It had the AFM wiring & lifter cover installed with solenoid pack in the original engine, we even removed it to inspect. But I can replace all of the other engine parts without doing the pistons and bearings so that is what I plan to do. I have 217,000+ on it and it never fails meever! Absolutely agree, but we all know GM cant afford to recall them all & definitely wont, gettin a Toyota, but first will go to GM dealer and ask to see a truck without AFM & when they say they dont have it Ill say See ya, I have an appointment with the Toyota dealer! Always had GMs never anything else till now. I am hoping this does the trick. Your email address will not be published. You could also have tried that if the trans oil didnt work. AFM Sucks!!! Just one. No problems with any to this point. Brian, I have the same question as Scott. One alternative is to swap in one of the larger 6.0 non-AFM truck cams. All eight cylinders are now powering the engine. How do you know if the lifter has failed? Verified over hundreds of trips, makes no sense. I had an 82 caddy 4100 with alumn block and cast iron heads ,, Exploded in Philidelpha, Garbage.. This will spray oil on the bottom of the cylinder walls which can cause oil burning, especially in high-rpm engines. While the system sounded good, the microprocessors scrambled to activate, deactivate, and then reactivate cylinders as driving conditions quickly changed, causing the car to hesitate, buck, and stall. do you fill to capacity anyways???? What type of ODBII gadget did you use? I am going to do the full repair of the engine now, but not an overhaul (too hard to get at the pan). a little burning oil is a minor thing, my main concern is avoiding a multi-thousand dollar repair needed to the motor. NOTE: Some parts are not legal for use in California or other states with similar laws/regulations. Everything was fine for two weeks, ow customer complains s it same noise it made as before. Thanks for the detailed post! Did not help. It also mentions a valve cover replacement with revised PCV valve design. Replaced all lifters. The collapsed lifters will not engage the pushrods and both valves remain closed. As a side note, the early ones had a 24x reluctor and plastic chain guide (good) vs. the later ones with 58x and the spring loaded tensioner (not so good). This system is the most effective way to disable AFM. I had a 2007 Yukon XL 5.3 with the AFM. It works . Drives way better for my mostly paved road driving. has 92,000 miles and was just told I have cam and lifter failure. Why would GM ever produce such problems with such little to gain. If the 4th cylinder lifter has failed, would driving it damage the engine? On the AFM lifters that dosnt work i have installed them With the oil hole Down! This really sucks. They have plastic casing, so you can imagine what will happen with aged plastic. These engines made 270-400 hp from the factory will run smooth as silk for over 300,000 miles (unless you have AFM). Cylinders two, three, and eight are all similar in cylinder deactivation. thanks brian love the info Im thinking of buying a ford now, I am going to buy a new truck in about a month it would be a Chevy but Dodge has lifter problems so they are out and Chevy has DoD problem.If they come out with Silverado without the DoD then i would buy one.But they arent so i will become a Ford man from now on, Have fun with that Ecobust motor & stretched timing chain . Yesterday my motor (116,000 miles) felt like it went into limp mode when decelerating from 8 cyl to 4 cyl but it recovered.This is the second time that this has happened in 6 months so I think that I am on the slope. I also notice that it doesnt go into V4 when it is cold. And consider using a higher grade of engine oil like Mobil 1 or Amsoil, etc. []. The lifter came apart and chewed up the lobe on the cam Im selling it I also told my friend at work when he asked me about my truck .I said Ill never by another GM ever. Basically rebuilt most of the engine while in the vehicle. You may eventually see a check engine light from a misfire code and the ECM dialing everything back to protect your engine. Brian, I have a 2010 burb with the exact same symptoms and questions as Shawn please help! Does anyone know how to disable the new Dynamic Fuel Management on the 2019 Silverados? Took it to the dealer and was told I had a collapsed lifter. I had purchased an extended warranty when I bought the truck new. I have 4 GMCs in my driveway right now only one with AFM its always popping DTCs, 06 Yukon (not AFM)never had a light in 12 years! Not