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Post by the94z on Sept 4, 2005 18:23:50 GMT -5
I just got the car, its a 355 with bored out prw pistons .030over. It has an lt4 hotcam with all the accessories like 1.6 rr, and so on, basically a 355 lt4 with out the lt4 intake and heads, just p&p stg 1. Car turns on ok, but at startup it alwasy puffs a small cloud of white smoke, and at idle it does it some time too....the car is idling at 900rpms in park, and 800 rpms in drive, and 600 rpms in reverse! Is this normal with this setup? The motor shakes a little bit is that normal? I have a little haze of of smoke coming from the crankcase when i open the oil thing. Runs good, just dies in reverse sometimes. Has no tune whatsoever(since no money) but I was wondering if yall could help diagnose the problem? I just changed the oil and filter with Q advanced full synthetic 10w-30 and fram toughguard oil filter, and put some slick 50 advanced forumla in it. It is running a 75 shot right now. Is there any smoke additives that will help me or any additives, or is the tune? I do need a pcv valve right now though( dont think thats it) Thanks I just really need help
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Post by jaberwaki on Sept 4, 2005 18:55:32 GMT -5
idle quality and rpm, are both functions of the tune, so yes if the car is not tuned then this could explain your idleing issues. are you sure you are not feeling the normal lope from the cam, along with what are probably worn out motor mounts? although that can be normal on a older motor i would guestion your exhaust valve seals on a brand new setup... with the oil cap of plug the hole with your hand, if there is a noticable vacume or presure on your hand, that is a tell tale sign of valve stem seals going bad... wow... none of the above, the only real synthetics out there are amsoil, royal purple, mobil 1, and imported german castrol syntec. everything else is just dyno oil repackaged.... the toughguard series from fram is one of the most resticive oil filters out there and should only be used if you see ALOT of off road in your car... other wise stick to the fram PH series and K&N oil filters. lastly DO NOT ADD ANYTHING TO GOOD OIL...... (repeat that last part 3 times) although i think you need a tune to fix your idleing troubles. i do not think your smoking trouble is in the tune... and if you do not have a good tune, knowing if you are running lean, or running fat, or how much timing advance you have , then why in the hell are you putting a shot on top of it??? that is VERY poor judgement... you might be walking a fine line of detonation NOW... what do you think would be happening every time you spray it That, i do believe has a VERY good chance of being your trouble right there.. your PCV , if clogged, will creat a vacume that can often times have oil slowly dripping into your TB making , you guessed it , smoke... if that turns out not to be it, then i would suspect a hairline crack in one of your head gaskets....
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Post by 1bad2k2ta on Sept 4, 2005 18:56:15 GMT -5
Do the white puffs linger in the air, or dissipate rapidly? Sounds like a blown head gasket. Do you smell the sweet odor of antifreeze at all?
I also posted this reply to your question on the SAFBA board.
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Post by jaberwaki on Sept 4, 2005 19:00:34 GMT -5
although i leaned the same way, i question his eye for smoke... PCV's are a 5 min fix... head gasket would be my second guess...
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Post by the94z on Sept 4, 2005 19:21:57 GMT -5
Well car doesnt overheat, radiator doesnt leak, and doesnt smell like antifreeze, just like a burnt smell, so I should redo the oil change again?........car already came with nos, i havent used it, dont want to. Sounds like a normal lope as of now, and motor doesnt shake extremely badly, motor mounts are supposedly new, (overhauled last year on july) how can i check the mounts? Thanks for the quick and ingenious responses!
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Post by metalbeast on Sept 4, 2005 19:41:59 GMT -5
Well car doesnt overheat, radiator doesnt leak, and doesnt smell like antifreeze, just like a burnt smell, so I should redo the oil change again?........car already came with nos, i havent used it, dont want to. Sounds like a normal lope as of now, and motor doesnt shake extremely badly, motor mounts are supposedly new, (overhauled last year on july) how can i check the mounts? Thanks for the quick and ingenious responses! I would not worry about your motor mounts. Do you happen to know the specs on the cam? Any cam will a smallish LSA (112 and lower) tends to have a nice lopey idle. I would definately look into getting the car tuned.
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Post by the94z on Sept 4, 2005 19:50:28 GMT -5
For the specs just look up lt 4 hotcam on google, cuz im not sure.
