Replaced engine new engine isnt running right.

I have 97 k1500 pickup. The engine was shot so I found a Tahoe with a bad transmission but the same 350 vortec. I swapped the engines. it seems to run fine in park when I give it gas, but when I drive it around it acts like its only hitting on two cylinders. It acts like its running rich. The Tahoe only had two o2 sensors but the truck has duel exhaust and has two before the cadys and two after. That's about all I know. Thanks for any advice!
Experienced mechanics share their insights in answering this question :
From what you’re described, it sounds like you have two different engine and harness problems. You may also have a problem with the new engine ignition not being compatible with the other engine. In order to get the car working properly it will require more work than just swapping out the engine.

You may have compatibility problems with the engine harness not being the same. Another possibility is that a component, like the crank or cam sensors, can be different depending on the vehicle. Take a look and see if they all match. Pay special attention to the sensor rings, make sure they are the same and undamaged.

If you want a second opinion on this, consider having the engine inspected by professional mechanic to diagnose your engine problem and ensure a clean installment.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

These vary from car maker to car maker. However, the typical break-in period is within the first 500-1000 miles. If you give in to the common urge and start pushing your engine too hard early on, you risk accelerating this process, causing minute imperfections in the size and shape of engine components.
If you just had the engine replaced, then have the system scanned to see what is causing the light to come on. There may simply be something that was left loose or a sensor problem that needs to be repaired.
If you run your engine correctly with proper loading on your vehicle, you should start to notice increased engine performance. You will feel the engine running a lot more smoothly and even increasing the miles per gallon. However, the recommended break-in time for a rebuilt diesel engine is around 150 hours.
In short, yes, they do. Most automakers advise a brief mechanical run-in, or break-in period, at least for the first few weeks someone takes home a new vehicle. Each vehicle will have different requirements, owners are encouraged to take a closer look at their vehicle`s owner`s manual for specific information.
The reasons for a check engine light turning on can range from something minor like a loose gas cap to something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
It is possible that your automobile`s check engine light has come on because of a false alarm. This being said, if the engine control module (ECM) turned on the check engine light for no reason, the ECM could be malfunctioning itself. This crucial part is the heart of your automobile.
Doing an engine break-in used to be a standard procedure with new cars. And it`s still the case that you should avoid running the engine at high RPM for the first 1,300 miles. Experts recommend a maximum 3,500 rpm and 90 mph in diesel models and 4,500 rpm and 100 mph in gas models.
New engines offer a long-term, reliable solution to your car troubles. On the other hand, used vehicles may come with their own set of engine problems. If your used vehicle replacement encounters engine issues, you could end up paying twice as much in the long run.
Starting at around 800 to 1,000 km, once the engine has reached its running temperature you can accelerate a bit more aggressively and rev the engine more. As the mileage on your odometer creeps up, you can rev the engine higher before shifting and start to use the full range of the engine`s power.
With today`s rings, especially moly-faced versions, this can be achieved in a very short period of time and certainly within 20 to 30 miles of street driving. In WOT dyno testing, likely the rings are seated by the end of the first few runs.
Once you have your oil, make sure your car is again parked on level ground. Your engine should be cool, and you should wait at least 20 minutes to give the oil time to drain fully back into the sump. 4. Check the level again using the dipstick, and keep adding oil in small amounts until you are happy with the level.
Starting at around 800 to 1,000 km, once the engine has reached its running temperature you can accelerate a bit more aggressively and rev the engine more. As the mileage on your odometer creeps up, you can rev the engine higher before shifting and start to use the full range of the engine`s power.
Once you have your oil, make sure your car is again parked on level ground. Your engine should be cool, and you should wait at least 20 minutes to give the oil time to drain fully back into the sump. 4. Check the level again using the dipstick, and keep adding oil in small amounts until you are happy with the level.
A: Most new cars don`t require running-in, but you certainly won`t do your engine any harm by taking it easy for the first few hundred miles. It`s worth checking your car`s handbook to see if there`s a specific running-in procedure, though.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

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.

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.

Replaced engine new engine isnt running right.
ANSWER : From what you’re described, it sounds like you have two different engine and harness problems. You may also have a problem with the new engine ignition not being compatible with the other engine. In order to get the car working properly it will require more work than just swapping out the engine.