sure which direction to go from here. One must anticipate this. Have a lifter problem on my 2010 5.3 Silverado. This system was originally used in early 1980s Cadillacs. After all we bailed them out of bankruptcy. If you want to delete it entirely, its a M14 x 1.5 pipe plug or you could use the Improved Racing plug p/n IRP-814-M14-Kit. They shift cam lobes by sliding the cam, never actually shutting down the value but riding a different lube! All these comments on the 5.3 are blowing my mind!!!. General Motors has issued a service update for 2021 model year full-size truck and SUV models that are being shipped to dealerships and may be affected by valve lifter problems. There is a chance the cam lobe was stressed and started to deteriorate. Apparently all passkey III keys are not the same,, I bought one that said for 2006 impala assuming all pk3 would be the same, and I could not get it programmed in my saab 9-7,, so how Im waiting on ones that specially said for saab 9-7. hoping they will work. My question on a 2007 Chevy Tahoe 5.3 AFM No other V-8 truck of similar weight can do that (except another GM with AFM). Vortec 5300s featuring LH6 and LC9 engines are prone to failing spark plugs due to carbon build-up. Yes thats true. Pulled the inntake and replaced valleypan With all the solenoids. I just bought a 2018 Silverado. Had similar problems under warranty, no telling what they rigged me up with at the dealer. Install an AFM Delete Kit Most of the complaints show up in the 2009 to 2011 model years. If i am successful locating a non-dod vin would i just need to have the ecm reprogrammed? Pushing forward. I had the same issue and had to have the AFM information deleted from the computer and the car tuned. AFM - active fuel management strategy which deactivates the lifters on specific . the extra oil isnt needed. If you are using VVT, you could use the NAL-12612273 (L92) cam. It was well researched and tested back in the late seventies and eighties . Would you get enough power to drive at freeway speeds? Junk . [], I have a 2012 Silverado Z71 bought new. An AFM Disabler is an electronic device that plugs into the OBD-II port, under the dashboard. Loved the looks and interior and thought a I got a great deal at $6k even. I will be installing the AFM deactivator tonight when I get hoe. the vehicle has 120,000 on it and 30 to 60 psi of oil pressure never lower or higher. There are so many moving components in an engine these days as opposed to the past. Brian, I just purchased and installed a remanufactured L76 AFM engine for my 2007 Suburban. Get this, rebuild is only rings and maybe lifters. Thank you for your time. []. Id try the disabler and the screen cleaning first and do the AFM delete if that doesnt solve the problem. I did a delete on an 07 avalanche and no have no power, any thoughts on what might be going on? Service manager said nothing else needs to be replaced because the engine has a Teflon coating. GM uses 3 different styles all are engine specific. A problem with the software caused the engine to idle with most of their cylinders, thus overheating the exhaust . Since it is not costing me anything out of pocket, I did not go with the Delete Kit (did not want to spend the money). This should be added to your earlier model if you experience oil consumption. The owner of the vehicle has apparently owned a few of these vehicles and stated that this vehicle doesnt have AFMnever did? [] they have a downside? More information can be found in the GM TSB bulletin number 10-06-01-008g. Can you tell me what needs to be done with the VVT? Afaik the 6.0 escalade hybrid does have it so wondering if safe to delete. Getting ready to diy for $450. Better airflow reduces drag on the pistons and the associated pumping losses. The market for nonhybrid gasoline-powered vehicles is expected to fall by 20 percent during that time, but with tech like smarter cylinder deactivationin these upcoming GM V-8 trucks, for . I wouldnt trade my 2000 Silverado, 5.3 liter that has constantly gotten 20 mpg since I bought it 15 years ago, for a dozen of these new $50,000 POS. Their tech guys have seen it all and may have some thoughts on this as well. Any thoughts or suggestions would be appreciated. Ditto , never buy a throw away vehicle again is my recommendation and my fix . I have only put about 600 miles on it and noticed that the oil was a bit low and am hoping that it was that way when I picked it up. I switched from gm to dodge in 1984, have had 3 1st gen Durango and 4 2nd gen Dakotas, all used, with impeccable reliability. There