oil pump question

[bluebuick91]

i have a 97 blazer with 4.3 now it sounds like a sewing machine up top and the oil gauge is going up and down. motor is full on oil dip stick so has oil in it. was getting hot just changed the radiator cap and thermastat solved that.but now the noise like lifters are not getting enough oil to them. has any one had this problem can changing oil pump cure this or do i need a motor. thanks for all replys
jenn

[Southern Comfort]

It is possible your screen on your oil pump is stopped up. That can make the lifters rattle. The fact that your oil gage is going up and down, it could be a bad oil sending unit, but I would rather replace the oil pump first and see if that makes any difference. You may want to run and oil flush threw the engine block.
SC

[wirenut699]

Also check that there is no antifreeze in the oil and/or that your are not loosing antifreeze slowly. These blazers have a common problem of blowing the intake maifold gasket. The antifreeze can get into the oil and the top of the engine doesn't get lubricated properly.

I had this happen to my 1996 blazer - it ruined the engine after about 5 months like that. The symptoms were:
1-slow loss of antifreeze
2-tappits sound from lifters
3-slight loss in average oil pressure.

If I knew about AF back then, I could have prevented my little tragedy.

[bluebuick91]

it had a heating problem changed the thermastat and rad cap fixed that problem, don't see water bubbles in oil just thin from miles, was going to replace the oil pump see if that fixes it, this just started doing it a few times but now it makes lifter noise and oil gauge goes up and down on it's own but if you give it gas the pressure goes up.but still has noise i parked it untill i can pull pan off. can any one tell me how and what needs to be taken off to get to the oil pump i had a book but can't find it now,may have to go to library to get info
thanks
jenn

[Chris Stewart]

My '97 developed a cold tapping a coupla winters ago. I changed the oil & filter and the tapping went away(???). Same thing last winter with the same cure. Guess what I'm gonna do if it starts tapping this winter?

[bluebuick91]

what weight of oil are you using and what oil filter .were i am it snows alot during winter, and the oil is thin like water so i will try this trick first thanks
jenn

[Chris Stewart]

Here in Tennessee I use Kendall GT 10W-30 & the AC Delco PF-52...north of Kentucky I'd use 5W-30. The problem is the oil gets too thick to enter the oil feed hole to some of these lifters...funny it seems to be only one lifter/motor.

[534BC]

The noise AND low gage together indicate to me that the gage is correct and if the oil level is ok and the oil isn't terribly thin then there's something really hurt or opened up from the overheating.

The overheating may now be fixed, but another condition is present probably After the pump (on the discharge side)

I'd start diagnosis by making an rpm x pressure chart and then introduce a temperature chart and then introduce a vehicle orientation chart . It sounds bad, but is very simple and mayu tell a whole lot about where to look for the problem before taking anything apart.

[bluebuick91]

Hey Chris Stewart...your idea worked in my case too...I changed the oil and filter, I even added some Lucas oil treatment/stabilizer...Started it up, and It took a few minutes, the oil pressure is at a steady 60, and the gauge is working just fine. the loud tapping noise went completely away after 5 min running! The belt is a little sqieaky, but I can live with that! Thanks for the help! This forum has saved me money and time, thanks for all the help!

PS-The oil was water thin, but didn't have any water in it. The overheating problem was fixed a few weeks ago and the water level too has not gone down since