32v Northstar V8 vomiting coolant

[Baba Ganoush]

'99 Cadillac Deville V8, when it gets warm it starts pushing the coolant out of the overflow. Otherwise seems to run fine. Suposedly has new waterpump, thermostat, radiator and hoses.

[4king]

Replace the radiator cap and burp the system. My mustang did the same thing after it got an air pocket in it.

[Baron Von Crowder]

and blown head gaskets.

[AArod]

Notorious for headgaskets and head bolts pulling out of the block.

[DON SVO]

sounds like the old owner threw everything possible at the overheating issue aside from the notorious blown head gaskets.

[CJ]

check the oil for coolant.

[dangerous_sep]

ooooorrrr throw that bitch in the garbage where it belongs!

[Baba Ganoush]

Replace the radiator cap and burp the system. My mustang did the same thing after it got an air pocket in it.

Cap looks good, it's the lever release type and it seems to hold, it has been burped. Car gets hot, geyser city.

and blown head gaskets.

That seems to be the worst case scenario, so I'm finding out.

Notorious for headgaskets and head bolts pulling out of the block.

This is what I was looking for. So it could push the coolant out if this happens?
I'm trying to wrap my head around the fault in the process.

sounds like the old owner threw everything possible at the overheating issue aside from the notorious blown head gaskets.

This is also a red flag to me. Someone threw parts at it and didn't understand it was something different altogether.

check the oil for coolant.

It seems to me that there is may be water in the oil, but definitely no antifreeze. Its all water at this point!

ooooorrrr throw that bitch in the garbage where it belongs!

I most certainly agree here, but it's a buddie's car, just trying to help him out.

[slow84lx]

Generally, when the Northstar has a head gasket issue it just blows all of the coolant out through the exhaust. Mine never boiled over, just had to keep adding.

The problem is the design of the Northstar has large openings of the water jackets without adequate support. There is a term for this that I cannot remember off the top of my head.

The fix is to take the engine out of the car, remove the heads, and Time-sert all of head bolt holes. The job isn't all that bad but is time intensive. The cradle -engine, trans, steering, suspension - all comes out of the bottom of the car pretty easily. Getting the timing chains back in time is the most difficult part of the whole ordeal. Be sure to use new head bolts as they are TTY.

[slow84lx]

Have your buddy do a leakdown test and determine whether or not it is the headgasket and which one. The front bank can easily be done with the engine in the car although it is a royal pain in the backside to get the timing chains back in time. If the rear bank has the problem the engine is coming out.

Who knows, it could be something else entirely.

[Baba Ganoush]

Generally, when the Northstar has a head gasket issue it just blows all of the coolant out through the exhaust. Mine never boiled over, just had to keep adding.

The problem is the design of the Northstar has large openings of the water jackets without adequate support. There is a term for this that I cannot remember off the top of my head.

The fix is to take the engine out of the car, remove the heads, and Time-sert all of head bolt holes. The job isn't all that bad but is time intensive. The cradle -engine, trans, steering, suspension - all comes out of the bottom of the car pretty easily. Getting the timing chains back in time is the most difficult part of the whole ordeal. Be sure to use new head bolts as they are TTY.

I appreciate the knowledge!

I wondered if unbolting the front subframe was the ticket, or how hard it would be to fix the threads in the block.

Answered a few questions I had, but you said it blows out the exhaust....could it push it back through the system and out the overflow? That would mean compression leaking into the jackets, correct?

[Baba Ganoush]

Have your buddy do a leakdown test and determine whether or not it is the headgasket and which one. The front bank can easily be done with the engine in the car although it is a royal pain in the backside to get the timing chains back in time. If the rear bank has the problem the engine is coming out.

Who knows, it could be something else entirely.

Definitely a good place to start, I have never seen this occur, so I'm confused as to why. I'm hoping it is something else, but I'm not sure where to start.

It be a shame to scrap it.

[slow84lx]

Yes, it could blow back out through the cooling system and this is probably what is happening in this case but verify with a leakdown test.

Unbolting the cradle - 6 bolts - is definitely the easiest way to remove the engine from a Caddy. I lifted the front of mine in the garage with my engine hoist. You need to have a sturdy 4-wheeled dolly under the engine when you do this so it can just roll out. You will need 2 good floor jacks also.

I did this by myself and have done the same basic process twice.

These cars are way too nice to scrap but the headgasket issues these come with is a big downside.

[slow84lx]

When the engine is out is also a great time to service the filter in the transmission and, if necessary, replace the shift solenoids in the transmission. The internal transmission filter can only be serviced with the transmission out of the car.

[slow84lx]

The time-sert kit cost over $250 used back when I needed one and i sold it for the same price after using it.