Expert: Rob Painter - 4/27/2011

Question
how to remove heads on a 4.6l northstar engine

Answer
Hello,

I cannot tell you al the specifics as to what it takes to remove the heads in this specific engine in your specific car (you did not state) and even if I could give you a general idea, a general idea will possibly cause you to remove parts you didn’t have to.

To even attempt such a feat, even for a professional that works on engines on a daily basis, it would be fool-hardy without specific information on that make and model. You must have a factory service manual, and you are going to run into real troubles if you don’t have this information for reinstalling the heads, because critical information such as how tight the bolts are to be torqued when reinstalling the heads and intake manifold. It will cost you $30 (saving you hundreds of dollars) to obtain a downloaded version for a year at http://www.alldata.com

If you are asking how to remove heads, the only reason I know of requiring this, is that the engine was overheated. It wasn't overheated just a little bit and for both heads needing to be pulled, the engine might be junk.

Here is what the manual doesn’t tell you and this information is shared with you by a guy that has owned over 20 Cadillacs and has serviced thousands in over 30 years of being a technician.

Your engine most likely is not worth attempting to change two head gaskets because if the engine got hot enough to blow both gaskets, there is most likely more than head gasket problems with this aluminum engine.

What people don’t understand and I have explained this often here, (look in my archives here for over heating and head gaskets) is although this engine is great for performance and mileage, it Achilles’ heal is heat. People are so used to (evidently) over heating engines and continue driving them until it is convenient for them to shut them off. Yes, one can get away with this with at the very most a blown head gasket in an iron blocked, iron head engine. You do it on one of these Cadillac aluminum engines, first introduced in 1982, the results can be fatal for the engine and I suspect that may be the tale of the engine you want to remove the heads from.

I answer an average of these over heating issues on Cadillacs once a week and yet these questions continue the pop up over the last 10 years.

As I stated in my last overheated aluminum engine question, the next time I have a bon fire going, I am going to video an aluminum can being thrown into it and melting in seconds. Picture this as being your engine above 212 degrees f. with water or 220.degrees w/coolant. By the time the hot light comes on, there is already severe engine damage and you don’t even know the extent of the damage until you remove the head. If you need two head gaskets, you might need new heads, possibly an engine block and that is just figuring for the effect damage and not the original cause for over heating!

Well, you figure; “alright, I will just get a new (junk yard) engine.” I have never seen a junk yard Cadillac engine that wasn’t over heated and damaged.


How about new? If some dealer still has a new crate motor, you are looking at $4k minimum just for the engine without labor and fluids (and you still do not know if you fixed the over heating issue that caused the head gaskets to blow)

Cadillac engineers ripped the consumer off here in my opinion. Either that or their engineers that designed the engine were inferior to those with Renault/AMC and the Alliance and Encore.

If the aluminum engines in their cars were over heated (all the time) and destroyed by the drivers, at least one could still have a good engine block at least, because a piston liner kit was available. The cylinder head may have been warped, cracked or junk, but the block would not be because the pistons and cylinders could be replaced.

I have said it before-trial attorneys really dropped the ball here. They go after anyone they could, but they left GM alone on this issue where 9 out of 10 of these Cadillac engines had over heating issues costing the owner substantial cash. GM made billions and billions on either replacement engine parts, or engines.

One person asked if they should have the head gasket replaced from the dealer. My answer was GM already ripped offed countless people and then you would give them more money to repair their inferior product?

Think about this—talk about a guaranteed cash flow—they made this aluminum engine varying in cubic centimeters, but the concept was the same since 1982!

Good luck on those heads!

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