Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

[alwayscode390]

I was wondering if you guys with the "smoke at startup" valve seal leak issue notice that your truck smokes more with synthetic oil vs dino oil?

I have always heard that engines will leak more oil with synthetic since the molecules are smaller and squeeze through worn gaskets more.

Does this happen with our valve seals too?

Just curious. Its been awhile since I ran regular dino in my truck ... but my truck puffs a huge smoke cloud on startup with the synthetic in it LOL ---

 

[ajt86]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

I havent had my typhoon long but its got 130k... sythetic oil and no smoke. Valve seals arent a terribly hard job to do

 

[alwayscode390]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Hmmm, that makes me think that the trucks that smoke were the ones that sat for awhile (had time to dry out), and not driven regularly?

Either that or your valve seals are new.

The smoke issue is common on SYTY's .

4-5 hour job for valve seal replacement? ---

 

[ajt86]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Its not just a syty problem its a 4.3 problem. I was a tech at a gmc dealer for years. Alot of early 90s 4.3l engines got valve seals replaced. I forgot a previous owner did vortech heads at some point on mine. You just need to pop the valve covers and use an on car spring compressor. Some guys pull the spark plugs and fill the cylinder with small rope. I converted a compression gauge to fill the cylinder with compressed air to keep the valves from falling

 

[alwayscode390]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

My 90' ZR-1 doesn't even have exhaust valve seals, LOL.

Must be a common early 90's GM trend ---

 

[gobabygo]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

It wasn't just the 4.3 it was most of the gm cars and trucks.

 

[atkonkler]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Yes mine does sometimes, (twirls finger in the air) ! Truck still boots it and not many are up and running but rather on jack stands

 

[sychris]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

169,000 miles no smoke

 

[2500avalanche]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

mine gives a good puff when it starts,

 

[gobabygo]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

One of mine does every now and then.

 

[Josh Young]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

I believe it's an age issue more than anything else. My Syclone smoked on startup when I got it, before I put new valve seals in. It had 100K miles, Mobil 1 Syn. always. I had a 92 4.3 blazer standard oil always, smoked on startup. Rubber components get old and dry out, it just happens. I've seen trucks with 20-30K that smoked on startup. If one has nearly 200K, I bet they have been replaced at some point, or a rare fluke. I'm sure there is some out there with super low miles, always kept climate controlled that don't smoke. I'd bet they are few and far between though.

 

[Logan]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

My 92 S10 smokes on start up. The Ty has a new engine so no problems there. Valve seals are cake. 4-5 hours without beer, 6-? Hours with beer.

 

[GEMELLI]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

My Ty has 45k on it and it smokes after sitting for more than an hour or so. It has definitely spent time in its life sitting though. I've only ever ran synthetic in it, so I'm not sure what it would do with dyno. I might give that a shot next oil change.

 

[Black Knight]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Ive never seen any rhyme or reason to it.

120k Sy = no smoke
70k Sy = big puff on start up
150k Ty = no smoke
70k Sy = no smoke
150k S10 = no smoke
85k S15 = lil puff on start up

All original engine as far as I know.

 

[RealFastV6]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

I have always heard that engines will leak more oil with synthetic since the molecules are smaller and squeeze through worn gaskets more.

:rotf:

Nothing to do with the oil itself.

Dyno oil has additives that makes gaskets swell. If you run an engine on dyno oil it's entire life and then switch to synthetic, the gaskets will have been conditioned for the dyno oil additives and may leak once the additives are taken away or reduced. If you run it on synthetic early-on, it shouldn't ever be a problem.

 

[JAY]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

136k on mine. has done it since 104k/2004

 

[Damian]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Synthetic also has better cleaning detergents.

 

[alwayscode390]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

:rotf:

Nothing to do with the oil itself.

Dyno oil has additives that makes gaskets swell. If you run an engine on dyno oil it's entire life and then switch to synthetic, the gaskets will have been conditioned for the dyno oil additives and may leak once the additives are taken away or reduced. If you run it on synthetic early-on, it shouldn't ever be a problem.

Thanks for the knowledge ---

 

[midnightbluS10]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

:rotf:

Nothing to do with the oil itself.

Dyno oil has additives that makes gaskets swell. If you run an engine on dyno oil it's entire life and then switch to synthetic, the gaskets will have been conditioned for the dyno oil additives and may leak once the additives are taken away or reduced. If you run it on synthetic early-on, it shouldn't ever be a problem.

Personally, I think that's an old wives-tale. I've never seen it actually happen. Even on my Blazer, I didn't have any new leaks when I switched to synthetic oil at around 190-200k miles. In fact, I had no leaks at all, new or previously leaking.

Synthetic also has better cleaning detergents.

I always thought this is what contributed to more leaks. More-so than the "smaller molecule" theory.

 

[Baythan]

Re: Does your truck smoke more at startup with synthetic oil vs dino oil ? ---

Its not just a syty problem its a 4.3 problem. I was a tech at a gmc dealer for years. Alot of early 90s 4.3l engines got valve seals replaced. I forgot a previous owner did vortech heads at some point on mine. You just need to pop the valve covers and use an on car spring compressor. Some guys pull the spark plugs and fill the cylinder with small rope. I converted a compression gauge to fill the cylinder with compressed air to keep the valves from falling

Also very common in Turbo Regals.

EVERY vehicle in my signature ALL had smoke on start up and each was a low-mileage (45k or less), synthetic-filled, well maintained ride.

I put an extension hose on my truck when I start it in the garage so the garage does not get smoked.