Smoking is worse after valve stem seal replacement on a 350 V8

[jdmccright]

Here's a bit of history...grab a cup of joe, beer, what-have-you and read on....

Shortly after buying it in September 2008, I noticed my truck was using a fair amount of oil and some coolant it seems, so I ran a compression test and got between 130-145 psi across all the cylinders. Back then, I read that compression should be around 150 psi so I wasn't concerned about worn rings and focused on new valve stem seals. Went to the local parts store, they rang me up with new sets of Fel-Pro intake (72527) and exhaust (72526) seals.

Went to install them on the driver's side first shortly thereafter and found out that the exhaust's umbrella seals were way too large. So I had to button her back up with just a new intake umbrella and new o-rings (the old ones broke upon removal) on cyl #1...back to the store. I measured the exhaust valve diameter and had them order a set of exhaust seals that matched (72525). They arrived, but did not look like the other set. The -6 was a dark color opaque plastic while the -5 was a translucent creme color. Neither new set had rubber grommets to seal against the valve stem like the old seals, though the -6 could have been large enough to put some in if they had one. I had the parts guy look and I looked and could not find any seals with grommets. Time passes....

After waiting nearly a year for a chance to devote time to the task after much searching and ordering and buying the valve stem seals, I was able to install new valve stem seals on the passenger side of my truck's 350 V8 (VIN K). I chose that side since it was showing fouling and carbon build-up on the plugs, especially #2. The new seals went on fine, just took alot of time to clean off the 200k miles of build-up on the valvetrain.

Unfortunately, upon start-up, the truck is now smoking worse than before. Now, it was fairly cool and humid last night so it may be the water vapor, and it did smell like gas, so it may not be burning oil after all. I could not tell if the smoke was white or blue as it was late-late night but it did linger in the air, which means either coolant or oil. But it was disappointing to spend nearly 12 meticulous hours of wrenching, cleaning, cleaning, tightening, loosening, retightening, only to be rewarded with a sicker truck.

Granted, I have a new intake manifold gasket awaiting to be installed as well, but I'm asking if there's anything obvious that I did wrong or is it the seals I bought? I will give updates as I learn more. But any thoughts are welcome.

[RahX]

Might have some worn out valve guides too.

[jdmccright]

I wouldn't rule guide wear out, though I did give them a wiggle test and did not feel excessive play. After 200k miles, I would not be surprised if they were in fact worn, but I'm in no financial position to yank the heads...at least not yet. And if I was I'd just go and spend the money on a Vortec conversion setup rather than installing new guides/valves.

Well I started her again yesterday afternoon and did not see any noticeable smoke save for a few puffs while still cold. I still hear a valve ticking so I think I missed one lash adjustment...it was late and I was tired, thus lazy. But this thread could be moot. I guess I wanted reassurance that the exhaust seals I bought were in fact the correct ones since they were so different from the old ones. If I can post pics of the old & new guides I will do so.

I've also read that this generation of 5.7L (1995, VIN K) should have ~180 psi compression not 150 that I believed. If so, worn rings would explain the oil consumption and low compression. Which is correct?

Any other thoughts are welcome...thanks for reading!

[jonnik]

After 200,000 miles, some compression loss is to be expected. If the compression figures are within 10% of each other, go on your happy way and start saving for a rebuild or replacement. A switch to a good synthetic oil may get you a few more miles, if you haven't already done so.

[maxwedge]

A leak down test is the correct way to determine ring seal.

[jdmccright]

Thanks all...already working on doing a follow-up compression test (after the seals on both banks are replaced and can get some oil in the cylinders to test the rings) and a leakdown when I get the chance.

[dstrick32]

Did you ever find where your coolant was going?

[jdmccright]

I have not confirmed where yet, but I do know that I get quite a bit of dripping water coming from the exhaust along with the soot from running rich. My hope is a failing intake gasket to which I have a new one waiting to be installed. I also notice a small leak from somewhere around the thermostat neck...either the hose clamp or the neck gasket. But this small amount can't account for what I'm losing. It's either intake or head gasket. Hopefully, a leak-down test will help nail it down. I'll update when I can get time to investigate more.

As far as switching to synthetic, I feel it to be a waste of money to pour $5/qt oil into an engine that will just burn it. Besides, the truck isn't run on a daily basis, so keeping tabs on the oil level isn't that hard. Mobil Clean 5000 10W-30 with some Lucas Oil Stabilizer gets me by for now.
Stay tuned....

[jdmccright]

Welp, I pulled the valve cover off the right (passenger side) bank again last night because I thought I heard a light ticking, thinking I missed adjusting one of the rockers. I had to put my head in next to it to hear it well but couldn't determine which one, so I redid them all on that side. No change. You can't hear it in the cab and doesn't get louder with revving it. So I'm guessing it is normal. At least the spark plugs don't look sooty anymore and were dry.

I did find the upper rad hose leaking at the clamp. I had replaced the OEM spring-type with the screw-type clamp and I'm beginning to rue that decision (unknowingly did this with the Camry a while back yet did not learn my lesson). They may have looked like crap being old and rusty, but they did a better job at keeping things sealed. Anyhoo, I don't think this can account for all that I lost. As mentioned before, I get sooty water dripping from the exhaust, so for sure it is getting into the cylinders.

Stay tuned....

[jdmccright]

Quick update....

Finally got a warm enough day on the weekend (~50°F) to do the driver's side bank (1,3,5,7) stem seals. Same thing happened afterwards with increased smoking just after. But unless I'm mistaken I think it is much less now. I still think I have coolant getting sucked in through the intake manifold gasket...that is next...probably contributing to the smoke. Note again when I finished it was quite cool out (1:00 am and ~47°F). For now I'll watch the oil level and the weather forecast for an indian summer Saturday or Sunday.