1982 Cadillac Seville from North America - Comments

I purchased an 82 Coupe Deville with the ht4100 and it is crap. I needed to change the oil after 40miles and being oblivious to that it died. It's a lemon.

Great info. Thanks for the posting - especially the info on the book.

My family has had an 84 SDV since 85, and all the stories are true. When I was a kid, I remember my dad telling me about the milkshake problem, which happened at about 80k miles. My dad (and I) loved the car - I took my driving test on it for crying out loud. We loved it so much that he went to the dealer and paid $5k for a new HT 4100 engine. Not long after, the transmission died, so we had it rebuilt at AAMCO.

Since then, the car was retired and sat in my dad's garage until this month. He drove it around the block every once and a while, but the engine and tranny have no more than 5k miles on it. They look brand new.

Other than paint, tires and some minor interior issues, the car is in mint condition. My dad recently decided that he needed the room in his garage and wanted to unload the Cadillac. I had it shipped to me, and have it sitting (covered) in my driveway. In my heart I'd like to paint it and get it back to the way I remember from when I was a kid... but my head is saying that maybe I should cut my losses and move on.

Thanks again for the info.

My 88 Deville with a 4.5 (HT4500) V8 had the same milkshake problem as the HT4100. So the gasket problem wasn't limited to just the HT4100. The HT4100 came out to replace the V864 mainly because of CAFE standards. The Government did not take the cylinder shut-down feature of the V864 in consideration when they rated the fuel economy, so it was EPA rated as a 6 liter V8 at only 15mpg. The succeeding Cadillac built engines have the same gasket problem as the 1982 HT4100 and they all require the use of block seal;including the NorthStar. Unfortunately for we Cadillac lovers, the last good Cadillac engine is the 6 liter V864 (with the V864 unplugged). My 87 Brougham (307 Olds),91 Brougham (305 Chevy), and 93 Fleetwood (350 Chevy) were 3 excellent cars and surely better than any HT or NorthStar powered Cadillac.

I think the nail was hit directly on the head here-the comment about the HT4100 being the wrong engine for the heavy rear wheel drive and Eldorado/Seville models. I was a mechanic in the 80's, and it became obvious that the 4.1 was underpowered for the cars it was installed in. To safely accelerate onto the highway and keep up with the traffic, one had to constantly keep the accelerator floored. The engine had to be revved highly for normal everyday driving, causing them to run hotter and under higher load than designed for, hence the short life of the engines.

In all fairness, any downsized post 1985 transverse mounted 4.1 Cadillac I ever drove actually performed quite well. I presume the engine despite engineering problems had a much better chance of surviving.

Does anyone know whether a SBC would fit into a '82 Caddy Coupe de ville? As you can imagine, the original engine has thrown a conrod so I am looking for an alternative that is both cheap and long lasting.