1998 Lexus es300. Can no engine compression mean bad computer and not engine replacement?
Purchased used last month. Noticed at start slight ticking when engine engaged, but car still drove smooth– only at high speeds slightly rough idle. Nothing major until last week, car idle while driving became extremely rough. Wanted to shut off. Mechanic changed all six spark plugs. 1 of the 3 ignition packs, THEN checked and found there was NO compression in engine. Cab driver told me that the engines in that car hardly go bad and more than likely it is a bad computer. He said the engine can be replaced and I could still have the same problem. 1.How likely is it that the issue is the car co
Experienced mechanics share their insights in answering this question :
An engine computer cannot control, or affect, "basic" engine mechanical compression, that is the level of cylinder compression measured in a static test. Even in the complete absence of any engine computer, the basic specified compression of an engine will exist. If the engine doesn’t have the minimum specified compression, then the engine is mechanically broken. If the timing belt on the engine is in the correct position, the SOLE determinants of engine compression, during the typical static test, are: 1) the condition of the cylinder walls and the piston rings; 2) the condition of the engine valves and valve train; and 3) the condition of the head gasket. Consequently, if the engine has no, or little, compression during a test with the throttle held open, there is a mechanical problem with the engine, not an electrical problem. I would first check to be sure the timing belt has not slipped; that fault alone can ruin compression. If the timing belt has not slipped, and you desire a run down of your options to get this resolved, please request a rough engine operation diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.
How to Identify and Fix Common car Problems ?
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Compression loss is a result of a leak in one or more of the cylinders caused by normal engine wear and tear. If you experience compression loss in one cylinder of the engine, it can cause misfiring and poor vehicle performance. A decrease in power output is a sign of worn-out internal parts.
If you discover you do have low compression, the only solution is to replace the leaking part whether it`s the piston, piston ring, camshaft, head gasket or valves.
Once the fuel injector is spraying in a different direction, this can clean oil off the walls of the cylinder. As a result, the walls will heat up, and this will result in a loss of compression.
If one cylinder has low compression, try pouring about a teaspoon of oil into the spark-plug hole and retesting. If compression increases, it`s likely the rings are stuck or worn. The oil acts as a seal and helps close the gap between the rings and the cylinder wall through which the cylinder is losing pressure.
A spark plug ignites the combustion in an internal combustion engine. If the spark plug broke or got damaged, you either lose the compression or get no compression at all. If the spark plug breaks down, it won`t ignite the small explosion to move the piston.
Modulation of intake valve closure (IVC) timing dictates the effective compression ratio (ECR) and influences the total amount of charge trapped inside the cylinder, and in doing so allows manipulation of the concentration and temperature history of the reactants prior to and during the combustion process.
The severity of low cylinder compression can range from needing a full engine rebuild to simply needing a new head gasket. Unfortunately, the majority of compression issues are related to the internal components of the engine which can make it very costly to repair.
Is it possible to have a bad head gasket (or cracked head) without a loss of compression? Yes, if the break or crack doesn`t compromise the seal of the chambers. Your gasket can break from oil to coolant, coolant to coolant, oil to oil, or oil to outside, or coolant to outside.
Yes. If the valves are not fully closing due to a slipped chain or belt it will cause a lack of compression.
Bad, damaged, or worn spark plugs will cause the ignition coil to weaken, resulting in a cylinder misfiring. A clogged fuel injector will keep gasoline from mixing a good balance with the air/fuel mixture, resulting in a cylinder misfiring in the engine.
Modulation of intake valve closure (IVC) timing dictates the effective compression ratio (ECR) and influences the total amount of charge trapped inside the cylinder, and in doing so allows manipulation of the concentration and temperature history of the reactants prior to and during the combustion process.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
1998 Lexus es300. Can no engine compression mean bad computer and not engine replacement?
ANSWER : An engine computer cannot control, or affect, "basic" engine mechanical compression, that is the level of cylinder compression measured in a static test. Even in the complete absence of any engine computer, the basic specified compression of an engine will exist. If the engine doesn’t have the minimum specified compression, then the engine is mechanically broken. If the timing belt on the engine is in the correct position, the SOLE determinants of engine compression, during the typical static test, are: 1) the condition of the cylinder walls and the piston rings; 2) the condition of the engine valves and valve train; and 3) the condition of the head gasket. Consequently, if the engine has no, or little, compression during a test with the throttle held open, there is a mechanical problem with the engine, not an electrical problem. I would first check to be sure the timing belt has not slipped; that fault alone can ruin compression. If the timing belt has not slipped, and you desire a run down of your options to get this resolved, please request a rough engine operation diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.
I have a 2010 camry. I just recently replaced the engine with a 2014 camry engine. Now I have Four engine lights on. I replaced on
ANSWER : If you swapped the engine from a vehicle that is 4 years newer than the car is then you are going to have electrical and sensor incompatibilities that may not be able to be fixed by just a few sensor replacements. There were many changes in computer and emission related items between 2010 and 2014 engines. I would recommend having a mechanic like one from YourMechanic come to you and compare the two engines to isolate the possible differences and see if the problem can be fixed.