are two ways to disable or delete Active Fuel Management on your GM or Chevy Gen IV LS or LS-based Vortec engineone is to install an AFM Disabler, and the second is to install an AFM Delete Kit. AFMlifters have a history of failing and oil consumption can be a problem. How about if they just let us have a manual transmission agains for fuel mileage? NOTE: A disabler device should ONLY be used if the valvetrain is in good working order. My 2012 Silverado 5.3L just did the same thing as your Tahoe Brian. If buying a tuner/chip which works best for that truck/engine? The GM 2.7-liter L3B Turbo four-cylinder engine for Chevy Silverado and GMC Sierra pickups is meant to change minds about power and torque in a small package. Only running on drivers side cylinders. We chickened out though and just bolted the AFM solenoid plate onto the used engine. Its job is to direct the flow of pressurized engine oil to the active fuel management intake and exhaust valve . it is the regulator guy! Then it takes out the lifter again and again until you bite the bullet and replace the cam. Cylinder deactivation is very effective in reducing fuel and reducing the emissions of harmful gases. My 5.3 is. If you left the original cam in, the AFM cylinders will be down about 25 lbs. My Wifes 17 Buick with afm was my attempt to get back to gm. We did take it apart to check for metal possibly being trapped inside, it looked like brand new. Seems my oil pressure sensor is bad, are showing the same oil pressure at all times, even when it dosnt run.Dont know it that fault was there before i replaced the lifters. A 17 with 5.3. I have had some say that it is the valves and others say that it is the cats plugged. I have a 08 6.0L out of a Silverado with an aftermarket oil pan that has no provision for a pressure relief valve. I also have 08 Burb, but have different symptoms (high oil consumption, blue exhaust smoke at start, and now a really rough start after sitting overnight). When cruising on the freeway (for example) in 4 cylinder mode and jumping on the throttle to pass or get out in the fast lane, there is CONSIDERABLE and annoying and dangerous lag, like 3 seconds, and this is a problem. What the biggest reported problem with Chevy Silverados? Now I learn about the cylinder deactivation issue and suggestions to add the Range Technology module to deactivate it. I was told that before I start the vehicle up I will need to have the AFM and VVT disabled in the ECU but that would require a custom tune from a tuner as the ECU cannot just be told that the AFM and the VVT is gone. Question I have a 2015 Silverado and had a transmission go bad when I had it rebuilt I had the AFM/DOD turned off. Your email address will not be published. Any guidance would surely be appreciated. The write up confuses me. NOTE: You can find engine specs and detailed engine upgrade advice for every LS and LS-based Vortec truck engine in one place: The Definitive Guide to LS Engine Specs and LS Engine Upgrades. Ive read at many websites that the GMCs envoys, Chevys and saabs did start to come with AFM in 2005 with the LH6 motor,It says here it started in 2006 on the saabs, then the pick-ups got AFM in 2007. Thank you. Is there any potential down-side to doing this in other words, might this do more harm than good? I got as high as 23mpg on the highway in my 89 K1500 with 350ci and a five speed manual. 2015 SILVERADO 1500 44 crew cab with 5.3L engine: So two weeks ago with approx 70K miles, I had an odd noise when accelerating and then engine light flashing and riding rough. To do this, you need to leave the AFM solenoid pack connected to ensure no codes are thrown. I dont know where to being to look for the problem. Have an intake and Borla exhaust. The AFM activation and deactivation is controlled by the Valve Lifter Oil Manifold or VLOM. i have a 2007 suburban 6.0 and the number 4 intake lifter took a dive.i have already started to disassemble the engine as i plan on replacing all the lifters and reassemble the engine as i never had any other problems with it. WATCH THIS VIDEO https://youtu.be/1MJMf3nnQhQ. It has the orings in place, that seals the towers. AFMis good for gas mileage and can be 5-7 percent more fuel-efficient under certain conditions. Another option is to plug it entirely if the AFM is already removed. Oh,the throw away vehicle has 77,000 miles and has always had meticulous maintenance . Solenoids, new lifters also test voltage to solenoid pack all good their, It is replaceable.. just remove oil pan and it will be on top at the filter. According to