View Full Version : 93 Seville?

11-07-06, 12:54 PM
A friend of mine for a 105K mile Seville for $2500 locally. He wants me to go look at it, but I am not well versed in N*'s. 4.9's, 4.5's, LT1's, Vortec 454's and 350's, but N*, not really, just a plug change is my experience.

Any advice for the 4T80E then and the N*? what to look for an what to avoid?

And the other car he is looking at is a 99 Deville for $3500. They are desperate for $. So given a choise, what would be a better investment? Ultimately they might get fixed up and sold to make a few $$, then again, maybe not!

11-07-06, 01:44 PM
If the '93 Seville is an SLS, it will have the 4.9L engine. If it is an STS, it will have the 4.6L Northstar. Obviously, the most expensive area of concern is bad headgaskets on the Northstar, so check it out real well if it is the STS. As far as the 4T80E is concerned, it is a fairly robust transmission with the exception of the shift solenoids on the '93's and 94's.

11-07-06, 02:56 PM
Are all N*'s issues on headgaskets, or does it fade away after some year? Has anyone determined the root cause? Crappy parts? Poor torque? Weak or changing torque on the bolts due to block core shift? Poor design for the pressure they see? Someone screwing up at the engine plant? Poor machining? etc?

Just wondering.

I have always wanted a N* STS, but the head gaskets have scared me all the way to a 94 Fleetwood LT1. If a limo can live 400K miles, that is what I need, dead on reliability. I drive 600 mile a week, and would love the fuel economy of the N*, but not the headaches. I can't afford to have to take my ride into a shop for head gaskets. My LT1, them heads would be off in a hour or 2. No big deal at all. I have ditched all my FWD cars over the lack of ability to pull the engines easily compared to the RWD cars. But that is me, I don't have a garage to work in....yet....

11-07-06, 04:31 PM
For a $1000 more, I'd opt for the '99. The Deville and the Seville are vatly different so that will make a difference as to his choice.

The biggest single reason for head gasket failure is lack of cooling system maintanence. The '93 used green coolant and should have been changed every 2 years. The '99 used Dex-Cool and should be changed every 5 years. So the '93 should have had 6 changes and the '99 should have had 1.

11-07-06, 05:53 PM
The Northstar headgasket issue has been prevalent for a decade, through and including the 2003 model year. The newest vehicle I have personally seen in the shop for headgaskets was a 2003 with 84,000 miles. In 2004, the headbolt thread was changed to help eliminate the block thread failures, but only time will tell if this is the complete answer. Struts are another high dollar item that may need replacement on a high mileage Caddy. Check for stored codes. How many miles are on the '99 that you are considering? Take your time and look around. There are plenty to choose from 5 years old and older for under $4000.

11-08-06, 12:14 AM
The 99 got sold to the mechanic who was holding the car for the repair estimate charges (great shop eh?).

He found a 96 Concours that he got for $1500. Had some trans codes that came and went. Speed Sensor Lo was one of them. It later cleared on the way home. I'll check it out tomorrow. Even had the chrome wheels. Not bad for $1500...

Thanks for the help guys!

11-10-06, 03:38 PM
The Deville he got smells of antifreeze, are there any common leaks on the N* to look for? I will be getting the car this weekend to go over and work on.

Anythings I should deal with?

140K miles, not well taken care of.

1. Oil change w/filter
2. Trans Fluid change w/filter
3. Coolant change (does this car need the pellets?)
4. Find rattle underneath, around middle of car, something like the suspension or exhaust.
5. General go over to make it road worthy....

11-10-06, 07:38 PM
Trans filter is in the side cover and only gets changed with a complete overhaul. There are 2 screens in the pan that can be cleaned and reused if there is any debris in them.

Check the water pump cover. Those gaskets have been known to leak. Side tanks are plastic and also have been known to crack. GM quit using the sealant tabs at some point (late '90's I think). They were mandatory on the 4.9 but can't hurt. Just be sure to put them in the radiator hose, not the surge tank.