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| # | Post Title | Result Info | Date | User | Forum |
| Answer to: Lexus V6 Twin Turbo Longevity? | 21Relevance | 2 years ago | Justin Shepherd | Submit Your Question HERE | |
| Twin-turbo V6s look good on paper, if you don't drive like a maniac, but as soon as that turbo kicks in, it's cramming more air into that cylinder than a naturally aspirated engine, and more fuel is being injected to compensate, massively lowering MPG. Most people don't drive conservatively, especially with a turbo. They like the fun it has. My wife's Mustang is an EcoBoost, and I tend to put it through its paces the once-in-blue-moon time I drive it. Combine that with GDI fuel injection, where 200 PSI at idle is the norm (it was 60 PSI with ordinary fuel injection) and new piston rings that I can squeeze with my bare hands is a recipe for engines prematurely wearing out if you drive like a maniac constantly. Gas is a solvent, and it bypasses weak piston rings at high RPMs, getting into the crankcase, that then creates more work for the PCV valve. Old engines like my Pontiac that have a carburetor are more durable than new engines. A more viscous oil is required because the piston rings are very stiff. Gas isn't easy to blow by the pistons, thus it's not producing a lot of work for the PCV valve. Weak piston rings for MPG, combined with turbochargers and GDI, are a recipe of premature engine wear if you're always hard on the throttle. | |||||
| Answer to: Should i purchase? 2000 Chevy 2500 6.0L | 21Relevance | 2 years ago | Dad2LM2 | Submit Your Question HERE | |
| Getting a working 3/4 ton for 5 Grand is pretty good, even a 20 year old one. The engine situation will need some homework on your part. The GM 6-liter was notorious for piston slap (excessive side to side movement of the piston in the bore), which led to premature engine wear. I suspect that was the reason for the replacement engine. But that raises the question: what are the details of the new engine? Does it have piston slap, too? Did the engine builder fix GM’s mistakes? (You can mitigate piston slap by using taller pistons with a slightly larger diameter.) For sure, I would want to listen during a cold start (when the slap is more pronounced). But it’s probably ok. Don’t forego an inspection, though, because a truck that old is bound to have other issues you’ll want to know about. | |||||
| Answer to: 1.8 liter improvement | 21Relevance | 4 years ago | Justin Shepherd | Submit Your Question HERE | |
| What are you talking about? The piston doesn't extinguish the flame, consuming all of the fuel available in the power stroke extinguishes the flame. The burn is finished before the piston reaches Bottom Dead Center. If it tried to return toward Top Dead Center while burning were still in progress, you would hear a knocking sound or the engine would outright tear itself apart. The flame itself lasts only a tiny fraction of a second in the overall power cycle, the resulting heat and pressure rise are what drives the piston back down. Advancing ignition timing when the engine is revving up and retarding it when revving down is how you control the finish point of the combustion. The fuel/air mixture doesn't burn at the same rate at all RPMs. | |||||
| Answer to: ATS Chemical Treatments | 21Relevance | 4 years ago | Wayne Benham | Submit Your Question HERE | |
| 2012 Volvo S60 T5 (2.5L 5 cylinder) oil consumption - will I benefit from ATS 505 CRO oil additiveBought at 20K miles from Volvo. Meticulous maintenance. Now at 113K and using oil depending on how I drive. Highway cruising on new oil = little or no oil use. Local driving (with turbo use) adding 1/2 qt every few hundred miles. I know there is a class action lawsuit on this. Volvo's solution per service bulletin TJ29871 is to install new rings. I assume the oil ring design is changed to eliminate the problem. Since I'm not going to do the expensive ring change, is it possible that I would benefit from trying the ATS 505 CRO oil additive to clean out the carbon-clogged rings? A Volvo oil consumption class action lawsuit alleges a piston ring recall should have already been issued for Volvo vehicles equipped with 2.0L 4-cylinder or 2.5L 5-cylinders engines. Those engines are allegedly defective because of the pistons, piston rings and/or piston heads. The oil consumption class action alleges the piston rings cannot clear engine oil from the side of the cylinder walls during the downstroke. | |||||
| Answer to: 2001 Lexus ES300 Dragging After Brake Job | 16Relevance | 4 years ago | Doc | Submit Your Question HERE | |
| When you replace brake pads, you usually have to gently push the piston back into the caliper to account for the thicker shoes. As the piston is now in a new position in its bore, it may be stuck in the "on" position causing the drag. When this happens, I usually rebuild the calipers. I could be wrong about this but I believe you need a scanner to set the ABS module piston position to properly bleed this brake system. | |||||
| Article: Turbocharged Engines | 16Relevance | 5 years ago | Razmig Bartassian | Submit Your Question HERE | |
