2G P0505, P0446, P0420 Codes, smoke and hesitation problems.

[tbag1122]

Hello all, I am new to dsm's and turbo cars. I just recently purchased a 99 gsx with 72000 miles on it. Just wanted this car because I thought it was a great looking car. Plus I wanted better gas milage than my jeep was giving me and awd was a big plus. I am using this as my daily driver and have no intentions on modifying it. Before I bought it I test drove it twice and all seemed good. I even got a mechanic to look it over and he said everything looked ok. I am still happy with my purchase but I do have some concerns. I've been wanting to ask this for a couple weeks now but I've been doing a lot of research so i don't ask a question that has been answered before. Now I know some of these concerns have been addressed but my main question will be is one of these problems causing all the other ones.

So when i picked my car up I drove 30 miles to go home and as soon as I enter my town the check engine light came on. Also my dad followed me home and he said he saw blue smoke coming out of my exhaust. Now occasionally when I'm downshifting to slow down and stop at a stoplight I'll see a huge cloud of smoke. But not all the time. From what i read it could be turbo seal, valve stem seals, piston rings, and pcv valve. Well i replaced the pcv valve and for some reason it seemed to have gotten better but I'm not certain on that. So I popped of the intake side of the turbo(the hose leading to the air filter) and there wasn't any oil in there. I also reached my fingers into turbo and didnt really feel any play in any direction. I took off hose going into throttle body and again no oil in there. So then I took off inlet side of the intercooler and that was pretty moist with oil. But from what I've read, it is normal for some oil to be in there. It wasn't dripping out of there either. So does this rule out the turbo? Now when i first start the car absolutely no smoke comes out. So i would think that would rule out the valve stem seals as well, leaving me with a possible piston ring problem. I plan to buy a compression tester very soon so i can test that theory.

Now for the codes. I have 3 of them. P0505, idle air control fault. P0446, evap fault. P0420, catalyst efficiency fault. Now my main question would the oil burning be causing any of these faults? My idle is a little funky which is why the p0505 code is probably being thrown. But could the burning oil be messing that up some how. I have ran a bottle of injector cleaner but that didnt help.

Now for the hesitation. Usually occurs in 2nd and 3rd gears between 1700 and 2800 rpm's. Don't feel it in any other gears so that part is weird to me. But is this the oil burning dirtying something up making it act this way. Now the previous owner said he changed plugs and wires pretty recently. But it could've been b.s. so i will change those as soon as possible to rule that out. I did check the gap and it was at. 028. The plugs didnt look horrible but I'm not much of a mechanic. I guess it could also be fuel filter but still curious if the burning oil ain't doing some thing goofy here.

Ok it's getting late and I think I've dragged this out long enough. I will add that I'm not a total noob when it comes to mechanics but I'm not great at it by any means. Used to be a mechanic in the army but never did the trouble shooting just replaced parts when told to. Also my tools are extremely limited. Also like i said this is my daily driver so if I don't feel confident in doing something i will take it to a mechanic. Just want to get some advice so i don't get murdered in labor costs of trouble shooting the problem.

Thanks for any advice in advance.

Travis

 

[CleverDSMusername]

how often do you notice it burns oil? if its like every 2 weeks or so then it could be whatever internal problem my car had, i never did take the time to pinpoint the exact cause of my N/T burning oil but i did change my oil as soon as i could & went with Royal Purple 20w-50 w/ a half qt. of Lucas Synthetic Oil Stabilizer (keep in mind i live in TX & its in the 105-115 range right now), ever since i've used that combination it hasn't burnt any oil or leaked any since & it been roughly 500 miles or so. So i'd try going to a stage or two thicker with some of that Lucas Synthetic Oil Stabilizer to see if that fixes it. My suspicions are that i either had valve guide issues or oil rings that were trying to deteriorate, but since the car feels like it has plenty of power for a 1G N/T (pretty much ruling out funky compression across the cylinders from the side effect of having leaky oil rings), i feel more like it has leaky valve guides.

As for the hesitation issue. does it only happen in those gears & revs you stated when the engine is below the "normal" operating range? if so, let the car warm up right to the low end of the "normal" range & see if that helps.

As for the DTC's i'm not sure what to tell, except, if that idle air control valve peters out on you, you won't be able to keep the car running for long after you get it started if you manage to get it started with it not working.

hope was of help
Jacques (pronounced Juh-keiss, not the french way. just fyi)

 

[nickk90]

Id change the PCV valve and see if it stops. Look under the exhaust manifold to see is oil is leaking out. It could also be the turbo check for shaft play.

