Oldsmobile 88 Shudders and Dies at Idle P0102 plus Evap small Leak P0442

howdy folks welcome back today we're working on this 1999 Oldsmobile 88 it's got the legendary 3800 Buick v6 under the hood and it runs but just barely I went out and pulled some codes looks like it probably has a mass airflow sensor problem and there's a laundry list of other issues as well so I pulled the codes with the autel here looks like p0 one or two for the mass airflow sensor that's probably gonna be our main problem a small evap leak p18 one one maximum adapt and longship okay no big deal so yeah same thing here but if you go to these additional DTC's she's got a laundry list here looks like most of the monitors have not run so I don't know probably because the mass airflow sensor is bad but yeah it basically hasn't run any monitors traction control Hey so got here let's go over here well I don't know it's running good now so yesterday when I did the same thing the long term fuel trim was minus 18 and the mass airflow sensor was showing zero so it's actually reading high now so normally your grams per second would be about equal to your displacement at idle so we'd expect to see about 3.8 maybe 4 grams per second I know maybe it fixed itself yeah so you see what happened with the mass airflow sensor when I tapped it you know good so now let's actually reading low let me get a blunt instrument [Music] yeah check out the fuel trims now [Music] so the mass airflow is stuck at 1.75 C our fuel trims way- [Music] let's back probe the mass airflow sensor plug here should be all attest this with the multimeter 3 point 6 volts alright so we got almost 11 volts there now I should be able to go here it hurts this should be a frequency generating mass airflow sensor so see right now it says 115 Hertz it doesn't change so that's it click on our long term fuel trim - 28 probably gonna die they won't know what to do it's gonna cool their frequency matches what we saw on the multimeter too so we can actually trust the scan tool [Music] alright guys that's as far as we have to go super simple diagnosis no wiring diagrams no scopes required you do need a multimeter that will read frequency but most decent multimeters these days will do that so we could break out a wiring diagram if we want but all you need to do is just do musical chairs there and find your power and ground so we got 11 volts to the sensor that's good enough and then the third leg is gonna be a frequency generated by the mass airflow sensor so that's typical GM and the frequency should match the mass airflow so the higher the frequency the higher the flow this one is stuck at 115 Hertz which must be correspondent to 1.75 grams per second that must be a baseline so this car needs a mass airflow sensor which I already ordered we're gonna swap that out first see what happens with our fuel trims I imagine that's gonna take care of that issue and then we'll go after the evap leak I will warn you guys I am not strong on evap systems hey you guys plan on moving out anytime I finally got us a new mass airflow sensor that was kind of an ordeal so this is what came out of the car and if you look up this part number right here they'll find out that this is an AC Delco reman sensor and that's what i wanted to buy but my parts guy talked me out of it the way he broke it down for me it was like this the Delco reman sensor is about fifty percent more expensive than the aftermarket sensor and they have a one-year warranty and they don't they don't last he says they replace a lot of them the new sensor from ACDelco is twice as expensive as the aftermarket sensor also has a one-year warranty and he said they're either a rebadged hitachi or rebadged delphi and they also don't last so when he talked me into doing was buying this bwd sensor it's actually made by standard motor products it is made in the USA it's new it does not have a core charge and it has a lifetime warranty he said they're all junk basically the point the difference is the warranty so so there it is designed and built in USA and looks to me like it's gonna be the right one now as far as a lifetime warranty I can tell you that the guy who owns this car is staring down his 93rd birthday and he's a tough old boy so I don't have any trouble believing that we're gonna be putting another one of these in this car someday but at least it won't cost us anything for parts and labor is you know basically zero these are super easy to change out so that's what I did you guys can go ahead and type down in the comments about you know all the horror stories with these mass airflow sensors it's a known issue on these engines but basically what the parts guys told me is that there aren't any good options your best option is just to get one that you can get replaced when it fails again these GM mass airflow sensors have these tamper proof Torx screws so it takes a time on focus special tamper proof Torx bit or you can do what I do a lot of times to just break the little tab off turn it into our regular Torx I guess we could call it tamper resistant not