Lb7 cp3 leaking into crankcase 5 nitto at on 20 inch American Racing 20x10 wheels, Stage 5 Built Transmission by Mike Cole with triple disc billet low stall converter, 4 inch Injen cold air intake, Profab Intake LB7 . Fuel in oil at the same rate as pre injector swap. It would burn or foul Im thinking and they said. 290ms CYL 5 3. Im just looking for a place to start. 2004LB7 Super Moderator. Dual Feed Line, BD blow-off valve, BD exh. A bad injector pattern or leaking fuel into the cylinder outside the power stroke can allow fuel into the oil pan around the piston (as well as washing down the cylinder wall and reducing lubrication of the piston and ring against the cylinder. I have my original unmodded CP3 & it's done this since new. It's always best to consult a manual fo The return plugging can happen, but it will typically leak internally. Shut it off wait a few seconds, needs reprimed. but not getting under the upper valve cover and into the crankcase. truck does (pre tear down obviously). After all of this I'm leaning towards it being the CP3. was idleing a little rough, not bad before i left on the trip. If the main seal where it meets the block leaks, that fuel will go into the crankcase also. So to end the night, I had a buddy trailer me home. Turned out to be a plugged return orifice in the tank. Duramax CP3 I'm assuming its return line on my cp3 that's leaking, it's the rubber line and its leaking were the fitting threads into the cp3 pump, could I pull the in this thread in this sub-forum in the entire site. Advanced Search Lb7 cp3 return line leaking. SO where is the diesel coming from. Check your oil level and see if you have fuel in it. The parts were quality compared to what we originally received and installed. Jump to Latest 8. Like the title says. Brimmy New member. Cab Short Bed 4x4 249k miles (SOLD) 2001 GMC Ext. Usually if the return lines are leaking you would notice the fuel in the oil before the tank of fuel is burnt. was able to isolate leak coming Seals rarely (if ever) leak fuel into the crankcase. I put a tech II on it and tried maxing the pump out and it would only On an LB7, if the CP3 were leaking, would that cause fuel to get in the oil? My truck is going BACK to the dealer in the next day or two with fuel in the oil. This can be done with many different scan tools. The only way to find the leak is to loo for it with your eyes. I had an airdog 4g 100gpm lift pump installed at the time of injectors. I pulled the suction pump off and orings were good. I'll be ready to get my 200 bucks back when the cp3 gets here for Chevy / GMC Duramax 01-04. 5 LB7 Forums. Just plenty of fuel being put into the oil. 99% of the time its a cracked body. It did not throw a CIL but I'm gonna get someone with a scanner to check the balance rates and rail psi with it. could one or more of the injector cups be leaking coolant back into the crankcase (oil) and not letting the engine build compression??? I am way out of options and over six GM mechanics at the local dealership have NO clue either. Truck has been very laggy before and after injectors. CP3I hope at this point. replaced injectors and I'm having the same issues as before. So its going to be obvious. SOLD Very little LB7 experience here, but have an 03 that in less than 100 miles driven since oil change, will fill the crankcase with fuel. Well, it is, but it has a crankcase full of diesel. . O. Injector body cracked 2. OK replace CP3 now we're done right? wrong. I had a massive oil/fuel leak, over 2 gallons My '03 LB7 with mid-240k miles began "making" oil recently. I pulled the intake tube off (the one that mates up to the turbo), cleaned the valley/CP3 with brake parts cleaner, soaked up the afterbirth with some papertowels that I '08 2500HD CC SB 4X4 D/A, ATP EFILive with DSP5, AFE Test Pipe, Magnaflow DPF back 4" exhaust, 20" PYS or 18" PYR, XDP EGR block plate '02 2500HD CC SB 4X4 D/A, Kennedy headlight kit, OilGuard bypass, Amsoil air filt, Nicktane fuel filt, Pred 1. bump stops, custom 4" downpipe into 5" pipe out to 5" stacks TTS extreme 32psi. That will most likely not be and intermittent I have an 03 2500HD with 119k. Changed my oil Friday and found the leak, it was about five quarts over full with fuel and coming out the blow by tube. 2004 CCSB 4x4 LB7 EFI Problem with replacing it is that Lb7's are prone to dropping a bunch of rust in the injector when you unscrew them from the injector. Unpluged FPR as well to see if CP3 was leaking before I got my hands on a Tech 2. 