| Turbocharged Engines Almost all auto manufacturers are moving towards direct-injected turbocharged engines. This is because turbocharged engines are more efficient compared to naturally aspirated engines, in terms of fuel efficiency and power. Turbochargers allow smaller displacement engines to have more power compared to their naturally aspirated counterparts. I have created this article for those who are considering a vehicle with a turbocharged engine, as well as those who already own one and willing to learn how they operate and perhaps troubleshoot any issues. As you read this article, you will get an idea on how complicated turbocharged engines really are, but learning how a turbocharged engine works will at least give you the necessary knowledge on how to approach any issues should they arise. So my goal with this article is to help those who have any sort of issues with their turbocharged engine, or those who just want to learn about them! How it Works: A turbocharger is simply an air compressor that forces air into the engine to increase its volumetric efficiency, and therefore, power. The turbocharger itself has two main components, the impeller and the turbine. The impeller is found on the cold side (or compressor side) of the turbo, and it's responsible for sucking in air to force into the engine. The turbine is found on the hot side (or exhaust side) of the turbo, and it's connected to the impeller by a shaft and center bearings. The exhaust gases from the exhaust manifold are used to spin this turbine, and therefore, powers the turbo by spinning the impeller. Now that we know how a turbocharger works, let's look at the turbocharged system as a whole: We just saw that the turbocharger compresses the air it sucks in, but when the air is compressed it generates heat, which increases the temperature of the air and lowers its density. You might be wondering...what's the point of a turbo if it forces in hot air into the engine? Hotter air doesn't make more power, does it? Well, the compressed air needs to get cooled down before it's forced into the engine. This is where the intercooler comes into play. The intercooler is a heat exchanger (usually air-to-air, but can also be coolant-to-air) that is responsible for cooling down the compressed air before it is forced into the engine, and this cooled air is known as charged-air, and the extra air pressure created by this charged-air is known as boost. This is why turbocharged engines use additional MAP sensors (manifold absolute pressure) along with a MAF sensor to meter the air entering the engine. This is the air that provides the engine with more power. Cooler air is more dense, and denser air has more oxygen molecules in a fixed volume. The more oxygen an engine can get, the more fuel it can inject, and therefore, the more power it can make. Remember that this air is being forced into the engine, and this ultimately increases the volumetric efficiency of the engine. Volumetric efficiency is exactly what it sounds like: the engine's efficiency of sucking in the proper amount of air to fill up the cylinders' volume. Naturally aspirated engines typically have a volumetric efficiency of around 80% (80% of the cylinder's volume) to a maximum of 100% (full volume of the cylinder), and this is because naturally aspirated engines use vacuum to intake air into each cylinder. The piston traveling downwards during the intake stroke acts like a "syringe" that sucks in air, but most of the time this effect doesn't completely fill the cylinder's volume with air (i.e. 80% of the volume is filled with air), especially at higher engine speeds when the valves and pistons are moving faster. Now in the case of turbocharged engines, the air is being forced into the cylinder rather than being sucked in by the piston, and this basically allows 100% of its volume to be filled with air and perhaps even more air than the given volume as the turbo builds boost (more than 100%). This is why turbocharged engines are known to have a volumetric efficiency of 100% or more. It is the increased volumetric efficiency that makes the engine more powerful. Now let's talk about the two other components that are used in a turbocharged system: the bypass/blow-off valve and the wastegate. The bypass/blow-off valve is used to release excess boost out of the pipes found between the turbo outlet and throttle body. When you let off the accelerator pedal, the throttle plate closes, leaving the pressurized air inside the pipes with no where else to escape other than back out the turbo impeller. Boosted air escaping out of the turbo impeller is known as compressor surge, and it is detrimental to the turbo's health because it puts stress on the impeller and bearings. So the bypass/blow-off valve that is found either on the turbo housing or charged-air pipe releases the excess boost when the throttle plate closes to prevent compressor surge. This valve operates off a vacuum line connected to the intake manifold, so when the throttle plate closes, the manifold pressure drops relative to the pressure of the charged-air pipe, which causes a pressure imbalance that allows the piston to open up to release the excess boost. The wastegate is responsible for regulating the amount of exhaust gases used to spin the turbine on the exhaust side, which regulates the amount of boost a turbocharger can generate. It is a physical "gate" that opens and closes an alternate exhaust path that bypasses the turbine side of the turbo. Again, it uses a vacuum line connected to the intake manifold to monitor boost, so when the intake manifold reaches maximum boost (determined/set by the pneumatic wastegate's spring force), the wastegate