Cadillac Owners Forum banner

1 - 20 of 28 Posts

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #1 (Edited)
Ok, so gotta make this quick. Im at Kinkos paying 20 frieken cents a minute for internet cause I couldnt find anywhere else to log on in Wichita lol.

I checked out two different vehicles today. One was the Q45 which I had mentioned before (thanks Jesda for giving me some tips there too) which was just in beautiful shape except for little things that are to be expected on a 12 year old car.

THE OTHER, was a 2001 Cadillac SLS which is basically outfitted identically to a Cadillac STS sans engine hp of course. The car has 96k miles and is in excellent condition sans a cracked a windshield and an engine problem. I would basically be getting it for a trade of my 2000 Elantra, which in the real world is only worth about 1500.00, and 3500 cash.

Heres the problem I need help with...

At idle this car lopes TERRIBLY. The engine VISIBLY shakes in the engine compartment when its idling and shakes the whole car. When you get up to speed its as smooth as it should be with only the occasional stumble here and there (which is probably CPS sensors anyway). But when Idling it can not hold a steady idle. My dealer friend was told it is some sort of computer module, as well as that there is some sort of manifold gasket that needs to be replaced, which the wholesaler said would run him about 1500.00. When I popped the hood with the engine running, I could hear a very audible hissing noise coming from somewhere within the engine compartment, as well the poor engine stumbling trying to keep a steady idle.

There is no smoke coming from the tailpipes, there WAS a little bit trapped in the engine compartment when I opened it. just a tad. And unfortunately there is a bit of a burning oil smell. The strangest thing is the car is not throwing ANY codes whatsoever. NONE. Occasionally it will get bad enough to where it stalls out completely, but this has only happened a couple of times so far.

The other odd thing its doing, possibly in attempting to maintain a proper idle speed, is that occasionally when I let off the accelerator pedal, it continues as if I hadnt done anything at a steady speed! Almost like if the cruise control was set, but the cruise is completely off. The car just really seems to be struggling with the engine issue but otherwise is in gorgeous shape.

Anyone have any idea WHAT THE HECK is going on with it, and what it might cost to get it fixed? Moreover, if I continue driving it like this, what risk of major harm am I inflicting. I liked the Q45 alot, but I am in love with this SLS. Id like to take it home to florida tomorrow. Ill be checking in on this thread when I get to my buddies dealership in the morning.

Please help me out guys!! Dont tell me Ive got the Northstar CURSE HERE!

Heres a pic and the webpage (anyone got carfax?). It says 13980 but I will basically be getting it for 7500 to 8k. And really its more like 3500 to 4k because the Elantra didnt cost me anything, and the transmission is going out on it anyway....




 

·
Registered
'87 Jeep, '10 Thruxton, '00 Duc 748, '01 748R (853cc)
Joined
·
3,703 Posts
I would say vacuum leak from somewhere. Under load, the engine isn't producing much vacuum, if at all, so it wouldn't be affected. At idle though, a vacuum leak big enough to hear loudly over the engine could cause a rough idle. That would be my first guess. Try and locate the hiss. It will probably lead you towards a vacuum hose of some kind. ALso check for code to see if anything else could be wrong.
 

·
Registered
1992 Town Car Cartier & 2014 Accord LX MTX
Joined
·
34,087 Posts
The Tranny is going out on the SLS?
 

·
Registered
'98 Buick Regal LS - '91 Caddy Seville - '87 Caddy Seville!
Joined
·
4,425 Posts
The hissing noise is most likely vaccum. From the sounds of it though, it's not just some little hose that broke off, so perhaps a vaccum test will help tell the tale.

The other possible thing is that it could be the idle speed regulator (if so equipped on the Northstar). If that's in bad enough shape, it will have some sort of hiss (more like a ratcheting/buzz-saw sound) and make the idle go nuts down low. When the RPM's are up high like on the highway, the idle speed regulator doesn't really affect anything. When you come down to a stop, if the regulator is bad, it will keep the RPM's up high for a second or two, then drop very low because of the internal damage of the regulator.

