First post! Mods move if needed... My name is Kevin, and I want to say thanks in advance for any and all replies! I have searched the first 10 pages of results for info and also googled the crap out of this and there's very little info about low oil pressure issues. Which leads me to believe its at least somewhat uncommon.

So the story goes... I bought a 2006 HHR LT 2.4L with a bad engine about a year ago and then a month later bought the replacement engine from reputable junkyard. Just got around to installing the new engine last week and the low oil pressure light is coming on, which didn't even come on with old engine that knocked something fierce and had a TON of glitter in the oil. It originally had the 2.4 with oil cooler which leaked and made it run low which is what trashed original engine. So I bought one without oil cooler to replace it, which from what I read on here is simply a matter of swapping lower radiator hose. New engine fired right up on second crank, it runs for 15 seconds or so then low oil pressure light comes on. Absolutely no noises and filter showed no signs of metal. Of course junkyard won't do anything a year or so later...


What I've done to try and troubleshoot:

I cranked it for a second with filter out just to see if oil was flowing and it was. I then started it for maybe 2 seconds and it poured about a quart of oil out on the ground, which says to me that pump is moving a lot of volume at least. I attempted to replace oil pressure switch with one from previous motor(it looks aftermarket to me) and I snapped the threads off in block. Luckily it came right out by hand with an extractor lol. I then installed another oil pressure switch from a 2006 2.2L engine which matched part numbers and issue still persist. Tested both sensors for continuity and blew in tip with air wand and both switched on and off just fine. No idea what kinda pressure was actually applied though. Also ran it for almost a minute with sensor unplugged and light never came on.

What puzzles me is that even if you rev it up the light doesn't go off, and on a cold morning(40*) it doesn't take any longer for light to come on. Which I would think it would because oil pressure would be much higher with the cold thick dino sludge oil I put in. I'm gonna try to buy a tap or some fitting I can weld onto the broken thread piece of the other switch and check pressure with a mechanical guage next. I'm just really puzzled why it seems to take 15 seconds each time and it comes on no matter what and doesn't go off ever. Most cars I've seen with low oil pressure issues, the light will flash a bit then come on steady at idle once fully warmed up. Or light will go off with a quick rev when you build pressure. Any help or advice would be greatly appreciated, I don't have a lot of experience with these engines as I mostly do LSx stuff.

 

Make sure you put it in the right spot. Apparently if you put it in the head you will get low pressure. Found this
Ecotec oil pressure - Maintenance and Repair Forum - j-body.org - The J-Body Organization

And this
oil pressure on ecotec

Many other sites also, all say the same thing, make sure it's in the block in the right spot.

Oh yeah, to the forums!!

 

Thank you for the welcome! I think I've read through those on my google quest already lol. It's just a factory oil pressure switch in a factory location. If I do the mechanical gauge route tomorrow it will be in place of factory sensor too.

 

Welcome!

Is the ECM from the same year/model? I'm not sure if the tables are the same.

I would expect low pressure on start up to cause a code, you don't mention a CEL?

New oil pumps are fairly cheap. Oil Pump Repair Kit Fits 00-15 GMC Saturn Aura 2.0L 2.2L 2.4L DOHC 16v ECOTEC | eBay

 

Welcome to the site, what oil are you running?

 

The motor is from a later 06 model that didn't have oil cooler, using the original PCM/ECM. I have HPTuners and it was reading no DTC's at all...



I always start with just cheapo walmart oil when I install a new engine, its 5w-30 as recomended with about a 1/2qt of 10w-30 in there just get it used up.

 

An update, I decided to just let it run for a bit. I had only previously ran it a max of 30 seconds at a time cause I was scared to do any damage. After running a bit the light did go on and off a few times. But after about 10 minutes of running it won't come back on yet. It's idling in the driveway as I type this... I'm hoping that it was just gummed up from sitting unused however long the junkyard had it on top of me letting it sit nearly a year. I'm going to drain a QT of oil out and add in a QT of some ATF and maybe a can of seafoam to help clean it out some more and will report back in the morning.

 

We'll wait.

 

Well I put the hood and the rest of the little things back on yesterday evening, drove it a few miles around and it never came back on. I even drag raced my daughter in her gokart when I got back home lol. I did put about a half a QT of ATF in there to help clean it out. Actually drove the kids to school this morning with it and went and filled the gas tank. Seems to run really well, and maybe its just in my head but that 2.4 seems a little peppier than the 2.2 in my wife's 09 HHR. Was a really aggravating issue with no real clear solution in the end. Like I mentioned previously, something must have been gummed up from sitting a while and it worked it self out when I let it get up to temp finally. I'll never truly know I guess... Now to find me some inner fenders, a blower motor&controller, and get my remote start key fobs programmed. Thank you so much for the input and kind welcomes!

 

Fixed, enjoy the ride!!!