seizure to 2400 F."; P/N 51605, 9oz.

It was their bestest, mostest goodest high-temp stuff available to we mere mortals about a decade back.

[SVOJames]

..
As long as the gasket mating surfaces are flat, I personally wouldn't hesitate to ruin that housing.

Mike, this was your response when I posted the picture of cracks in the outlet elbow around the waste gate flap. I don't recall having g a gasket between the outlet elbow and turbine housing.

Is there supposed to be a gasket in there, or did you just mean "mating surfaces"? (I'm not trying to be an ass, first time to disassemble a turbo, car has been down over a year, I'm just trying to do it right.)

[MikeFleming]

There is no gasket between the turbine housing and the turbine outlet elbow. I heard some aftermarrket place made one several years back, but I've never seen one.

Yes, mating surfaces.