Hey guys. Since the motor was built, it's been consuming oil like crazy, an abnormal amount, maybe a full quart every 300 miles or so. Granted most of those miles are on the track, but that still seems a bit excessive to me. I can see it smoke through the tail pipe, it's pretty visible. I've had the motor checked out, and compression is still pretty decent (between 180-190 psi across all cylinders), leakdown is between 9-11%, and the motor still makes pretty solid power. Is it possible for all this to to be within spec, and still have a major oil consumption?
Engine oil consumption question
- Thread starter ReplicaR
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apsmith49921
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Running a catch can at all? Could be rings or just something like crank case ventilation
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What heads are you running?
ttocs
Post Whore
have you checked the pcv?
apsmith49921
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What does your intake piping look like. Large amounts of oil residue?
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You mean in the actual intake manifold?
apsmith49921
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That or the tube after the crank case vent is.
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apsmith49921
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Just a lot of oil residue. Large amounts of blowby
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I can tell you that there is a pretty good amount of blowby. When I had a catch can on there that vented into air (filter on top), even at idle you would see a good amount of oil smoke come through the filter.
sounds like the ring gaps are too loose or the rings are not sealing. Maybe the bore finish wasn’t correct for the type of ring that was installed?
I don't know if you remember, but I had another shop literally tear down the whole build and redo all of the original work, because it was complete shit. The only thing that wasn't touched were pistons and rings... I am swiftly regretting it at this point. I'm starting to price things out, to see what it would take, brainstorm different scenarios. I thought about upgrading to 347 combo, while the motor was apart, but apparently it's just a bore and piston change, you have to change the crank as well, which gets significantly more expensive, so if I have to bore the block further, I'd rather buy another block and keep the piston set, since a new set of Mahle's is around $800 and a new block (which will need all the machine work anyway) is around $150
TrickVert
Active Member
A little thing, but perhaps the rings were installed with the gaps lined up instead of offset?
You could likely just hone the block and reassemble it with new rings and be done with it. Check all of the bearings while you’re in there and take the opportunity to make any other upgrades you can dream up at the same time.
All things are possible, but it's the kind of stuff you don't find out until you actually open the engine up.
That's what I'm mostly hoping for, a quick hone of the cylinder walls, new rings, bearings, gaskets, back together and working well. I've contemplated doing this myself, but with two small kids, no experience working on bottom end, and a real possibility of overlooking something from just being inexperienced, I'd rather pay someone to do this and know that if something is wrong, I can bring it back and have them fix it without spending any money or time.
One way to control oil consumption past the rings is by pulling a vacuum beneath the piston. You may want to consider reinstalling the PCV.
Our 69 Mustang with a 390 also smoked at idle after rebuild until we installed the PCV.
The 2018 and newer 5.0 engines have a significant oil consumption problem. Can read about this on the F150 forums. Fords is retrofitting the crank case ventilation system on the vehicles to solve this.
Our 69 Mustang with a 390 also smoked at idle after rebuild until we installed the PCV.
The 2018 and newer 5.0 engines have a significant oil consumption problem. Can read about this on the F150 forums. Fords is retrofitting the crank case ventilation system on the vehicles to solve this.
This is significantly cheaper than tearing the engine down @ReplicaR.
Thanks for heads up guys. I actually just had PCV valve reinstalled on the car, and removed the open air catch can. I'll monitor the oil consumption now, but one thing to keep in mind is that the motor consumed oil like crazy even before I went to catch can from PCV