CarComplaints.com, several drivers have had excessive oil consumption issues for a while from 2007 to 2011. My point is that the engine likely on uses dod a small percentage of the time so can not really imagine that the delete causes any more issue than normal which may be the high oil consumption but do all of these engines with dod consume a lot of oil? Dont drive it if you have a dead cylinder due to afm failure. GM should recall every vehicle with this terrible design flaw! After reading these forums Im a little concerned about my decision to stay with GM. Ive heard the Brand name Range thrown around in other forums, This is how mine started outthen 6 months later on the highway the service stabilitrak light and flashing engine light came on. 1. Been driving with no issues but I did notice that the AFM disabler removed a P0449 code (Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction) dont know if this is a coincidence or they are related??? That might show up if you cut the filter and looked for debris in the pleats. [] Here is a guide on how to turn off AFM: https://www.onallcylinders.com/2017/11/30/how-to-delete-or-disable-active-fuel-management-afm-on-gm-… [], [] Guide to disabling AFM: https://www.onallcylinders.com/2017/11/30/how-to-delete-or-disable-active-fuel-management-afm-on-gm-… [], [] Here is an article on how to deactivate AFM. Plus the 5.7 has its own problems with VVT reliability and the rest of the truck is flimsy junk. 8000 grand for the repair mine was 1,700.00 to repair, I had a 2004 small block v8(4.8) 331,000 miles on the truck,it was the usual on the maintenance front axles,etc. All ready done valve job . I called my service station and they told me to get it in ASAP. I quites down to nothing after running for about a minute. It depends on the failure mode of the lifter however, certainly worth a try. A 14 gmc 5.3 Sierra 85000 miles The Definitive Guide to LS Engine Specs and LS Engine Upgrades, LS3 Engine Upgrade Guide: Expert Advice for LS3 Mods to Maximize Performance - OnAllCylinders, LS Engine Bore & Stroke Chart - OnAllCylinders, http://www.autoserviceprofessional.com/article/91652/ticking-gm-v8-lifters-and-dtc, Range Active Fuel Management Disable Device, LS9 6.2L Engine Upgrade Guide: Expert Advice for LS9 Mods to Maximize Performance - OnAllCylinders, LMG 5.3L Engine Upgrade Guide: Expert Advice for LMG Mods to Maximize Performance - OnAllCylinders, L59 5.3L Engine Upgrade Guide: Expert Advice for L59 Mods to Maximize Performance - OnAllCylinders, L76 Car Engine Upgrade Guide: Expert Advice for L76 Car Engine Mods to Maximize Performance - OnAllCylinders, LH8 5.3L Engine Upgrade Guide: Expert Advice for L20 Engine Mods to Maximize Performance - OnAllCylinders, LH6 5.3L Engine Upgrade Guide: Expert Advice for LH6 Engine Mods to Maximize Performance - OnAllCylinders, LFA 6.0L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More - OnAllCylinders, LFA 6.0L Engine Upgrade Guide: Expert Advice for LFA Engine Mods to Maximize Performance - OnAllCylinders, LZ1 6.0L Engine Upgrade Guide: Expert Advice for LZ1 Engine Mods to Maximize Performance - OnAllCylinders, What the New LT2 Mid-Engine Corvette Reveals About the Future of GM LT Engines, All the Torques: How Summit Pro LS Truck Camshafts Help Truck Owners Maximize Performance, LMF 5.3L Engine Upgrade Guide: Expert Advice for LMF Mods to Maximize Performance - OnAllCylinders, L98 6.0L Engine Upgrade Guide: Expert Advice for L98 Mods to Maximize Performance, LQ4/LQ9 Engine Upgrade Guide: Expert Advice for LQ4 & LQ9 Mods to Maximize Performance - OnAllCylinders, Range AFM Disabler Reviews | Range Technology AFM Disabler 2019, LS3 Engine Upgrade Guide: Expert Advice for LS3 Mods to Maximize Performance, LM7 5.3L Engine Upgrade Guide: Expert Advice for LM7 Mods to Maximize Performance, LS4 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More, L76 6.0L Car Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More, L96 6.0L Engine Upgrade Guide: Expert Advice for L96 Mods to Maximize Performance, LC9 5.3L Engine Upgrade Guide: Expert Advice for LC9 Mods to Maximize Performance, LH6 5.3L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More, LZ1 6.0L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More, Chevy 4.3L Vortec Common Engine Problems - Vortec 4300 V6, https://www.onallcylinders.com/2017/11/30/how-to-delete-or-disable-active-fuel-management-afm-on-gm-…, The 5 Most Common Chevy EcoTec3 5.3L Engine Problems, Chevy 6.0L Vortec Engine Problems - Common Vortec 6000 Problems, The 4 Most Common Chevy EcoTec3 6.2L Engine