56 gears front and rear, 3 I had fuel leaking into the oil and I found it was my passenger side injector return line leaking fuel, got it all back together and now it cranks but doesn't start. I am assuming that the dripping that I see in the valves and off the low points in the fuel return lines is the fuel oil mixture from the Here I have a LB7 CP3 pump that was leaking diesel into the crankcase originally I had replaced all 8 injectors and sure enough still I was getting diesel in It was pooring fuel into the crankcase really bad. But why the code!? Does that seal, if defective, compromise rail pressure? While all of this was happening, a whine/wistle was coming from the front of the engine bay like its either the CP3 or a pulley. emissions ECLB 2500 HD. How is the cp3 is it dirty usually the shop I was at we would replace replaced the lines and cp3 2003 LB7 EFI LIVE CAT FUEL FILTER 5 inch flo~pro Sitting The leakage from these chambers spills out into the internals of the CP3, where the fuel pressure is 80 to 180 PSI. . DIY Cracked injector bodies can leak fuel under the valve covers under pressure, which drains back to the oil pan. Put all clear lines on filter head to cp3 then decided cp3 return. Thought I had a fuel leak because of fuel on the ground but couldn't find it. I had to replace the CP3 in my 03 last week @ 187K Upon picking up 2002 Chevrolet 2500HD 4x4 LB7 Crew Cab Short Bed, 325k miles and still running strong, 5in exhaust, efi, gauges (SOLD)2006 Cummins 6spd (SOLD)2003 GMC DURAMAX LB7 Ext. If you want to check you can run the truck with the valve covers off and Let us know the findings of pulling the oil fill tube and checking for a CP3 leak. Aftere some research i found out later generation cp3's will work and even supply slightly higher fuel Take both hoses off at the middle and see if its just coming out of one side. Is there a way to check the front seal of the cp3 for leaking into the Here are the possible causes that I know of 1. 03 2500HD, Industrial Inj. Reinstalled them with new I installed a FASS 150 on my truck and a day later my crankcase was full of fuel. Please offer some advice. com/user/BigStallion80Rustbelt It's a 2001 LB7 EC/LB with 201k miles on it. **Forgot to mention before but the truck just rolled over 101K** Hey guys I have an LB7 that is leaking oil into the crankcase. There is a good possibility it was run in this condition for several months, & after new injectors & an oil change, it's still running strong 4 years later. My question is do i replace it with a modded lb7 cp3 or a modded lbz cp3 with lbz fpr and who sells a good one, I have efi live (still figuring it out though) and will be getting a scV transmission pretty soon. 2002 CCSB LB7 285/75/16 Mickey Thompson ATZ tires/ 16'' XD Hoss/ Autometer factory match triple pod/ Hewitt dual boost/drive/ Scan gauge 2/ S&B intake/ Pro-fab horn/ Pro-fab downpipe/ LML DS manifold/ DE 4'' full exhaust Found out my cp3 is leaking from the plugs in the back. LB7 Duramax engines are very prone to leaking on the injector return line underneath the valve cover, causing the crankcase to fill with diesel fuel, which l Thanks everyone. Has anyone else ever had that problem? My simple logic is wondering if I had a weak CP3 (always It is a low fuel pressure leak as it leaks with the lift pump on only without the truck running. This is performed on a 2001 Chevy 2500hd Duramax LB7 engine. was still running good before i had it towed to the shop. 5 LB7 Duramax Powertrain. If so then it's probably that vent valve. Thanks. changes. (blow by or Lastly, the CP3 is gear driven. Split the halves of the suction pump and that oring was good also. It is possibe the front seal in the CP3 is leaking, but that is a lot of $$ and a long shot, to be just guessing on your $$. Too much PSI apparently leaks in the CP3 and dumps to crankcase. B. My thoughts were CP3. It was not any of the lines. 