well 87 coupe deville. Blown head gasket. Should i replace the gasket? should i replace the engine? should i get a different size engine? If i should swap to a different size which one??? I would like to keep the mpg and that sort of stuff. So maybe if i have to swap the computer but i dont want to have to swap a ton of stuff. this is a free car with a pretty good body that my girlfriends dad wants off his driveway.

 

Hello, I had a similar issue with my 4.1, and the wisdom around here is to go to the 4.5, since the 4.1 seems to be plagued with a bunch of issues.Both engines had a throttle body injection version. I believe the 4.5 TBIs were installed in Cadillacs in 88-89. Anyhow, you'll get a bit more torque, but you're still not going to drag race anyone! What type of mpg do you get now? My 86 Eldorado gets around 13-14 with city only driving. Seems bad to me but others seem to bearound the same number. And the computer swap Q--I'm going to start a new thread on that b/c I have the question myself. Hope this helped.

 

4.5 is not a simple swap,due to calibration issues. It will be easier to repair 4.1.If blown head gasket is suspected due to coolant in oil only; it may just need intake gasket.

 

Has anybody read or found the book titled "The HT 4100 4.1 Liter Digital Fuel Injection Metal/Aluminum V8 Gasoline Engine - Cadillac's Miscarriage of the Millenium".

I would be interested in what it said about this engine. I'm sure it's not all good judging from the title!