Chevy Suburban 04 Low on Oil Again
| Username | Post: chevy suburban 5.7 oil pressure loss after warm up (Topic#313997) |
|---|---|
| NVC Forum Newbie Posts: 4 Reg: 07-24-14 User Info Send Individual Topic | 07-24-14 09:xix AM - Postal service#2471501 My 97 Suburban K1500 five.7 (325,000 mi) looses oil pressure after warm upwards. Have been using the recommended oil grade (v-thirty) since I bought the motorcar at 75K. The oil pressure sending unit of measurement is fine. On cold start engine sounds great smooth no noise or smoke, pressure reads 40. Later warm upwardly (nearly 20 min at idle continuing notwithstanding) the oil pressure drops steadily just with a footling gauge giggle. At the fourth dimension the check gauges lite comes on (at about 1-2 psi) and the engine becomes noisy but not lifter or tap noise. Kinda sounds like the engine is in labor. Before shutdown, increasing the RPMs increases the pressure level, simply the pressure immediately drops back downward later letting up the gas. Since I don't feel like wreaking it, I shut it down when the check gauges light comes on. At get-go I thought the oil pump needed replacement> Since I do most repairs myself, I called the Chevy dealer regarding a new oil pump. I was told they rarely (well-nigh never) demand replacement. I trust this dealer since it has been under their advice that I have gotten the good mileage. They wanted me to bring it in, only 1) it is besides far to drive and I don't desire to pay for towing, 2) I would like to do the work myself. Lastly, I would non like to do an unnecessary pan pull if it is something else. Thanks in advance for your comments. |
| | |
| 50hotrod Frequent Contributor Posts: 1081  Loc: Wisconsin Reg: 07-25-11 User Info Transport Private Topic | 07-24-14 09:38 AM - Mail service#2471505 In response to NVC Engine is worn out obviously and simple. Cheapest and quickest at this betoken is a replacement engine. 1950 CHEVY 2 DOOR 327 TRI Ability FENDERWELL HEADERS HEIDT Front SUSPENSION 700R4 TRANS 411 REAR |
 someotherguy Senior Moderator Posts: 29562  Loc: Texas Reg: 08-01-03 User Info Send Private Topic | 07-24-14 02:00 PM - Mail service#2471547 In response to NVC Welcome to Chevytalk, You *could* replace the oil pump - some find that with lots of miles, the spring inside does get weak and pressures drib. However equally you've already read, most likely the engine is merely worn. To me, 325K out of a Vortec minor cake is pretty proficient, considering all of them suffered intake gasket failure around 100-150K and a large number got coolant in the oil, prematurely wiping out the bearings. If non for intake gasket failure I would say 300-350K would be an expected lifespan from the engine with normal use and care. (Yes, I know more than a few have gone much further.) Richard 06 Silverado ISS / 06 Silverado SS / 06 300C SRT8 |
 Vaughn Member #455 "15th Twelvemonth" Gold Supporting Fellow member Posts: 18770  Loc: Colorado Springs, CO Reg: 08-08-04 User Info Transport Individual Topic | 07-24-14 02:thirty PM - Post#2471555 In response to someotherguy Switch to 20w-50 oil. Bearing wear causes an increment in the gap between the rods and mains on the motor, and the gap allows more oil to period out from between the bearings and the rods/mains. Your bearings are worn, so y'all need to increase the viscosity of the oil in order to get some oil pressure back. Viscosity just ways that the oil is thicker - then the thicker oil won't flow as easily out of the gap betwixt the crank and the bearings. Yes, the ultimate way to ready the trouble is to supersede the motor - however, in the near term you need to switch oil viscosity. This is a common practice on motors that take high mileage. If you fail to switch to the higher viscosity oil, the harm to the bearings will increment the distance between the bearings and the crank, farther shortening the life of your motor. During winter functioning, you may take to switch to 10w-40 to get oil that volition flow well plenty at lower temperatures. |
| NVC Forum Newbie Posts: 4 Reg: 07-24-14 User Info Send Private Topic | 07-25-14 04:33 AM - Postal service#2471688 In response to Vaughn Thanks for your comments and advice. A new engine is non possible at this fourth dimension ($$$). The intake gasket did neglect some time ago but equally far every bit I could tell the leak was to the outside considering coolant was not seen in the crankcase. So the question is do I do the oil pump replacement or not? Also which grade oil do you recommend later on the job? |
| someotherguy Senior Moderator Posts: 29562 Loc: Texas Reg: 08-01-03 User Info Send Private Topic | 07-25-xiv 06:22 AM - Postal service#2471706 In response to NVC You could exercise the oil pump equally in cheap take a chance (that is, if you're doing the work yourself.) It won't solve excessive begetting clearances due to article of clothing, but IF the pump is weak at all, the new one might bring your pressure up to a more adequate level. Information technology is a gamble in that it may help cypher at all. If it brings pressure level up to normal using 5W30, by all means continue using 5W30. If information technology doesn't, then chalk it up as a adept try, and crash-land upwardly the viscosity to something thicker every bit suggested, in an attempt to bridge the gap. It's a band-aid at best but may get you through for a while. Get-go saving for a replacement. Richard 06 Silverado ISS / 06 Silverado SS / 06 300C SRT8 |