tamper proof there's always a way much better see our fuel trim is actually positive now instead of negative so you want our total fuel trim to be around 10% it's kind of high right now we'll see if it comes down got it down to normal idle before we'll see the right numbers here Oh careful and getting a second opinion what do you think kiddo is I look good okay hey guys we're looking good so total fuel trims down to around six it's probably gonna get better to to see our mass airflow it's finally settled down so it should be around 3.8 but 4.5 is not out of the realm of possibility so it looks good yeah I'm happy with it all right guys let's have a little chat about evap systems I'm sure you're all super excited to learn about this I'm not the greatest with evap systems just because I don't work on them that much but I think we can walk our way through it and hopefully everybody will understand what's going on so the point of an evap system is to capture evaporative emissions from gasoline so if you want to do a little experiment take some gas put it in a container set it outside on a hot sunny day come back in maybe 20 minutes and see how much of that gasoline is still in that container chances are it's gonna be a whole lot less the gas is pretty volatile and at normal you know above-ground temperatures it very readily becomes a vapor and those vapors are considered by the EPA to be a form of pollution so ever since obd2 basically the early 90s automakers have been required to have evaporative emissions capturing systems an evap system that's what it is and I think California was doing it even before then so like back in the early 90s maybe even the late 80s I don't know anyway all of these evap systems basically worked the same and the basic principle is that the vapors from the gasoline in the in the fuel tank are going to get trapped by a charcoal canister and the charcoal canister basically stores the gasoline vapors and then when the engine you know the computer decides the engines at the right operating conditions it's going to open up a purge valve and use the amount of fold vacuum to suck those vapors right into the engine and it's going to burn them just like it does any other kind of gasoline and the systems you know very how they how they're set up but most of them have a few common components you have your charcoal canister here you'd have a vent valve which is gonna allow fresh air into the charcoal canister you have a purge valve which is going to allow the fuel vapors to go into the engine then you have a sensor pressure sensor that monitors the pressure in the tank and the pressure sensor is there to do several things it controls you know kind of controls how the computer runs these valves and then it's also used for monitoring so we want to know whether or not this EVAP system is working with obd - everything's basically closed-loop and we're using sensors to monitor whether or not the commands are actually being followed so on this old 88 i'm actually not even sure it has a vent bail now you're sure if we can get to the charcoal canister it's buried underneath of the ECM to find that out it might show up as a pit in our our bi-directional control so I guess we can figure it out that way but I believe on these older GM systems the way that it monitors for leaks in the evap system is it just closes the purge valve and kind of records the temperature and watches for changes in pressure when the system is completely sealed and you know if the temperature goes up the pressure should go up the temperature goes down that the pressure should go down and if it doesn't see any changes then it assumes that there's some kind of a leak so I don't want more modern car they're gonna close the vent valve and then they're gonna open the purge valve slightly and introduce a vacuum into the system then they're gonna close the purge valve completely and watch how long it takes for that vacuum to decay so basically how long it takes for the pressure to go back to nominal and depending on how long it takes determines how much of a leak you have so that could be you know evap small leaky that large leak etc now if that wasn't complicated enough what a lot of the newer cars are doing is actually running the monitor when the car is turned off so instead of opening the purge valve to introduce a vacuum to the system they actually have like a separate vacuum pump and that pump is elect electric and it runs while the cars turned off so I'm sure it has to meet some like temperature or time criteria or whatever and it's going to turn that vacuum pump on introduce vacuum to the system while it's sealed and then monitor for decay that way I don't know why that's better but that's how some of them are doing it now when it comes to to troubleshooting these evap systems the codes can point you in the right direction but it's not a you know it's not a silver bullet and usually the evap large leaks aren't too hard to find a lot of times it's gonna be the valves the evap small leaks are a little more tricky and a lot of people call those