Burning/losing 2-3 quarts after 100-200 miles
06-22-2018, 07:21 PM
#1
Burning/losing 2-3 quarts after 100-200 miles hello I recently LS Swapped my Porsche about a month ago, runs and drive great, we put a gen 3 LS1 5.7 with about “50k” miles. I have a catch can, everything dry no noticeable oil leaks. Had 6 quarts of oil in it, I’m not sure if I’m using the wrong dip stick or what, but after about 100-200 miles, dipstick is reading dry. And catch can is about 3/4 full of oil, intake is like soaked with oil. What the hell is going on?? Is it piston rings? Or what else can I check? I’m not getting any smoke coming out of exhaust either. Any ideas??
06-22-2018, 07:49 PM
#2
TECH Senior Member
Drain and measure the volume of oil to be sure about the dipstick. How large is the catch can?
06-23-2018, 10:14 AM
#4
I think it's possible that your Porsche's LS needs new valve seals.
My 99 TA got so it would burn 1 quart every ~ 600 miles with the old LS1. The intake was wet with oil inside too. If I drove hard with a few spins to 6,000 - 6,500 rpm, the TA would give off a death fog that would kill all the mosquitoes in a five mile radius
The TA would literally suck down oil so fast with a little hard driving I would estimate the car burned a quart every 100 miles.
The valve seals were bad and needed replaced. My car was also due for valve springs. Norris Motorsports used the BTR spring kit and replaced valve seals, springs, locks, retainers. Exhaust #5 had a broken valve guide at the very top. The top had sheared so the new valve seal didn't have as much are to seal too. I didn't want pull the heads etc as another motor was already in the works. Anyway, with the new valve seals the oil consumption dropped to half a quart every 2,500 miles.
With new valve seals there was a hint of smoke are 6,000 - 6,500 rpm probably due to the #5 exhaust valve guide issue.
My 99 TA got so it would burn 1 quart every ~ 600 miles with the old LS1. The intake was wet with oil inside too. If I drove hard with a few spins to 6,000 - 6,500 rpm, the TA would give off a death fog that would kill all the mosquitoes in a five mile radius
The TA would literally suck down oil so fast with a little hard driving I would estimate the car burned a quart every 100 miles.The valve seals were bad and needed replaced. My car was also due for valve springs. Norris Motorsports used the BTR spring kit and replaced valve seals, springs, locks, retainers. Exhaust #5 had a broken valve guide at the very top. The top had sheared so the new valve seal didn't have as much are to seal too. I didn't want pull the heads etc as another motor was already in the works. Anyway, with the new valve seals the oil consumption dropped to half a quart every 2,500 miles.
With new valve seals there was a hint of smoke are 6,000 - 6,500 rpm probably due to the #5 exhaust valve guide issue.
06-25-2018, 12:40 AM
#7
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Mine started using oil noticeably. Head cam car.... tune was bad and I melted piston 7. After it cooled it cracked.... after I noticed it using oil (I check often) I pulled the plugs. Cylinder 7 burning oil. looking in the intake runner I didn't notice oil on the valve. Since cylinder 7 has a reputation in the ls1 I pulled the head..... engine builder told me it was a good thing i stopped driving it when i did... the cylinder wall could be bored out...
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06-25-2018, 03:45 AM
#9
Also I drained my oil this weekend, I lost roughly 1 quart after about 60mi.
I also changed heads to refurbished ones this weekens as well. So we will see how that goes. All pistons and cylinders looked in good shape.
I also changed heads to refurbished ones this weekens as well. So we will see how that goes. All pistons and cylinders looked in good shape.
06-25-2018, 11:16 AM
#11
TECH Junkie
Imo it's definitely pcv related.
I would cap the back passenger side off. Run the clean side to the back driver's and dirty to front passenger. Also put a 1/8 in. restrictor in the dirty side. You're oil consumption will be massively reduced.
I would cap the back passenger side off. Run the clean side to the back driver's and dirty to front passenger. Also put a 1/8 in. restrictor in the dirty side. You're oil consumption will be massively reduced.
06-25-2018, 11:27 AM
#12
Awesome haha will be so relieved if it is in fact PCV related. where do I get an 1/8” restrictor?
06-25-2018, 12:53 PM
#13
TECH Junkie
anything that you can think of to put in the hose to restrict it to 1/8 in. Something like a barbed end and cut it so it fits snug in the hose but has a 1/8 in. hole. If that makes sense?
06-25-2018, 04:04 PM
#14
Do a leak down test before you waste any more time trying to guess. Using this much oil if its burning it you will see it out the exhaust and usually it collects on the body around the exhaust outlets. I was using a qt every 200 miles, number 7 piston was toast. I actually never saw and blue smoke but the body panel above the exhaust outlet was black. There is so many reasons you could be using this much oil.
Last edited by RockinWs6; 06-25-2018 at 04:11 PM.
06-26-2018, 08:31 AM
#15
Do a leak down test before you waste any more time trying to guess. Using this much oil if its burning it you will see it out the exhaust and usually it collects on the body around the exhaust outlets. I was using a qt every 200 miles, number 7 piston was toast. I actually never saw and blue smoke but the body panel above the exhaust outlet was black. There is so many reasons you could be using this much oil.
Or what do u mean exactly?
06-26-2018, 08:36 AM
#16
so your saying instead of the clean side going to the intake, go to Rear driver, and the dirty side instead of going to the Rear driver to go to front passenger and plug the Rear passenger? Then the catch can will no longer go to the intake? Is that a normal way to route it? Or am I wrong?
06-26-2018, 03:44 PM
#17
Broken, the top ring gets hot expands and pops the top ring land off the piston in places. It started using oil and eventually failed. Do a search on number 7 piston failure. Quite common.
Last edited by RockinWs6; 06-26-2018 at 03:57 PM.
06-26-2018, 03:55 PM
#19
TECH Junkie
so your saying instead of the clean side going to the intake, go to Rear driver, and the dirty side instead of going to the Rear driver to go to front passenger and plug the Rear passenger? Then the catch can will no longer go to the intake? Is that a normal way to route it? Or am I wrong?
