Traz... Feel around on the passenger side Floorboard under the compartment housing the Heater Core for any leak that will cause dampness and take notice of anything smelling musty like PEG (Poly-Ethylene-Glycol). The other possibility might be a Pin-Hole Leak in the Radiator... not enough to notice until enough of the Coolant gets expelled to drain the Reservoir over time.
As the Engine cools down, the Interior of the Water Jackets form a partial vacuum inside to replenish itself via the Reservoir... but with less and less available over time. You can demonstrate this Vacuum Principle the next time you have an Empty Plastic Water Bottle handy. Pour some Very Hot Water into it... then drain it and cap it suddenly and place it instantly into the Freezer for one minute. Then have a look at it after that ...and you'll see what I mean.
And Last but not least will be a possible Failing Radiator Cap that will not
reveal itself because it simply dumps any excess back into the Reservoir via the small Overflow Hose...and leave no trace that it will not hold pressure.
I haven't been able to find anything. Thankfully nothing is in the oil. It's all good there. I'll replace the cap to be sure. And keep an eye on hoses.
Update on the Turbo Build:
Finishing on the list of parts, that will be released during the build or at the end.
Next: Finalizing Routing plans for: Exhaust, Intercooler, oil cooler.
Working on a custom Airbox for the intake. Along with some other custom ideas that are being planned and discussed.
Finishing routing plans for AC lines because I'm not giving that up.
Right now we are mounting air speed sensors to the vehicle using magnets to verify airflow so we can mount things in the best locations possible and document for everyone else. Looking at the removal or relocation of reservoirs and the like. Will keep everyone updated.
Sketches might be released of the initial plans. Looking to start the actual fabricating in March or April when it gets warmer.
I would also like to announce that me and the crew are planning on making a YouTube channel to document as much of the build as possible as well as other upgrades.
Some of the custom stuff we want to make we are going to try to get blueprints made up in a PDF for everyone. But for those that dont we will be looking into making those parts.
A lot is going into this. We are working with Former Dyno technicians and former air flow designer to get everything just right for locations. As well as the proper build for the custom air intake box.
Hey guys. So a lots been going on lately. Theres been a lot of questioning on how exactly to approach this turbo build. So I wanted to go over a few things.
My 2007 Envoy has 102k Miles on it. I am the second owner. The first was a guy that took obsessive care of the vehicle. however after talking to him it seems he was originally on Trailvoy website and had planned on becoming one of the Turbo Gods that walk among us. Originally my plan was to rip out the engine, and upgrade everything short of rods, pistons, crank etc. you know, the big stuff.
Now this still might happen, but where I am running into problems is that at 65k miles he had replaced a few things. Notably the rod bearings, and a freshen up on the timing chain.
After seeing proof of these actions I am now questioning if I will pull it out and tear into it.
Whats your thoughts?
I'm hoping some of you remember Conekiller, Mike with the silver turbo envoy? After blowing up his email for the past few days ive seen some things about his turbo build that weren't originally posted and I thought I would bring them up to see what everyone thinks.
The first and biggest is that per his words his oil feed to his turbo came from a sandwich adapter between his oil filter, then he drilled into the pan for the return line, Thoughts?
Stock Fuel Pump,
Custom built Up Pipe compared to buying the Lime-Swap one,
Basically I want to open this up to questions, comments, concerns, even ideas. If this build is going to happen I want to be able to give back to this community and make some sort of outline for this build. Of which, after the replies on here come in, would be partly built "By the Community"
Yeah it is. I Emailed him yesterday asking for maintenance records to help me make my decisions and he was curious why and He started laughing. Apparently he gave up and went and bought a TBSS. To each his own, saves me from having to do the work lol
If you look at the 'Superstructure" of the GM 4.2L Side Block Casting... You can see a series of vertical (Stunted Pyramid) Shaped Hollow Passages along both sides of the Inner Block. These Tubes allow the Returning Engine Oil coming from the identically shaped Engine Head Drain Down ports where after the Motor Oil that has been Pumped through the Valve Train has the need of clear paths to Gravity Drain BACK down into the Crankcase... This design serves TWO purposes:
(1) The ‘semi-pyramid’ design provides a wide open, thin walled structure of Aluminum Metal that adds to the Engine Block’s Strength and Rigidity. SEE THE 'YELLOW' HIGH-LIGHTED AREA IN THE ATTACHED IMAGE.
(2) It also serves to Protect and Cool the Oil while it drains back down to the bottom of the Oil Pan AND it keeps that Oil Stream from being exposed to the Whirling Action of the spinning Crankshaft, Rods and Pistons ...churning away violently within inches at up to 6,500 RPM.
So my thinking is that you COULD probably Drill a Hole anywhere IN BETWEEN the Solid "T" Wall Hollow ‘semi-pyramid’ sections and better yet… place and TIG Weld an Aluminum Bung to attach a Hot Turbo Oil Return Line coming out of a Secondary Oil Cooler built to deal with the extreme temperature of the Oil Exiting the "Hot" Side of the Turbo-Charger.
However... you would ALSO have to be mindful of the adjacent Exhaust Manifold or Header Pipes so the Oil Line and Fitting into the Block do NOT accidentally rub up against the Headers/Manifold and literally “Boil The Oil” inside of the lines. So the very PLACEMENT of the Turbo Oil Return Line Port is critical in dealing with those Thermal Threat aspects.
As for the notion of being able to perform this and any other serious Engine Upgrades ...without Dropping the Pan... This will prove extremely difficult. This is because as soon as the Drill penetrates into the Hollow area inside any one of the Aluminum ‘semi-pyramid' shaped vertical Tubes... or if you follow Mike’s Design… then Drill through the side of the Crankcase-Oil-Pan. But nonetheless ... the Aluminum Metal Shavings will drop down into the bottom of the Oil Pan and need cleaning out.
So If you’re intent upon getting EVERYTHING you need to ‘touch’ done right inside of this Motor... that Engine deserves to be pulled and torn down ....at least to the extent required … and allow you the chance to have Extraordinary Access as a Mechanic to its complete "innards" and get everything done right while it is mounted on an Engine Stand. This image illustrates the possible Side Block Oil Drain Down Channels that you might consider using to pipe that Oil Return Port into:
Went with a water cooled turbo, its down the line of things to do but anyone have any input on how I should route the plumbing? ive already thought about running another cooler before It returns to the radiator, but that's about it
You might consider running a "T" fitting (One Each) into and out of the Two Hoses that feed the Heater Core through the Firewall... but if that Core is clogged up with debris and junk... the Hard 90 Turns heading back towards the Turbo-Charger...might make the Coolant Stream get a little too "sluggish" to do an adequate job.
If you have the Room (and the COOLING AIR STREAM) available to not only house the thing... but provide enough Ambient Air being driven through it. Without that Heat Exchange... it will complicate the "HOT WATER" problems by simply becoming a Heat Sink for the Coolant Column heading into the Water Jacket of the Turbo-Charger.
There MUST be some others out there who can give you some better advice on how to arrange this hardware to work properly as intended. The other issue involves the possible need to change the Thermostat to suit ALL of the conditions that have to be satisfied in your design... and still maintain the 210 Degrees needed for a normal Engine Head Temperatures and achieve nominal combustion and power.