Not on a Blazer but it could possibly apply.

I've been posting on a Dodge Stratus forum for 4 years now and have come up with nothing as far as suggestions or helpful hints. I'm working on a 2000 Dodge Stratus with a 2.5L 6G73 engine.
Symptoms are: Oil pressure light on at idle once it reaches operating temp and an SES light for Misfire on 3&6

This has a distributor so it is not a coil pack that is common between the two cylinders. They are not across from eachother and not on the same side of the engine.

So list of possibilities are:
Injectors
Main/rod bearings
Oil pump

My thinking is the low oil pressure is causing the lash adjusters(lifters) to collapse and cause the misfire. However I could have bad injectors and they are causing it to go lean and heat up the oil to the point of losing pressure. The oil light goes away once it gets below operating temperature.

I've verified the TPS, I need to do a vacuum test. I think the oil pressure port is metric because I have not found anything that screws into it but I'm not sure because the block is about 3" away from the engine cradle so it's pretty hard to even get something in there.
I have tried different weights of oils as well as different filter brands in case that was causing issue. Oil level is good and never goes down or discolored besides normal oil dirty.

Aaannnd Go.

 

Maybe the oil pump bypass valve is stuck open... Weak or broken spring in it???? What is the oil pressure at 2k rpm? Any engine knocks?

 

I have not figured out how to test oil pressure yet. I'm not sure if I need to stop in to a local Mitsubishi or Dodge dealer to ask what fittings I need or where to test at. I'd likely get the run-around over the phone.
I had thought about the oil pump bypass valve and need to drop the pan to inspect the pickup anyway.

 

You can check oil pressure by removing the oil pressure sending unit and attaching the gauge there.


On the 4.3L, the oil filter adapter needs to be removed to get at the valve, not the oil pan. No clue where the valve is on the Dodge. Rest assured, it does have one though.

 

I just came across a site with a page that tells how to test the oil pressure and it calls for 1/8 pipe thread. Unfortunately it's on a site that is in Russian which makes no sense to me so I can't even trace it back and find out what kind of vehicle it is for.

I'm pretty sure I tried 1/8" but maybe i was just pissed that day or couldn't get my hand in close enough to get the fitting started. I'll give it another try and see what happens. Luckly this page even gave specs as far as what the pressure readings should be. 29kpa or more at idle and 294-686kpa at 3500rpm. That converts to 4.2psi at idle and 42.5 to 99.5 at 3500rpm. A guy at work suggested I just tweak the idle speed up a hair. So with the minimum allowable at 4psi and that I have read that the switch comes on at 4psi it may be as easy as figuring out why I have the misfire and that could take care of the oil pressure issue.

I have to come clean on this one. This seems to have started about the time I did the timing belt and I'm starting to worry that I screwed something up. I had not found conclusive information as far as changing the belt and therefor the only thing that could possibly happen when a guy takes the belt loose happened. The cams did their little dance and where they stopped was anyones guess. I turned them in either direction until I felt contact between the valve and the pistons, then went to the middle and lined up the timing marks. This seemed like the most logical way to do it.
I do remember that when I started it that it ran like complete crap for a few minutes and then smoothed out. So, those could have been the few minutes when damage happened. The firing order is 123456 so I'm not sure how 3&6 are related in any way. I guess only testing will reveal the problem. I might have to do a compression test to make sure it does not have bent or damaged valves/pistons. I verified timing and all the marks line up.
I'm ashamed now that I had to admit my failure.

 

You can always copy and paste the text into a language translator website. Done it a few times and it works pretty well. Had a member in Mexico with questions about his Blazer. His English was better than my Spanish It took a while, but it worked.


Timing dual cams is a trick. Ford 2.0 DOHC uses a special tool, (like most DOHC engines) but the cam sprockets are not keyed to the cams. What a BS set up THAT is.

 

I read through the procedure and it looks like I would have got it right but I'll pull the covers off in the spring and verify. They don't seem to need anything as far as special tools except a torque wrench for setting the initial belt tension before the automatic tensioner is released.