6 lb7, it ran great for an hour but fuel from an under torqued return line banjo bolt caused fuel to leak into the oil, overpressure the crankcase and pus It sounds like you're leaking fuel into the crankcase. I was getting a P0193 code and then my water pump started leaking. I tore it all apart and changed out the CP3 pump and the water pump. ) It leaked 16 extra quarts into the crankcase or at least 4 gallons of fuel in 130 miles. 03 Dmax LBZ Conversion Mod List: 06 HOOD and Grill, EFI Live, 8" Fabtech, 37 toyo MT's, 22" TTIS, 4. LB7 FUEL IN OIL. If its coming out of both then possible 2 vent valves (not likely) or excessive crankcase pressure. Cab Short Bed 4x4 189k miles (SOLD)two 2003 Cummins/ autos (SOLD) two 1999 Cummins one auto/one 5spd The only thing left that I can think of is the CP3, which can leak fuel into the crankcase when the seal goes bad. Well I'm still at it trying to find the leak. In other words, you most likely need injectors. causing them to leak excessive amounts of fuel into the crankcase. It is slow but still a leak. I finally found the issue with my P. When the truck was brought to me I tore it apart and inspected all of the injector bodies and lines. 2003 GMC Sierra 2500HD 4x4 Crew 275k miles | CAI, Magnaflow downpipe and exhaust, Edge Insight CS2, SAC CP3 injection Pump Replacement "how to" walkthrough video. 5th wheel. The LB7 engine can dump diesel in the crankcase if an injector is leaking. Well. Thoroughbred Diesel gear removal video Drop some oil on a paper towel-- the oil will make a spot, and the diesel-[if any] will make a halo around the oil spot. IF they are out of spec, don't just replace the bad ones do them all. Ever since then i have to reprime it for every start. I've read all the post and injector replacement appears simple enough. Split the halves of the suction For what it is worth CP3s do fail but it is rare in stock form. CYL 1 1. 34 . found the problem. Best way to find if the injector lines are leaking on a LB7, is run the engine with the valve covers off-- only take a tiny leak to have 5 gallons in the oil. S. Try disconnecting the fuel line into the CP3 and pump the primer bulb to see if you can get any fuel there . That's where I'd start. Really the best way to clean them out is to remove the injectors and tap them upside down, you don't want to go through that just for this. So now where. Staff member. It is a low fuel pressure leak as it leaks with the lift pump on only without the truck running. And online or phone support is free any time. cp3 leaking fue from under housing? 2004 lt crewcab 3500 dually with an lb7/allison, straight piped, glowshift gauges, alum flatbed, 235/85r16s, 307,000 miles and stock for now driveshaft loops, adj. Pulled oil fill and no leak out of the CP3 so I have to assume injector problem. So in my last post about my duramax leaking air into the system after being turned off, and doing multiple tests to rule out possible air leaks, I've finally ordered a new OEM Bosch cp3 from Lincoln Diesel Specialties along with the install kit. Mine get's wet, never a drip on the ground under it, in the winter. nozzles!!! :evillol: & Modded CP3 In-Cab Boost control Plugged Intake heater, Summit billet LP LOWERED Lb7 CP3 Removal/Installation. EFI Live by Idaho Rob, 695K+ and rolling, Undercover Bed Cover, Vortex spray in bed liner, Odyssey Extreme Batteries, Westin steps, Bilstein Shocks, Road Master Active Suspension, M/A Pump Rub Kit, PPE Trans Cooler, PPE 3" downpipe, MBRP 5" Exhaust, Edge Insight CTS, K&N drop in filter, AirDog II 100 w/ If your making oil, chances are your return rates are way out of spec causing fuel to leak into the crankcase. No rough spots through acceleration or smoke. 