Burning oil after H/C swap...need help/advice!
10-11-2006, 09:47 PM
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Burning oil after H/C swap...need help/advice! As the title states, did my H/C swap a while back (May or so) and now my engine is consuming oil much faster than I prefer. All mods in sig....
I've got some hunches as to why this is happening:
1. Good old LS1 PCV problem.
2. Rocker bolts aren't sealed good (heads were heavily CNC'ed)
3. Bad valve seals/guides (hope not since the heads were brand new from TSP)
4. Rings are going bad from wear/mileage
I'm hoping it's a combo of the first two. I have a hard time believing that the valve guides/seals are bad since TSP sold me new heads. And I'd like to think the rings aren't a problem since the car didn't smoke a bit before the swap. Thought maybe the big cam I'm running (233/239) was promoting the consumption, but I'm not sure how much effect that would have.
Plan right now is to put in a new PCV and a catch can. Maybe seal the rocker bolts somehow.
Any ideas? Help me figure this out!!! Mobil 1 isn't cheap!
I've got some hunches as to why this is happening:
1. Good old LS1 PCV problem.
2. Rocker bolts aren't sealed good (heads were heavily CNC'ed)
3. Bad valve seals/guides (hope not since the heads were brand new from TSP)
4. Rings are going bad from wear/mileage
I'm hoping it's a combo of the first two. I have a hard time believing that the valve guides/seals are bad since TSP sold me new heads. And I'd like to think the rings aren't a problem since the car didn't smoke a bit before the swap. Thought maybe the big cam I'm running (233/239) was promoting the consumption, but I'm not sure how much effect that would have.
Plan right now is to put in a new PCV and a catch can. Maybe seal the rocker bolts somehow.
Any ideas? Help me figure this out!!! Mobil 1 isn't cheap!
10-12-2006, 02:04 PM
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I would start with a leakdown test on all cylinders to determine if the problem is in fact the rings or valve guides. Did you use sealant on the intake rocker bolts when assembling? If the engine did not burn oil before the swap I would venture to say it's the latter.
10-12-2006, 07:54 PM
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I am the middle of a nightmare with this same issue. Here is what I have learned along the way and I'm not done yet - I hope this helps you and I hope to God that your problem has a more obvious and less expensive solution:
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
2. While the plugs are out, do a compression test. A leakdown test won't tell you anything about the valve seals unless your valves are shot (assuming that you are performing the leak down test at TDC on the compression stroke). In my case all cylinders read close to 180psig with #1 at 225 and #5 at 205 (I assumed this was due to excessive oil in the cylinder).
3. Plug the PCV port on the intake manifold and run the PCV line to a can (small tin can, put it behind the headlight). Put a rag over the end of the line in case this is your issue. Drive the car around and check the can - in my case it was bone dry.
4. Get serious - short circuit the whole process and pull the intake manifold. Look in the intake ports - is oil pooling there behind the intake valves? Is the manifold full of oil? In my case I had the oil pools, the intake manifold was full of oil. I replaced all the new valve seals AND resealed all rocker bolts. - no change.
5. I ignored the result of #3 - figured I was going nuts. So I installed the LS6 valley cover AND a catch can. Drove for 180 miles - 1 quart of oil - nothing in the catch can but distilled water. In short, no change.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
2. While the plugs are out, do a compression test. A leakdown test won't tell you anything about the valve seals unless your valves are shot (assuming that you are performing the leak down test at TDC on the compression stroke). In my case all cylinders read close to 180psig with #1 at 225 and #5 at 205 (I assumed this was due to excessive oil in the cylinder).
3. Plug the PCV port on the intake manifold and run the PCV line to a can (small tin can, put it behind the headlight). Put a rag over the end of the line in case this is your issue. Drive the car around and check the can - in my case it was bone dry.
4. Get serious - short circuit the whole process and pull the intake manifold. Look in the intake ports - is oil pooling there behind the intake valves? Is the manifold full of oil? In my case I had the oil pools, the intake manifold was full of oil. I replaced all the new valve seals AND resealed all rocker bolts. - no change.
5. I ignored the result of #3 - figured I was going nuts. So I installed the LS6 valley cover AND a catch can. Drove for 180 miles - 1 quart of oil - nothing in the catch can but distilled water. In short, no change.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
10-12-2006, 09:28 PM
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Originally Posted by Ryan02SS
I would start with a leakdown test on all cylinders to determine if the problem is in fact the rings or valve guides. Did you use sealant on the intake rocker bolts when assembling? If the engine did not burn oil before the swap I would venture to say it's the latter.
So what do you guys recommend sealing them with?
Thanks.
10-12-2006, 09:32 PM
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Originally Posted by malott442
How many miles are on the motor? If you are high on the odometer and you seal up the top end with new heads, those rings show their ***
Well, it's got 112k on it now...had 106 on it when I did the swap. I'm sure the increased cylinder pressure (new heads, different cam) will show the rings age, but I'm hoping that's not so much the case. Especially since it ran so well prior to the swap.
