Alt, Rough Idle & Eng Light

[CodeCode]

I replaced my alternator last week after seeing it begin to fail (occasional tach fail, rough idle & batt light).

After replacing the alt with a remanufactured one I noticed that there was a squeal at startup, only when cold. <O></O>
I made sure to use the original pulley bearing (is that what its called?) even though I thought the belt may have seemed a little too tight.

<OI any event I drove the truck for a few days without any real issue – then yesterday I had the rough idle return. When I finally made it home and was pulling into the garage the idle was very rough and then I saw the tack go dead. I put the truck in neutral and gave it a slight amount of gas. The truck idle fluttered roughly, tach came back to life and the check engine light came on.
<O</O
What the heck is going on? Any ideas? Why did the engine light come on?

Thanks fellas!

 

[Busted_D1]

It is possible that the reman alt you bought is bad. I have been through several of those before until I got one that lasted more than a few months. That one good one is now at almost 100,000 miles.

I bought one with the lifetime replacement from Checker so it was just a matter of getting another one the next day.

The voltage regulators are shit in most of the reman ones. Funny thing about it is sometimes when you take it back to the store, they put in on their little machine and it says it's fine. It's not fine. I fought with them for over a week until it failed enough to actually show up as bad on their equipment.

 

[CodeCode]

Could it be that the alt isnt the prob? Why does it squel at startup? Why the engine light?

 

[Jake1996D1]

Squeal might be tensioner and check engine may be un related. I would get your codes read so you know what you're dealing with

 

[CodeCode]

Squeal might be tensioner and check engine may be un related. I would get your codes read so you know what you're dealing with

The check engine light came on right after rough idle and tach fail.. has to be related. I hope. I will try and get the error codes.

 

[Jake1996D1]

The check engine light came on right after rough idle and tach fail.. has to be related. I hope. I will try and get the error codes.

You check your belt routing? I'm sure the rough idle and check engine light are related but unless you have the codes read it's a shot in the dark.

 

[CodeCode]

You check your belt routing? I'm sure the rough idle and check engine light are related but unless you have the codes read it's a shot in the dark.

Not sure what you mean by routing but the belt is uninterfered.

 

[CodeCode]

Anyone?

... Alt died on me lastnight

 

[Busted_D1]

Anyone?

... Alt died on me lastnight

Did your reman alt come with some sort of warranty?

If it did, get a replacment put it in and make sure the battery is is good shape. Charge it up with bench charger if you have access to one. Once both of those items are crossed off the list start it up and then you can look at other issues.

If your belt has cracks in it replace that too. My bet on the squeel is just the belt being a little loose or old, cracked and dried out.

I suspect you will have a properly running truck after those steps are taken. Mine did all kinds of weird things when the alternators were going bad.

 

[ptschram]

Replace the alternator and start over again.

Will Tillery sometimes has new ones at a smokin' price.

 

[singingcamel]

I had in the shop a d11 with alt issues, alt changed twice before it came in.. The problem was the 150 amp fuse in the fuse box (engine bay) was all corroded and shorted .
The alt would slowly die, was'nt able to charge the system due to the fuse..
Are you having any charging issue other than the alt ..Whats it showing for a charge to the battery..

 

[CodeCode]

I had in the shop a d11 with alt issues, alt changed twice before it came in.. The problem was the 150 amp fuse in the fuse box (engine bay) was all corroded and shorted .
The alt would slowly die, was'nt able to charge the system due to the fuse..
Are you having any charging issue other than the alt ..Whats it showing for a charge to the battery..

I will check the battery - i hope to have my autoparts store swap out another remanned alt - My idle is really rough at this point and Im having alt failure (stall or batt light and tach fail)

The engine light comes on after rough idle (i know because i disconnected the batt, hooked back up and got the light after another rough idle)

:banghead:

 

[CodeCode]

I will also look at the fuse - thanks for pointing me in the right direction fellas..

 

[CodeCode]

At the shop right now - swapped the alt (again) - went on a test drive and had rough idle (although it was better)

Onboard diagnostic is reading error code "44" - I am pretty sure my truck is running OBDI

What does that mean?

 

[CodeCode]

Heres what ive got so far...

<dl><dt>Code 44 - Lambda sensor A - left bank</dt><dt>Code 45 - Lambda sensor B - right bank</dt><dd>If one of these fault codes (#44 or #45) is displayed check the wiring to that particular lambda sensor. In addition this fault will be displayed if the vehicle has a condition which causes it to run very lean or very rich on one side (example - a vacuum leak or a bad injector). This code often appears in conjunction with the misfire codes in cases of bad ignition misfire (cross-firing plug wires)
If both codes are displayed, the voltage supply to the heater coils of the sensors must be checked. Check for 12V appearing on the O2 signal lead, and check the heater circuit for shorts.</dd></dl>

 

[CodeCode]

Update:

So ive been driving around with a slight rough idle at times, lastnight as i was pulling into my garage the rough idle went rougher and the motor stalled.

I climbed under the truck and saw a small leak from the oil preasure switch. I have been running a semi synthetic 1040 and am wondering if the oil preasure switch could be cuasing me to run lean.

Is it possible?

(I am planning on flushing my oil and running 5w30 for the coming months tonight)

Im worried about the cost of replacing my cats and o2 sensors and want to try and identify the problem immediatly.

Ive also noticed that the rough idle is mitigated by putting the truck in neutral and feathering the throttle.

suggestions?

 

[DMac25]

doubtful a oil pressure switch has anything to do with a rough idle/lean code. You could have bad o2's, intake leak, poor wiring, etc. Need to do some diag and troubleshooting. The squeel you heard may have been from belt hop on a laboring engine and your lights coming on may have been from the same thing.

 

[CodeCode]

You could have bad o2's, intake leak, poor wiring, etc. Need to do some diag and troubleshooting.

Where do i start? (famous last words)

 

[Jake1996D1]

Where do i start? (famous last words)

Take it to a shop who can diagnose the problem and fix it. You're going to spend the same amount throwing parts at it to hopefully fix it.

 

[stocksuspension]

do you have a 3.9 or 4.0?