Look under the car and see if their is a cat. and is the evap canister is still there.

The oil could have killed the cat. if it is still there.

Id also change the plugs they could be oil fouled and causing the idle problem and code.

How many miles are on the car?

Sounds like valve stem seals are most likely the problem.

 

[miguelmcv]

Replace all the parts mentioned from the CEL, Your hesitasion could be because of the malfunction ICS (P0505), for your evaporator, do what stated before, check to see you have all the emission system, if not, then you have to put everything back, if you have everything), then, replace the evap (P0446), and about the Catalytic, it might be bad because all the oil passing through and messing everything, But once again, check to see if you still have it, if you don't have it, then you need a new one or hack it.
Concerning the smoke, It sounds like valve steam, Did the plugs were wet when you removed them?, if they were dry, then it will be valve steam or turbo seals, But, if the plugs were wet, then, it could be your piston rings.
Also, a Boost Leak Test would be good for the hesitation.

 

[tbag1122]

how often do you notice it burns oil? if its like every 2 weeks or so then it could be whatever internal problem my car had, i never did take the time to pinpoint the exact cause of my N/T burning oil but i did change my oil as soon as i could & went with Royal Purple 20w-50 w/ a half qt. of Lucas Synthetic Oil Stabilizer (keep in mind i live in TX & its in the 105-115 range right now), ever since i've used that combination it hasn't burnt any oil or leaked any since & it been roughly 500 miles or so. So i'd try going to a stage or two thicker with some of that Lucas Synthetic Oil Stabilizer to see if that fixes it. My suspicions are that i either had valve guide issues or oil rings that were trying to deteriorate, but since the car feels like it has plenty of power for a 1G N/T (pretty much ruling out funky compression across the cylinders from the side effect of having leaky oil rings), i feel more like it has leaky valve guides.

As for the hesitation issue. does it only happen in those gears & revs you stated when the engine is below the "normal" operating range? if so, let the car warm up right to the low end of the "normal" range & see if that helps.

As for the DTC's i'm not sure what to tell, except, if that idle air control valve peters out on you, you won't be able to keep the car running for long after you get it started if you manage to get it started with it not working.

hope was of help
Jacques (pronounced Juh-keiss, not the french way. just fyi)

Ok thanks for the reply. Well I used to notice the big cloud of smoke at least a couple times a day. But when I replaced the pcv valve it seemed to have cut that down a little. I would say I see it once every other day now. So would that have actually solved that problem and what I'm seeing is residual from that. I'd say I did that about 500 miles or better ago. I haven't had to add any oil yet either so it's not burning that much. I will try what you suggest on my next oil change. Couple more thousand miles to go for that.

As for hesitation yes it only happens in those gears & revs. It also happens at all operating ranges. I'll notice it right away after I start it up and take of. I usually let the car idle for at least 30 seconds before taking off. I'll also notice it after driving 20 miles. If that's what you mean?

Yeah I don't know what to tell either on IAC code. I'd hate to start throwing parts it don't really need at it. One time it will idle at 1200, then 1000, and get down to 800 rpm's. It will also drop when turning things on like the ac, lights, applying the brakes, and turning the steering well. It won't recover until I stop using them either. Not sure what a normal rpm range is for this car, but it seems to like 1000 rpm's.

Id change the PCV valve and see if it stops. Look under the exhaust manifold to see is oil is leaking out. It could also be the turbo check for shaft play.

Look under the car and see if their is a cat. and is the evap canister is still there.

The oil could have killed the cat. if it is still there.

Id also change the plugs they could be oil fouled and causing the idle problem and code.

How many miles are on the car?

Sounds like valve stem seals are most likely the problem.

The car has just over 72,000 miles on it as stated in original post and also stated checked for shaft play (didn't feel any) and I already replaced the pcv valve.

Well I had to to get a wheel bearing replaced last week and got to look under my car on the hoist and the cat is still there. Didn't think to look for the canister, not really sure where to look. I'm guessing close to the gas tank. Now one thing I forgot to mention last night is mostly every time I come to a stop light/sign I smell the exhaust pretty badly. Is it possible that I have an exhaust leak near the cat causing the p0420 code. Also the old owner had the o2 sensors both replaced around 71000 miles. (I got the service records for proof of no b.s. on that one). I will look for the canister (if possible with out lifting the car) once I get outside.

