Thread: Smokes at idle!!!!

I have maybe 400 miles on my recent build. The motor is from a 98 with 150k.

Build is XP cam, hinson ported heads, valve seals from intense. I believe they were the one to allow for high lift but hinson installed them.

Now this oil smoke will explain why I get KR every now and then. Whats everyone think??? Bad valve seals? You can see the color contrast on the blue cx7.

Pull the valve covers and look at the seals. You'll be able to see if there's one out of place.

I remember people saying they saw chewed up ones with rockers or cam. How would this even happen if that's my case? Using the smaller one is better or worse? Im contacting intense to see if they can inform me what I bought 2 years ago.

Actually.. since they are press on, they can slide back off.

Seems like you did enough work that maybe it's a gasket etc, but that's not common on a 3800. These motors don't typically burn oil, my best guess is that one of the seals popped off. Kinda depends on how they are put on. I like to use the Fel Pro vitons (look exactly like the zzp ones, but always come with the right number of them in the box). Then I use a 1/4" 10mm deep socket to clear the valve stem and lightly tap the socket a couple of times with a rubber mallet. Oh.. and in the last couple of sets I got, there was a nice sleeve to go over the stem and keep the seal from being chewed by the groove for the locks.

valve stem condom. both my felpro sets had them. ive seen a few guys here who had seals slide off.

I bet 2 or more seals popped off the exhaust valves. Don't ask me how I know

I contacted intense

Looks like you bought the ones for a machined valve guide, with a 0.500” diameter

Ok I pulled all the plugs and #2 is horrible but then #4 has a slight hint of white also. So the back is the suspect unfortunately. My oil level was also down a tad as well.

As for the valve seals they look to be in place. I did not remove the springs or anything but tried moving the seals with a screw driver on #2 and 4.

Compression test was also performed

#1--150--#2--145--#3--150
#2--160--#4--140--#6--135

Originally Posted by BillBoost37

Actually.. since they are press on, they can slide back off.

Seems like you did enough work that maybe it's a gasket etc, but that's not common on a 3800. These motors don't typically burn oil, my best guess is that one of the seals popped off. Kinda depends on how they are put on. I like to use the Fel Pro vitons (look exactly like the zzp ones, but always come with the right number of them in the box). Then I use a 1/4" 10mm deep socket to clear the valve stem and lightly tap the socket a couple of times with a rubber mallet. Oh.. and in the last couple of sets I got, there was a nice sleeve to go over the stem and keep the seal from being chewed by the groove for the locks.

Hey Bill. Where did you get your valve seals from? Might you have a part number? My only problem is will they work with my XP cam?

I used Viton seals with my XP.

I used the same seals on my Thrasher.

Never burned a drop of oil.

I had my heads done locally; everything measured when it was put together.

i used flepro twice now, put new on the new engine, so far neither set popped off. no smoke either.

I put the car on back burner but now I'm slowly getting back to it. See I doubt the seals were installed wrong by hinson but I also doubt bad piston pings as it is VERY rare.
From what I can see the seals on that cyl look like the others height wise. It sucks as a leakdown test will only tell me if its bad rings along with valves that are not seating but not if the seals were bad.

Originally Posted by Slappyn

You can figure it out. That one plug that is wet seems out of place so I would focus on that cylinder. It also seems more white than the others. The blue smoke that you showed a pic of should make the plugs foul a bit more. All the plugs dont look to bad really. If it is a leak from the rings your compression would be low as well since both the oil ring and compression rings wear at about the same rate. It could be a worn out cylinder but that really is rare I believe. You can do the leak down test to rule out the bottom of the engine. Then rebuild the top. You might as well rebuild the top anyway since its the cheaper and easier way to go first vs changing the bottom.

My bad for not being more specific on my build. This build has less than 400 miles maybe even 300 miles on the top end. The heads came from hinson that I supplied to him and are ported. I think the seats were clearance for extra lift as well if the time ever came. He also installed the seals to accept my XP cam. So that means all the other gaskets are new on the motor and GM which I put together. Indeed cyl #2 is my culprit. Cyl 4 has minor white on it too but nothing crazy. So those are my culprits on why it smokes blue. More so cyl #2 at the threads are wet. But what gives they are right next to each other. Seeing my compression number in #2 is higher than all the others due to it being so wet with oil. The funny thing is I was watching a tv show this weekend on flipping cars and they were working on an old vette. Well it smoked bad at idle and startup and they were like well that's the culprit of bad valve seals. So they pulled the plug and it was wet with oil like mine. Then showed how the seal was wasted. I thought to myself well isn't that nice! Of course it was a totally different design lol

But I will have to do a leak down test on that cyl and a known good one in the front.

Plug threads being wet shouldn't tell you which cylinder is having the issue since the plug seals itself into the cylinder. I've seen a lot of plug threads be wet..and usually it's a VC gasket. Understanding that yours are new and shouldn't be leaking, those threads seem odd to be wet.

As for fouling, you likely haven't run enough to show a good fouling from oil.

TMK leakdown test is only going to tell you if Chris did a good valve job. I don't see how it can tell you about the valve seal which would be next up from the valve sealing to the head.

The way I'd try to diagnose this problem is to pull both valve covers. I'd start by looking at all valve seals and all springs. Give it a good look over to see if anything seems out of place, to tall/short or has any rub marks. Thinking of how oil flows in our motors, can give you a lot of ideas on what to look at or test. Oil is under pressure at the cranks and cam bearings, gets pushed up by the lifters into the pushrods and then trickles back down over the rockers/seals and returns to the oil pan. It also passes through the rear engine cover, that typically shows up as a mix with coolant and shouldn't apply to being burned. Only other thing we didn't suggest is rings, while possible the rings on 3800's are low wear and great sealing. This is part of how we have these motors running so clean for upwards of 200K miles w/o rebuilding. Rings are one of those things that is a one off oddball. (Kinda like when I hung a valve, doesn't happen enough for us to consider it.)

I can always tell when I popped a valve stem seal. When driving I had no smoke at all. Came to a light and idled for a minute and poof, nice puff of oil comes out the back. It also happens when I take the off ramp when I come home from work and then a mile sitting at a light. Almost seems that with the body roll the oil will seep down in the stem hole.

On my seals they are ONLY the exhaust seals. All of my intakes have been fine since replacing them a few years ago.

Take off the valve covers and grab your phone. Start taking pictures and you can see which one popped off.

Notice the picture below. The left is the exhaust seal that came off the last time I dorked with my car. The right is the intake and is seated down correctly.

I just tripple checked all my rear valve seals and all of them look even as seen above (blue). Its 100% not the valve cover gasket as the heads not even wet by the plug hole. Chris didn't do an actual valve job he just visually made sure they were good. At least I have another good coat of dust on the car again...lol

I would think my affected cylinder is the one that's all oily as the other plugs don't have any discolor. In the gm truck world esp. 08+ style if the plug looks white and is almost a barnacle you have a problem with rings. But those trucks have DOD and the rings sludge up and stop working from what I hear from fellow GM friends.