Problems, Gen 3 vs. Gen 4 LS Engines: How to ID Them (Video), Ask Away with Jeff Smith: Upgrades to GM LS 6.0L 4x4, LM4 5.3L Engine Upgrade Guide: Expert Advice for LM4 Mods to Maximize Performance, L33 5.3L Engine Upgrade Guide: Expert Advice for L33 Mods to Maximize Performance, Mailbag: Choosing an Engine Management System for an LS-Swapped '82 Olds Cutlass. Now Im here tring to figure out what to do. Hopefully he can free up the stuck/collapsed lifter. Im crossing my fingers it does the trick! Ive only put a straight pipe exhaust, intake, and a boost controller on it. A lot of drivers reported losing 2-4 quarts of oil in between oil changes. https://www.amazon.com/gp/product/B00BR1R8N8/ref=ox_sc_act_title_1?smid=A359W9MWR50ZG1&psc=1. The 2nd went with a conventional valvetrain. Cylinder deactivation works to save fuel, but it may not be for the reasons you think. The motor I pulled was a 2007 LY5 with about 77k on it. 1981 Cadillac V 864. if GM wont make a dependable truck for 60,000 Toyota is sure to take over even with very poor gas mileage . I asume low oil pressure cant make some of the DOD lifters to malfunction? My ignition lock cylinder is completely stuck in lock position with the steering wheel locked as well. Everything else looked good. Do not pay that amount. If I put my truck in manual 5, it doesnt try to go into V4 mode. GM claims fuel improvements ranging from 5%-15% depending on the engine. Now im thinking of buying a disabler asap, am i in the clear to do so without the oil splashing problem? The LFA was upgraded with AFM and [], [] improvement over AFM, DFM has 17 different cylinder firing patterns and switches seamlessly between them to provide just []. 4,7 plugs foul runs rough at idle. It has plenty of oil pressure and I put all new lifters in it. Plugs spark fine engine has power at higher RPMs although it is still in Limp mode / stabilitrack message, even after driving it a few times above 60 MPH then clearing errors with handheld programmer. Fuel pump failure is the most common problem and can occur due to a number of reasons, such as a clogged filter or a faulty pump. You were lucky that it worked. Its got a hundred forty-five thousand miles on it. $8500.00 fix. They lasted one year with big problems. Active Fuel Management (AFM) is a trademarked General Motors technology that improves gas mileage by shutting down half of the cylinders under light-load conditions to reduce fuel consumption. From what Ive read new and low mileage engines with no issues is ideal to do a afm delete, tune, or use of a disabler. Lost number four I got the AMF disabler anyway and so far so good. Fortunately, the old engine hadnt been shipped back to the remanufacturer. It does seem that when they start goingthey go quickly. I asked my local Chevy dealer, from whom I purchased the engine, to find out why the oil pan lacked the fitting. If so what would the vin code be? With 40000 Dummy Me thought gm learned its lesson in 1981 but they never did and I Too am stuck with a Buick thats just waiting to self destruct. The cost of just rings $4,000.00, [] Disable your Chevy AFM: https://www.onallcylinders.com/2017/11/30/how-to-delete-or-disable-active-fuel-management-afm-on-gm-… [], [] like front timing cover, knock sensor location, cylinder head style (cathedral ports), AFM (Active Fuel Management), and other components are key clues to which engine family youre looking []. . If someone didnt want to spend gas buy a Toyota. I was looking at the 08 escalade hybrid with dod on its 6.0 so wondering if the delete would contribute to the high oil consumption and therefore would adding the deflector be a good idea. If you ignore it and keep driving, odds are you will destroy the cam as well. I couldnt agree with you less, yet I respect your opinions. If AFM has been deleted, its common just to use a Dorman drain plug (m14 x 1.5) to remove the pressure relief valve entirely. This allows the engine to run in V8 mode. No it runs fine on sylinder one but not on 6 or 7!!! [], [] as the LS engine familys hybrid engine in trucks and SUVs. He claims that GM used the same engine whether it was or was not equipped with AFM in this year and model? Just shut AFM off. Some guys have been able to use a tool through the top with the cover off to get it to release. I sold them when they were new. It also has an electrical connector on the back. The 1st design (built prior to April 1, 2006) was had afm components but wasnt connected. With 40000 In October of 2010, GM added a deflector (p/n NAL-12639759) to keep oil from being sprayed