2, 8 speed trans, s&b intake, elite engineering e2x ultra catch can SOLD 16 CCSB Z71 LTZ 2500 - SDP cp3 conversion, exergy sportsman, SDP y bridge intake and intercooler pipes, FASS titanium 165, 5” jamo straight pipe, UDP tuned I have fuel leaking into the crankcase. Unfortunately I developed a major fuel leak while driving to work which I'm still assuming is coming from the CP3 pump. (which would be leaking internally into the crankcase correct?) How is fuel The only other thing that I am thinking is. So far I have replaced all (8) injectors and the vacuum pump. I have a 2002 LB7 I bought about 2 months ago. 04, Autometer Ultra-Lites, ARE Z-Series, DX-959, KL203, Mich XPS Tractions, Xferflow filler kit, Kennedy Other than a miss every now and then it ran great. Probly just a return line fitting came loose, check you Mr hard line fittings on the injector fuel lines first 2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, Rick Fletes Dsp 5 on v2, 33x12. boost mod. The local auto store should carry UV dye kits. OK 8 injectors simple done right? wrong. 2002 Duromax LB7, MPG dropped from 18 to 10, Oil pressure dropped = major fuel in crankcase. With the rail pressure cranked up to 23,000 PSI via Tech 2, no fuel spray out of the seal on the Front 08 CCSB LMM - HSP s369sxe, s&s 10mm cp3, built trans with 1058, Danville tuned. Funny how Bosch should offer 1mm thicker o-rings How do I diagnose which, either injectors or cp3, is dumping fuel into my oil? Truck starts and runs like it always has. Nov 22, 2020 #12 Update on my 2003 2500 HD LB7 issue with fuel in the crankcase after new injector install. Hey guys, need some help with my my 03 lb7. Most leaks are significant and show themselves within 50 miles, by thinning the oil enough to drop oil pressure (5-7 gallons of fuel and oil mixed in the crankcase). I too have run an LB7 that was leaking fuel into the crankcase. This time from Lincoln Diesel. Had a customer friend with truck in on a fuel in oil complaint. I should have monitored more of what the boy purchased. Guess ill have to run her with the valve covers off and see which one it is 2nd time on my lb7. Had it towed to shop. It has been getting harder and harder to start, and sometimes won't start. FYI Oil Pressures never changed since I bought it with 77000 miles ( 50 to 60 on highway and about 30 at idle) Truck ran great for the 1000 mile trip, got 20 mpg. fuel leak update. like leaking into the cylinder or something. 70 . I took it to a reputable (seriously) local dealer anticipating the dreaded "injector" diagnosis. This is how I troubleshoot a P0093 code on a LB7 duramax. We got some dye for it to possibly see where it was Leaky CP3 w/ pics *Update* ***Update*** o-rings and shaft seals in tomorrow. 3K views 1 Everything has been torqued to spec per Hanes manual and Identifix. It starts right up My pickup has been slowly dripping fuel down the back of the engine case, from the valley. Dec 15, 2010 7,521 2,470 113 Norcal. First time diesel owner. I had smoke and some fuel in the oil, roughly a gallon every 400 - 500 miles. from what I can tell after my pump teardown I'm thinking the winterblend fuel is the major culprit to the cp3 leaks,but who knows I may be wrong . Here are the numbers I came up with. Anyway I replaced all 8 injectors and high pressure lines. com/nv4500, nv5600, g56, 4 Pressurize it no leaks. (blow by or fluid transfer causing overfill). lb7 duramax. (which would also be covered by their warranty), or 3) a bad CP3 pump leaking fuel into the crankcase. Next to the crank balancer is a crankcase vent tube- if the oil is over full, it will blow oil out the tube and show leaks at the front of the oil pan. This turned out to be a tired CP3 fuel pump. Everything has been torqued to spec per Hanes manual and Identifix. I had all my money on a leaking CP3 front shaft seal. This is a quick reference test to determine if there are possible issues w injectors OR cp3 pumps in the LB7 Duramax. $500+ in oil is getting nuts and still can't find it,Did the dye in fuel again with the covers off and from what I can tell the dye/oil is coming from the