Also, in my experience the idle speed regulators don't always seem to throw codes, but that was for my 4.9 liter when the regulator went bad. I knew it was bad because of the aforementioned symptoms, thus I replaced it. Problem solved.

Anyways, I would look into that and see what can be done.
 

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #6 (Edited)
Im not quite sure how to check for codes on a 2001. I know the MIL light was not on and there are no messages appearing on the DIC except for check fuel gauge.

The color of the smoke in the engine compartment was whitish I guess and it smells a little like burning oil, but when I started it this morning I made sure to check and see whether anything came out of the exhaust at cold start and there wasnt a single hint of smoke back there anyway. The poor thing sounds like an old beater car when its idling but at WOT it sounds and feels just like a NS should. I dont detect any hint of performance loss or anything like that.

Like I said, the wholesaler that made the bid on the car initially, dropped by his bid by 2k when he noticed the manifold seal problem or whatever it was he found. Unfortunately my dealer buddy is not that great with mechanics so I have to see if he can find one of these guys to find out exactly what the problems were.

So the things I know are... Person that traded it in knew about the idle problem and had been driving it that way for a while... At WOT and regular speeds it behaves ok except for an occasional lurch here and there, most likely CPS in my past experience, and the car is in otherwise pristine shape with no major smoke or anything like that. Also never overheated, I drove it all night like that.

I guess the question then becomes, is it a deal for 7500 bucks?
 

·
Registered
1992 Town Car Cartier & 2014 Accord LX MTX
Joined
·
34,087 Posts
Could it be something like a faulty fuel injector?
When my injector for the #5 cylinder went out on my deVille, it had a very rough idle and it shook while cruising, but when I would get it WOT, it would feel like it always did...smooth and powerful!
 

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #8 (Edited)
OK... So heres what the service guy said about the car...

The IDLE problem has nothing to do with the gasket problem. It is most definitely a computer issue, and I believe they sourced the part at around 207.00 dealer cost.

The gasket problem which the wholesaler bid the car lower for is apparently a common deal on most Northstars, and most people apparently never fix it because since its a machined surface, I guess the engine needs to be removed and entirely resealed or something? (Northstar curse... again) But apparently none of this is showstopping crazyness that means new engine or anything like that.

I think Im going to get it. Worse case scenario Ill have to dump 3 grand into it at some point to fix it permanently. If I could find someone in FL who worked on Northstars, Id be alot more comfortable about it rather than taking it to the dealer everytime though.

Im going to take the Q for a spin one more time and then make my decision. When you hear from me again, Ill be driving a new car.
 

·
Registered
1992 Town Car Cartier & 2014 Accord LX MTX
Joined
·
34,087 Posts
Well its a lot better looking car than that Q45, but do you really wanna dump $3000 into a car you didnt plan on keeping for a long time?
 

·
Registered
Joined
·
442 Posts
Im not a mechanic.

It could be an exhaust leak. If it is burning oil due to carbon build up, the smoke might be coming out the exhaust manifold? It happened to me after my head gaskets were replaced, they had to retighten some bolts to fix it.

Are they willing to fix that problem?
 

·
Registered
94 ETC,97 STS
Joined
·
3,531 Posts
First, I never believe anything a wholesaler/dealer says about mechanical problems. At best they're blowing smoke, at worst they are outright lying (apologies to your friend).

It sounds like a vacuum/injector problem and if you don't work on cars you have to get someone familiar with N*'s.

I don't know whare the engine coming out of the car started. You've been on the board and I havn't seen this being any kind of common problem. I honestly don't know what he's talking about with pulling the engine for an idle problem.

I'd say take a chance and go for the Caddy and get it fixed. Sounds like checking the inj, resealing the intake (maybe ISC), and plugs & wires should fix it.
 

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #12
Well my dealer friend who runs the lot over here isnt mechanically knowledgeable, so he is only telling me what the wholesalers told him. I dont know whether he called one of their mechanics to find out about the engine coming out, or the wholesaler guy. But apparently, SOMETHING needs to be resealed, and your probably right, it probably IS the intake manifold or something.

