Maddogg20 Posted March 16, 2011 Report Share Posted March 16, 2011 Hey guys quick question. The other day I noticed that my oil cooler line assembly was seeping oil out of one of the joints where the rubber meets the metal, so I went to autozone and low and behold they had one. I bought it and installed it but now im having a weird problem and its driving me nutz. The oil pressure used to always be stable and the only way the needle would move was if i accelerated or came off the gas but now, the overall pressure is noticibly lower through all the rpm ranges (used to be like 40 at 2000 rpm's and now its at like 25), but the biggest thing that worries me is that the needle will dance up and down about 7 psi when i am maintaining a constant rpm. Im not sure what oil pressure ranges are safe for my engine, so im a bit worried. Im wondering if anyone has seen this before, because im considering removing the new oil cooler line assy and going with a different brand one. By the way I am running 5w30 full synthetic and my truck is an 05 vortec maxx 6.0 with 115,067 miles on it. I dont know if it has anything to do with it but I have been having another weird issue with the dash where the gear position indicator is very dim, or not lit up at all. Any help would be appreciated because this is my daily driver and im border line scared to drive it. Thanks guys, Andy Quote Link to comment Share on other sites More sharing options...
misterp Posted March 16, 2011 Report Share Posted March 16, 2011 ... the biggest thing that worries me is that the needle will dance up and down about 7 psi when i am maintaining a constant rpm... I would put the old leaky part back onto the truck! Yes what you describe is not normal, and I would not operate the engine that way; the earlier oil pressure that you describe is how the motor should be running. What exactly did you replace? Mr. P. Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 16, 2011 Author Report Share Posted March 16, 2011 I replaced this part http://www.napaonline.com/Search/Detail.aspx?A=BK_8234060_0241708466&An=599001+102005+50014+2014021# but I got it from autozone instead of napa. Im gonna try and use the napa one and see if it fixes it. Id love to get my old leaky one back but the garbage got picked up last night :-(. I did add some 5w30 to the 10w30 that I have in there to top it off because i lost some while draining the oil cooler, but I wouldnt think that mixing one quart of 5-30 with 5 quarts of 10-30 would have any effect on it. Quote Link to comment Share on other sites More sharing options...
misterp Posted March 16, 2011 Report Share Posted March 16, 2011 No a single quart of 10W-30 won't hurt. Ok so you replaced the entire oil cooler line assembly; it is possible I guess that you installed a defective part which was very restrictive to oil flow. Oil goes from the pump, to the filter, then out the oil cooling lines to the cooler, then into the motor (where it is seen by the pressure sending unit). So I guess it's possible that a blocked/defective oil cooler line assembly could cause the behavior you are seeing. For future reference, NOT at all trying to pull an "I told you so" but for future readers with this same issue - all you need to replace is the litle gasket (GM dealer, $11) and continue using the existing lines, unless a leak is present where the rubber hose is 'swedged' to the metal line... Sorry for the hassle, make sure AZ gives you your money back! Mr. P. Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 16, 2011 Author Report Share Posted March 16, 2011 Yea P, im thinking maybe its a defective line assy, or its just not a good fit because the hoses are VERY soft compared to the rock hard ones that it had before, and it looks like they even may be kinking a bit. I only replaced the line assembly because they were both wet and one was dripping right where the rubber was crimped onto the metal pipe. The new ones come with a gasket too which is nice. Weird thing is i just went to the parking lot and fired it up and reved it to 3000 and the pressure went up to 45 so maybe when i replace the line assembly Ill change the oil and filter just for good measure and go to 10w30 instead of the 5w30 I have been using. Seeing the needle sitting at about 30 and dropping down to 20 and going back up to 30 at 2000 rpms while ont he freeway scared the $hit outta me. Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 16, 2011 Author Report Share Posted March 16, 2011 ill make sure that az gives me my money back. Note to anyone replacing their cooler lines... there is a small retaining clip assembly that holds the lines side by side to the fan shroud, and when you unclip the lines to replace them, the clip tends to try to pull out of the fan shroud. Make SURE that when u clip the new ones in that you wrap a large strong zip tie around the retaining clip assembly to keep it from pulling out of the shroud because if it does the return side hose will rub on the harmonic balancer and spell disaster for sure. Andy Quote Link to comment Share on other sites More sharing options...