push rods running down the rockers but pulled fill tube and ramped pressure but cp3 seal looks sound (no leaks there either )Already swapped 2001 Chevy CC/SB 4WD EFI Live DSP 5, LBZ Short Block, Cut LB7 Pistons,keyed crank and cam, balanced,LBZ Intake Runners with RDL Shorty Y-Bridge, EPR Twins, Big Dipper 40% overs, MBRP Cool Duals, LBZ CP3, ADII, BD Manifold, C2 Gauges, H2 Wheels, Cognito Sleeves and Braces, Hids-Hi-Low-Fogs. 2004 305/555 6sp. Gave it the flat foot for the first time going around a corner and truck dies. could be return lines but if nobdy has been into the fuel system under the valve covers most likely an injector body has cracked. there is a seal in the CP3 which can fail and leak fuel into the oil. mojito5000 Member. If I wipe it down in the spring it's virtually dry all summer until the weather gets cold again. '02 GMC LB7 Crewcab Longbed, Just Replaced all Sounds like that injector is leaking enough fuel that the CP3 can't build sufficient pressure at idle, but when the engine is revved the CP3 turns faster and is able to build up enough pressure to overcome the loss of the injector hence the 21k. com/user/BigStallion80Rustbelt On the supply side, it comes out of the pump into 1/2 hose into a double filter set up under the frame, a cat water seperator and cat fuel filter on Baldwin fuel filter heads threaded together on a custom made bracket, from there it goes straight to the factory inlet on the drivers side back of the engine and is connected with another quick Justin 2001 LB7 Silverado 2500HD LT CCSB 4x4. For it to leak into the engine it would need to blow out the front seal. See if you can get it to stop leaking from making sure it is to spec first. 86 . All back together now thing runs beautiful. Duramax First Generation: 2001-2004 (LB7) 03' LB7 CP3 failure after injectors replaced? Jump to Latest 4K views I have a problem and need some help. I drove it less than 50 miles as it was leaking into the crankcase very bad. For those that are a bit amiss like me with these CP3's, it seems to be some-what common with the steel/aluminum housings of the CP3 and o-rings with temp. It is on the 2nd set of I'm not seeing anything conclusive. I have been getting trouble codes and working things off as I can. About two days of driving I get low oil pressure and oil/fuel out of the breather. 61 Leaking return line? fuel in crankcase? xtreme torture 2003 duramax diesel lb7 six inch fab tech lift, fabtech tie rods, amp electric steps, 20 inch forged weld racing rims, suncoaststage5 trans, sd nitrous, TTs extreme programmer,TTs dual lift pumps ,power shot propane injection stage 2 afe air intake, and 4 inch turbo back tts exhaust Play Truck - 2002 LB7 2500HD Crew Cab Short Bed Any precedent for the CP3 leaking fuel into the crankcase? All my injector balance rates are within spec - would that rule out a bad injector? Suppose if i'm this far into the thing, I should probably pull the valve covers & check all the return line banjos? 2002 RCLB chevy LB7, twin turbos, s475 over modded stocker(big head wastegate), ProFab uppipes, 5" exhaust to 7" Flo Pro black chrome stack, modded cp3 (FPR), EFILive by Idaho Rob, airdog II 165, Built trans (ML converter and Alto clutches), Stock injectors and head studs Downerrr Took my drivers side valve cover and rocker box off yesterday and reassembled and ran to see if we could see any obvious leaks, what we saw and heard was the #4 injector was leaking from what we thought was the line, went to the stealer and bought a couple new lines, still leaked, once we looked closer it was coming from the fitting that is threaded into the injector, it Ran great for three days. No air in but a good bit is coming out the return. Maybe this winter ill swap to the lbz . I originally had a shop replace the CP3 and since then I have noticed Take both hoses off at the middle and see if its just coming out of one side. custom engine compartment. youtube. Put it all back together and it still leaks. Just in case you wanted to buy a cheap LB7 these are some things to look for. If that's uneventful, it may be that now the new CP3 is working as it should (providing pressure), Took a light and looked down in there and could see diesel fuel running into the oil fill. LB7's are notorious for injector issues, the injectors and injector cups carbon up and they don't perform as intended. I just replaced all the injectors on a 2001 6. These are designed to color the fuel so you can see it with a blacklight. The CP3 was a month old rebuilt unit and fuel was going right past the seal and into the crankcase. 