gas cap codes you know it's like that you go to autozone and get your codes read and if you have an evap small leak they're gonna say you need to replace your gas cap but I'm telling you guys that is almost never the case in fact I don't think I've ever seen a bad gas cap cause an evap code now a gas cap being left off absolutely will cause an evap code but don't think I've ever seen one from the gas cap just being bad usually what happens around here is you get small leaks in the purge valve small leaks in the vent valve or you get a rusted-out filler neck or sometimes you get you know corrosion and this if it's a steel line that runs from the tank to the charcoal canister you'll get some kind of corrosion in that the best way to troubleshoot a evap small leak is to close the system so we'll close the purge valve close the vent valve and then we'll hook up a smoke machine and the smoke machine is gonna have a small amount of pressure and a large amount of smoke and we'll basically just watch for where the smoke comes billowing out and that'll be x marks the spot all right here's my weapon of choice this is an old-school OTC leak tamer the great big one works great and I've got it hooked up the shop air regulated down to about 50 psi and if you read the beam warning labels on here it's gonna tell you that you have to use a Newark gas like nitrogen for testing an evap system I'll tell you that I've been in a lot of shops and I've never once seen anyone use nitrogen for testing evap leaks so I guess there must be some kind of flammability risk with oxygen in the evap system but I don't see how it's any different than the vent valve being open so seems a little bit overblown to me but if you want to follow the book you do have to use an inert gas with this and I believe on this car the charcoal canister is buried way down underneath of the ECM kind of in the driver's side wheel well the purge valves right here one side gets hooked to the charcoal canister the other side goes right to the throttle body that's your vacuum and right down here is a service port so that's where we're gonna hook our smoke machine up and somehow I lost my little Schrader valve adapter so we're gonna have to figure out a way to tie into this thing I ordered a new one but way things are going on it could be Christmas before we see that thing we're gonna pull the Schrader valve out which can be risky this one's in a good spot plus it's plastic so I don't think we're going to worry about screwing up the threads now it's bigger than a normal trailer valve like what you would see in a valve stem for a tire it's this larger size I don't know who makes this tool I've had this thing forever anyway it's right there and then these are left hand thread don't ask me why there we go isn't that weird I don't remember where I got these I've got two of them I think they're actually sold for air conditioning but anyway looks good for this so this is our vApp bi-directional stuff so it does have a purge seal test so we could actually do that that would be more useful probably if we had a evap large leak let's uh go here so it does have a vent solenoid interesting you can hear it clicking right there so I was wrong about that okay that's good okay we hear the purge solenoid clicking away Oh so let's close that vent solenoid start smoking just have a pretty good-sized leak okay well let's just start checking and my janky adapter here must be leaking a little bit well I'll be jiggered could it be could it be the unicorn the bad gas cap I don't know sure looks that way don't tell me it was just loose come on guy so you guys probably can't see it but there's smoke all around it up here looks pretty crusty I don't even really want to touch it so that's gonna be my recommendation there place that super crusty filler neck so it looks like the mounting tabs broken off as well pretty crusty there's quite a few problems back here in the back see this heat shield for the exhaust lay in there and then this wire for I guess for the side marker lights just hanging down looks like it's been ripped apart so we got some work to do back here well looks like the heat shields mostly intact and it attaches to this subframe so I'm thinking we can just do this kind of the quick and dirty redneck way oh yeah of course by the way I get questions almost every video about these lights so this is a Braun brand light sold at Harbor Freight I've got four of them keep them on a constant rotation so the batteries always charged works well under them it's a little bit delicate or I'm a little bit hard on it one of the two I've broken a few of them and there's no warranty on them so once you break them it's coming out of your pocket same thing on the other side a little bit less material to work with scars pretty rotten underneath as you might expect [Music] so looks like just snip it there just wouldn't be one of my videos without some kind of a wiring repair [Applause] I'll give her the old super 33 tune up here guys ever watch project farm on YouTube Murphy's got a video about testing electrical