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Post by metalbeast on Sept 4, 2005 20:53:13 GMT -5
For the specs just look up lt 4 hotcam on google, cuz im not sure. Oh, a Hot Cam. Don't bother I know the specs. 218/228 0.525/0.525 lift 112 LSA. I am running the same cam in my Vette. My car idles at around 900 RPMs and tends to lope pretty nicely. I think this is what your seeing when you think that the engine is "shaking".
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Post by Alex94TAGT on Sept 4, 2005 21:11:08 GMT -5
Well that doesn't sound good.
First off, white smoke is typically coolant/moisture. Blue smoke is burning oil. How did the oil look when you changed it recently? Was it at all "milky'?
If it is smoking on startup, then I would second what Jaberwaki stated above. Small leaks in the valve seals can drip down onto the valve or into the combustion chamber, causing smoke upon startup.
But, if you are certain that the smoke is white, and there is an abundance of it, then it sounds like you might be getting coolant in the combustion chamber as well. This could be a bad head gasket. I've also seen some issues with head studs leaking coolant, if you are running studs -- which could potentially find it's way to the combustion chamber.
The 'huffing' out of the oil fill cap on the valvecover could be associated with piston ring blow-by. This would also be a source of smoke. Perhaps some of the rings didn't seat properly during the rebuild/break-in. Now would be a good time to run a compression and/or leak-down test -- to determine the nature of the problem...
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Post by metalbeast on Sept 4, 2005 22:29:51 GMT -5
I think I am going to disagree with the coolant being the smoking gun (no pun intended). He indicated that the car only does this at first start up or at idle not while driving. If the smoke is actually a bluish or darker color (sometimes people say "White" smoke is coming out of the exhaust when its more of a bluish I would say that your injectors may be loading up the combustion chamber at start up and when idling. In other words your car may be running rich. Now when you say the exhaust smells "burnt" do you mean it smells like burnt OIL or something else?
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Post by the94z on Sept 5, 2005 1:26:22 GMT -5
woah you guys are on the ball its like a scientist poll, but everything sounds right, except let me dexribe it further, when I changed the oil it was pure black and if you mean milky by white....no prescence of white, but just black oil....and on startup there is not an ABundunce of smoke just a puff, and sometimes on idle it puffs out some smoke, and it smells like burnt gas, I heard to check the crankcase for milky residue if head gasket is blown? May just be the rich problem....or the valve seals, it had a compression test recently and passed it, but does it have to pass both of them? Yall scaring me with so many things i have wrong!!!
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Post by the94z on Sept 5, 2005 1:46:28 GMT -5
btw i am running no tsat right now....
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Post by the94z on Sept 5, 2005 2:41:20 GMT -5
also one more thing could this be because of running straight exhaust with no cat?
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Post by DocSpeed on Sept 5, 2005 7:03:27 GMT -5
also one more thing could this be because of running straight exhaust with no cat? Nope. I would recommend you install a thermostat too, keeps your car from overheating in hot weather. As for your oil, run it 3k miles and use a better oil next time around. It doesn't cost that much more to run an oil like Mobil 1 and you don't have to change it as often due to it being far better than dino oil. If its just a puff a smoke at startup and maybe a little during idle, I wouldn't worry about. Metalbeasts vette does the same thing and his engine is fresh. Get a tune as soon as money comes available, this alone may eliminate alot of your issues.
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Post by metalbeast on Sept 5, 2005 7:29:32 GMT -5
btw i am running no tsat right now.... Don't do that! That would be the first thing I would do would be to go to autozone and pick up a thermostat.
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Post by metalbeast on Sept 5, 2005 7:31:48 GMT -5
woah you guys are on the ball its like a scientist poll, but everything sounds right, except let me dexribe it further, when I changed the oil it was pure black and if you mean milky by white....no prescence of white, but just black oil....and on startup there is not an ABundunce of smoke just a puff, and sometimes on idle it puffs out some smoke, and it smells like burnt gas, I heard to check the crankcase for milky residue if head gasket is blown? May just be the rich problem....or the valve seals, it had a compression test recently and passed it, but does it have to pass both of them? Yall scaring me with so many things i have wrong!!! Sounds like what I said before. Your running just a bit rich. What year is your car? You can get a mail order tune from PCMforless.
