Question about 1999 Cadillac Seville

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My 1999 cadillac sts overheats alot i was told i have a cracked head but i think it is just the gasket how hard is it to change the gasket on this cadillac?

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  • heromnk18 May 18, 2009

    if you have read my problem it says it is an STS and i have been told that there is nuts on the other side of the head bolts is this true?



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It hasn't been stated whether this is a Cadillac Seville STS, or an SLS. No matter, as they both use the 4.6 Liter, Dual Overhead Camshaft engine.

I would rate this as an 8, on a 1 to 10 scale. It would be a 10, if this Cadillac used wet sleeves. (Some Cadillac engines had a basic engine block, that had the water jackets open. The cylinders, are simply thick metal round tubes, with an O-ring at the bottom, and top. These set down in the block, and are held in place by the head.
There is a head gasket used also. When doing head work, or anything that involves removing the cylinder head, the wet sleeve cylinder, must NOT be disturbed from it's setting. If the cylinder is bumped, it can move, and the pattern the piston has made, will be disturbed. This means re-honing that cylinder. Lots of fun, these engines!)

Have you had experience with dual overhead camshaft engines? If yes, this is right up your alley. If not, be prepared for a small learning curve.

The engine must be removed. This is a transverse engine. The rear cylinder head May clear the firewall, it may not, if trying to remove it in the car. However, it is absolutely no fun trying to lay across the engine, and clean the gasket surfaces of the block!
This is just the tip of the iceberg, of bad things to come, when trying to replace the head in the car!

Just my advice.

Posted on May 18, 2009

  • joecoolvette
    joecoolvette May 18, 2009

    There are three external M6 metric bolts in the front. There are ten
    internal M11 metric bolts.
    External, means the bolts are located outside, of the head to block area.
    They go down through the head in the front, pass through the rear
    transaxle brace, and have a nut. The nut has a flange on it. A built
    on washer.

    Suggest at this time you buy the manual for it, or go to your local library,
    and see if they have a manual. You may be able to have pages copied

    Be sure to not disturb the engine, when removing the heads. After you
    remove the heads, you need the crankshaft right where it was, before
    removal. The engine will be timed. I state this, because you have to remove the camshaft drive chain from each camshaft, on each head,
    before you can remove the head. (Secondary camshaft chain) Be sure the camshafts do not get rotated. Each head has it's own camshaft.
    Dual OverHead Camshaft. DOHC.

    Where the crankshaft sits, in relation to how the camshafts are sitting,
    is the correct timing for these components.



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