When passing a vehicle the other day my oil pressure dropped quite low now its about 60 at start up but once its warmed up its dangerously low.
The other day while passing another vehicle my oil pressure dropped very low so low that it cut the fuel pump off. I was able to get it back started and get the mile and a half home taking it easy now when I start it the pressure is fine to high but once it warms up its at about 18-22 when driving and and about 2-7 when at a stop once its really warmed up recently I changed the head gasket so I looked all around it and the valve cover gasket and no leaks oil level is where it should be but went ahead and changed the oil and filter just cuz thought that would be a cheap fix and it was time to do it about anyway.
The person b4 me that had it really slacked on the oil changes which was evident when I took the head off and had to clean out all the gunk around the rockers push rods etc. I have heard the oil pumps in these s-10 are " bullet proof and almost never die out so am I looking at a possible clogged screen or something more serious like a rear main bearing or something.
Also the last time I was on here it turned out to be the timing chain and tensioner and the fuel pump to totally unrelated things went out at the same exact time? What are the odds so those have both been changed to in the last month along with 4 out of 8 push rods when I did the head gasket cuz they were showing sighs of wear are the tops where they meet the rocker arms all the advice I can get would be greatly appreciated. Ohh and somebody said something 2 me about a oil pressure switch does that control the pump in any way on my 2000 chevy s-10 2.2 auto rear wheel drive?
The pressure switch keeps the pump running. Manually check your ioil pressure when warmed up. That way if it's good then it will be an easy fix. Whee did the junk go that you cleaned up? In the oil pan? Then it might have clogged your pump screen. Which if this is a 4wd it's easier to pull the motor than to take pan off in truck.
May, 4, 2012 AT 4:56 AM
Ok had to pull motor cuz rain it 8 inches means might as well just pull it its 2wd but still u cant lower pan without raising it at least 8 inchs more like 10 but that wouldn matter anyways cuz whoever had it b4 me was an idiot and instead of using a gasket he literally epoxied the pan to the engine so I had to pull it torque converter and all since I couldn't get the pan off at all until it was pulled.
. Pump screen clean a few pieces of plastic from the timing chain tensioner that got ate up about a month ago on that fix but that was it and lil gunk og old oil but ive seen alot worse. Pump gears seem tight and show no wear impeller that meets with cam shaft shows no wear either but the damn felpro head gasket that I had put on obviously is a piece of shit because even tho my mating surfaces were spotless and not warped or anything it showed signs of oil leakage ( very slight hardly any but still could see the signs of it)in 3 out of four cylinders and a lil in the coolant( and I torque them to specs and in the proper chiltons order 43 for short bolts 46 for long then plus 90 degrees for all of them) so wtf guess perma seal shit aint all that great and maybe next time il have to over torque a tad or was it just a faulty gasket. Idk. My question now is could that slight leakage cause that loss of oil pressure?
Because the head gasket that was in there b4 was in pretty bad shape nut no pressure drop I only changed it cuz I noticed a tiny tiny bit of oil in the coolant and I love working on cars and trucks and like my equipment to be perfect. Are there any specs for the oil pump so I could check it out other than the 56 psi at 3000 rpm thing cuz since its pulled I cant exactly check things out. Oh the sender was fine its #'s matched the mechanical gauge within about 2-5 psi. But I have to get a new one now anyway since I cracked the damn thing while pulling the motor I accidentally grabbed it while jiggling the motor forward to get the damn thing out with the freaking torque converter still attached.
. I mean epoxy are you kidding me? Good news I found where a oil leak was coming from. Not the rear main seal but the lil 3 bolt on plate at the back of the came shaft the three bolts were barley even finger tight so that explains the oil all over the starter etc. Oh the bearings didn't look worn really either maybe a little but since its pulled im going change them. Anything else I should do while its pulled any advice would be greatly appreciated this is my first engine pull for myself iv helped people before but never all by myself so hank you in advance for any advice or insight : )
May, 4, 2012 AT 4:58 AM
Wait so if that presure switch was clogged it would not let the pump run all the time? But how would you explain high presure at start up. Wouldnt that mean its running at start up but then somehow stopping once it gets warm? That doesnt quite make sense to me?
