1990 Silverado K1500 Z71 350 TBI

[smokensteve]

Purchased a 1990 Silverado K1500 Z71 short box step-side 5 Spd manual with a 350 TBI about a month ago...really happy with it ..only has 145,000 original KM...very clean.. original paint...runs real well,very strong motor..installed Airaid TBI spacer and had a noticeable increase in gas mileage as well as throttle response and a little more power.. I've notice that when I start truck in the morning or after a long sit..I have a puff of white smoke from exhaust..Only when I start motor after a sit..truck does not burn oil after it has started or when running..but I get a puff of white smoke when I start it that is bothering me...any info would be greatly appreciated...

[rbmcveigh]

When the engine is cold, all the seals have contracted just enough to allow a small amount of oil to seep down in through valves. Once you fire it up and get it running for a few minutes the seals expand back to where they are supposed to be and stops your oil leakage. I had an old 78 Chevy 350 that did the same to me after it had sat for a few days. I ran some Lucas Oil Stabilizer with the oil and it worked, no more puffs of smoke on startup.

[mrjohnwayne]

It's the valve seals. You can try the Lucas, or you can run quaker state high mileage. Both have additives to help recondition seals. The only sure way to fix it would be to replace the valve seals.

[smokensteve]

Thanks for the info...I kinda thought it was valve seals...truck had sat for awhile before I bought it...probably dried out seals...thanks for the help I will try the Lucas stuff and let ya know if it works...thanks again.......now anyone know much about the L05 350 ...is this a good motor ..someone told me it was the same motor interceptor cop cars had...is this right??..also been told that this motor has 4 bolt mains and has a tougher bottom end..any thing on this paticular 350 would be helpful...thanks

[dstrick32]

There good engines if you'll keep the oil changed at the 3,000 mile intervals. I have found that some ofthe trucks do not have 4 bolt mains but could confirm that they were the LO5. Don't know about what they use in the police interceptors were you are but down here in Florida they were using the 4.3 V-8's in the mid 90's.

[bradrhale]

what are you planning on putting this engine into?? are you looking for just a replacement engine or something to build up??

[smokensteve]

Originally Posted by bradrhale

what are you planning on putting this engine into?? are you looking for just a replacement engine or something to build up??

the LO5 engine is what is in the truck I just bought...I was just wondering if there were any known problems with this motor...or any other info people have on this engine....also like I said this truck is very clean..only 145 km on er, runs real strong..interior is pretty much mint except for oil stain on floor carpet..every thing is stock...original paint still has some luster..no rust at all..brakes, tranny, tires--everything is good!! I also bought it from a friend who bought it new in 1990..he ordered it, not off the lot. do ya think $7000 Canadian was to much or did i do good????

[bradrhale]

dont know what canadian dollars are. if you are using your truck as a daily driver and not a toy, 2 bolt or 4 bolt mains aint going to make you a bit of differance. drive that chevy!! it loves it.

[smokensteve]

Originally Posted by bradrhale

dont know what canadian dollars are. if you are using your truck as a daily driver and not a toy, 2 bolt or 4 bolt mains aint going to make you a bit of differance. drive that chevy!! it loves it.

At todays rate $7000 Canadian would be about $6052.75 US funds..I use my truck for a daily driver as well as a mud toy.... ..I am somewhat of a tweaker...all I really had plans for with this motor is a cold air intake system, a better intake manifold and a Holley TBI unit.. Maybe new cam and head as well and maybe some headers...don't really want to loose gas mileage though...just want alittle more power and better response...looking to make truck run efficiently..

[bradrhale]

doesnt sound like that bad a deal if it is what you say it is. are you sure that the thottle body you have on it aint already a holley?? check on that before you end up replacing that with a new $300 unit or $750 TBI setup. go with that single plane intake. i think that you would be happier it or even a high rise. understand about the mileage. i have been beating my head against the wall with the chevy i got at home with mileage.