: 2000 Deville Head gasket?



AJxtcman
07-22-08, 09:53 PM
I had a 2000 Deville in today.
What do you think?
The head gasket looks like coolant has been weeping out of it
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Crossover%20leak%20not%20a%20Head%20GSK/HPIM3724.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Crossover%20leak%20not%20a%20Head%20GSK/HPIM37241.jpg

CadillacSTS42005
07-22-08, 10:05 PM
wow
i dont think ive ever herd of one leaking EXTERNALLY

AJxtcman
07-22-08, 10:13 PM
wow
i dont think ive ever herd of one leaking EXTERNALLY
I think I have seen about 50% leak externally on 99 and prior blocks.


Look in the valley in this picture
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/hole2threadsnogood.jpg

AJxtcman
07-24-08, 06:46 PM
NOT A HEAD GASKET

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Crossover%20leak%20not%20a%20Head%20GSK/HPIM3727.jpg


http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Crossover%20leak%20not%20a%20Head%20GSK/HPIM3726.jpg

http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/Block%20failures/Crossover%20leak%20not%20a%20Head%20GSK/HPIM3725.jpg

Eldo1953
07-24-08, 10:31 PM
Alright so what is going on here?

Submariner409
07-25-08, 10:24 AM
Water crossover gasket leaks. Unfortunately, fairly common and labor intensive.

Go down to the picture of the head bolt hole and cylinders. Notice the open design of the water passage around the cylinder liner. Doesn't leave much sealing surface around a cylinder, does it ? That area is exactly where exhaust gas blows into the coolant if a head bolt loses tension.

AJxtcman
07-25-08, 09:20 PM
How many untrained Tech's would look at that Head Gasket and say it was Leaking?

Now think about how many people think that Northstar's have Head Gasket problems and if they saw that residue on that Head Gasket would think that it was appearing to be coolant leaking out of the Head Gasket

I know that location is known to have coolant residue build up from a Leaking Crossover Gasket!

All of a sudden you get a bunch of Ignorant and Unexperienced people blasting Northstar Head Gaskets That are not really bad in this type of case and posting that they failed on the Internet!

It Iis bad PR

I am dishing out bad PR on the Ignorant People

Submariner409
07-26-08, 11:03 AM
AJ, Did GM ever come out with redesigned water crossover gaskets like they did with the intake manifold units? Those leaking crossover gaskets show up in here a lot..........

AJxtcman
07-26-08, 01:49 PM
AJ, Did GM ever come out with redesigned water crossover gaskets like they did with the intake manifold units? Those leaking crossover gaskets show up in here a lot..........

They are on the 3rd or 4th design for the 00+ engines
The current ones are white plastic with a black rubber seal in them.

jeffrsmith
07-26-08, 08:13 PM
I understand that these types of gaskets are meant to be put on dry, but would it be wise to put a coating of hylomar on them when reinstalling?

Just wondering, I am getting ready to start putting my '99 N* back together and it seems like it would be cheap insurance.

AJxtcman
07-26-08, 10:16 PM
I understand that these types of gaskets are meant to be put on dry, but would it be wise to put a coating of hylomar on them when reinstalling?

Just wondering, I am getting ready to start putting my '99 N* back together and it seems like it would be cheap insurance.

I am not sure about that.
I have used Hylomar
The reason the gaskets are made with a rubber seal is so they will be able to move around and still seal when the engine expand and contracts with heat

jeffrsmith
07-26-08, 11:14 PM
My thought is that hylomar is non hardening so it should help seal while allowing for slight expansion and contraction.

AJxtcman
07-27-08, 10:53 AM
My thought is that hylomar is non hardening so it should help seal while allowing for slight expansion and contraction.

That is what I was thinking, but I know of a tech that used or uses pipe sealer (PTFE) and it made them leak. It also made a mess to clean up.

I have used TransGel on them. TransGel is a petroleum jelly that should not damage the seal