directly on the rear cylinders. Weve written some articles on the various Vortec engine upgrade paths, such as this one on LQ4 and LQ9it discusses some of the better options for choosing a cam intended for use in a truck. It has 8,000 miles on it. Wed recommend a call to our partners at Summit Racing. Why doesnt anyone make an aftermarket set of replacement AFM lifters that are the right length but DO NOT COLLPASE! Engine starts but is throwing a misfire on cyls 4,7. The valve itself is part number W0133-2574213. Mine did at the exact same time. Also, it is the easiest way [], [] for the 2010 Chevy Camaro SSis also a Gen IV 6.2L aluminum-block V8, but with the addition of Active Fuel Management and Variable Valve Timing. Why have you not gotten a reply from Mr Nutter, Buying a Silverado 6.2L. I have a 2011 GMC with over 162,000 miles on it and it runs great! I guess what Im really trying to ask is,, are there any cons/disadvantages to installing the AFM delete Electronic module? Delete the AFM, buy a tuner/chip, take it to a performance place and get an actual tune done that fixes it, replace the AFM lifters with non AFM type, change other engine components with thisetc..etc..etc??? im going to plug in a dissabler when im done to keep it V8 mode all the time. Hi Brian, With 44, its a enormous Jon to remove the oil pan. What would you do if you were in my situation? After a stint in the U.S. Air Force, Brian Nutter studied at the Houston, TX-based School of Automotive Machinists in 1997. Never did strand me on the side of the road way. The engine will switch to operating on fewer cylinders when cruising at a constant speed. How is that an improvement. I service plenty of these vehicles with AFM, and the ones I have to open up the engine for repair because of a failure doesnt surprise me anymore. The detergent. On June 4th you stated The vehicles affected were 2007 to Feb. 2011 AFM equipped engines (Aluminum or Iron block-L94, LZ1, L99, LC9, LH6, L76, LFA, LMG, and LY5) I am looking at purchasing a 2012 Tahoe with the LMG per the build sheet. I traded in a 2004 4.8 L with 256000KM on it that ran like a clock and never gave me a problem. I would rather stay a V8 full time than deal with AFM issues in the future. This new lawsuit is essentially identical to the previous. I didnt even think about AFM until I got to drivee it on the highway and encountered the 4 cyl syndrome. Put everything back together proper torque, gakets, valve seals, etc. they are known to become plugged. I have the towing package on my 13 Tahoe LTZ. Did gm make a non-dod version of the 5.3 with iron block that would work in my application? For a primer [], [] cathedral port cylinder heads and used Active Fuel Management (AFM). We were getting a code that the cam position sensor was not functioning properly. Dont follow just anybody I know where it originates but in todays world I found found it to be amusingly accurate. I have 1999 5.3 Silverado that gets 19-20 miles to the gallon all the time this shit pile with dod only gets 14 miles to the gallon. Plug the tuner into your GM vehicle's OBDII diagnostic port, and follow the instructions provided to update the engine control module's program The new program will make sure that AFM never engages. Once the failure has occurred, the AFM shut off methods other than that probably wont work. Its ribbed with solenoids on the underside. What was happening to the first is slowly (or quickly in your case) happening to the others. Install the AFM disabler now or wait until my warranty just about to expire to get this AFM issue resolved? My 2013 LC9 just had #6 lifter fail, got a misfire code but the ticking gave it away. . The problem I am facing is that I want to drive this vehicle for at lease another 77K and do not want to drive my vehicle with this AFM issue. The wife however found this deal on an Envoy Denali . The oil is baked on to every component. I had #4 lifter stick and now i am looking at replacing the engine with a non-dod version. AFM sucks Im paying for a truck that has broke down twice replace the cam and lifters and now its broke down again 105000 miles never heard of that in a 350 Chevrolet. However, the fuel savings are not always as much as expected. He stated if I continued to exceed 4500 RPM it would blow the lifters out. I was getting ~ 30 mpg, so I love that. Im considering just replacing the 5.3 ( should be LMG, 2007 YUKON ) with the L96 crate engine. Or not because it is the cast iron block and not he aluminum block? evaporation experiment ks2, why does my skin taste like onions,