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General Information => Troubleshooting => Topic started by: TPW on May 07, 2008, 06:09:44 pm
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I've read here that it may take a few thousand miles to break in a rebuilt engine, but is 10 miles a quart excessive? New bore in block, new pistons and rings, rebuilt head, and I replaced the turbo. This one is not leaking oil like the last one. Any ideas?
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You are burning/losing a quart every 10 miles?
That is excessive to say the least, did you assemble the engine or did you have a shop do it?
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I assembled it myself, but I had a shop doe the block to specs based on the new oversized pistons that were there to measure when the work was done. I had a similar problem with the old block that I used gapless rings with new pistons. Replacing the turbo helped, but could there be a problem with a small crack in the head?
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If you were burning that much, you should have tons of smoke and I'd think your engine would be pretty much running away. You sure it isn't leaking out of the engine?
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There is a ton of smoke, especially when I push the pedal. I vented the valve cover to the underside of the car to help prevent a runaway. There are no leaks out of the engine.
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Houston I think you have a problem :cry:
A fresh engine will have a bit extra smoke/noise/oil consumption... but only a bit.
If you're seen tons of smoke and huge amounts of smoke it's probably worth some serious investigation... compression test might show a problem cylinder (it will read low but should be pretty consistent)
Any strange noises ??
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No noises, starts easy, and run swith pretty good power.
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What color smoke are you getting with the loud pedal?
Blue or Black?
I agree with doing a comp test to see if you have a problem cylinder, but even if the ring gaps were lined up creating a clear pass to the combustion chamber for the oil, a quart in 10 miles is huge, there is something else going on.
Have you checked the cooling system for oil?
The only places it can be going is burned up, blown out, or pushed into the cooling system.
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You put on new valve seals, and used something to protect them when you put the valves in?
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Also, you say it doesnt leak, and you vented the valve cover to under the car, have you let the car idle for any length of time sitting still?
I would park the car on a concrete surface and run the idle up to 1500 - 2000 rpm and let it sit and run for 10 min or so and see if you are getting and blowby or leaks under increased idle.
Any evidence of blowby under the car, the floorpan would be coated with oil at 10 miles to a quart.
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I have a catch can that the vent off the top of the valve cover goes through. It catches about half of the oil that vents off the top. There is a lot going out the tail pipe too. There is no oil collecting in the coolant reservoir. The shop that welded the head installed new valve guides and seals, although the new viton seals take more abuse than rubber ones. The part that leads me to believe that something could be wrong with the head is that I had the very same problem with the last block and pistons. Could there be a crack in the head between the swirl chamber and the oil passages that builds pressure in the block to push the oil out the valve cover, and leaks oil directly on top of the pistons? Would a compression test indicate this possibility?
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is it a turbo?
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Yes
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Yes, mentioned in first post that it was replaced. I tested it , and it is not blowing oil into the intake manifold.
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Another thing that I think is odd is that when the engine is cold there is very little oil mist going out the valve cover, but when it warms there is more.
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Another thing that I think is odd is that when the engine is cold there is very little oil mist going out the valve cover, but when it warms there is more.
My friend has the exact same problem with his AAZ. We believe we traced it to worn rings in cyl #1 but have not taken the engine apart to confirm this. We did a wet and dry compression test.
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I'm trying to find an inexpensive compression tester to get more insight into this problem.
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I'm trying to find an inexpensive compression tester to get more insight into this problem.
ebay has some cheap ones that work well.
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I just bought one off ebay that I can test through the glow plug threads. I should have it by next week
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I just bought one off ebay that I can test through the glow plug threads. I should have it by next week
be sure to disconnect the fuel stop solenoid when checking :shock: :lol:
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what grade of oil are you burning?
15w40? or thinner?
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Rotella 15-40
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I finally got around to pulling the head today. I plan on replacing it with another, but I noticed there was a lot of play in one of the exhaust valves. even with the pressure of the cam on it it moves about 1/4 inch side to side. I think the valve guide is gone. Would that cause this much oil consumption?
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yes, and your lucky it hasn't run away. haven't you said that the valveguides were replaced?
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Yes they were just replaced less than 3000 miles ago. What caused them to go out so fast?
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someone put a wrong diameter guide? only a possibility, but either way, the machine shop should be responsible for that.
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or an inferior valve guide... magnesium would last a long time 8)
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Who sell magnesium guides?
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or an inferior valve guide... magnesium would last a long time 8)
magnesium?
Are you thinking Managese Bronze (CDA 863)? Known as Mag Bronze, Its good for heavy loads at low speed.
The stock Bronze valve guides are actually top notch, it used to be an upgrade for the US built engines to go to bronze valve guides from their POS iron guides.
I don't know what the stock guide alloy is. Befor we condem the stock guides right straight to heck, maybe we should find out what the alloy is. It could very well be mag bronze all ready.
My job involves working with (and knowing, to a certain extent) allot of different alloys.
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this ones lasted 3000miles... I doubt they are stock, or someone put the wrong ones in.
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this ones lasted 3000miles... I doubt they are stock, or someone put the wrong ones in.
I doubt that they wore out in 3,000 miles.
I suspect the guys that put it togather are a couple of hacks and delivered it screwed up.
Kind of makes you wonder if you should take it back to them to fix, they my not be capable...
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or an inferior valve guide... magnesium would last a long time 8)
magnesium?
Are you thinking Managese Bronze (CDA 863)? Known as Mag Bronze, Its good for heavy loads at low speed.
The stock Bronze valve guides are actually top notch, it used to be an upgrade for the US built engines to go to bronze valve guides from their POS iron guides.
I don't know what the stock guide alloy is. Befor we condem the stock guides right straight to heck, maybe we should find out what the alloy is. It could very well be mag bronze all ready.
My job involves working with (and knowing, to a certain extent) allot of different alloys.
u mean manganese? i heard that some of the old aircooled motors used magnesium guides or something like that.. and they never wore out. could have been manganese bronze though...
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Yah, manganese bronze. I know alloys, can't spell them though. :oops:
The aircooled valve guides are bronze too, so I would guess the material is the same.
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I did get the head fixed by the place that rebuilt it. It was covered by warranty. They replaced all the guides and looks like they replaced all the exhaust valves. Their diagnosis was that something got into the head and broke out the guide. That's hard to believe with no entrance wounds on the piston, and no exit wounds in the turbo. My guess is that a bent valve stem wore the guide down to nothing. Whatever the case, there are about 400 miles on this rebuild, and the last 200 miles the oil consumption was next to none.
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nice to hear man! :)