Replace all the parts mentioned from the CEL, Your hesitasion could be because of the malfunction ICS (P0505), for your evaporator, do what stated before, check to see you have all the emission system, if not, then you have to put everything back, if you have everything), then, replace the evap (P0446), and about the Catalytic, it might be bad because all the oil passing through and messing everything, But once again, check to see if you still have it, if you don't have it, then you need a new one or hack it.
Concerning the smoke, It sounds like valve steam, Did the plugs were wet when you removed them?, if they were dry, then it will be valve steam or turbo seals, But, if the plugs were wet, then, it could be your piston rings.
Also, a Boost Leak Test would be good for the hesitation.

I think I'd like to get to the root of the oil burning problem before replacing ICS because correct me if I'm wrong couldn't that possibly be messing up my injection system causing my idle issues. I'm not trying to doubt anybody here I just don't want to waste a lot of money.
The plugs seemed dry when I pulled them.
I'll have to do some searching on the boost leak test. If memory serves me correctly that's usually a homemade deal and I need an air compressor which I don't have. I will say that it doesn't have any problems that I can tell when in boost. The gauge in my car would go up to about 11psi which seems normal. Unless I'm not understanding the need for a boost leak test.


Now I see a couple of you mentioned valve stem seals. Not trying to doubt you's here but wouldn't I see smoke right away on a cold start up. The way I took it when reading about them is when the engine stops the oil will drain down the bad seal and pool on top of the piston which would cause smoke immediately after start up, which I'm not seeing at all.

Thanks everyone for the replies so far, I really do appreciate it.

 

[nickk90]

The EVAP canister is either under diverside headlight, under the baterry or since you have a 99 by the gas tank.

I would go ahead and get new plugs and gap them. They are supposed to be changed every 15,000 anyway. See if it helps. Also might as well change the fuel filter.

There ia a video on youtube on how to test the ICS. All you need is a DVOM.

My car had bad valve stem seals and would only smoke after it warmed up. I changed them when i did my timing belt it wasn't to hard to do.

 

[tbag1122]

Well I was trying to see the canister but my car is too low to get my noggin under the car too look. Does the evap fault really have an affect on the driving. If not I'll worry about that problem later. I'm going to order new plugs and wires tonight. I did notice tonight that it has bosche wires on there, will that affect anything. I know I've seen everywhere to use ngk wires.
Now is there any sure way to check if it's valve stem seals. From what i saw there isn't. Or should I do a compression check first to rule out rings. Ain't gonna lie though not feeling totally confident on doing the valve seals. The seals themselves don't seem real hard but messing with the timing belt scares the hell outta me. Which i believe is a must when doing this job. Would like to mention the timing belt was changed at 71,000 miles too.

Fortunately I actually have a digital voltmeter. Now i just gotta find the video you speak of. Thanks.

 

[TrevorS]

Definitely check the compression -- reasonable testers are available pretty cheap. If you see oil at the SMIC, that suggests either Turbo shaft play (allowing oil seepage) or piston ring blow-by exiting the valve cover breather. A compression test will help evaluate that.

PS. My understanding is valve stem seal problems will result in pooled oil burning at engine start up, but not so much afterwards. However, ring blow-by could definitely be a problem.

 

[nickk90]

the video is by jafromobile. he has a ton of DSM videos on there.

 

[tbag1122]

the video is by jafromobile. he has a ton of DSM videos on there.

thank you so much for that tip, I've been searching all morning for a good video. Here's the one I found: DSM ISC motor testing & Replacement - YouTube just in case anyone else was interested.

I will test this as soon as I can get away from my kids, they leave me no time to get anything done.

napa has the bpr6es plugs so I will go later today to pick them up and try them. I'll have to order the wires though.

I'll also pick up a compression tester tomorrow hopefully and give that a whirl. I'll need to do some deeper research on that to know how to use that. Doesn't seem to hard, but it's the stuff you do before the compression test I'm not sure of

Thanks for the help again, and I will keep posting any results I find so this thread could be of some help to someone else in the future.

Well I managed to get some stuff done today. So I will start with the test of the IAC. 1&2 was at 40.4 2&3 was at 40.4 4&5 was at 41.3 5&6 was at 40.8. So most of what I read it is supposed to be between 28-33 ohms. So is this telling me that I should be searching the junk yards for a hopefully a quality part. I just found it odd that they are all in the same range, I thought maybe one would be whacked.

