HELP!!! OIL PRESSURE!! FIXED
Thread Starter
|
Champion
Joined: Jan 2008
Posts: 2,899
Likes: 0
im not gonna go into a full tune up, because you can search it, or make a new thread.
as for buying an early 4.7, such as the 02, dropping the pan isnt exactly fun, but from my personal experience as a lot of the guys have seen that helped me so much through the whole process, its not something you want to have at all. but doing research outside of DF, there has been numerous cases, i mean A LOT. even a guy i was talking to in the parts department at dodge had a the same problem i did in his 4.7. this being said its clearly a problem that a lot of 4.7's have, therefore one of the first things i would do if buying a new one is, besides for plugs and fluids and any other obvious tune up perspective is to drop that oil pan and clean it up. messy job due to the sludge. laying down on the carpet underneath the truck, there was so much sludge that came out that it started dropping and it managed to find its way in my hair, only way i could get it out was degreaser hahaha. drop the pan and unfortunatly i bet you theres a good amount of sludge with that many miles on the sludge built 4.7. i knew the guy who previously owned my truck. he didnt use synthetic but was pretty on top of his routine maintenance. look a few pages back and youll see my pics. the dust structual cover comes right off with 8 bolts. youll also have to remove the crossmember of the frame, 4 bolts. then you have bolts all the way around the pan. your going to completly demolish your gasket with a flat head. took my dad and I to get it seperated from the pan and then we had to get it off the motor. theres 3 bolts to pull the gasket off along with the pickup tube. dont yank on the gasket like i did. i first thought it would pull off, but its connected to the pick up tube with bolts. the tube was some what clean, but the screen was completly gunked. like i said only thing that took it out was my pressure cleaner. bottom of the pan had about a solid 1/2" layer of sludge through the whole thing. even more in some spots, especially by the drain hole. also on the bottom of the pistons youll see more "chunky" sludge built up on the bottom of the pistons. i took a flat head and tried to get as much off as i could. if you actually go ahead and do this i have all the specs on the bolts and the correct bolt up pattern and everything
as for buying an early 4.7, such as the 02, dropping the pan isnt exactly fun, but from my personal experience as a lot of the guys have seen that helped me so much through the whole process, its not something you want to have at all. but doing research outside of DF, there has been numerous cases, i mean A LOT. even a guy i was talking to in the parts department at dodge had a the same problem i did in his 4.7. this being said its clearly a problem that a lot of 4.7's have, therefore one of the first things i would do if buying a new one is, besides for plugs and fluids and any other obvious tune up perspective is to drop that oil pan and clean it up. messy job due to the sludge. laying down on the carpet underneath the truck, there was so much sludge that came out that it started dropping and it managed to find its way in my hair, only way i could get it out was degreaser hahaha. drop the pan and unfortunatly i bet you theres a good amount of sludge with that many miles on the sludge built 4.7. i knew the guy who previously owned my truck. he didnt use synthetic but was pretty on top of his routine maintenance. look a few pages back and youll see my pics. the dust structual cover comes right off with 8 bolts. youll also have to remove the crossmember of the frame, 4 bolts. then you have bolts all the way around the pan. your going to completly demolish your gasket with a flat head. took my dad and I to get it seperated from the pan and then we had to get it off the motor. theres 3 bolts to pull the gasket off along with the pickup tube. dont yank on the gasket like i did. i first thought it would pull off, but its connected to the pick up tube with bolts. the tube was some what clean, but the screen was completly gunked. like i said only thing that took it out was my pressure cleaner. bottom of the pan had about a solid 1/2" layer of sludge through the whole thing. even more in some spots, especially by the drain hole. also on the bottom of the pistons youll see more "chunky" sludge built up on the bottom of the pistons. i took a flat head and tried to get as much off as i could. if you actually go ahead and do this i have all the specs on the bolts and the correct bolt up pattern and everything
I think you missed my point
Ummm, I hate to argue, but in this case, you're way off on both the speed in relation to the crankshaft, and how delicate they are.
1. Camshafts spin at a 1:2 ratio to the crankshaft. They are only spinning half as fast as the crank at any given time. Remember, automotive engines are all 4 stroke. Intake on the downstroke of the piston, Compression on the upstroke, Power on the following downstroke, and Exhaust on the last upstroke. That means that either the intake valve or the exhaust valve is only open every other revolution of the crank, hence, the 1:2 ratio on the cams.
2. Bearing speed is described as the speed the two surfaces (in this case, the bearing and the cam journal) are moving against each other. The larger the diameter of the supported journal, the faster the comparative speed of the surfaces to one another. The cam journals are some of the smallest in any engine, and far smaller than either the crank journals, or the rod journals.
3. As far as the fragility or delicacy of the bearings, they're actually quite hardy. The babbitt they are coated with is very soft, but due to the relatively minor loads on them, can last the life of the engine and then some. I've seen many rebuilds of various brands and models of engines, and very few of them ever really needed the cam bearings replaced, even after a few hundred thousand miles. They have no axial load, and they don't take the kind of pounding that rod or crank bearings do.
4. If the tensioner has gone slack, he would have definitely heard it by now. In addition, I believe the tensioners have a one-way system designed into them, not unlike a ratchet. they only go one way. That keeps the chains from going slack when you shut the engine down and oil pressure bleeds off. If they didn't have this feature, as mileage and wear on the chains increased, the chains would slap and possibly go slack enough to jump teeth on the sprockets.
Honestly, mmstar, I would recommend that you NOT remove the valve covers unless you hear some kind of slapping from the chains, or you have a leak in them. If not, you're just wasting money, and asking to make them leak when you're done.