2001 Silverado 2500HD LB7, efi live by longhorn , Helo wheels, 33" nitto trail grapplers, tonneau bed cover, Dixie horn, LONG LIVE THE SOUTH One of the fuel lines right above the CP3 was leaking (I dont know what exactly it is called where it was leaking from). SOLD 18 CCSB Z71 LTZ 1500 - 6. Truck has 136xxx on it and by the looks of the rtv on the valve covers it has had injectors replaced. should have check the oil then. Aug 11, 2015 6 0 1. The pressure on the CP3 seals that leak is 80 to 180 PSI. CP3 leaking (rare). Its a daily driver but i would like to be in the low 13's or high 12's. com/channel/UCDZtnfGgbXUhAI9VfB6oDiQ/featuredBertrand850:https://www. say 20/30 lbs into the return fuel line that goes up through the Y tube to the PCV valves on the valve covers. Jump to Latest I have a 2002 LB7 dmax that is having serious oil dilliution issues. I had to agree to pay $$ for the "11 hour test," which would be washed if it turns Once again i have a bad injector thats leaking diesel into the crankcase. leaking return lines 3. Unless the leak was into the crankcase then I would think it would be a +. It co Like/Comment/Subscribe for more DURAMAX videos!Follow me on Instagram! @optimalweldingCheck out my website! https://optimalwelding. I did an injector return rate test with my EFI Live. 397ms CYL 4 -1. FOLLOW THE GANG!Truck Master: https://www. You can run the engine with the covers off and watch for the 2004 LB7 Chevy 2500HD LT CCSB 4x4, 4" RCD Lift 35" Toyo A/T2, Bilstein 5100s 238,XXX mi, PPE Downpipe, If my new CP3 was leaking, could I see that through the oil fill tube? I just can’t talk myself into buying injectors on a guess. 2004 lb7 Cali. *SOLD* 02 Chevy 2500 LB7 CC LB ZF-6 speed 97k miles 4X4 toolbox, UltraLite II Boost/Pyro B&W Gooseneck hitch 285/75/16 Firestone Destination A/T Straight piped. 397ms CYL 2 -1. With the rail pressure cranked up to 23,000 PSI via Tech 2, no fuel spray out of the seal on the Front of the CP3. ? You can remove the oil fill neck tube and you should be able to see if the CP3 seal is leaking especially with the dye and a blacklight. The previous owner gave receipts saying that both sides of injectors and the CP3 have been replaced just over 3000 miles ago and the truck ran perfect before I parked it. Narrowed leak down by (wish I knew this trick b4) apply air pressure from compressor . manifold, Coolingmist stage2 meth/H2O, TTS fuel pick-up, S& B intake, EFILive V2 "MytNasty" tuned!, Big @ss 6" exh out the side!!! FS-2500 bypass filter 50% Extrude Hone inj. 01-04. Give us a call, we have OEM Bosch remans and will beat any price. 58 . Tows 12K lb. Aug 20, 2019 It was just leaking diesel into the crankcase. you could take the valve covers off put the lines back on on and connect the I have a 2002 LB7 with about 175K miles and the injectors have about 30K miles (replaced by shop before buying the truck). I've already torn down the passenger side and someone has obviously been in here before. 3 valve cover Allens were rounded out and 2 of the return line screws share the same fate. 305ms CYL 3 1. We also give you instructions on the install to do it yourself. I don't know where you live but it is common (including mine) for the CP3's to weep a bit of fuel when the weather gets cold. TC 2003 LB7 Crewcab 3500 Dually Blackstone Labs is a great way to test your oil samples. Couple of questions: 1. I had all new injectors installed, cups, lines and even glow plugs. Litteraly ever start. wrkq lkvklt jrkre vww ypkv rbxmm oqwx axqmc tqfezq byw xwgmiy rtd gmmx otsm ukhn