04 Silverado 5.3 Blue Puff when starting???


quadtrac
03-01-2010, 08:03 PM
I have an 04 silverado with the 5.3 engine. When I start it after its been sitting for a while, a puff of blue smoke comes out the exhaust. Im thinking its just valve seals, but dont really want to spend the money to get it fixed. I seen that Lucas makes a engine oil stop leak product, They say it should mostly stop the blue smoke. Do you think I should try it? or could it cause anymore damage inside the engine like hurting other seals? Thanks alot!

old_master
03-01-2010, 08:10 PM
Classic symptom of at least one valve stem seal leaking. Additives at best are a band aid and more than likely will not fix the problem. Rather than screw up the additive package already in the oil, live with the puff or replace the seals.

j cAT
03-01-2010, 08:43 PM
I have an 04 silverado with the 5.3 engine. When I start it after its been sitting for a while, a puff of blue smoke comes out the exhaust. Im thinking its just valve seals, but dont really want to spend the money to get it fixed. I seen that Lucas makes a engine oil stop leak product, They say it should mostly stop the blue smoke. Do you think I should try it? or could it cause anymore damage inside the engine like hurting other seals? Thanks alot!

whats the mileage on this engine ? what oil do you use ?

quadtrac
03-01-2010, 09:37 PM
truck has 129,000 on it, I have always taken it in to have an oil change so I dont know what they use. Thanks

j cAT
03-02-2010, 09:45 AM
truck has 129,000 on it, I have always taken it in to have an oil change so I dont know what they use. Thanks

I suggest you take a greater interest in this , in the future with your next vehicle...the damage is done ....


whenever oil changes are done by these service centers make sure the engine is hot ....this will remove the most debris when they drain the oil for 1 minute...then you must insure that they fill with the correct oil, this engine uses 5-30wt..also the filter used is by far the greatest importance on engine life. using cheap filters can cause great damage/wear to your engine...check on the filter used and if possible ask for a better oil filter or bring your own...

before driving away on level ground check the oil level...they usually don't fill to the proper level ! this is how they save a few $$$$.

my 5.3L engine takes 6.25 qts ...I doubt they would put the extra .25 qt in..

your problem of blue smoke on start up with this engine is not common at this low mileage ...these engines go to 200,ooo mi easy with proper care..

jdmccright
03-02-2010, 10:05 AM
Valve seal replacement isn't too difficult, especially if you only have to do a couple versus the entire engine. But some special tools help ALOT. While I usually advocate replacing all of them (the reason being that if one is failing, the others will likely fail soon enough), 129k is a little early for today's engines. You might be able to just replace those that are leaking, or just one side/bank of cylinders.

Remove the spark plugs when the truck has been sitting overnight and look at the tips. The one that looks oily is where the valve seals are leaking. If there is more than one on one side you can have that bank of seals replaced. If there is one leaking on each bank of cylinders, then I would recommend replacing them all since the interfering accessories and both valve covers would have to be removed anyways for access.

The only other factor that you mention is the oil used by the shop. If you took it to the dealer, I'm willing to bet they'll use a reputable brand or the OEM approved oil for your engine. Independent shops and the quick lube places may or may not use the better brands or even use a single brand consistently. The franchise oil lube shops are more brand consistent since they will buy in bulk for distribution. I'm not saying they're bad, but some brands protect your engine longer than others. If you've been diligent about oil changes at the proper intervals, then I'd say your seal leak is abnormal. Start to let it go and you may be rolling the dice.

Finally, oil additives to reduce smoke such as STP, Lucas Oil, and Bardahl's No Smoke accomplish this by increasing the viscosity of the oil. You pour it in and it pourrrsssss ssssslllllloooooowwwwlllllyyyyyyy into the crankcase. If the oil is thickened with additives, especially when it is cold, then it will have less tendency to leak through the worn seals. Are they a bad thing? I don't believe so...they do have other additives to supposedly help replenish the oil and increase its anti-wear and anti-corrosion ability. But they are not meant to be a cure-all...it is merely a crutch or as mentioned, a band-aid at best. Some will even tout their "stop leak" ability. I haven't seen one do this yet, though I will tip my hat to Bardahl's to help with smoke reduction....helped me pass the visible portion of emissions tests long ago.

My point, have someone check to see if it's just one seal leaking and what it might cost to replace that one, that cylinder's pair, or the one bank. Might be less than you think. Good luck!

j cAT
03-02-2010, 10:30 AM
Valve seal replacement isn't too difficult, especially if you only have to do a couple versus the entire engine. But some special tools help ALOT. While I usually advocate replacing all of them (the reason being that if one is failing, the others will likely fail soon enough), 129k is a little early for today's engines. You might be able to just replace those that are leaking, or just one side/bank of cylinders.

Remove the spark plugs when the truck has been sitting overnight and look at the tips. The one that looks oily is where the valve seals are leaking. If there is more than one on one side you can have that bank of seals replaced. If there is one leaking on each bank of cylinders, then I would recommend replacing them all since the interfering accessories and both valve covers would have to be removed anyways for access.

The only other factor that you mention is the oil used by the shop. If you took it to the dealer, I'm willing to bet they'll use a reputable brand or the OEM approved oil for your engine. Independent shops and the quick lube places may or may not use the better brands or even use a single brand consistently. The franchise oil lube shops are more brand consistent since they will buy in bulk for distribution. I'm not saying they're bad, but some brands protect your engine longer than others. If you've been diligent about oil changes at the proper intervals, then I'd say your seal leak is abnormal. Start to let it go and you may be rolling the dice.

Finally, oil additives to reduce smoke such as STP, Lucas Oil, and Bardahl's No Smoke accomplish this by increasing the viscosity of the oil. You pour it in and it pourrrsssss ssssslllllloooooowwwwlllllyyyyyyy into the crankcase. If the oil is thickened with additives, especially when it is cold, then it will have less tendency to leak through the worn seals. Are they a bad thing? I don't believe so...they do have other additives to supposedly help replenish the oil and increase its anti-wear and anti-corrosion ability. But they are not meant to be a cure-all...it is merely a crutch or as mentioned, a band-aid at best. Some will even tout their "stop leak" ability. I haven't seen one do this yet, though I will tip my hat to Bardahl's to help with smoke reduction....helped me pass the visible portion of emissions tests long ago.

My point, have someone check to see if it's just one seal leaking and what it might cost to replace that one, that cylinder's pair, or the one bank. Might be less than you think. Good luck!

I like your detailed posting on his issue ...since this vehicle owner does not do his own oil changes , I doubt the owner will ever do this work...

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