Diagnostic code read o2 sensor bad, replaced o2 sensor, cleared code but engine light came back on, is it caused by bad air filter
ANSWER : Hello there. Typically jump starting a vehicle doesn’t trigger an OBD-II error code. However, one of the most common misdiagnosis issues with the P-2270 is replacing the O2 sensor before diagnosing if there are any exhaust leaks. Obviously, you’ll want to check for the exhaust leaks first, repair the damaged component, and then clear the codes before scanning the vehicle again. Sometimes the electrical harness attached to the O2 sensor is damaged or dirty which will also trigger this error code. The noise and vibration may be an indicator of a loose exhaust pipe, which may be the source of the error code staying on. If you need any help, have a technician from YourMechanic come to your home or office to diagnose your Check Engine Light and make the necessary repairs.
Hey Allen. I just rebuilt (?) the engine on my 06 Acura TL. Now the engine line went on. They told me the engine? can blow up if I
ANSWER : Hi there. I think it may be a good idea to find a new mechanic. Fortunately, our mobile mechanics are able to complete most diagnostic inspections and complete a lot of repairs services at your location, and on your schedule. In what you are describing above, the current issue seems to be with your EVAP system, which is designed to relieve pressure in the fuel tank and also collect harmful vapors before they escape into the air. Now, in regards to the car "blowing up"; that’s a bit dramatic, but it is important to have your issues repaired if it’s related to the EVAP system. Here is what I would recommend. Set up an appointment to have one of our mobile mechanics come to your location to complete a check engine light inspection – (click here to set up an appointment). This will allow them to download the stored error codes that cause the light to illuminate and determine what parts need repair or replacement. Then, they’ll be better prepared to provide you with a repair estimate and complete the repairs in most cases for you.
How do you replace the rear & side engine mounts without lifting out the engine? & how do you lift the engine out?
ANSWER : Hi…thank you for your questions. If required in the application, a portable engine support bar is used to support an engine during mount replacement. The support bar has lifting capability as well so that the mount can be unloaded and removed. If a particular repair application requires a "crane" (complete engine removal for instance), such are portable these days in any event. With regard to the exhaust system repair, mechanics use ramps to gain access. Six ton portable jack stands will safely support a car two feet into the air which provides more than enough access to repair or replace any exhaust system component. If you desire replacement of the mounts, please refer to YourMechanic’s motor mount replacement service page. For exhaust leaks, please use the exhaust system inspection/repair page page. Once on each of those service pages, if you click on "Get a Quote" and enter your vehicle information (year, make, model) you can obtain cost info and schedule the service. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Check engine light
ANSWER : Hello,
This kind of condition could be related to other things such as faulty fuel injectors, a faulty or dirty mass air flow sensor, or potentially a fuel pressure problem related to the fuel pump or fuel pressure regulator. The original diagnosis of the oxygen sensor being faulty would have been the initial correct approach, however the oxygen sensor may have been properly reading an abnormal fuel condition that is actually causing the rough idle. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.
This kind of condition could be related to other things such as faulty fuel injectors, a faulty or dirty mass air flow sensor, or potentially a fuel pressure problem related to the fuel pump or fuel pressure regulator. The original diagnosis of the oxygen sensor being faulty would have been the initial correct approach, however the oxygen sensor may have been properly reading an abnormal fuel condition that is actually causing the rough idle. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.
Hi, I got my corolla 2012 engine overheated due to bad radiator, I replaced the radiator but the engine pick is not the same.
ANSWER : Hi There,
Depending on how severe the engine overheating before was, this may have resulted in a blown head gasket or a head gasket that may have partially caused a cylinder leak. When this happens, this can cause the compression in any given cylinder to drop as a result of the cylinder head gasket being damaged. As the gasket leaks and cylinder pressure (or compression) drops, this will result in a loss of power. A blown head gasket may cause a number of different symptoms. A head gasket that fails between cylinders will generally cause a misfire and potentially compression leaks from one cylinder into another. Low compression will eventually result in a rough idling engine. When the head gasket fails between a cylinder and the coolant port, coolant may leak into the cylinder causing it to be burnt with the fuel charge in the combustion chamber. This often results in misfires on startup, especially after the engine is run, turned off and restarted. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle to determine what the proper diagnosis may be.
Depending on how severe the engine overheating before was, this may have resulted in a blown head gasket or a head gasket that may have partially caused a cylinder leak. When this happens, this can cause the compression in any given cylinder to drop as a result of the cylinder head gasket being damaged. As the gasket leaks and cylinder pressure (or compression) drops, this will result in a loss of power. A blown head gasket may cause a number of different symptoms. A head gasket that fails between cylinders will generally cause a misfire and potentially compression leaks from one cylinder into another. Low compression will eventually result in a rough idling engine. When the head gasket fails between a cylinder and the coolant port, coolant may leak into the cylinder causing it to be burnt with the fuel charge in the combustion chamber. This often results in misfires on startup, especially after the engine is run, turned off and restarted. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle to determine what the proper diagnosis may be.
I have a 96 Ford ranger with cel p0340 I have recently done a timing belt, engine runs great replaced cmp sensor cel still on
ANSWER : Hi There,
This may happen for a couple of reasons. First, check to be sure that the connections to the sensor are clean and not faulty or broken. Secondly, check to be sure you replaced the correct sensor as there are two camshaft position sensors in some applications. If you need further help with this, please reach out to us here at YourMechanic as we are always here to help.
This may happen for a couple of reasons. First, check to be sure that the connections to the sensor are clean and not faulty or broken. Secondly, check to be sure you replaced the correct sensor as there are two camshaft position sensors in some applications. If you need further help with this, please reach out to us here at YourMechanic as we are always here to help.