I also managed to get the plugs and I borrowed a compression tester from auto zone for a 40 dollar deposit which I'll get back when I return it. So I didn't get very far with the compression test cause the hose popped a hole in it when doing the second cylinder. The 1st one I tested (closest to the timing belt) came in at 176. Then I did the next one and got 160 but I forgot to push the gas pedal down so I went to try it again and heard a pop and it wouldn't hold pressure anymore. So the 16psi difference kind of scares me. Does the gas pedal not being depressed make the difference. Either way I'll trade auto zone for a working one (hopefully they don't try to make me pay for that one). I planned on doing the test 3 times and taking an average, so we'll see if I have time tomorrow to attempt that again.

So I decided to put the new plugs in since I already had them out. I triple checked that I got the gap right at .028. It honestly felt like the hesitation/sputtering got better but that just may be placebo affect of me hoping that it got better.

Ok, so after taking back 2 compression testers I finally got a good one at least for a little while. I was able to do 2 test before the damn thing popped a hole in the hose again. Not sure if I was doing anything wrong to make it do that? Anyway's here are my results (these are readings from right to left, closest to timing belt to furthest away in order). 1st test: 165, 150, 162, 160. 2nd test: 166, 155, 165, 165. I wish I was able to do a 3rd one to take an average but i'm not going back to get another tester. Maybe next week I'll stop being a cheap ass and actually buy one, but a little scared I might pop a hole in that as well, so if anyone has insight on that I'd be glad to hear it. Unfortanatly I was unable to do a wet test either. So is this enough info for anyone to tell me that these results are good or bad? I thought if it was within 15 psi I was ok. So going off the average of both test 166 ,153, 164, 163 the biggest gap is 13psi. So that 2nd cylinder does have me concerned anyways. Is it safe to say that even though it's within the limits that it may be a start of a problem and that is why it only smokes out occasionally. So if I take "CleverDSMusername" advice about the oil this would help remedy this problem.

thanks guys.

 

[nickk90]

Service limit also says all cylinders within 14psi of each other. Was the engine warm?
I personally would do a leakdown test on cyl. 2.
Is the car losing coolant at all?

 

[tbag1122]

Service limit also says all cylinders within 14psi of each other. Was the engine warm?
I personally would do a leakdown test on cyl. 2.
Is the car losing coolant at all?

Well i drove it to get another tester so it was plenty warm then. But then i went to do the test the damn hose came off the fitting so i took my girls car to get a different one cause i had everything apart so it cooled a little( like a 20 min delay). But before i tried it the 2nd time I put it back together and let it run til the fan came on and did the 2nd test immediately after that. So the 2nd test was definitely at operating range. I don't have the equipment to do the leak down test so maybe I'll call around tomorrow to see about getting that done.

As for the coolant I really don't know. Do I go off the bottle near the radiator? I've looked in there a couple of times but it didn't seem to drop at all.

Also just wondering if you had any ideas on the numbers i got on the IAC?

Thanks.

 

[TrevorS]

FWIW -- I recommend buying a compression tester and seeing what it says with your pistons dry and then with some oil added to the cylinders to transiently improve compression sealing. If you removed the intake pipe from the compressor and could feel no play either sideways or in-out on its axis, then the turbo should be good. Given you replaced the PCV valve, and there's no blue/black smoke at engine start, it just sounds like ring/cylinder wear to me.

PS. If you own an OBD II car, you should really consider picking up an OBD II code scanner. True, Autozone will scan it for free, but it's much less convenient than if you have your own.

 

[tbag1122]

FWIW -- I recommend buying a compression tester and seeing what it says with your pistons dry and then with some oil added to the cylinders to transiently improve compression sealing. If you removed the intake pipe from the compressor and could feel no play either sideways or in-out on its axis, then the turbo should be good. Given you replaced the PCV valve, and there's no blue/black smoke at engine start, it just sounds like ring/cylinder wear to me.

PS. If you own an OBD II car, you should really consider picking up an OBD II code scanner. True, Autozone will scan it for free, but it's much less convenient than if you have your own.

I plan on buying a compression tester. Would you know why the hose keeps popping on the loaners though. It seems like it's happening after I crank it and right when i go to disconnect it, I hear a popping sound. Am I doing something wrong or is it cheap shit. The brand they have is oem.

Also i used an auto zone brand pcv valve. Will this matter?

On a side note I actually got a baux elm 327 a couple weeks ago so I'm able to check and reset any codes with the torque app.

