: 93 Eldorado 4.6 Northstar "chuggle"



T93Eldo
08-24-05, 02:28 PM
I have a 1993 Eldorado 4.6L Y engine, with the famous oil consuming Northstar engine. I have found a TSB # T93101 which is acknowledging Cadillac's problem with the 4.6 Northstar "chuggle". It has an intermintent skip when accelerating from 45-60 mph. that bulletin was issued in 1993, and my Cadillac service guy has replaced, the fuel position sensor, cleaned the fuel injectors, plugs, plug wires, ECM,etc etc. and still the chuggle. Has anyone had this problem and if so, have you solved it???

diamond159
08-27-05, 05:14 PM
done all those things and still have a problem at take off runs fine when I don;t have aur conditioner on.

Ket me know if you solve the problemI have

brmurph
08-28-05, 11:13 PM
I just started having this problem myself . Started just after the dealer replaced the AC compressor, no problems with the AC off. Sure would like to get this fixed as well so good luck.

peteski
08-29-05, 12:17 AM
brmurph:
was your AC dead before replacing the AC compressor?

I'm asking becasue when AC is on and working, the compressor cycles on and off. WHen your are driving, you can feel the load change when the compressor kicks in. It puts enough of a load on your engine to feel it. You'll be able to feel it at any speed but it will be most pronounced while driving at a light throttle application (like steady 40MPH).

That is quite normal. Also the dead giveaway is the fact that if you turn the AC off, the problem goes away.

:D

Peteski

brmurph
08-29-05, 10:21 PM
brmurph:
was your AC dead before replacing the AC compressor?

I'm asking becasue when AC is on and working, the compressor cycles on and off. WHen your are driving, you can feel the load change when the compressor kicks in. It puts enough of a load on your engine to feel it. You'll be able to feel it at any speed but it will be most pronounced while driving at a light throttle application (like steady 40MPH).

That is quite normal. Also the dead giveaway is the fact that if you turn the AC off, the problem goes away.

:D

Peteski

The car has about 92000 miles on it, I have had it since 35,000 miles. The original compressor worked just fine for the first 90,000 + miles, never noticed before when the compressor kicked in, only noticed it after the compressor was replaced. A lot of folks seem to agree with you though. Also this seems more like what I would think transmission chugle would feel like not just extra load, very annoying.

peteski
08-29-05, 11:37 PM
I suppose that I'm used to it. If it only does it with the AC compressor on, then it is not the transmission. If it isn't broken, the dealer can't fix it... :)

Maybe the new compressor is working better (better compression) and it puts more of a load on the engine when it is engaged.

delzy
08-29-05, 11:42 PM
I sometimes notice a little pop in the exhaust when I first turn on the AC. As a matter of fact, I had just turned on the AC when I burned out my PCM in July. Perhaps it is a coincidence, but I wonder if there is a voltage spike when the AC clutch engages or disengages that messes with the computer or injector voltage.

Some enterprising N* owner should try to capture some test voltages at the computer, injectors, etc. with an oscilloscope while the AC clutch engages and disengages. I bet there are some massive spikes when some solenoids and actuators release. Comments?

T93Eldo
08-30-05, 01:49 PM
My Northstar chuggle is a constant problem, whether the AC is on or not. We just drove up to upstate NY and it was great on the road over 65mph, but in the city driving was the hesitation at 45mph. Very annoying. If anyone has any ideas, the cadillac dealer has done the whole run of what they think and it is still there....:hmm:

T93Eldo
09-12-05, 10:02 AM
We love our 93 Eldorado. Great trip car. Still has what Cadillac calls the "chuggle" a slight hesitation at 45-60mph. Been thru wires, plugs, fuel sensor, even threw a code for the Quad II being bad, so we replaced the PCM. Still the ever present "chuggle". Now, for me, I don't mind, I have decided that I will either drive it under 45mph or over 60mph and just explain to the "officer" that I couldn't drive between 45-60mph because of the "chuggle" that Cadillac can't seem to get rid of... but my husband seems to think he can find the answer. He keeps referring to her as the Eldo money pit, the N* oil pit, etc. But I am fond of the pretty black twodoor car, and am happy to drive her. And until someone can come up with the answer to the "chuggle" she will be my husband's money pit and my excuse to speed happily down the road.:D

Ranger
09-12-05, 10:40 AM
Have you tried cleaning the EGR valve and the "mouse holes" inside the intake manifold?

T93Eldo
09-12-05, 01:49 PM
Ranger,
Thank you for your reply, but it has not thrown an EGR code but we have tried cleaning it. still chuggling along...
When i called Cadillac and mentioned to them that there was a bullentin out about the stumble or chuggle they could not tell me they fixed it, just to do everything we have already... so, we keep trying.

zonie77
09-13-05, 12:19 AM
The 40-45 mph hesitation could be the torque convertor locking and unlocking. Someone had a similar thread a few weeks ago and felt that was probably their problem. In 4th gear with tc locked you have very little power and no slip in the tc. Just like having a stick in too high a gear.