Cadillac Owners Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
I recently bought a 1993 STS that poured smoke out of the exhaust. It begins doing this after a few minutes of idle. The first time it had the problem it went into limp mode and the previouse owner was barly able to get it home. The car has just over 100k on it; Not knowing what to do they bought a 2003 STS engine an tranny, both having never actually been put in a car.

My question is whether or not anyone has ever had this problem and how they solved it. And also how difficult would it be to put the new engine and tranny in... would that be a matter of having to get a a whole new computer and wiring, or could I just switch over the differnt part and make it work.

thanks for any help or insight.
 

·
Registered
94 Eldorado, and a 99 ETC
Joined
·
3,887 Posts
OPtimus360 said:
I recently bought a 1993 STS that poured smoke out of the exhaust. It begins doing this after a few minutes of idle. The first time it had the problem it went into limp mode and the previouse owner was barly able to get it home. The car has just over 100k on it; Not knowing what to do they bought a 2003 STS engine an tranny, both having never actually been put in a car.

My question is whether or not anyone has ever had this problem and how they solved it. And also how difficult would it be to put the new engine and tranny in... would that be a matter of having to get a a whole new computer and wiring, or could I just switch over the differnt part and make it work.

thanks for any help or insight.

Wow this might be interesting. I'll never say it can't be done.

The easiest way would be to sell that engine and tranny and use the money to buy the right engine and tranny.

There is a possibility that it's not a head gasket at all if they didn't test the coolant for exhaust chemicals. I would suspect spark plug wires and spark plugs if that was the case.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #3
Krashed989 said:
Wow this might be interesting. I'll never say it can't be done.

The easiest way would be to sell that engine and tranny and use the money to buy the right engine and tranny.

There is a possibility that it's not a head gasket at all if they didn't test the coolant for exhaust chemicals. I would suspect spark plug wires and spark plugs if that was the case.
Well head gasket was my first thought so I just took the heads off and they both look fine...one thing I forgot to mention is that there seems to be a pool of oil in the intake...I can only assume that this oil is getting sucked into the cumbustion chamber and that's what is causing the smoking.
 

·
Registered
94 Eldorado, and a 99 ETC
Joined
·
3,887 Posts
Ok you checked both heads gaskets. That must mean that you have the engine out already? I would just rebuild the engine if its already out. That may take a while though. The pool of oil, I don't know what its from but my engine has it too and it runs fine.
 

·
Registered
1989 Sedan DeVille is now just a fond memory ....
Joined
·
10,429 Posts
OPtimus360 said:
I recently bought a 1993 STS that poured smoke out of the exhaust. It begins doing this after a few minutes of idle. The first time it had the problem it went into limp mode and the previouse owner was barly able to get it home. The car has just over 100k on it; Not knowing what to do they bought a 2003 STS engine an tranny, both having never actually been put in a car.

My question is whether or not anyone has ever had this problem and how they solved it. And also how difficult would it be to put the new engine and tranny in... would that be a matter of having to get a a whole new computer and wiring, or could I just switch over the differnt part and make it work.

thanks for any help or insight.
My guess is that dropping the 2003 into the 1993 would be quite a complicated project for the most experienced mechanic if it is feasable or possible.

What diagnosing proceedures have you done to the original engine? If you have already pulled the heads I would have them checked for cracks, cleaned up if they are sound and put them back on. The original problem might have been a leak in the intake manifold.
 

·
Registered
'87 Jeep, '10 Thruxton, '00 Duc 748, '01 748R (853cc)
Joined
·
3,703 Posts
You are going to need to timesert the old block if you are going to reassemble it. If the 2003 engine/trans is in mint condition, you could probably sell both a buy a nice 1995 STS, or similar year. Northstars, and 4T80E transmissions go for alot of money if in good running condition with low mileage. I would look into the value of both, before working on that car. No sense in putting too much effort into it, if you can use that engine/trans to buy a newer, lower mileage, better running STS.
 

·
Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
·
86,242 Posts
I think the pool of oil you are seeing is normal. It is from the PCV. The old carburated engines had a "wet" manifold as gas was constantly washing them down. Our fuel injected engines have a "dry" manifold as nothing but air (and PCV gasses) flows through them. When you shut the engine down, the crankcase gasses condense on the interior manifold walls. You have 12 years worth, so some pooling would be normal I would think.

As far as an '03 in a '93 goes I think it would take a lot of rewiring and a new PCM plus, I suspect a lot of things we are not thinking of, including money
 

·
Registered
2008 SRX-V8, 1991 Eldorado
Joined
·
1,543 Posts
The best rule of thumb is to look over each engine, photograph the old one in place, and then make your decision to go ahead with the project, or not.

The 1993 computer will NOT match the 2003 sensors. That is a given because they are two entirely different diagnostic systems.

You may be able to use the shortblock from the newer engine and the transmission but sensors are key here.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #9
Yes I do already have both heads off and the engine out...I figured my best bet with the engine is to use the shortblock and take any sensors off of the old one...I guess I had never really thought of selling the new engine and tranny. The both look like they were pulled off of the assembly line seconds before going into a car so they both are brand new. I haven't done the research on what they are worth if anyone could tell me I would appreciate it.


The swap isn't really beyond me from a mechanical standpoint it would just be the financial aspect that would elude me.
 

·
Registered
2008 SRX-V8, 1991 Eldorado
Joined
·
1,543 Posts
OPtimus360 said:
Yes I do already have both heads off and the engine out...I figured my best bet with the engine is to use the shortblock and take any sensors off of the old one...I guess I had never really thought of selling the new engine and tranny. The both look like they were pulled off of the assembly line seconds before going into a car so they both are brand new. I haven't done the research on what they are worth if anyone could tell me I would appreciate it.