opens so that the turbo doesn't over-boost the engine (safety feature). *Note: Modern turbocharged engines now use electronically-controlled bypass valves and wastegates instead of pneumatically-operated ones. So the ECU uses various MAP sensors instead of vacuum lines to monitor boost, which helps the ECU determine when to open/close the bypass valve and wastegate. Misconceptions: The biggest misconception about turbochargers is that they wear out the engine faster due to the the extra power and pressure associated with them. Well, this isn't exactly true because engines are built specifically for a turbocharged application. Auto engineers are not taking naturally aspirated engines and just slapping turbos on them. The engine itself has to be built with stronger internals in order to handle the turbocharger's boost. When a person turbocharges a naturally aspirated engine, does it blow up most of the time? Yes, because that engine wasn't built to handle boost from a turbocharger. When you buy a turbocharged engine, does it blow up most of the time? No, because it was specifically designed and built to handle boost. Now I am NOT saying that turbocharged engines are trouble free. In fact, turbocharged engines have a bigger potential for issues compared to a naturally aspirated engine, and this is because of the complexity (which we just observed). For example, if you get a code for running rich on your naturally aspirated engine, then either it's getting too much fuel or not enough air or sometimes both. In terms of diagnosing air restrictions, you just have to deal with the air box, intake pipe, or the MAF sensor depending on the issue. But if you get a code for running rich on your turbocharged engine, then you have a whole turbocharger to deal with because it's part of the air intake system. It could be the bypass valve stuck open, it could be the wastegate stuck open, it could be the physical turbine/impeller that is stuck. In other words, there are a lot more components to check when you have an issue relating to the turbo. In my opinion, if you know exactly how a turbocharged engine works, you'll have a significantly better time diagnosing and fixing the issues. When I first bought my BMW 428i, I learned the ins and outs of how the turbocharged system works specifically on my car (and in general), so if an issue ever comes up, I will be better prepared to deal with it. And it will also give you a better idea on how to take care of it to prevent issues. Turbocharged engines don't like slow engine speeds, they like to be driven hard to get the turbocharged system working to its full potential. Carbon build-up is the main killer for turbocharged engines, and so you want to get the turbo nice and hot to burn off any carbon before it builds up and causes problems with the wastegate, turbine, or impeller. The PCV system on these modern turbocharged engines vent the crankcase pressure into the intake before the turbo, leading to potential carbon build-up on the impeller itself. Direct injection paired with turbochargers only exacerbates the carbon build-up issue. Direct injection is well-known for causing carbon-build up on the intake valves because gasoline doesn't "wash" over them like it would in port injection. This is why carbon cleaning is a MUST on turbocharged engines every 60-80k miles or so. Troubleshooting Tips: When it comes to turbocharger issues, you NEED to data-log to see how the engine is operating while driving. Turbocharged engines operate completely different at idle and under acceleration. Data-logging is necessary in order to see how the turbo is functioning in terms of the boost it is making. Do some research to find out how much peak boost your turbo is supposed to provide and at what engine speed. Then compare and see if your turbo is providing peak boost, under-boosting, or over-boosting. Some example trouble codes relating to turbocharger issues: P0299 -- Turbocharger Under-boost condition P0234 -- Turbocharger Over-boost condition P0045 -- Turbocharger boost control solenoid circuit/open P0047 -- Turbocharger boost control solenoid circuit low P0172 -- Engine rich running condition P0171 -- Engine lean running condition Things to check: Induction piping and Intercooler: You want to make sure all the clamps/C-clips from the turbo all the way to the throttle body are sealing the pipes and intercooler tightly. Turbocharged engines operate with a pressurized system, so loose piping/clamps WILL cause boost leaks. There are many ways to test for boost leaks, and you can search up some potential ways on YouTube and Google. Vacuum lines/Electrical connections: Vacuum lines are VERY important on turbos that are pneumatically operated (depends on your application...refer to the note stated earlier). If any vacuum lines are cracked or disconnected, it will cause issues with how the turbo operates. Now if your engine uses an electronically-controlled bypass valve and wastegate, then check the condition of the wires and harnesses to make sure they are not corroded. Wastegate: The wastegate determines how much exhaust gas is diverted to the turbo to spool it, and therefore determines how much boost the turbo makes. You want to make sure the wastegate is operating properly. You can have someone rev the car while you look at the wastegate. You should see the wastegate arm "push" or "pull" as the person revs the engine. If you don't, then the wastegate