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1995 sls
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Discussion Starter #1
Hello, I am new to this forum, and a new Cadillac owner and have a few problems I need help with. I have a 1995 sls.
My first problem is some days weather it is hot or cold it has trouble starting, but some days it will start right up no problem.
Second problem is when the car is in park, or when i let my foot off the gas the cars rpm jumps up and down and the gas peddle pushes down on it self. When this happens the car jerks back and fourth and some time, but very rarely stalls out.
I had a mechanic take a look at it and he said everything was fine. He told my the air filter, fuel filter, and spark plugs are good. The only thing he said was to put 91 octane gas in it. I've been doing that for the past couple weeks and hasn't solved a thing. The rpm jumping happens more when the engine is fully heated up but still does it most of the time.
It recently had an oil change and a new radiator was put in.
Could this be a head gasket problem?
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,272 Posts
Re: Cadillac sls problems and questions?

Hello, I am new to this forum, and a new Cadillac owner and have a few problems I need help with. I have a 1995 sls.
My first problem is some days weather it is hot or cold it has trouble starting, but some days it will start right up no problem.
Second problem is when the car is in park, or when i let my foot off the gas the cars rpm jumps up and down and the gas peddle pushes down on it self. When this happens the car jerks back and fourth and some time, but very rarely stalls out.
I had a mechanic take a look at it and he said everything was fine. He told my the air filter, fuel filter, and spark plugs are good. The only thing he said was to put 91 octane gas in it. I've been doing that for the past couple weeks and hasn't solved a thing. The rpm jumping happens more when the engine is fully heated up but still does it most of the time.
It recently had an oil change and a new radiator was put in.
Could this be a head gasket problem?
------------------------------
Could this be a head gasket problem?
ah - NO -

check for Diagnostic Trouble Codes -

if you don't know how - go here and read the ENTIRE post -

http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/138257-how-pull-codes-dtcs.html

if you have any codes - post them here -
ALONG WITH THEIR DEFINITIONS -
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,458 Posts
............ and do some homework in here and in Engines; Northstar Performance concerning throttlebody cleaning, spark plug wires, and Idle Speed Control solenoid work.
 

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Registered
1995 sls
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24 Posts
Discussion Starter #8
Thanks for all the help. I had the isc motor replaced and is now running great!!! But I have another quick question. When ever I run the car some smoke comes out of the tailpipe but not a whole lot. The car is only driving 4-5 miles a day and never gets above 160-170 degrees.
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
Go back and get a good whiff of the "smoke" and tell us if it smells like gas, oil or coolant.
 

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1995 sls
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24 Posts
Discussion Starter #10
At first start up for a few minutes it smells like gas but then after smells like nothing
 

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1995 sls
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Discussion Starter #12
I checked and nothing. I had my cousin look at it(he is a Auto technician) and sad everything was good. He said because it is only driven 4-5 miles a day water builds up in the exhaust which is causing all the smoke. Does this sound right?
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
Water does not smell like gas. Condensation is a normal byproduct of combustion. All cars steam from the tail pipe in cold weather (just look at other cars, yours should be about the same). The colder it is, the more the steam. Also any water left in the system should drain out of the muffler via the weep holes in it (assuming that they are not clogged).
 

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1995 sls
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Discussion Starter #14
Hi I have seem to have spoken to soon about the rpm problem. I haven't driven it for a few days now, but when I went to drive it today it started surging again. And now it sometimes does it when accelerating. I got the codes and there were no current codes. The only code was pcm history po95. Do you guys think it is a bad throttle position sensor of a vacuum leak?
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
Codes are meaningless without their definitions.

Surging is usually a vacuum leak.
 

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1995 sls
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Discussion Starter #17
Po95 is engine stall detected. So today my mechanic took a look at every thing he tested the tps, idle speed control motor, and check for an vacuum leaks and found no problems any where. He is now telling me it is either a leaky fuel pressure regulator of a bad fuel pump. Do you guys think this could be the problem. Thank you
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
FPR and fuel pump are both very easy to test. Why didn't he check them?
 

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1995 sls
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Discussion Starter #19
Oh I didn't know but it is going back tomorrow so he can look at it. Are these hard, costly repairs to do? and do you do think this could be causing the problem?
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
Neither is terribly expensive, but in rereading post #1, neither sounds like the culprit either.
 
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