The swap isn't really beyond me from a mechanical standpoint it would just be the financial aspect that would elude me.
I have done many engine swaps in my time, and have never had one go completely smooth without a glitch. One special molex connector, or bastard length bolt is enough to hold up a simple job. Maybe I'm just not that lucky when doing engine swaps, but everyone I've talked to usually runs into some kind of glitch, so expect it. When it does NOT happen for you, I will salute you!

I don't know how other people buy used engines, but if I can not hear and see it run first, it is a core as far as I'm concerned. I have been fooled by pretty women and shiney paint, so that holds no points with me. But that is just my opinion.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #11
91TexasSeville said:
I have done many engine swaps in my time, and have never had one go completely smooth without a glitch. One special molex connector, or bastard length bolt is enough to hold up a simple job. Maybe I'm just not that lucky when doing engine swaps, but everyone I've talked to usually runs into some kind of glitch, so expect it. When it does NOT happen for you, I will salute you!
Believe me I always expect the unexpected...but I am pretty experienced with engine swaps...My brother has put a 3800sc from a '98 GTP in his '91 Lumina, he has put northstars in fieros and all of that stuff...so he is a good resource for this stuff...I myself have put a '93 3.1L in an '89 cavalier Z24...but they were pretty much the same engine with different cranks and a few different sensors...this would be a much tougher job that's for sure.

but putting that new engine in may be more time consuming and costly than I would like.
 

·
Registered
2008 SRX-V8, 1991 Eldorado
Joined
·
1,543 Posts
I will agree with time conusming, but cost may not be an issue at all, since you have both engines and transmissions for comparison. You will extend the life of that 93 for at least another ten years though. So I hope you really, really like it!
 

·
Registered
Joined
·
161 Posts
OPtimus360 said:
...I guess I had never really thought of selling the new engine and tranny. The both look like they were pulled off of the assembly line seconds before going into a car so they both are brand new. I haven't done the research on what they are worth if anyone could tell me I would appreciate it.

I'd say a 2003 STS N* and mated tranny with low miles would probably sell in a heart beat for somewhere between $3,500 and $4,000 on ebay.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #14
sjwoodruff said:
OPtimus360 said:
...I guess I had never really thought of selling the new engine and tranny. The both look like they were pulled off of the assembly line seconds before going into a car so they both are brand new. I haven't done the research on what they are worth if anyone could tell me I would appreciate it.

I'd say a 2003 STS N* and mated tranny with low miles would probably sell in a heart beat for somewhere between $3,500 and $4,000 on ebay.

This doens't have low miles...it has no miles
 

·
Registered
'87 Jeep, '10 Thruxton, '00 Duc 748, '01 748R (853cc)
Joined
·
3,703 Posts
With Zero miles, it should bring alot more. Just as an example, a brand new N* Long block/less trans is over $7000 from the dealer. A brand new 4T80E I would suspectto be around $35-4000 alone by itself as well. If they truly both truly have zero miles, then I would have to say that they would be worth (sold as a n assembly) well over $4000. These engine are very expensive. That's why I suggested seeing how much you could get for the 2003 engine/trans, before you start tearing apart the car. You could probably by a nice, relatively low mileage 1996-1997 STS for what that engine and trans is worth.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #16
like I said this stuff has never been in a car, everything is perfect on them, they have everything but the wiring and the sub frame...it even has the a/c compressor
 

·
Registered
Joined
·
161 Posts
I'd venture a guess that a supplier that can offer a warranty would be able to get quite a bit more money than a private party for the same exact compont(s). If your drivetrain has a transferable warranty, that would definitely add value. For comparison, there is a brand new, unused GM 5L50E (New STS/CTS) automatic transmission with torque converter on Ebay right now for $950 and a brand new N* Longblock for $3,200. I believe both have a three year/100K warranty.

Obviously the fact that the '03 has some of the components is a major plus. I'd be willing to bet you could sell that assembly for a very handsome amount on Ebay, or maybe even the classifieds on this site. To think you'd be able to get anywhere near dealer retail value is probably not realistic though. Most people looking for a replacement powertrain are going to shop around quite a bit. I'm sure you could get top street value for it though. I'd list it on there with a reserve high enough to ensure you don't give it away, and maybe you could make some real nice $$ on it. Good luck.
 

·
Registered
94 ETC,97 STS
Joined
·
3,531 Posts
1) Someone (who's name I don't remember) had this exact scenario about a year ago. Bb ob gave some info about it that helped him get the new engine to work. There are differences in the trigger wheels and spacing. The guy was able to make the new engine work by modifying the old sensors. You'll have to search to find any of it.

2) Did you do a compression test or anything to tell which cysl may be leaking? The visual evidence of the gasket leak may be minimal. Look for any rust spots on the fire ring.

3) Were any of the head bolt holes stripped?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #19
No, I didn't really think to do a compression test...all of the symptoms seemed like a bad head gasket so I just took it apart...realizing about half way through that that was a dumb idea.

None of the head bolts were stripped and there was no visible evidence of any rust or aluminum oxide anywhere.
 

·
Registered
94 ETC,97 STS
Joined
·
3,531 Posts
Someone bumped the thread I mentioned. It was by Olaf. Read that if you havn't already.

The visual evidence is subtle at best. If we didn't know which cyls we wouldn't have seen where the leak was. The gasket was compressed as much and there was some rust on one (or more) of the leaks. We didn't notice the rust until we went back to reexamine much later. The big thing we had was stripped threads.

Timeserting would be good insurance if you decided to reinstall the original engine. We had someone, long ago, that had the last bolt strip as he reinstalled the heads!

Considering what's involved in using the new engine I would try redoing the head gaskets before tearing the new one apart.
 
1 - 20 of 21 Posts
Top