may be your problem. But of course, you can search up other ways to test your wastegate for your specific engine on YouTube and Google. You should check the wastegate for an under-boost or over-boost condition. Turbo Bypass Valve/blow-off valve: You want to make sure the bypass valve is working as it should. This valve controls when to relief excess boost pressure when you let off the throttle. If it is stuck open, then the system won't build any boost in the first place. Check the vacuum lines (or electrical connections if electronically-controlled) associated with it. You should check this valve for an under-boost condition. MAP sensor(s): You want to make sure your MAP sensors are giving correct data to the ECU on how much boost the turbo is producing. Maybe give it a cleaning as it may be super dirty. As a final note, I highly recommend using an API SN+ rated oil in ANY turbocharged engine to prevent LSPI (Low Speed Pre-ignition). SN+ rated oils use a different formulation (the phrase "calcium down, magnesium up") to reduce the risk of LSPI. It was determined through various experiments that the calcium content in oil increased its ability to ignite under high pressure and heat, which therefore, causes LSPI. You can learn more about SN+ oils here and LSPI here. I hope this article was useful to those who are considering or already own a turbocharged engine. - Razmig Bartassian (@razmig) | |||||
| RE: Toyota Oil Burning | 16Relevance | 5 years ago | Kerem | Submit Your Question HERE | |
| They key part is "It's come to my attention that the 2AZ-FE engine can burn a lot of oil in 1 thousand miles. This is due to the piston rings in engines 2007 to 2009 or so fail to let oil pass through the piston and back into the crankcase, thus burning it all up in the combustion chamber. For most people this problem happens at around 100,000 miles, which is sad considering piston rings are supposed to last much longer then that." Even though I am not mechanically experienced at all I think that this could cause major harm. I hear that a Toyota TSB said cylinder misfire could occur and engines just blow up. Good job Toyota! | |||||
| Answer to: ford ranger coolant smells like gas | 16Relevance | 5 years ago | Razmig Bartassian | Submit Your Question HERE | |
| @omgitzjojo A piston ring wouldn't cause an EVAP system leak. A bad piston ring will cause fuel dilution in the oil, low compression, or oil burning but it shouldn't have anything to do with an EVAP system leak or even fuel getting into the coolant. I would first start with a compression/leak-down test on all the cylinders first to see if the piston rings, valves, and head are in good shape...then go from there. | |||||
| Answer to: Rear Brake Rubbing | 16Relevance | 6 years ago | Razmig Bartassian | Submit Your Question HERE | |
| Did you push the caliper piston all the way back into the caliper? This is crucial because the new brake pads are thicker, so it WILL rub against the rotor if the piston adjustment hasn't been fully reset. If you did push the piston all the way in, then there is something wrong with the fitment (the rotor is thicker than normal, the brake pad compound is thicker than normal). Did you perform the break-in procedure where you accelerate to 60 mph and fully depress the brake until you get down to 20 mph a few times? This helps readjust the pistons and shaves down the brake pads a little. | |||||
| Answer to: 2016 Accord engine tapping | 21Relevance | 4 years ago | Justin Shepherd | Submit Your Question HERE | |
| Do you have any codes? Does the engine idle smoothly, other than the noise? piston slap is caused by the cylinder bore and piston not quite fitting together perfectly, the piston head is slightly loose in the block, and it shifts back and forth as the engine runs, until it gets hot enough that the expanding metal seals the gap again. Generally, that's caused by insufficient lubrication, and it can appear in engines that have been driven really hard for an extended time. You might try running a compression test on the engine when it's cold and look for a deviation in compression. The cylinder with noticeably lower compression is indicative of piston ring/ cylinder wall or valve sealing problems. You should find a better mechanic. He should know you can use a mechanic's stethoscope to listen to the valvetrain and see if the noise is coming from the top of the engine, or in the middle of the block, especially if he's charging $2,000 to replace something and not guaranteeing it will fix the problem. A spun bearing and rod knock is a pretty distinctive sound. It comes from low in the engine and has a heavy banging sound, you would know it if this were the issue. | |||||
| 01 Saturn SL2 Engine Problems Question | 21Relevance | 5 years ago | skizzym | Submit Your Question HERE | |
| Hi there, I have an 01 Saturn SL2 that has a Cylinder 4 misfire with 0 compression. I've done everything I possible can to fix the issue (replaced 4th fuel injector, o-rings, cleaned fuel rail, tested the fuel injector plug [it works]), other 3 cylinders have lower compression than what they're "supposed" to have according to factory specs. A while back ago it was under recall for worn piston rings (surprise GM product quality 🙄). Originally I was driving 70 on the highway and it suddenly lost power (I was thinking oh the cat is clogged?) I couldn't get above 60MPH, started idling really rough but drove fine so I drove it back home and then that's when I started doing all the testing... Basically my question is:Is this engine done? Could it be the worn out piston rings just need to be replaced? It also burns oil (is that from the piston rings?). Would the piston rings being worn cause the compression issues? Sorry if this is all over the placed, can't structure the thoughts. If I were to rebuild this engine, what exactly would I have to replace? Any help would be greatly appreciated. Thank you! | |||||
