Smokes when I start the truck for about 2 second smells like burnt oil. What could cause it?

2005 Chevy 5.3

 

Our 05 Suburban did this after about 225k miles; mechanic suggested time for a new ride. How many miles on your chevy?

 

Usually the result of normal wear. As valve guides and valve stems wear and intake valve stem seals deteriorate sources for loose traces of engine oil appear in their place. After engine shutdown it is common for tired valve stem seals, and worn valve stems and guides to allow engine oil on the top of the heads to drain into any cylinder that has an open valve or bad seal. The older the engine the more common the startup puff of blue smoke and smell of burnt oil. Before these modern engines existed it was a signal to start recording gauge readings while the engine was running at highway speeds. It was called trend monitoring. You monitored engine oil pressure, water temp and you can even take oil samples at every other oil change. These three observations help you decide when your engine is in dire need of a rebuild. In your case it appears you have not been recording your engine's internal performance and now with a very large number of miles you are noticing the oil smell & smoke on startup. Back to the old days a gradual decrease in oil pressure at cruise speeds was indicative of crank and rod bearing wear. Lowering compressions readings at tune-up time were indicative of piston ring and bore wear. and finally blue smoke on start-up with oil smell was indicative of valve stem/guide wear and valve stem seal deterioration. Problem with todays engines are the lack of attention they receive during their life because they are built to be run to the end and thrown away and the owner buys a new one. Modern engines and their manual dictate a normal service life span of 100,000 to 150,000 service free miles and then they die. Back in the old days periodic tune-ups because spark plug and distributor point life were quite short IE. 2500 to 5000 miles and you had to open the hood, replace them and look things over during tune-up. Today folks are hood winked into ignoring their engines for 150,000 miles.

So back to your current problem. If your mechanic's only suggestion is to sell the truck then find a mechanic that enjoys making your money by repairing your truck and who has the training and experience to figure just how healthy or unhealthy your engine currently is and make a well founded decision on the true state of being of your engine. This may turn out to be a very tired engine that needs a complete overhaul or it could turn out you only need a top overhaul which is just removing the heads and restoring valve to guide clearances to new limits and replacing intake valve stem seals and re-installing the head. Don't overlook the rest of your truck's physical condition when deciding how much money to spend on repairs is a smart move or not.

 

allot of things ?!

* mine smelled awful for a few minutes after start, did it for over 10 years. to my horror, last tune-up, i found #1 spark plug gapped over .08 instead of .06 (i usually have all plugs gapped in all engines in the garage - what an embarassment!). after i gapped it the starup smell went way down. i didn't expect that and didn't even think it'd run smoother, but think it did.

* iron rings aligned to let oil through. when sitting you notice it. perhaps the oil was once over-filled way too much. doesn't mean you need a new engine though

* way too much oil. insure your level and hot (ie, drive it after oil change to warm up oil) before checking. even then don't fill it all the way to "full hot". that's a maximum mark. stay away from maximum.

* wrong oil filter, keeping pressure out of range. use the oem oil filter - after market not worth the risk

? pcv oil-vapor re-circulation somehow letting (too much oil vapor) in when you start. doesn't make sense there shouldn't be allot of oil vapor when cold.

you know, you say only happens on startup. that makes me suspect it's something that happens only while sitting. if it passes emission inspection and runs smooth good (well normal, sierra never good) gas mileage? forgetta bout it.

 

$0 paid for advice, and explination not given

advice: "sir leave me alone and go get a new car" (was it a millenial that did this to you??)

YOU GOT WHAT YOU PAID FOR.

 

My understanding is that valve stem seals are the most likely culprit for initial smoking at start up and then dissipating.