T-Bag Posted March 16, 2011 Report Share Posted March 16, 2011 I wanna see ur truck, got pics? Quote Link to comment Share on other sites More sharing options...
misterp Posted March 16, 2011 Report Share Posted March 16, 2011 (edited) Yea P, im thinking maybe its a defective line assy, or its just not a good fit because the hoses are VERY soft compared to the rock hard ones that it had before, and it looks like they even may be kinking a bit. I only replaced the line assembly because they were both wet and one was dripping right where the rubber was crimped onto the metal pipe. The new ones come with a gasket too which is nice. Weird thing is i just went to the parking lot and fired it up and reved it to 3000 and the pressure went up to 45 so maybe when i replace the line assembly Ill change the oil and filter just for good measure and go to 10w30 instead of the 5w30 I have been using. Seeing the needle sitting at about 30 and dropping down to 20 and going back up to 30 at 2000 rpms while ont he freeway scared the $hit outta me. The rubber lines are supposed to be supple; the reason they get hard over time is because of the heat combined with the chemicals from the oil penetrating the rubber and embrittling it - you were right, between that and the crimps leaking the assembly was bad and needed replacing. I personally would not use 10W30 - I would use 5W40. In my own truck I run the lightest/thinnest oil I can because it easily passes through a dense filter like the Mobil-1 or K&N or Purolator Pure-One (everything else on the market is junk IMO) and after 90K-miles I still hit 80+ psi at 5500-RPM. The issue could also be <gulp> that in the process of removing and replacing the lines you inadvertantly got dust/dirt into the openings on the side of the engine block, and that dirt has now jammed the bypass valve open on your oil pump. Every situation where a person complained of erratic oil pressure behavior it's turned out to be that bypass valve (requires oil pump replacement). Get a good oil cooler line assembly on there ASAP and change the oil/filter. My 2-cents. Mr. P. Edited March 16, 2011 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted March 16, 2011 Report Share Posted March 16, 2011 If you can find an auto part store that sells AC Delco, get a set of Delco replacement lines, or get them straight from your dealer. My SS is on its second set of oil cooler lines, a friend of mine got me a set of Dorman lines as replacements, I took one look at them and had them sent back(cheap junk).....I wound up getting a set from my local dealer. When it comes to parts like these, sometimes aftermarket parts should be avoided, especially when the life blood of your motor is directly effected...... Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 17, 2011 Author Report Share Posted March 17, 2011 hey guys, Got a different line assy from napa. They swore that it was an ac delco part, but after I installed it I noticed that the bag had been re-labeled, so i removed the outter label and low and behold... its a dorman line assy. :-( DAMN!! im gonna go to the gm dealer today at lunch and get an actual guaranteed GM one. I changed the oil and filter too while I was at it and much to my dismay, the oil had the metalic sheen resembling anti seize, and even with new oil and filter my oil pressure issue persists. I know this may be a dump question but how tolerant are these engines when it comes to crank and rod bearings, like are they known for throwing rods or spinning bearings? Also.. if the line assy from chevy doesnt fix the problem then ill probably replace the oil pump this weekend. Are the pumps in these motors known for failure, and if so how hard are they to change? Thanks guys, and sorry for rambling on. Andy Quote Link to comment Share on other sites More sharing options...
