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We just got 1991 Cadillac Sedan Deville. Currently there are a couple of problems. First, there is a very annoying whinning noise coming from the engine. The person we got the car from has a basically identical 93 with the same noise and a new power steering pump. That is where it sounds like it is coming from but they still have it after replacing it. Our car has a new serpentine belt. I read on the internet about the idler pulley or A/C compressor but the noise does not get worse with the A/C on.
The other problem is that sometimes it seems to stall. Driving down the road it sometimes stalls and dies other times it gives a couple of chugs and recovers. If it dies it usually will start right back up. Has made an improvement by running premium gas. Fuel Filter or fuel Pump? Please help. I am not really familiar with cars this old.
Answer -
Hi Mary, With you whineing noise 2 sources come to mind. First is the alternator. If there are high electrical demands of it then it can make a whine noise. the fact that the power steering pump was replaced still doesn't eliminate it eithor. If air is getting in the line somewhere...fluid looks tanish and smallbubbles are seen...that will cause a whine. Also if the person started up the engine without first turning the steering wheel side to side 15 times to get air out that could cause a good pump to make noise. Noises with this engine can be sneaky so much so that Cadillac came out with a special serpentine belt kit that has differant lengths to eliminate all the items/pullies one at a time. Short of that you could take a 3 foot length of 3/8" hose or bigger and hold one end to your ear and the other wave it around and try to isolate where the whine is the loudest. The best method would be to use a mechanics stethoscope that can be bought from Sears and place the metal tip on things that don't turn or use the hose open or with a piece of pipe as an extension to extend the reach. With the engine running and turning the steering wheel side to side increases the whine then somehow it is a p/s pump problem.
About the stalling condition Cadillac had a problem with their fuel tank vents being restricted and that would cause the engine to sputter or die. It is located on a bracket by the radiator and LH cooling fan. To test this theory try driving with the gas cap off and if the stall/stumble is gone then test the vent for a restriction. A restricted fuel filter or lower pump pressure could this but poor performance whould happen all the time. There is a test port for a screw on fuel tester on the fuel rail that should be done to eliminate fuel pressure as a cause. I have even driven cars with the gage taped to the windshield so I could see whats going on. A throttle position sensor with an open spot could on it. A bad ECM/computor with a bad soldier joint inside and hitting a bump maybe. Also a battery cable that isn't makeing good contact with the engine near the starter could do this. Even though it looks clean Caddy went to an unpainted starter bracket and we had to wire brush the cable end and engine and install a new bolt or clean the old one because they can't carry a higher electrical current. Most computors use a 5 volt signal and if the ground was dirty it could be more like 4 volts to the computor and that will cause it to run differantly. The last thing is did you replace the battery or unhook a cable and then this started to happen? Then there is a relearn procedure that needs to be done for the ECM to know idle speed and throttle position.
Those are some of the things to check and taking the car to a sharp tech should locate the cause if you don't as they have differant testers and know where to look and how to test. Let me know if I can be of anymore help. Bill
I first want to say that you did a great job at explaining everything in great detail. There could be a possibility that it may need to go through the relearning procedure. The car not been ran for quite some time because of a broken serpentine belt. We replaced it but the battery was dead. This was the way it was when we bought it. I don't know if it was disconnected but I know that the battery was completely drained. Will this cause the need for the relearning procedure? If so, how do you do it?
AnswerHi Mary, Thanks...Its always nice to hear when my explanations or directions help out. You are correct in that the relearn procedure needs to be done and is the first step whenever a battery was changed, went dead or the ECM computor was replaced to making the engine run normal again. Otherwise the idle could be very slow or have a 30mph idle.
To do the relearn here's what to do. 1) disconnect the battery cable for 1 minuit and then hook it back up. 2) Turn the key on so your dash lights up but don't start the engine and turn the climate control panel to off. 3) Push the off and warmer buttons on the climate control panel at the same time and hold for up to 5 seconds for the computor to go into diagnostics. On the fuel panel it will display 888 then E52 and then 70. When it gets to 70 shut off the key for 1 minuit. 4) repeat step 3 2 more times. 5)Start the engine without pushing on the accelerator pedal and let it run for 18 minuits with the climate control panel off. 6) After 18 minuits put your foot on the brake and shift into drive and wait 1 minuit. 7) Then turn on the a/c by pushing the auto button. It needs to be warmer than 60 degrees F so the compressor can engage. Wait 1 more minuit. 8) Put the shifter back in park and turn the key off. 9) wait 1 minuit 10) idle relearn is now complete and the engine should start and run correctly.
If you need more help then let me know. Hope this helps. Bill
