2 threaded holes on the back of the cylinder block

[odonovj]

2002 Automatic Jeep Liberty limited 3.7 6 Valve
When I was replacing the head gasket , a grounding strap was attached to the aluminum surface. The last time I checked you don't ground to aluminum.So, what are those two holes for.
Secondly I'm guessing /assuming that the strap gets sandw in ched between the motor oil dipstick brace and the transmission case where that meets the engine ..... But that's also aluminum..Ain't it.
Anyhow I'm trying to close everything up here but I can't comfortably move on .
I'd appreciate any knowledge.
PS, I think I'm on the right platform for asking this, please tell me if I'm not

UPDATE 2 DAYS LATER
Completed!
Both aluminum grounding straps attached, one to each cylinder head.
Does anyone see a difference between the two, I do

 

[turblediesel]

I think each head on the v6 has a braided groundstrap to the firewall but I don't have that engine.

 

[odonovj]

I think each head on the v6 has a braided groundstrap to the firewall but I don't have that engine.

That makes more sense. So the head is not the ground but rather the head is being ground to the wall.

Is that unusual to have a head that needs grounding.?.

 

[klc]

I think there’s two ground straps back there on mine.

 

[odonovj]

You're right now that I've looked closer, that's what's going on.
Thanks for clarifying that.

 

[mrlavalamp]

Generally speaking you dont want copper to be directly on aluminum without corrosion protection. the ground straps are not copper where they touch the aluminum and therefore totally fine.

No problem with grounding from to or through aluminum in general, the issue is galvanic corrosion created by dissimilar metals touching.

 

[odonovj]

Generally speaking you dont want copper to be directly on aluminum without corrosion protection. the ground straps are not copper where they touch the aluminum and therefore totally fine.

No problem with grounding from to or through aluminum in general, the issue is galvanic corrosion created by dissimilar metals touching.

Now it all makes sense. Thanks for the advice and insight to you Mr lava lamp and klc. It's the first forum where I've received straight up, to the point knowledgeable answers.
I really do appreciate it

 

[turblediesel]

Generally speaking you dont want copper to be directly on aluminum without corrosion protection. the ground straps are not copper where they touch the aluminum and therefore totally fine.

No problem with grounding from to or through aluminum in general, the issue is galvanic corrosion created by dissimilar metals touching.

My guess was a mysterious electrical dissonance causing the radio to hum but your explanation wins.

 

[odonovj]

My guess was a mysterious electrical dissonance causing the radio to hum but your explanation wins.

I must have missed or I'm getting my posts mixed up. When was there a mention of a radio regard my initial post/ question?
Or are there different posts running into each other

 

[Robochop]

2002 Automatic Jeep Liberty limited 3.7 6 Valve
When I was replacing the head gasket , a grounding strap was attached to the aluminum surface. The last time I checked you don't ground to aluminum.So, what are those two holes for.
Secondly I'm guessing /assuming that the strap gets sandw in ched between the motor oil dipstick brace and the transmission case where that meets the engine ..... But that's also aluminum..Ain't it.
Anyhow I'm trying to close everything up here but I can't comfortably move on .
I'd appreciate any knowledge.
PS, I think I'm on the right platform for asking this, please tell me if I'm not

Everyone I have worked on have the ground strap from the head to the firewall and I always put them back the same way, no issues! The head bolts are steel...

 

[turblediesel]

I must have missed or I'm getting my posts mixed up. When was there a mention of a radio regard my initial post/ question?
Or are there different posts running into each other

I was just agreeing with mrlavalamp's answer. My guess went with radio interferance grounding.

 

[odonovj]

Oh, I got it.

 

[klc]

Now it all makes sense. Thanks for the advice and insight to you Mr lava lamp and klc. It's the first forum where I've received straight up, to the point knowledgeable answers.
I really do appreciate it

I didn’t know anything about KJ’s when I stumbled in here a couple of years ago. Lots of good information can be found by searching.

 

[odonovj]

I'm digging it

 

[heartfulaluv]

Can anyone tell me if there's anything I can use to clean those grounds, aside from removing? I'm having starting issues which I believe have to to with the grounding, however, I'm don't have access to all my tools, (jack, jack stands etc)or at a place where it's possible to actually do it. I've gone thru and done the other ones in the engine compartment, as well as throughly cleaning the connections in the powder distribution box, and the connections to the starter itself. Those two on the the firewall to the heads I'm too short to reach. Any suggestions? I'm asking here because it's the first I've seen in any forum addressing them directly. Any suggestions would be greatly appreciated...

 

[KJowner]

Try running one straight from the battery to the engine block and see if that fixes it (temporary jump lead if you're short on tools?)
Also feel the battery terminals and leads just after starting up, I had a car where the lead corroded inside the battery terminal clamp.
Oh and when I'm struggling to reach I put the spare wheel on the ground and use it as a step.

 

[heartfulaluv]

Thank you so much! Great ideas! Phewww I might be able to quit using a jumper box every time I need to start it...

 

[heartfulaluv]

Question I'm limited with accessible wire, will any metal worl as ground, temporarily?

 

[KJowner]

Question I'm limited with accessible wire, will any metal worl as ground, temporarily?

Yes within reason, you need something reasonable heavy garage as it may see a fair bit of current if the starter has a poor earth elsewhere. Also don't forget the engine is rubber mounted and moves relative to the body and battery if you are thinking about using anything solid.

 

[heartfulaluv]

Thanks... I happened to have some 8 guage copper strand that I decided to use, and bought some 6 guage to add to the battery grounds. In the process of doing so, I noticed a potential culprit to grounding issues. The grounds were connected to the chasis, but it appears to have been only after the Jeep was repainted, and the connectors were in direct contact with primar, not the metal it should be. I sanded G105 and G106 to the metal, coated lightly with dialectic grease, and added an new wire(6 guage). I'm adding additional grounds, but due to the amount of paint I'm running into, it's taking me a minute to get things tied up. I should have expected to find that, because I found 2 grounds under the passenger seat, completely painted. Fingers crossed...