misterp Posted March 17, 2011 Report Share Posted March 17, 2011 hey guys, Got a different line assy from napa. They swore that it was an ac delco part, but after I installed it I noticed that the bag had been re-labeled, so i removed the outter label and low and behold... its a dorman line assy. :-( DAMN!! im gonna go to the gm dealer today at lunch and get an actual guaranteed GM one. I changed the oil and filter too while I was at it and much to my dismay, the oil had the metalic sheen resembling anti seize, and even with new oil and filter my oil pressure issue persists. I know this may be a dump question but how tolerant are these engines when it comes to crank and rod bearings, like are they known for throwing rods or spinning bearings? Also.. if the line assy from chevy doesnt fix the problem then ill probably replace the oil pump this weekend. Are the pumps in these motors known for failure, and if so how hard are they to change? Thanks guys, and sorry for rambling on. Andy LS-motors are flawless in the rod/mains are bulletproof as long as they are very well maintained. The rod/mains clearances in these motors are extremely tight compared to older iron, that is why you have to use much thinner oil and keep it CLEAN (i.e. use a good premium filter). But with clearances of 1-1/2 thousandths they are far less forgiving about trash in the oil. You're going to have to wait and see, but I would say from what you describe the bearings are fine because the motor IS capable of making good pressure, just not capapble of maintaining that pressure. In other words, it IS spiking to 40-psi - if the bearings were shot, it would only spike to say 20 or 25-psi or less! Since you are observing the oil pressure hitting factory spec, my judgement is the bearings are still in factory spec. I would not worry as much about low oil pressure in the LS-motors versus older engines, because the bearings are SO tight that 10-psi will keep them afloat, and I have even seen 5-psi at idle not damage the engine (8 UR HMI's truck developed the same issue/behavior). The one part that DOES NOT tolerate ANY garbage in the oil AT ALL is the little aluminum bypass valve built into the oil pump; the tolerances of that bypass are so close that any grit at all will wedge/hang it open, hence dumping all the pressurized oil from the pump straight back into the oil pan. The only fix once that happens is pump replacement, as memory serves I think the total parts bill when I helped 8 UR HMI was $150-ish?? If it comes to that, you need tools, Dex-cool, new crank bolt, pump, pickup-tube O-ring and optionally (VERY recommended) a new LS2 timing chain and cam sprocket - replacing the timing chain gained 8 UR HMI 2-mpg lol. The sucky part is that the job took a few hours to do and it wasn't fun but wasn't the worst wrenching job I've done either... Let's hope a correct set of lines & fresh oil change will put it right. Mr. P. Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 17, 2011 Author Report Share Posted March 17, 2011 well since ill have the timing cover off anyway I may as well do the chain and sprokets. Where can I get the LS2 set and how much was it if you remember? one more thing. Autozone sells an oil pump for the truck, its about 120, and i know it has been said not to use aftermarket stuff when it comes to things like that but.... its a melling pump, and I have used melling pumps before with absolutely no adverse result. What do you guys think? Quote Link to comment Share on other sites More sharing options...
misterp Posted March 17, 2011 Report Share Posted March 17, 2011 (edited) Two words: Scoggin. Dickey. Use all GM parts - Crank Bolt - $7 Pick-up Tube O-Ring - $6-8 Gen-III Oil Pump - $95 LS2 Chain & cam sprocket - under $50 ??? I don't have the invoice here but it was cheap! Don't bother replacing the crank sprocket, they don't get appreciable wear; it's the chain that stretches and the cam sprocket made of aluminum that takes it in the shorts. Mr. P. Sorry I never answered your question, the Melling is no better/worse than the OE pump, especially for bearing clearances that tight. Now if you had bearing clearances of 2-3 thou and were running 20W50 that might be a different story!!! Edited March 17, 2011 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 17, 2011 Author Report Share Posted March 17, 2011 hey, stupid question but... what vehicles came with an LS2? I called the dealer and they looked it up by my truck and they want 45.99 for the cam sprocket and 59.99 for the chain, lol i was like huh???? Quote Link to comment Share on other sites More sharing options...
Maddogg20 Posted March 18, 2011 Author Report Share Posted March 18, 2011 hey guys, I installed the line assy from the dealer that i got today and still, the oil pressures dancing. Im prolly gonna replace the pump this weekend but im wondering if thats even the issue. i took a video with my digi cam so lemme know what you think. Thanks.... Andy Quote Link to comment Share on other sites More sharing options...
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