Dexcool leak, PLEASE READ

[1Bradymichael]

I realize there is a thread for the !@### lower intake gasket, but wanted to post it here as my problem is unique
Fixed it 20k miles ago July of '06, and last month it was leaking again. Tore apart and used Felpro this time instead of OEM thinking that was the problem. 50 miles later is leaked worse than before. Tore apart AGAIN, and noticed the thermostat housing was damp, so I was hopeful that this was the problem, even thought maybe the second time this might have been it as I did not inspect that area when I had the intake off. Today, the wife gets home from a 200 mile shopping trip and guess what........LEAKING AGAIN No, I never reuse gaskets and checked the intake and heads for severe pitting, there was very little pitting on two of the coolant ports. I am wondering if my torque wrenches are that far off that I am not getting them tight enough.Anyone here ever cheated a little and gone tighter than what Felpro calls for? Or is the intake or heads warped. The van has never been overheated that I am aware of(2000 Montana)
Any thoughts would be great, otherwise I might post some pics of what a 308 Savage HP Rifle does to the 3400 engine.

[maxwedge]

. Even done wrong seems like an awful fast failure. Did you use the updated bolts and torquing sequence/specs.

[1Bradymichael]

Originally Posted by maxwedge

. Even done wrong seems like an awful fast failure. Did you use the updated bolts and torquing sequence/specs.

I used the updated bolts from Chevy after the first fix the second and third time, used blue locktite each time. Can intake bolts stretch that much? According to the FP instruction sheet you can use the old bolts and locktite them, and then I would tighten according to thier specs, which is 65 inch/lbs on the inside bolts, and then 115 on the inside bolts, and then finally 18 ft/lbs for the outside four bolts.

[kornjulio]

Wow....something's obviously not right.....where do you observe the coolant leaks - the little valley next to the oil pump drive???

[1Bradymichael]

Originally Posted by kornjulio

Wow....something's obviously not right.....where do you observe the coolant leaks - the little valley next to the oil pump drive???

Yeah, that is the exact spot, the same spot where I always see it. I thought maybe it was the thermostat housing as it was damp the third time, so I took it apart and siliconed it, but I still have a leak.

Anyone think my torque wrenches are way off on the calibaration?
Just grasping at straws here.

[534BC]

If the bolts aren't loose every time then there may be a problem with the surface. I noticed bad machine work on intake surface, not heads.

[rockwood84]

are you using enough of the sealer in the valleys on the ends of the intake and overlappping on the intake gaskets a little

[kornjulio]

The guys above me have a couple of key points.

I spent a lot of time prepping the surfaces....the intake surface was definately the worst of the two. Then plenty of RTV - work it up the head side a bit. Finally, I had a hard time getting good torque on those diagonal bolts at the end of the intake using a crows foot, extension, and click wrench......so knowing the new gasket has the metal buttons in them to prevent crushing; I gave it an extra 1/4 turn to make sure it was good n' torqued.

Been dry for 6 mos now....2000 Venture

[1Bradymichael]

Originally Posted by kornjulio

The guys above me have a couple of key points.

I spent a lot of time prepping the surfaces....the intake surface was definately the worst of the two. Then plenty of RTV - work it up the head side a bit. Finally, I had a hard time getting good torque on those diagonal bolts at the end of the intake using a crows foot, extension, and click wrench......so knowing the new gasket has the metal buttons in them to prevent crushing; I gave it an extra 1/4 turn to make sure it was good n' torqued.

Been dry for 6 mos now....2000 Venture

Funny you mention the problem with the crows foot, I had the exact same problem, I wonder if I am not getting the outer bolts tight enough? Any harm in giving them an extra 1/4 after she has been run a couple hundred miles?

[old_master]

A torque wrench is designed to give acurate results with a socket only. If an extension, universal or crows foot is added, the torque at the bolt decreases. Threads need to be clean, (chased with a tap and die if necessary), and lightly oiled for acurate results also.

[kornjulio]

Originally Posted by 1Bradymichael

Funny you mention the problem with the crows foot, I had the exact same problem, I wonder if I am not getting the outer bolts tight enough? Any harm in giving them an extra 1/4 after she has been run a couple hundred miles?

Well, if it's currently leaking doesn't sound like you could be much worse off....I'd say go for it!

[1Bradymichael]

Originally Posted by old_master

A torque wrench is designed to give acurate results with a socket only. If an extension, universal or crows foot is added, the torque at the bolt decreases. Threads need to be clean, (chased with a tap and die if necessary), and lightly oiled for acurate results also.

Thanks, I guess I did not realize it would be that big a deal. Any rule of thumb when using extensions? And would I need to increase the torque on all the bolts or just the ones that require an extension

[old_master]

Originally Posted by 1Bradymichael

Thanks, I guess I did not realize it would be that big a deal. Any rule of thumb when using extensions? And would I need to increase the torque on all the bolts or just the ones that require an extension

There are too many variables for there to be an acurate figure, such as the diameter, length, and amount of "twist" in the extension. You can "cheat" a little and come close to the torque you're looking for. Find a bolt that you can access easily using only a socket on the troque wrench. Torque it to the proper spec. Put the extension on the torque wrench that you need to use to access the "difficult" bolt. Using the bolt you just torqued, turn the wrench until the bolt just starts to move, notice what the torque wrench indicates; go to your "difficult" bolt and apply that amount of torque. This will get you closer, but not exact.