| Answer to: Do I need a maintenance or is this a sign of things to come? | 21Relevance | 5 years ago | MountainManJoe | Submit Your Question HERE | |
| There is a "fix" for this problem which is widely available all over the internet. I'll copy pasta one post I quickly found which does an ok job summarizing: A banging 1-2 shift is a very simple repair and no, the transmission does not have to come down. First, check for codes. If none are found do the following: Drop the pan back down, remove the 1-2 accumulator housing and pull the piston. Check for a torn piston seal or broken spring, but moreso for a wobbled out piston hole, which is probably the culprit. Now, if all these items are okay, the 1-2 check is bad (unlikely). This is where it starts to get dicey unless you've been into about a million of these things, because the valve body has to come down (you don't even wanna go there). I think you're gonna find a bad 1-2 accumulator piston. Wish you would have hollared before you changed the oil because you could have repaired this thing in just 10 minutes. Allan I say "fix" in quotes, because even though your 1-2 shift might improve, it's a sign that your transmission is getting tired, and other problems may soon follow. Instead of investing the time/money to do this, you MIGHT consider a more drastic solution. | |||||
| Answer to: '06 Mazdaspeed 6 Power Loss, Sputtery feel in Acceleration | 21Relevance | 5 years ago | Razmig Bartassian | Submit Your Question HERE | |
| @joshhuckSo if a cylinder turns out to be lacking in compression, then it may possibly indicate a stuck valve. Remember that your engine is an interference engine, but carbon build-up wouldn't cause the valve to stay completely open (because if it did, then your engine would have been toast by now). It may just mean that the valve is not sealing correctly when it closes because of the carbon build-up around it. Most of the time, carbon build-up causes the valve to "stick" shut during the intake stroke when it should be open, causing a lack of air in the cylinder. But regardless, if you want to go an extra step to figure out what's causing the low compression, then you need to conduct a leak-down test. So rather than the piston producing the compression while turning over the engine, you use an air compressor to add compression and monitor the pressure (to check whether the cylinder maintains that pressure). The whole point of this is to look for a "leak-down" in compression, and if there is a leak-down you can find out what it is. For example, if you pressurize the cylinder and start hearing air hissing out of the intake manifold, then it means the valves are not closing properly, or if you hear air coming out of the oil cap on the valve cover, then it means the piston rings are really worn out, etc. So a compression test just gives you a basic understanding of the engine's health, whereas the leak-down test is more for diagnosing the cause for low compression. I would do a "dry" compression test first and then a "wet" one to see if all the cylinders are within the compression range (130-180 psi). A "wet" compression test will give you an idea on what's causing compression loss. You add like a teaspoon of engine oil in the cylinder to "seal" the piston rings, so if the compression increases on a "wet" test then the piston rings are a bit worn (which is normal as the engine gets older). But if the compression stays the same during a "wet" test, then it may be a sign that the valves are not sealing properly. And remember that you're looking for ALL the cylinders to be within +/-10% of each other (so for example [150, 145, 148, 130] would show that cylinder 4 has some problem). I personally use Liqui Moly's SN+ oil, and now they even make oil formulations for Asian cars instead of just European. But you can use any SN+ oil... | |||||
| RE: Should i top off coolant or do a flush? | 16Relevance | 1 year ago | Justin Shepherd | Submit Your Question HERE | |
| There's a thermodynamic term for any liquid that has reached its boiling point that I forgot until just now, that is a "saturated liquid." It makes sense, too, the water can't absorb anymore thermal energy without boiling, so it would technically be "saturated". | |||||
| 2004 Toyota corolla Coolant flush | 16Relevance | 2 years ago | cmd_car | Submit Your Question HERE | |
| Hi all, I did a coolant flush on my 2004 Toyota corolla and after the first drain (about 4L pink liquid came out) , I filled the coolant tank with clean water, close the radiator cap and let the car idle for 20 minutes. I forgot to put the heater on full blast. I drained the liquid (still pink but about 2.5l) and refill again with clean water. This time I put the heater on full blast and drove the car for about 20 minutes. Car blows cold air. I let the engine cool down and open the radiator cap and let the car idle for few minutes. slight improvement as air ... | |||||