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10-12-2006, 09:40 PM
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Originally Posted by LS1Beginner
I am the middle of a nightmare with this same issue. Here is what I have learned along the way and I'm not done yet - I hope this helps you and I hope to God that your problem has a more obvious and less expensive solution:
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
2. While the plugs are out, do a compression test. A leakdown test won't tell you anything about the valve seals unless your valves are shot (assuming that you are performing the leak down test at TDC on the compression stroke). In my case all cylinders read close to 180psig with #1 at 225 and #5 at 205 (I assumed this was due to excessive oil in the cylinder).
3. Plug the PCV port on the intake manifold and run the PCV line to a can (small tin can, put it behind the headlight). Put a rag over the end of the line in case this is your issue. Drive the car around and check the can - in my case it was bone dry.
4. Get serious - short circuit the whole process and pull the intake manifold. Look in the intake ports - is oil pooling there behind the intake valves? Is the manifold full of oil? In my case I had the oil pools, the intake manifold was full of oil. I replaced all the new valve seals AND resealed all rocker bolts. - no change.
5. I ignored the result of #3 - figured I was going nuts. So I installed the LS6 valley cover AND a catch can. Drove for 180 miles - 1 quart of oil - nothing in the catch can but distilled water. In short, no change.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
2. While the plugs are out, do a compression test. A leakdown test won't tell you anything about the valve seals unless your valves are shot (assuming that you are performing the leak down test at TDC on the compression stroke). In my case all cylinders read close to 180psig with #1 at 225 and #5 at 205 (I assumed this was due to excessive oil in the cylinder).
3. Plug the PCV port on the intake manifold and run the PCV line to a can (small tin can, put it behind the headlight). Put a rag over the end of the line in case this is your issue. Drive the car around and check the can - in my case it was bone dry.
4. Get serious - short circuit the whole process and pull the intake manifold. Look in the intake ports - is oil pooling there behind the intake valves? Is the manifold full of oil? In my case I had the oil pools, the intake manifold was full of oil. I replaced all the new valve seals AND resealed all rocker bolts. - no change.
5. I ignored the result of #3 - figured I was going nuts. So I installed the LS6 valley cover AND a catch can. Drove for 180 miles - 1 quart of oil - nothing in the catch can but distilled water. In short, no change.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
Wow...sounds like you've about covered all the bases. I haven't really investigated anything yet, just trying to get some ideas of what it might be.
First thing I wanted to do was get a hold of a good catch can. AMW isn't making them anymore, so I'm at a loss as to what to buy.
After that, I'd like to pull those rockers and seal them up good. The TSP heads I ordered were heavily CNC'ed, so the bolts are protruding quite bit into the runners. What did you use to seal them up?
From there, I don't know...probably try to do the valve seals. Was hoping to hold off on that until I had to replace the springs.
I'm all too familiar with cracked intake runners. With the first set of heads I got from TSP, one of them cracked in three runners when I first got it back together. Fired it up for the first time and pumped about three gallons of antifreeze out the exhaust. Long story short, got a new head, swapped it out and been running fine ever since.
Just need to slow this oil consumption.
10-13-2006, 03:49 AM
#10
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Originally Posted by LS1Beginner
I am the middle of a nightmare with this same issue. Here is what I have learned along the way and I'm not done yet - I hope this helps you and I hope to God that your problem has a more obvious and less expensive solution:
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
1. Pull a few plugs. Are they oil fouled? In my case oil was pushed up the threads to the seat surface. The plug isulators and electrodes were butt-ugly.
2. While the plugs are out, do a compression test. A leakdown test won't tell you anything about the valve seals unless your valves are shot (assuming that you are performing the leak down test at TDC on the compression stroke). In my case all cylinders read close to 180psig with #1 at 225 and #5 at 205 (I assumed this was due to excessive oil in the cylinder).
3. Plug the PCV port on the intake manifold and run the PCV line to a can (small tin can, put it behind the headlight). Put a rag over the end of the line in case this is your issue. Drive the car around and check the can - in my case it was bone dry.
4. Get serious - short circuit the whole process and pull the intake manifold. Look in the intake ports - is oil pooling there behind the intake valves? Is the manifold full of oil? In my case I had the oil pools, the intake manifold was full of oil. I replaced all the new valve seals AND resealed all rocker bolts. - no change.
5. I ignored the result of #3 - figured I was going nuts. So I installed the LS6 valley cover AND a catch can. Drove for 180 miles - 1 quart of oil - nothing in the catch can but distilled water. In short, no change.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
I have ordered a new set of heads - PRC 200cc terminators - hope this works. I have made the assumption that the CNC porting broke through to an intake runner. I hope I'm right.
Note that all of this began with a H/C switch. I have the original plugs and they are clean. Good luck, and I sincerely mean that.
The pcv can be narrowed down by blocking it off and checking the consumption.
Be sure to check carefully for leaks.