tape should find out because there are massive massive differences in quality of electrical tape from the cheap stuff to 3m it's working with a guy one time you had some Harbor Freight electrical tape was horrible all righty got the wiring tuned up here got our heat shield screwed together that should stay there until at least the end of this video I went ahead and hooked him up with some custom body Clips here for the rear bumper cover and then I found that the exact same wire was broken in exactly the same spot on the other side so I went ahead and fixed that up screwed on the other side of the heat shield that looks good it's like the sounds are there's all rotted out somebody's already put brake lines on it it's like they kind of split them all here about midships and went with an eye cup towards the back so nothing wrong with that it must been done a long time ago cuz it's all looking pretty crusty again pretty wild it's like that when there's pretty scary these things are just the holders just hanging down must have rotted off oh it's supposed to be on that stud oh well parking brake cable I'm sure that doesn't work doesn't look too bad under here I guess sauce is gonna have to be replaced eventually it's looking pretty pretty sketchy it's leaking quite a bit of oil up that's from the valve covers or oil pan or what the deal is all right folks that's it we're gonna ship it I'm pretty happy with how it runs had to replace in that sensor I think there's a chance you might get lucky on that Eve a bleak it is definitely leaking somewhere on the filler neck but if you can believe the flowmeter on the leak tamer that actually went down below a 40,000 sore one millimeter leak after I tightened that fuel cap so maybe we just had that a little bit of skew or something and this will be our unicorn one-in-a-million evap leak fixed that was the gas cap so we're gonna go for a ride make sure everything's okay but so far we're looking better it would not even idle under a load when it first came in so I think we got the engine running problem solved yeah we're running good now the check engine light may come back on once it runs a drive cycle because none of the monitors had run when we first looked at it and you know we don't know if it's broken unless the monitors run I can tell you already that the evap monitor is not going to run because it's basically out of gas I think it has to be half full for the evap monitor to run so I mean it's not a big deal there's no there's no inspection or emissions testing here so if the monitors don't run doesn't really matter but we can't confirm whether or not that evap leak is a problem you know or if it was just that cat being loose without the monitors running so just something to make the customer aware of well thanks guys for watching I think this one checks a lot of boxes yeah it's old its crusty wiring problems we got to use some obscure specialized tools you know lots of fun stuff and I used to work on a lot of these Buick 3800 v6 engines this is a fantastic engine possibly one of the best engines that GM ever made they have a couple of problems that they all eventually will suffer from well underneath of this intake manifold is the inlet for the EGR so there's your EGR valve right there's a little tube that runs up under the bottom of this plastic intake manifold and what happens is over time the plastic gets brittle around the EGR tube from the heat and then they'll actually leak cooling around the EGR tube and it'll start sucking coolant into the engine now the other problem that happens very frequently is for some stupid reason GM decided to run the coolant through the alternator bracket so if you see right down there there's a plastic elbow that comes out of the valley and runs into this alternator bracket and a lot of times those will break and you'll get a coolant leak over here on this side of the engine and actually Dorman makes a aluminum replacement for that elbow it's a lot better deal than the plastic one but it's kind of a job to change it out you got to take the whole alternator alternator bracket tensioner whole thing off the side to get down to it but these engines are famously reliable I've run into several of them that have over three hundred thousand miles on them that have never had any you know internal engine work done even in a big sled of a car like this you can easily get 30 miles per gallon on the highway and you know these aren't a powerhouse engine but they had plenty of power for for these cars I don't have hard facts to back it up but I would guess at least half of the rural mail carriers in this area are driving a car that have some version of this 3800 v6 engine

Channel: Watch Wes Work

Views: 97,557

Keywords: car, olds, oldsmobile, 88, 1999, 3.8, 3800, buick, gm, maf, mass air flow, evap, evaporitive, gas, gas cap, smoke, smoke machine, leak tamer, test, meter, probe, diagnose, fix, mechanic, p0102, p1811, p0442, small leak, wiring, heat shield, rust, crust, rot, old

Id: rk84XQdzoTw

Length: 32min 7sec (1927 seconds)

Published: Sun May 24 2020