| Vaughn Member #455 "15th Year" Gilt Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Ship Private Topic | 07-25-14 02:52 PM - Post#2471822 In response to someotherguy If you are going to become to the trouble of replacing the oil pump, I would convert to a high volume Melling oil pump. Melling is the manufacture standard, don't employ annihilation else. I take done this on a few motors with badly worn bearings, information technology helped some, but not a lot. If you lot are going into the motor that much to swap oil pumps, I would pull the chief caps one at a time to check on the condition of the mains, then do it once more on the rods. Only exercise one at a fourth dimension, and re-torque them dorsum into place. If you lot observe that most of the crank rod and master journals are OK (non all of them volition be), you can put new upper and lower bearing shells on the UNDAMAGED rod and main journals - to effort to get the oil pressure back up near where it belongs. IF any of the bearings are into the copper, don't endeavour to replace them. This will exist simple plenty to practise on the rods, but you lot will probably be able to only remove/supersede the bottoms of the mains (unless you went to the trouble of removing the timing cover and unbolting and moving dorsum the transmission - in that case you could completely remove the crank and accept information technology turned, and put new bearing shells on all of information technology). This is a seriously bad way to bring oil pressure support, but it would probably work until your pinch (bad rings) is too low or you break a piston ring. Information technology would more often than not be better to get a long block from a junkyard and replace yours, it will be a lot easier than the in a higher place method. You tin generally observe a truck in the junkyard that had a new(er) motor put into it, then 10-50K miles later the truck was t-boned or something similar. Information technology may take a while to notice one, but they are out in that location. You usually can get one for less than one-half of a rebuild, if you keep at it. This is the dirt cheap method to getting an older truck back on the route. It too helps if yous have friends at the junkyard. |
| Stinky Senior Fellow member Posts: 1816 Loc: Whitewater, CO Reg: 05-25-01 User Info Ship Individual Topic | 07-25-fourteen 07:16 PM - Post#2471858 In response to Vaughn Vaughn, why not change the bearings if they are in the copper? |
| someotherguy Senior Moderator Posts: 29562 Loc: Texas Reg: 08-01-03 User Info Send Individual Topic | 07-26-14 07:09 AM - Mail service#2471917 In response to Stinky Bearing journals already likely scored at that point. Richard 06 Silverado ISS / 06 Silverado SS / 06 300C SRT8 |
| Vaughn Member #455 "15th Year" Gold Supporting Fellow member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Transport Private Topic | 07-26-14 12:39 PM - Mail#2471994 In response to someotherguy If the journals are into the copper, they are badly scored, and just having the crank turned volition ready it. If you supervene upon those bearings that are into the copper, they will merely wear rapidly - causing the oil system and the motor to exist flooded with bearing material. IF you leave the bearings that are into the copper alone, the motor won't exist flooded with begetting textile, and then in that location is less take chances of a critical oil journal beingness plugged upwardly. |
| Stinky Senior Member Posts: 1816 Loc: Whitewater, CO Reg: 05-25-01 User Info Ship Individual Topic | 07-26-xiv 08:nineteen PM - Post#2472096 In response to Vaughn Vaughn, thanks for the info, it makes sense. |
| NVC Forum Newbie Posts: 4 Reg: 07-24-14 User Info Send Private Topic | 07-27-xiv 09:37 PM - Postal service#2472364 In response to Vaughn To ALL: Give thanks y'all for all your comments and suggestions. This weekend I was able to get every thing apart in a few hours. The under abdomen of the engine looked great - make clean and no sludge except some brown at the very bottom of the pan (peradventure a 1/sixteen" deep) and absolutely no carbon anywhere. This indicated to me that my rings are good. The lower tip of the oil pump screen was gunked with some chocolate-brown sludge. This sludge may exist a residual from the intake gasket failure. I did observe a few (3) small very sparse flakes (slivers) nigh 1/16th x 1/8" of metallic in the pan which may exist bearing cloth. There is some play in the connecting rods where they are fastened to the crank shaft, but I had to utilize a neat deal of wiggle pressure level