Revving Up Your Engines: A Step-by-Step Guide to Diagnosing and Repairing a Smoking Engine

As we take a closer look at this Toyota, it's clear that something is amiss. The check engine light is on, and the car is smoking under the hood. Our first step is to figure out what's going on and how to fix it. We'll start by opening up the engine and plugging in our trusty scan tool. The code P0171 indicates a lean condition, which often means there's a vacuum leak somewhere in the system.

Our next move is to take a closer look at the freeze frame data. This will give us more information about what happened when the car was stationary, as that's where the lean code tripped. By analyzing this data, we can start to narrow down our search for the source of the problem.

Now that we've got our bearings, let's take a closer look at the engine itself. The car is smoking under the hood, so it's clear that there's an issue with the engine's combustion process. Our first stop is the valve cover gaskets, which are leaking and causing oil to spill onto the exhaust system. This is not only messy but also potentially damaging to the engine.

To fix this problem, we'll need to remove the valve cover and clean out any debris that may be accumulating inside. We'll also replace the old brittle gasket with a new one, making sure to apply a bead of sealant around the edges to ensure a tight seal. It's worth noting that these old gaskets have a tendency to leak unless we take extra precautions.

Once we've got our new gasket in place, we can start reassembling the engine. This involves reconnecting the ignition coil assemblies, removing the wiring harness, and carefully reinstalling everything in its original position. We'll also need to tighten all the bolts securely, making sure not to overtighten anything.

As we work on the engine, it's clear that our car has a history of vacuum leaks. To fix this problem once and for all, we'll need to replace the PCV (Positive Crankcase Ventilation) valve. If these valves become stuck or clogged, they can cause problems with the engine's combustion process. By replacing them, we should be able to eliminate any lean codes that may have been triggered by vacuum leaks.

Finally, it's time to put everything back together and test our repairs. We'll plug in the ignition coil assemblies, reconnect the wiring harness, and start up the engine. If all goes smoothly, we should be able to drive away with a car that's running smoothly and without any smoke coming from under the hood.

In this article, we've covered the steps necessary to diagnose and repair a smoking engine. From analyzing freeze frame data to replacing the PCV valve, every detail has been accounted for. By following these steps, you should be able to fix your own car's problem and save yourself some money in the process.

"WEBVTTKind: captionsLanguage: enrev up your engines alrighty here we havea Toyota that just came over it'ssmoking under the hood and the checkengine lights on so let's figure outso let's open it up and plug in the old scan tool all right it's got code p0171 system toolean so it's running too lean which isoften a vacuum leak in thefreeze frame data we can see that thislean code tripped when the vehicle speed waszero so what happened when the carwasn't even moving which is almostalways vacuum looks on now we'll try tofigure out why it's smoking under thehoodwell we're smoking on the backside hereso let's take this plastic crap off andlook inside come off comes the plasticcover do two things anyway they don't doit yeah we're going ahead and get themoff as we look around we can see there's a ton of oil right here dirty old oilhow'd you can see here the valve covergaskets leaking then it gets on theexhaust so we're gonna change that yeahwhen you look closer on the front youcan see the oil is leaking all over herefrom the valve cover gasket to so we'lltake all the pieces off to get the valvecover off while we're at it we'll lookfor vacuum hoses in a cracked really cuzthat'll often trip a lean code whereit's sucking air start with all theholes is that are in the way then go tothe back sideyeah well disconnect all the ignitioncoil assemblies and remove the wiring harness out of the waywhen we'll take each one of thecoil off the bolt just comes off here comes the coilsput them up here and we'll do allfour gotta get them out of that roomthe little bolts that hold the valve cover on it's all bunch of them okaybolt off and don't forget the oneshiding down here I got hitting all overthe place they get a little pry barand pry it upeventually the stupid thing comes off then youcan see the old brittle gasket comes offthen wipe all the corrosion off the edgeof it so it's nice and clean because youwant a nice shiny surface to put the newgasket anything in the way pull it off and clean if off all shinnyand get the new gasket set and thespark tube seal then you slide it allin and push it hard and this is reallyall car so I'm gonna put a little 3mgasket sealer around a two because these old ones have a tendency ofleaking unless you do that this stuffworks great I like the black stuff youjust squeeze it all around the wholething what an artistic job don't withthe seals on the top in place you flipit over carefully placing onwiggle everything around there's notmuch working space on it goes the tightenthe ten millimeter bolts in start in the middle and work your way out don'tforget the back ones they're hidden awaybut their in there make them finger tightthen start in the middle withthe ratchet and make them all nice andtight then put all the hoses back onthen put the ignition clothes back firstget them finger tight then finish themoff with the ratchet then plug theignition close in and for now if youremember had it running to lean code soI checked them there's no hoses that itcome off so I'm gonna change the PCVvalve if they leak they'll often suckair so we're gonna change that toobecause if the PCV valve sticks openit's up there then it runs link this isjob on this car, they sure stuck it on this car, you'd never get alongwithout the socket that's for sure now Ican finally at least using my handsthey got carried away with themselves inthis one how it comes then we'll put thenew one in these disease you're puttingin there is getting it up try to twistit could've been a lot shorter they kindof got carried away themselves now it'sgetting snug so we'll finish it up and putthe hose back on come on put the stupidbeauty cover back on it lines up withthese holes it's always a fun jobthen close the hood and start it upso if your car's check engine light iscoming on and the car smoking under thehood you know how to fix it yourself, soif you never want to miss another one ofmy new car repair videos, remember toring that Bell\n"