The oil reversion problem is I believe caused by oil getting past the oil rings on the pistons. Then with increased cylinder pressures and increased overlap etc. from cam swaps - the problem worsens. But others can better comment on this.
Again, take your time, try to narrow down the source and check back here often with your results.
Good luck to you both!
10-13-2006, 08:30 AM
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Just for clarification:
1. No external leaks, the oil is pushed up the threads from the inside.
2. I believe normal PCV operation pulls the valve closed with intake vaccum.
3. Plugs fouled badly in a few miles.
1. No external leaks, the oil is pushed up the threads from the inside.
2. I believe normal PCV operation pulls the valve closed with intake vaccum.
3. Plugs fouled badly in a few miles.
10-13-2006, 06:10 PM
#12
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1. Thanks for the clarification. Valve guide seals - unless you have a lot of oil in the rocker area and somme really bad guides and seals - will not foul plugs in a few miles. Do you get a good deal of smoke on start up? Are all the plugs fouled this way?
2. Yes, but many PCV systems, including the LS1 have problems because the oil splashes into the hose and is then drawn by the vacuum all the way to the intake. If the configuration of the hose or vent system were more vertical, the splashed oil would just fall back into the valve covers.
2. Yes, but many PCV systems, including the LS1 have problems because the oil splashes into the hose and is then drawn by the vacuum all the way to the intake. If the configuration of the hose or vent system were more vertical, the splashed oil would just fall back into the valve covers.
10-13-2006, 10:05 PM
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Thanks for the info guys, I needed the advice.
Changed the PCV valve today as a start. Old one looked fine and seemed in good shape. Can't tell if there is much change in the smoking.
Mine smokes mainly about 3-5 minutes after I cold start it. If I sit in traffic for a long time, it'll smoke at idle. Sometimes it'll smoke after I've ran it and then cut it off for a little while. As far as smoking while driving, deceleration especially, I'm unsure. I'm sure it's there, but maybe just not bad enough to see.
I guess the next step will be to find a good catch can. Anyone got any suggestions as to what to buy?
After that, I guess I'll try to seal up those rocker bolts.
I guess my final options will be new valve seals and check for a cracked intake runner.
I REALLY hope it's not a runner. I've dealt with those enough already.
If it's the rings, I don't know what I'll do...I guess it'll be time for a rebuild and a stroker kit.
Changed the PCV valve today as a start. Old one looked fine and seemed in good shape. Can't tell if there is much change in the smoking.
Mine smokes mainly about 3-5 minutes after I cold start it. If I sit in traffic for a long time, it'll smoke at idle. Sometimes it'll smoke after I've ran it and then cut it off for a little while. As far as smoking while driving, deceleration especially, I'm unsure. I'm sure it's there, but maybe just not bad enough to see.
I guess the next step will be to find a good catch can. Anyone got any suggestions as to what to buy?
After that, I guess I'll try to seal up those rocker bolts.
I guess my final options will be new valve seals and check for a cracked intake runner.
I REALLY hope it's not a runner. I've dealt with those enough already.
If it's the rings, I don't know what I'll do...I guess it'll be time for a rebuild and a stroker kit.
10-14-2006, 07:12 AM
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If it is smoking mainly on startup after sitting and after extended idling it is definitely pointing to rocker bolts or seals. Why not pull the covers and seal the bolts with RTV now. If the seals were new in May, it is likely not those so you have a good probability with the bolts.
10-14-2006, 09:18 PM
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Originally Posted by DaddySS
If it is smoking mainly on startup after sitting and after extended idling it is definitely pointing to rocker bolts or seals. Why not pull the covers and seal the bolts with RTV now. If the seals were new in May, it is likely not those so you have a good probability with the bolts.
If anything, it'll give me a good reason to upgrade to some Harland Sharpe's while I'm at it!
Any certain RTV work better in this type of application? I've got about three different types now (after doing various jobs on the car)?
I guess something resistant to oil and high temp would be best.
10-16-2006, 12:57 AM
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To DaddySS
Yes, I had smoke on startup but ONLY on startup that I could see. Big deccels and hard driving - no visible smoke. Nothing at WOT - very wierd.
Not all plugs were fouled equally. #1 was the worst followed by #5. All plugs had something though as near as I could tell.
As far as the PCV goes - there was never a trace of oil in the line, valve, etc..
Yes, I had smoke on startup but ONLY on startup that I could see. Big deccels and hard driving - no visible smoke. Nothing at WOT - very wierd.
Not all plugs were fouled equally. #1 was the worst followed by #5. All plugs had something though as near as I could tell.
As far as the PCV goes - there was never a trace of oil in the line, valve, etc..
10-16-2006, 10:12 AM
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Also, to the folks that have used a RTV sealant on the rocker threads, do you simply just coat the entire length of the threads or is there another method that works better?
How does this affect the use of Loctite? Can't use it I presume?
Thanks.
How does this affect the use of Loctite? Can't use it I presume?
Thanks.