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Post by the94z on Sept 5, 2005 13:23:26 GMT -5
Car is a 95......but its been rebuilt......and it has the vented opti.....so im really confused....but all in all I should just get some seafoam to clean injectors, pcv valve, tstat, and check everything, right?
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Post by metalbeast on Sept 5, 2005 13:58:54 GMT -5
Car is a 95......but its been rebuilt......and it has the vented opti.....so im really confused....but all in all I should just get some seafoam to clean injectors, pcv valve, tstat, and check everything, right? Not necessarily. The reason I asked the year is if it was a 92-93 I was going to recommend Alvin at PCMforless for the tuning. I think it is just a tuning issue IMHO. Nothing to get too worried about.Contact PCMforless. Here is the site: www.pcmforless.com/Its going to involve you removing your PCM and sending it to him. You let him know your mods, he sets the tune and sends it back to you. I believe Bryan does all of the 94 and up tuning for LT1s. FIRST GET THAT T-STAT IN THE CAR !
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Post by the94z on Sept 5, 2005 14:41:29 GMT -5
alrighty then!! And about letting him know my mods do i have to tell him specific or how do i tell him. Do I have to say for ex: lt4 hotcam lift/duration etc..for all my mods? And how mcu will it be and how long will it take....will miss my car!!!! Does it work as well as any other tuning? And will do get that tstat in the car!!!
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Post by metalbeast on Sept 5, 2005 14:54:22 GMT -5
alrighty then!! And about letting him know my mods do i have to tell him specific or how do i tell him. Do I have to say for ex: lt4 hotcam lift/duration etc..for all my mods? And how mcu will it be and how long will it take....will miss my car!!!! Does it work as well as any other tuning? And will do get that tstat in the car!!! Just go onto the website I left in my previous post. They have a form that you can print out and fill in all the necessary information on your mods. Its pretty straight forward. They usually turn things around pretty quick, but just give Bryan a call and he will tell you the pricing, lead time, etc. Good luck!
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Post by the94z on Sept 6, 2005 1:37:41 GMT -5
UPDATE: it only does it at startup, sometimes at idle, and all the time when erving or reaching high rpms, i now see that it is bluish in color.
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Post by Alex94TAGT on Sept 6, 2005 1:55:17 GMT -5
UPDATE: it only does it at startup, sometimes at idle, and all the time when erving or reaching high rpms, i now see that it is bluish in color. Ok, well, let's assume it's just blue smoke/burning oil for now. As I see it, you have three possibilities (or a combination of the three): 1) Valvestem seals 2) Intake manifold gasket (oil leak + internal vacuum leak) 3) Piston ring blow-by. -If the compression test showed good on all cylinders, then I guess we can rule out #3 (piston ring blow-by), which is the worst on the list. I'm still a little suspicious of this though -- with the crankcase huffing / smoke at higher rpm and whatnot. A leakdown test would be more reassuring. -Perhaps this isn't likely, but if the intake manifold geometry is a little off (milled heads or whatnot), then it's possible for the intake manifold gaskets to leak. If it leaks from the bottom, inside the lifter valley, this could obviously suck oil into the combustion chamber. However, it would also act as an internal vacuum leak, which doesn't sound like your problem. -Last but not least, I'm leaning towards valvestem seals. I replaced mine a few years ago, and when I pulled the heads apart this year, one or two of them popped off the valve guide and were eaten by the valvespring. However, I'm not really sure how this could be tested without physically removing the valvecover & valvespring. The seals are relatively cheap, it's just a matter of getting to them. I'll let someone else step in...
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Post by Alex94TAGT on Sept 6, 2005 2:05:34 GMT -5
I guess the PVC issue is also possible, but not likely. At any rate, you could test it with an in-line filter, or by capping off the PVC valve and TB connections & letting the crankcase vent to atmosphere (oil fill cap removed). If the smoke stops, you've found the problem.
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Post by the94z on Sept 6, 2005 14:39:05 GMT -5
O no i have replaced the pcv valve, but havent checked if the cranck case still puffs out smoke, if it only does this when i rev up then it has to be a rich problem....right? Its a gas thing i believe. And I put my hand over the crankcase and felt no sucking at all...i have a small vacumm leak but that i can hear from outside the car. And i believe its some hose to the tb.
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Post by the94z on Sept 6, 2005 14:44:55 GMT -5
since i posted the update on another site, they told me its piston rings for sure, and i should try some ring seal........but i passed a compression test!
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