I was reading about water glass and head gasket kits, and found this promo article (http://auto-inventions.com/pc-history.html). Down at the bottom it says:

"3. The Cadillac 4.1 liter engine is beyond hope for this formula. It does not blow head gaskets, it blows head bolts."

That agrees with something my mechanic told me, who said he does not do head gaskets on the 4.1 because the bolts are always stripped and spinning around.

Ah the joys of the first gen aluminum block!

Here's a simple/easy way to prolong the life of your car: let it warm up for about 1 minute before driving off. Then, drive gingerly until the vehicle warms up to operating temperature. This will help everything expand at a slower rate.

Or just don't get a cad with the 4.1. Its as simple as that. :D

:yeah:
and when it blows put a chevy 350 in it and call it a day...

Ah, the urban legends about how the HT 4100 can fail...

Simply put, that mechanic is full of it. The main issue, as has been stated on this site no less than 50,000,000,000,000 times was the intake gasket sealing. When the intake gasket would fail, water would get down into the rotating assembly and wreak havoc. That's it. Early series II 3800 engines had similar problems...

Actually my mechanic said that he had encountered spinning bolts, so it wasn't rumor

And that page I linked to, you'll notice that his first failures were with Cadillac engines

so... maybe the "rumor" has some basis in reality

I have heard of MANY head bolts stripping in 4.1 engines. That's why so many timesert kits were used. The head bolt situation is very similar to the Olds 350 diesel. Illumina is right, however, the intake gaskets were the worst part of the sealing system.

In any case, it's a good idea to just let the car warm up for about a minute before starting off. This is especially true if it's very cold outside.

I'll back letting these engines warm up. Another way to get a feel for how long it should take:

1. Key on.
2. Set climate control to 90 deg; LO, AUTO, or HI fan setting.
3. Fire it up.

Wait until the fan comes on. It won't until the approximate time the EFI enters closed loop, or the thermostat begins to open. Depending on the ambient temperature, 1- 3 minutes.

Yup, exactly like I suggested before, only you don't need to set the climate control at 90 degrees. Just place it at a comfortable setting. The fan will come on automatically when the engine temperature hits 48 degrees Celsius (about 120 degrees).

That's true (sometimes!), but I've noticed that sometimes they come on early (i.e. set to 72, fire it up, fan still comes on.) So it's a matter of your own experience, but worth considering, because Cadillac rightly figured that on a cold morning, you could actually keep your engine from warming up by doing just what I described...and they must have known what would happen if you just put 'er in gear and drive off...:thumbsup:
Warming it up is probably the best thing you can do for your engine. Hmmm...:stirpot:??

Oh, very true. It's only supposed to come on early if the inside temperature is above 75 degrees. So if the car is sitting the sun and it's only 45 degrees outside, the fan will come on when you first start it.