1. Camshafts spin at a 1:2 ratio to the crankshaft. They are only spinning half as fast as the crank at any given time. Remember, automotive engines are all 4 stroke. Intake on the downstroke of the piston, Compression on the upstroke, Power on the following downstroke, and Exhaust on the last upstroke. That means that either the intake valve or the exhaust valve is only open every other revolution of the crank, hence, the 1:2 ratio on the cams.
2. Bearing speed is described as the speed the two surfaces (in this case, the bearing and the cam journal) are moving against each other. The larger the diameter of the supported journal, the faster the comparative speed of the surfaces to one another. The cam journals are some of the smallest in any engine, and far smaller than either the crank journals, or the rod journals.
3. As far as the fragility or delicacy of the bearings, they're actually quite hardy. The babbitt they are coated with is very soft, but due to the relatively minor loads on them, can last the life of the engine and then some. I've seen many rebuilds of various brands and models of engines, and very few of them ever really needed the cam bearings replaced, even after a few hundred thousand miles. They have no axial load, and they don't take the kind of pounding that rod or crank bearings do.
4. If the tensioner has gone slack, he would have definitely heard it by now. In addition, I believe the tensioners have a one-way system designed into them, not unlike a ratchet. they only go one way. That keeps the chains from going slack when you shut the engine down and oil pressure bleeds off. If they didn't have this feature, as mileage and wear on the chains increased, the chains would slap and possibly go slack enough to jump teeth on the sprockets.
Honestly, mmstar, I would recommend that you NOT remove the valve covers unless you hear some kind of slapping from the chains, or you have a leak in them. If not, you're just wasting money, and asking to make them leak when you're done.
Seems to me that the cost of the valve cover gaskets and a little inspection, particularly for top end sludge and engine reliability would certainly be worth the minor money as compared to what could happen.
Maybe I'm being a little critical here----but, if it were me, knowing that the engine ran for near two weeks with "0" psi on the guage, I think I'd be inclined to check.
Good Luck
Registered User
Joined: Aug 2008
Posts: 8
Likes: 0
sounds like we are having same problem. i have already changed my oil pump o boy was that a ride . oil pressure doing better but like you it drops all of a sudden then jumps back up.i bought a code scanner and it told me my crankshaft pos sensor was acting up so i got one on order . question to you , has your rpms dropped from where they use to run ? mine is down to around 6,000 rpm
Thread Starter
|
Champion
Joined: Jan 2008
Posts: 2,899
Likes: 0
you mean 600? mines always been around there...maybe 650. i think thats just how they run. my issue is resolved. its just going back over because of another guy having the same problem. i didnt put in a new pump, decided that on the 4.7 it was way too much for me to handle. how was the install for you? and you did yourself? looking at diagrams i couldnt even imagine doing the oil pump. if you did the oil pump yourself, i imagine (hopefully) you checked your pick up tube and screen. i now know of 3 guys that have had this same issue, did not replace the oil pump, but after a good cleaning and removal of sludge in the pan, and removing ALL sludge and buildup from the scrren and pick up tube the oil pressure has been fine ever since.
Thread Starter
|
Champion
Joined: Jan 2008
Posts: 2,899
Likes: 0
my next question for you guys is.....now that i have cleaned my engine and im now running quaker state, 10w-30, what do you guys think of me going back to royal purple (a synthetic)? and if you think i can do it, how long do you think i should wait before going back to it?
Registered User
Joined: Aug 2008
Posts: 8
Likes: 0
the oilpump change wasnt to bad it took prob from start to finish 4 to 5 hours. i cleaned the pickup tube and cleaned the screen. i have no ticking now as i did before new oil pump . im going to put a new oil sensor on it sisnce it doesnt cost but maybe 15.00. it and the crank sensor comes in friday. i live in south carolina so come on down. i have to have a back fusion and i need all the help i can get.after i put the oil pump on i had to get 2 of my sons to pull me from under truck lol. i have it soaking in cleaner as i have another ride and i keep cranking it letting it move the cleaner around. by friday it would be soaking for 4 days trying to clean it good and if that dont work ill probly drop pan again and replace pick up tube .
Professional
Joined: Mar 2008
Posts: 138
Likes: 0
From: Detroit Suburbs
my next question for you guys is.....now that i have cleaned my engine and im now running quaker state, 10w-30, what do you guys think of me going back to royal purple (a synthetic)? and if you think i can do it, how long do you think i should wait before going back to it?
Do you plan on continuing to run the Seafoam in it, by the way?
Professional
Joined: Mar 2008
Posts: 138
Likes: 0
From: Detroit Suburbs
Regardless of the rotational speed of the cams, different engines are designed for different uses, The point of the whole question was whether or not the cam bearings have been scorched or scored due to severe lack of oil. While it would definitely be a sign of detioration if the chain WAS that loose, I be afraid of destroying the bearings surface in the heads due to galling of the bearing surface due to lack of lubrication, and unfortunately, welding of the bearing and destroying the head/heads.
Seems to me that the cost of the valve cover gaskets and a little inspection, particularly for top end sludge and engine reliability would certainly be worth the minor money as compared to what could happen.
Maybe I'm being a little critical here----but, if it were me, knowing that the engine ran for near two weeks with "0" psi on the guage, I think I'd be inclined to check.
Good Luck
Seems to me that the cost of the valve cover gaskets and a little inspection, particularly for top end sludge and engine reliability would certainly be worth the minor money as compared to what could happen.
Maybe I'm being a little critical here----but, if it were me, knowing that the engine ran for near two weeks with "0" psi on the guage, I think I'd be inclined to check.
Good Luck
And I didn't miss your point. My ending comment directly addressed your point. MY point was that the information you gave was incorrect and slightly misleading.
