unknown coolant leak GM 3100 V6`

[Rock_Hudstone]

Originally Posted By: RichardS
The upper leak is literally where the LIM gasket sits between the manifold and engine.

Yeah, thats where the LIM gasket typically leaks. Low coolant level in the overflow tank is another tip off.

 

[RichardS]

901Memphis, good to know! I'd be perfectly happy with Denso or Delphi, unless there's some voodoo magic in the ACDelco wires that I shouldn't pass up on.

Rock_Hudstone,
Admittedly, I didn't check the coolant level until I saw the drop on the driveway. The overflow tank is old and discolored, so I can't easily see the level in it. Since I usually have the hood up when the car is hot, I hadn't taken the radiator cap off to see if it was full.

 

[Trav]

ACDelco has three product lines Advantage which is usually offshore, pro which meets specs but not for longevity and OE which is exactly what was put on the car during assembly, it meets GM's 112K minimum life expectancy (I got that info some years ago, I have no idea if it still hold true today).
The OE line uses the highest quality materials of the three with OE fit and other little items like OE numbering on the cables that may or may not be present on the others, they also go through a stricter QC process to help prevent original warranty comebacks for a potentially cat damaging misfire.

If the car is a keeper after this repair and given the difficulty of changing them on the rear bank of an assembled engine IMHO its definitely worth the extra money.

 

[RichardS]

Trav, thank you! That was far more detailed information that I could pull out of google. You're right, obviously, that the rears are no fun to try and change. It's interesting that RockAuto lists the pro as a 'premium' replacement. Someone there may need a little informing.

 

[Rock_Hudstone]

Originally Posted By: RichardS
Trav, thank you! That was far more detailed information that I could pull out of google. You're right, obviously, that the rears are no fun to try and change.


Changing out rear plugs on the GM 3.1 isn't that bad.

The trick is to pull the bolts on torque arms that attach to the radiator support, then tilt engine slightly forward with a floor jack.

 

[Trav]

The difficult part in the car bodies is usually stuck plug boots that many times need to be cut off if they are original.
Vans are another story altogether even after rolling the engine forward.
I have found quite a few old plugs in the rear bank on vans that have had the plugs done even at dealers.

 

[Trav]

Originally Posted By: RichardS
Trav, thank you! That was far more detailed information that I could pull out of google. You're right, obviously, that the rears are no fun to try and change. It's interesting that RockAuto lists the pro as a 'premium' replacement. Someone there may need a little informing.


I think Rock uses the manufacturers description than actual quality. Some parts they list as premium are certainly no where near premium quality.
Look at a ACDelco Magnetic steering rack, the pro is almost a third the price of the OE, both are reman.
I have contact to a technical engineer at Delco, he told me the difference. The OE housing is SS sleeved, the magnetic unit is replaced with a new unit and new OE tie rod ends.

The Pro is only sleeved if the bore is damaged, the rack is checked as is the magnetic unit, hard parts are only replaced as necessary, tie rods if worn get pro line. Look at the info for both and its identical.

Steering Rack

 

[RichardS]

So silly. I'd think the pro line would be the better option. When I took out the o2 sensor a few months back, the OE part wasn't even ACDelco, it was bosch if I'm remembering correctly.

 

[Trav]

It probably was a Bosch they are a huge OE supplier and if you buy it at the dealer the ACDelco box may well have a Bosch made part in it.

 

[RichardS]

I RockAuto'd it. I'm usually a pretty staunch proponent of buying things from local shops, but none of the local parts shops around me align with my social/political views, so I've fallen pretty in love with ordering things online if they aren't reasonably priced with AAP discount codes.

RockAuto also seems to have a "actual OE part" designation on things for my car, as well. That's the only reason I had gotten a bosch as the replacement to begin with.