May, 4, 2012 AT 5:05 AM
No the head was off when o cleaned the gunk out. Im not an ase mechanic but im not an idiot either I wouldn't just let it fall down in there. But there was left over bits of the timing chain tension that got ate up from when the timing chain broke but no pieces made it past the screen that I can tell and even if they did they are plastic its a 2 metal gears type pump so it would chew out of any thing that's not steel or not to big. Is there anything on the pump that fails that I should be checking or is it probably the gasket that was causing that pressure loss. That seems like a lot of pressure loss for just a slight leak in a gasket to me?
May, 4, 2012 AT 5:31 AM
My oil pump is mechanical driven by the cam shaft so its pumping all the time the only faster or slower it gets is with rpms presure switch is actually just a presure sensor I dont think it caauses any thing to "switch" pleas correct me if im wrong?
May, 4, 2012 AT 2:13 PM
One of the tings that can happen is the pressure relief valve sticks and gives you low pressure as well. You can check that for junk in it, but take a look at all the main and rod bearings while you have it out. If you can send a pic of them while in engine, meaning don't take them out of the caps I can give you a better idea of things. Obviously the guy that had this before you was well aware of what was wrong with it and that is why he sold it.
May, 5, 2012 AT 1:21 AM
Ok that pressure relief valve spring loaded thing was stuck took sum working around a bit but got it back moving freely i'm curious if my bearings are in need of replacing for the 60 bucks I should probably just do them but im a lil broke right now. Good news is they honored the head gasket warranty and gave me a free new one. The bearing dont look that bad to me the only wear they show is a slight bit on the bottom obviously from cold starts but its minimal when u look at what would be the sides of the bearings there is absolutely no wear at all but il take some close up pics of them and post and get your opinion but I think that or something else was done recently cuz the rear main seal is so new I was able to get it out and its still perfect where I can reuse it which is something I would normally never even consider doing(reusing a gasket). Oh when I bought it I new it needed a head gasket and the timing chain was making noise thats why I paid 1900.00 and book is 3800.00 cuz to me my labor is cheap and parts for these thing are abundant and cheap so figured wtf I just fix anything wrong with it but the guy def slacked on the reg maintenance which sucks cuz reg maintenance prevents all this ya know. Pics to come soon ty again : )
May, 6, 2012 AT 7:32 PM
Ok pretty sure I found the problem the 3rd main bearing from the front is f'd wore down 2 almost nothing no oil channel left at all but whats weird is every other damn bearing in the engine is almost like new and they only sell the mains in a set so even tho I only need 1 I have to buy the whole set about $65 checking now to see "why" it failed going to make sure the oil passage way to that bearing isnt logged or something but from what it looks like the "hole" in the bearing got sealed by the melted (silver maybe)idk what it is the outer part looks like copper though so pretty sure this was the problem. Another question what can I use to very gentle polish the crankshaft this on has some very slight scoring but measures within factory specs so high #ed sand paper or what?
May, 6, 2012 AT 7:36 PM
If the crank is still good which I kind of doubt but y use some 600 grit paper to polish it. Tape a pieceall the way around the journal then take a long piece of leather, wrap it around it a couple times then move back and forth that will polish it right up. Normally when this happens though you need a crank kit which is a reground cranks with bearings.
May, 7, 2012 AT 2:00 AM
Well it doesnt seem that bad from what I read online if your finger nail doesnt "catch" or drag it can be slightly polished and mine doesnt catch but I have to get a measuring device regardless to make sure its within factory specs or its time to have it ground and and oversize bearings but really hoping its all good with my buddys c clamp looking measuring device it wa within specs but with that its hard to tell if your centered I measuredin a few spots though and seems good but I would like to find a more acurate way to measure maybe somekind of digital laser deal or something whats the most acurate way to measure the journals?