You may have compatibility problems with the engine harness not being the same. Another possibility is that a component, like the crank or cam sensors, can be different depending on the vehicle. Take a look and see if they all match. Pay special attention to the sensor rings, make sure they are the same and undamaged.

If you want a second opinion on this, consider having the engine inspected by professional mechanic to diagnose your engine problem and ensure a clean installment.

have code p0017 dealer is telling me i need a new engine is this because they dont know what to do next to my car .?
ANSWER : As you may have already learned, the code p0017 indicates an issue with the crankshaft position sensor. This would mean that that transmission doesn’t understand the speed and can’t send the same information to the transmission. I don’t think your car needs a new engine just based on this code alone. With all the repairs that you’ve done, it’s possible that the ECM is faulty and is producing the code. I recommend having a professional mechanic, such as one from YourMechanic, reset the codes and inspect the Check Engine Light thoroughly in order to make a proper diagnosis.

replaced bad coil pack and new coil not sparking car starts but runs rough engine light on blinks sometimes
ANSWER : Hello and thank you for your questions. If your engine was rebuilt about 10 months ago, the question is to determine if the management system has been installed as well. With the symptoms that you are having, it sounds like the coil packs are old and in need of replace. You replaced numbers 1 and 4 and now number 6 is not firing. I recommend replacing number 6, 2, 3, and 5. This will ensure that you have all 6 coil packs that are new.

Just because the coil packs are okay during a test doesn’t mean that they are functioning correctly. Coil packs on Buick vehicles from 1998 – 2005 last between 150,000 to 200,000 miles. I also recommend having your fuel injection system flushed. Unless you have new injectors, the old injectors could cause a cylinder to fail, even though it is working correctly. These symptoms can cause the engine to have a rough idle and rough running during conditions. If you need assistance troubleshooting the rough running condition, I recommend having a professional, like one from YourMechanic, inspect the car and move forward with repairs.

Engine light came on after washing engine 2 days later then went off and oil lamp came on three times – driving – went off.
ANSWER : Well, you have a couple of questions here and not a lot to go on, so I’ll address them as best I can. Your Check Engine light indicates that a trouble code from a sensor has been registered in the engine’s computer. You’ll need to have a certified technician, like one from YourMechanic, connect a scanner/code reader to the car’s diagnostic connector to inspect what trouble codes have been stored. Trouble codes are a starting point for any technician; in most cases, simply replacing the sensor that sent the code will not remedy the problem and it’s necessary to "look past" the code to get to the root cause.

If your oil pressure lamp is coming on after washing the engine but you haven’t previously noticed problems like knocking or valve noise, or haven’t seen the oil lamp come on before, there’s a good chance that the engine wash caused a short in your oil pressure sending unit or its associated wiring or connectors.

As for whether the Jeep is worth more investment, Kelly Blue Book puts the resale value of an ’04 Jeep Liberty at about $3,500. You’ve replaced a lot of parts, including a new transmission, so if the vehicle is reliable and solid right now it may be worth holding onto it for awhile longer. If you have to keep replacing parts at this point, though, you may be reaching the point of diminishing returns.

If you need assistance with this, consider YourMechanic as one of our mobile technicians can diagnose your car’s Check Engine and Oil Pressure Light firsthand to avoid any unnecessary repairs. Best of luck to you!

1973 Jeep CJ-5 304 V-8. Vehicle starts right away but dies as soon as the key is released to "run" position.
ANSWER : Hi there. I would assume that your problem is related to the ignition cylinder on the dash. It’s possible that either the ignition is damaged, or perhaps a ground wire behind the dash is loose. You should be able to access this area through the firewall on the old CJ5.

When engine is cold it studders and misses but when warm it runs juss fine no codes and engine light isnt on why is this happening
ANSWER : When an engine is cold it will need more fuel to run correctly. I would recommend having the fuel injection system cleaned to see if it helps to run better.

If the flush does not work then a scan will be necessary to see if the engine’s air and coolant sensors give the correct reading when cold and as it warms up. If either one is off, replace it. Also cleaning the mass air and throttle body of any dirt and soot would likely help as well.

Contact a certified mechanic if you need assistance with performing these checks. They will be able to diagnose your misfiring issue and make the appropriate repairs to get your car running smoothly again. Good luck.