 

[tbag1122]

Well I just can't get any luck with these compression testers. I actually went and bought a new one and unhooked everything and went to do the test and it wouldn't hold any pressure at all. Like the side relief value was stuck open. I tried 2 separate cylinders and made sure it was pretty snug inside spark plug hole so I don't know WTF. On a side note though I think I found a little vacuum leak and it helped out my idle a little. You see my boost gauge stopped working a couple weeks ago so in my search to remedy this I found a little plastic fitting connecting 2 hoses had a substantial crack in it. Got a kit full of them from auto zone and the gauge works again and the rpm's are steady around 900. The hose is ran through the right fender and I think when I closed the Hood it got pinched. I wish I could be hopeful and say that might get rid of my p0505 IAC.fault but the boost gauge used to work and it was still throwing that code. But I cleared them anyways and will see if it comes back. So I guess tomorrow I'm off to get yet another compression tester. If the next one doesn't work I'm giving up for a week at least. Gotta go for my 7 days of 12 hour shift stretch.

 

[nickk90]

what brand tester did you buy?
I have a OTC paid like 50 bucks never had a problem. I have their leakdown tester aswell and paid like 65 buck for that.

 

[tbag1122]

The brand name is Licota. Yes it is a cheapo, 21 dollars from a local tool shop. But for the amount I planned on using it I thought it would be good enough. The brands autozone was borrowing was OEM. I'll go back to the shop tomorrow and see what they say, maybe i'll step up to the next best tester.

Here's one like I bought. LICOTA Compression Tester Kit

 

[tbag1122]

Ok, so I'd like to update this since it's been a while since I've posted if anyone is still watching.

So last week what I got done. First I got my plug wires (NGK) (was bosche). That didn't seem to change anything but I do feel better knowing I got new wires on there and should be good for awhile.

Then I replaced my fuel filter (fram g6553). That was a pain in the ass let me tell you. Had to take a couple of attempts at it. "Almost" took it in to get that done. Glad I didn't cause that probably saved me 70 dollars or more. Anyways, that didn't seem to improve anything either.

So I then took my car to a muffler shop to inspect for leaks and they didn't find anything. I thought for sure they'd find something cause I can smell exhaust at almost every stop when my windows are down. Also I did that cause if there was a leak before the rear O2 sensor that would throw code P0420 right? Also I was wondering would that code cause my fuel to be delivered differently since the mixture works of the O2 sensors (I think, or am I way off?)

Then yesterday I cleaned my throttle body while in the car. I took off the hose and elbow, covered the holes at the bottom and sprayed some carb cleaner in there and wiped it down, then sprayed some on my towel and wiped it again and let it dry for a while and put it back together. I also took the IAC out again and wiped it with my carb cleaner cloth. Also checked the ohm's once again and they were all around 41. So after doing some searching it seems 40ohm's is normal for the black type, which is what I have. Additionally I was playing with the BISS screw and noticed it was out quite a bit. Well I was gonna take it out and check the O-ring but I ran out of time. So I just decided to tighten it all the way down. Now my rpm's are averaging around 750. So I got to take it out and test it this morning and the the sputtering is still there. No codes yet but I drove less than 10 miles so I know it will take a little before it goes through the cycles. Although my idle seems pretty steady now and even when I turn my ac on it doesn't drop anymore. Though the car seems to kinda shake a lot at the lower rpm's. Is 750 a little low for this car?

Still haven't gotten a good compression test yet. I got a replacement for the last POS and that didn't work either. I actually got the fitting stuck in the hole for a moment. Went to turn the hose out and it spun freely on the fitting not loosening it a bit. I'm guessing this is where it was leaking. So I had to pull the hose off (didn't hit myself in the face like last time). Then I ended up taking a small T-bit and it was tappered a little so I pushed it in the hole of the fitting and pushed semi hard and it turned right out. Thank god, that scared the shit outta me.

Lastly, I thought I'd mention it's been at least 3 weeks since I seen that big puff of smoke come from the exhaust. So I'm not really sure what I did. The only things I changed back then was the pcv valve, and plugs. This is not to say it isn't smoking on take off, I'm just saying I'm not seeing it at all anymore. I also had my girl follow me home one night and she didn't see any smoke. Mind you this was at night and it would probably be difficult to see smoke when dark out.

So things for me to do yet. Get a good compression tester and do the full test without problems hopefully. Leak down test if those numbers are goofy. I also will be looking into the boost leak test. I think I could probably make one by the few examples I've seen. Just not equipped with a air compressor though, so we'll see. I probably would have got more done but it's just to damn hot out there.

Is there anything else I can check for this? I'll look through this thread when done typing this since It seems like I didn't do someone's suggestion yet.

Thanks for everyone's help thus far, I really appreciate it. This has been quite a learning experience so far. It gives me something to do in my free time but I ultimately would rather have this thing running solid and not have to do this. I'm just glad I haven't broken anything yet messing around with my car.

Travis