to notice it. I partially disassembled the oil pump and information technology looked good. I will mensurate the clearances on Mon. (7/28). If changing the lower half of the connecting rod bearings is unlikely to improve pressure, I'd rather non mess with them. Withal, if removing them will permit me access to oil ways that I may check for clogging or other reasons, I would like to know. I liked the idea of measuring the begetting gap, but what exercise I do with info if I can only accomplish the bottom half? Volition not irresolute the bottom half of the bearing cause the connecting rod to rotate around a point off center? The pan is all the same off. If anyone has any suggestions prior to installing the new pump and reassembly, I would be interested in hearing them. Later assembly I'll let you know the results. Cheers in advance, NVC (Nick) PS. I am still utterly amazed at how clean everything was - nothing like the black and varnish encrusted motors they used to throw at united states of america in high school auto shop. |
| Vaughn Member #455 "15th Twelvemonth" Gold Supporting Member Posts: 18770 Loc: Colorado Springs, CO Reg: 08-08-04 User Info Send Private Topic | 07-28-14 03:32 PM - Post#2472570 In response to NVC No, changing the bearing halves will not cause them to rotate off center. Bearing halves, when joined, create their own center around which the crank will rotate. Every bit long every bit the clearance around the bearing isn't enough to permit the crank to move inside the bearing, then the creepo will not rotate off centre. Well-nigh all of oil pressure problems are bearing related. If you accept the engine far plenty autonomously to get at them, I would change them (it isn't expensive, and it isn't hard to exercise). An analogy would be like putting a band aid on a cut (oil pump) while a few stitches (bearing shells) would do much more. I guess I should improve my previous annotate to say that if the crank journals are generally undamaged, replacing the bearings can touch a large portion of the oil pressure issues you are having, merely if they are damaged then y'all might as well leave them lone. The lower shells of the MAIN bearings is where most of the bearing wear comes into play. The lower shells take all the force from the piston being forced down past the explosion in the combustion chamber, and they can oft be pounded thinner over the lifetime of the engine. You can modify both the upper a lower shells of a ROD bearing. Feeling how loose a rod bearing is side to side is NO indicator of how much bearing clearance there is between the rod and the rod bearing. It needs to be measured. (There is a measurement that is side to side though, you mensurate it with a feeler gauge, information technology has to be inside a certain tolerance.) For this you lot would utilise an inside and outside micrometer, or more realistically some plastigauge (it is a lot easier to get a measurement using plastigauge). You can get it from your parts store. Plastigauge is "squeezed" in betwixt the rod/main periodical surface when the cap is torqued downwards. The more it is squeezed, the wider it gets. You lot apply a gauge printed on the sleeve of the plastigauge to determined how much clearance there is between the journal and the bearing. Your bearing clearance needs to be on the order of .002 to .003. If information technology is more .003, information technology is too much. I would probably lean towards .002 for a motor with oil pressure problems. Yous can modify the upper shells of a MAIN bearing, if you accept enough play in them to get them out. Onetime you can remove the rearmost main bearing cap, and and then pry downwards on the crank to go at most of the main begetting upper shells. You lot won't be able to go to the front 1 unless you pull the timing chain cover, simply you should exist able to become to the 3 rear ones and possibly the 4th (there are a total of 5). Your oil pump may look good and measure out inside specs, but it is yet not providing enough volume for your bearings at hot idle. If you lot went to the trouble of dropping your oil pan, the very minimum that you should do is to replace the oil pump with a high book pump. It isn't a loftier force per unit area pump (although they have high volume/high pressure pumps), it pumps a lot more book to continue up with the bleed rate of oil out of the bearings. If you accept a look at your current oil pump gears, merely imagine a pump with taller gears in it - it will pump out more than volume to keep up with oil force per unit area loss. This is exactly what a high volume pump does, and information technology does have taller gears. This is a high volume pump, for less than $50. http://world wide web.jegs.com/i/Melling/689/M55HV/ane 0002/-i This is a high volume and high pressure pump for less than $70: http://www.jegs.com/i/Melling/689/M99HVS/ 10002/-one |
| | |
Source: https://chevytalk.org/fusionbb/showtopic.php?tid/313997/
0 Response to "Chevy Suburban 04 Low on Oil Again"
Post a Comment