Northstar Engines and System Technical Discussion Discussion, Starting to get rough idle in Cadillac Engine Discussion; The Eldorado had been running great. Happen to run the gas tank real low. Had not got gas yet and ...
The Eldorado had been running great. Happen to run the gas tank real low. Had not got gas yet and the wife decided to take my car to work without mentioning it to me. Ofcourse, she did not check the gas guage. I got ahold of her at work and told her to get gas (high octane) before she goes anywhere else. She got gas from a sorry gas station downtown where she works. One I would never trust.
Now, the car has a small, periodic fluctuation in the idle. When the car starts to accelerate, it is rather rough. There are no codes coming from the computer. I checked the throttle body and cleaned a little bit of soft carbon from around the throttle plate opening. It may have helped the idle just a little bit. I had cleaned the throttle body, egr valve (a pintle code had came up, has been gone since I cleaned it), and cleaned/ re-oiled the air filter back in May. When I am under the hood, I can hear the slight variations in the rpm. When I hear this, I also hear a click noise from around the plunger near the throttle cables. Maybe this is normal?
I have read plenty of other posts, but still have questions. At the moment, I am thinking bad gas. If my wife didn't put in high octane, what would the results be? Or what if it was bad gas in general? Should I run out this tank of gas and then see how it runs on a fresh refill of my normal gas? Or maybe, by running the tank so low, I sucked some sediment into my filter and it may be getting congested? I am hoping it isn't the egr valve, kinda expensive. I would think I would get a code for it anyways.
Any suggestions? Thanks, guys, for the help ahead of time.
Automobile(s): White Diamond '03 DHS (with DTS floor shift)
Re: Starting to get rough idle
There is a "sock" on the pick up in the tank that will trap most stuff before it gets to the filter but that doesn't sound like your problem. A pluged filter or sock would cause problems at high RPM ( high demand). I'd just run the tank down and fill it somewhere else and see what happens.
Thanks for the advice. That is exactly what I plan on doing.
To make matters worse, I started getting alot of noise from the bottom side of the engine while in park and neutral. I did a couple WOTs and the noise is gone. I think the noise was from a plugged lifter. I get that problem every once in a while. I have about 110,000 mi on the Eldy now. I had let the car sit up for two weeks, back in March, while I went on vacation. After that is when the plugged lifter noise first started hapening. I have done one oil change since then and used some oil flush. Right now is just an inoppurtune time for unusual noises. Plus, I can't do to much to my car because I have one arm in a soft cast. I just had surgery on Thursday for a torn bicep at the elbow.
Well, I went to pick up my daughter from her first day at school. Noticed that the engine is only making noise while in Park. Got home and decided to investigate while it idled in Park. Get this...the radiator started a steady stream coming out about a couple inches under the top hose. If I had two arms, I wouldn't mind so much. After all, it doesn't look hard to get to. My last drain/refill of radiator was in Jan2003 which was about 12000 mi ago. The Eldy apparently was going to need a rad soon. I take it, all the rough running made it come a bit earlier.
Hey, Twilight, I really appreciate that, man. I do plan on having this fixed by the end of this weekend though. My father-in-law came over last night. He hooked me up with a good throttle body cleaning. I usually take off the intake hose and spray cleaner into the plate area. He did the cleaning with the liquid, where you meter it through the hose inlet that is pulling vacuum into the throttle body. It is located just above the TB. I also dumped a bottle of STP octane booster in the tank to sweeten it up a bit.
I need to find some audio of knock and ping to verify if that is what I am hearing. By the way, I live in Jacksonville, about 10 minutes from I95.