Squeaky belt/cam synchronizer(?), erratic oil gauge needle

[1992redranger]

Hello forum goers,

Been trying to research this one on my own but since a failing cam synchronizer could be the problem I don’t want to mess things up more by doing a bunch of tests on things I really don’t know all that much about. I am a novice.

So here’s the issue: a couple days ago I had a pretty prominent squeak (wouldn’t call it a chirp but a squeak) sound start coming from the engine. After the engine warmed up the sound went away completely.

And then, just a few minutes ago, right as the engine was warming all the way up, the oil pressure gauge needle went haywire: bouncing up and down the length of the red line, making a tapping noise every time it came down on the peg where it’s supposed to rest (so it was bouncing around hard/fast).

I understand that the issue could be with the oil pressure switch and that I could try to replace that. I also understand that the squeak could be coming from the serpentine belt/belt tensioner/pulleys and that I could possibly(?) remove the serpentine belt and let the engine run a couple seconds to see if the sound goes away. If the belt is removed and I still hear the squeak, it may be more obvious that the cam synchronizer is going out. However, I don’t want to start the engine to test this if the cam synchronizer is too far gone because I guess that could mean lights out for the oil pump/engine?

Anyways, just wanted to see what y’all think the best plan of action is (and if you think the squeak and erratic gauge are related).

Also, not sure if it’s related but I just replaced the IAC valve with a brand new motorcraft one this morning. The bouncing gauge issue only showed up after replacing the IAC valve.

2002 Mazda B3000 at 127K miles.

Thanks in advance!

 

[Eddo Rogue]

Pretty sure the cam syncro drives the oil pump, so the issues might be related. I did the syncro on my 4.0, it was a bit of following instructions, but not too difficult. I think its easier on the 3.0.

I did the lower intake gasket while at it. All worked out well.

 

[1992redranger]

Following up on this.

I changed the cam synchronizer but the squeak was still there. Sprayed a little bit of water on the serpentine belt as it was running and it went away. Chalk up the new cam synchronizer to preventative maintenance, I guess.

What’s interesting is the oil pressure gauge needle. I’m guessing since the old IAC valve was keeping idle RPM a little higher than it was supposed to, when the engine warmed up all the way with the new IAC valve (which forced the adequate drop in RPM at idle), the engine lost oil pressure (slightly) and caused the needle to go haywire. Anywho, per RonD’s advice, I switched from 5w-20 (which is what the owner’s manual suggests) to 10w-30 and the needle is back to normal. No more jiggling. All but stopped a leak I had, too.

I did replace the cam synchronizer with an off brand one even though I read about a lot of people recommending against that. Seems alright so far but I’ll keep y’all updated…