Oldsmobile Alero, 2004, 3.4L V6.
I noticed a few days ago that PO128 had popped up and looks like its been tripped a while. I have another code PO401 that I have been tackling for months to no avail, so check engine lights been on non-stop and I missed this new code popping up. I think its been up for a few weeks. Here is a link to the code:
I cleared it and it hasn’t come back yet in two days, but I’m keeping a look out.
The code appears to mean that the car thinks my coolant temperature is not getting hot enough after a certain period of time. Says it usually points to a thermostat issue.
Thing is, the car seems to be working fine. Now that I’ve been paying attention I feel like the temperature gauge is resting a little lower than it used to. Usually within 10 minutes or so I hover around the middle. Now it takes a little longer and I hover around 3/8. I think my heat was SLIGHTLY weaker, but I also may just be tricking myself.
So seems like the cooling system is working too well? Downside would be heat is worse potentially? Any other actual issues of the coolant staying a little colder?
Regardless, I want to fix it. Thing is I feel like thermostats are all or nothing. This doesn’t seem to be stuck open or closed in my mind, or I would overheat or be always cold right? So maybe its one of the other parts the article suggests: ECT or IAT sensor?
Another question. I have a hard time finding youtube videos for my car. I’ve found other videos with similar under the hood 3.4L I think Monte Carlo rings a bell. Anyone know a nice list of similar cars I can search for when trying to find repair videos for my olds alero 2004 3.4l?