Coolant Leak...I searched, but more questions

[2K6TBSS]

I have discovered a leak in my 99 Denali, well actually what might be 2...

I can see coolant leaking from what appears to be the front passenger side corner of the motor, thinking this is probably the notorious intake gasket leak.

Also, from what appears to be the rear of the motor, the coolant is dripping from the passenger side and running down the side of the oil pan.

I have checked the oil, and there is no discoloration, or sludge building up. All looks good there.

Questions...

1 - Could the second leak that I see be a head gasket, or do you think it could also be an intake leak?

2 - Is there a coolant drain plug for the block? I know that my BMW M3 has a drain for the block. Reason I ask is because the previous owner did a coolant flush but used the green coolant, not the orange Dex stuff.

 

[961500]

Could both be intake related also check the heater hose connection on the intake also a problem area on the 5.7

 

[bishop]

I would say for sure both leaks are from your intake. and when you fix it, put green coolant back in it. dexcool is why you need an intake gasket.

 

[grnrpr68]

you might also want to check the frost plug on the back side we just replaced 1 here few weeks ago leaking in about the same place..just an idea

 

[2K6TBSS]

Thanks for all the responses!

I guess I will be ordering the gasket kit from Summitt Racing this morning.

---------- Post added at 10:03 AM ---------- Previous post was at 09:41 AM ----------

you might also want to check the frost plug on the back side we just replaced 1 here few weeks ago leaking in about the same place..just an idea

Is the frost plug easy to access with the manifold off?

 

[retorq]

There are 2 frost plugs. I think you can get to 1 of them 'easily' if I recall right the other is behind the motor mount.

 

[juniorwatson]

[SNIP]


2 - Is there a coolant drain plug for the block? I know that my BMW M3 has a drain for the block. Reason I ask is because the previous owner did a coolant flush but used the green coolant, not the orange Dex stuff.

I just bought a 1998 Tahoe, and I'm getting familiar with it, so I'm not exactly as familiar with the engine as I am with the 1996 LT-1 I have, but...

The LT-1 has knock sensors on both sides of the block, and I pulled them when I flushed the cooling system to totally drain the engine block.

 

[blueflamed03]

also, verify it's not water pump on front that may be leaking.

 

[branndon_b]

i second the intake leak. i just had mine done recently and it flunked a pressure test badly. the intake gaskets are notorious on these 5.7's.