I dunno, I guess Im stupid for passing on the Q, but I fell in love with the Caddy when I drove it, and the condition is just gorgeous. No rattles, no problems with the air suspension, nothing falling apart. If it werent for the engine problem it would be worth every bit of 12k.

The bottom line is, NO ONE is going to give me the money my buddy is giving me for the Hyundai. It is out of sheer luck that he has a buyer for the Hyundai that doesnt care one iota about the condition of the car. My Hyundai has been hit multiple times, the tranny slipped all the way down here, and its in generally rough shape and Im getting basically 4000.00 for it which is insane.

My biggest fear is this... What if I need a whole new Northstar?
 

·
Registered
94 ETC,97 STS
Joined
·
3,531 Posts
I'm not there but...Why do you think it needs a whole new motor? Is it knocking? Does it run good at speed? Does it leak badly? How does it feel above idle?

From what you're telling us it's an idle problem. The bottom end sounds good???
 

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #14
It runs fine at speed (and thanks for your help by the way), it doesnt knock that I can hear or overheat at all. It just idles really really rough I mean you can see the engine visibly shaking when it idles. It shakes the whole car and it sounds almost like its kinda sputtering a bit when it does this. But yea, once its moving it feels perfectly normal.

Heres the codes I pulled:

P0101 HISTORY: MASS AIRFLOW SENSOR PERFORMANCE
P0171 CURRENT: FUEL TRIM SYSTEM LEAN
P0174 CURRENT: FUEL TRIM SYSTEM LEAN
P0300 HISTORY: ENGINE MISFIRE DETECTED
P0335 HISTORY: CKP SENSOR A CIRCUIT (HEHE I WAS RIGHT!)
P0385 HISTORY: CKP SENSOR B CIRCUIT
P0386 HISTORY: CKP SESNOR B PERFORMANCE
P1372 HISTORY: CKP SENSOR A/B CORRELATION
 

·
Registered
1992 STS / 2005 MB G500 / 2003 STS / 2006 XLR-V
Joined
·
11,694 Posts
Discussion Starter #18
mcowden said:
How many miles on the car? What options does it have?
2001 SLS, 96K Miles Dark Forest Green

Bose Sound
Park Distance Sensors
Heated Seats
Painted rocker mouldings
Onstar

and everything else that was pretty much standard on the SLS and STS including the fancy gauges.

Got it for 4k plus the elantra. Im thinking what it needs is the Mass Airflow Sensor based on the Lean fuel mixture and the MAS codes.
 

·
Cadillac Owners Connoisseur
Joined
·
1,164 Posts
Playdrv4me said:
2001 SLS, 96K Miles Dark Forest Green

Bose Sound
Park Distance Sensors
Heated Seats
Painted rocker mouldings
Onstar

and everything else that was pretty much standard on the SLS and STS including the fancy gauges.

Got it for 4k plus the elantra. Im thinking what it needs is the Mass Airflow Sensor based on the Lean fuel mixture and the MAS codes.
NADA says $12775 average retail for the car. It definitely needs crank position sensors and a MAF, and it sounds like there is an intake leak somewhere. Change the coolant, clean the throttle body, replace the plugs and wires, check/change the belt, give it an oil change with Havoline 10W-30 and an AC-Delco filter, and drain and refill the transmission fluid right off the bat. (assuming there is no maintenance history with the car) I specified that exact oil change because dealerships sometimes put heavy oil and empty filters on cars to get high flow and mask any noises the engine could make because of broken or worn parts, etc. If you put the recommended oil and filter on it and it makes noise, get it back to the dealership right away. Might also want to rotate the tires and check the brakes, CV boots, and tie-rod ends while you're in there. Once that's all done and the CKPs and MAF is replaced and the intake leak is solved, you should be in good shape barring any hidden problems.
 
1 - 20 of 28 Posts
Top