Engine using oil

[stkelly]

My money is on the valve guides (what others may be calling seals). Oil consumption generally comes from there or the piston rings. Saying it doesn't use oil just because it is at the full mark at change time is a little simplistic. They all use oil, even modern tight tolerance engines. The level doesn't drop because contaminates fill the oil at the same rate as oil is used. Having said that, I would be happy if you "lost" 1/2 quart every 4000 miles on a higher mileage engine.

I have no idea what a Ford modular V8 should use but consider that Chevy engineers consider 1 quart every 1000 miles acceptable on a small block normal. I never would but they do. Point is arguing what is normal consuption is a loosing proposition.

Now if you can show a combustion chamber leak that's a completly different story. A compression test may help ( big difference in the cylinder they worked on= leaking valve seal/guide). For a leak that leads to 1 1/2 qt of oil every 5000 miles you will likely need a leak down test but now we are starting to get a bit more pricey. I'd pull the plug on the suspected cylinder, the one they worked on. At that rate of consumption I'll bet it shows alot more oil deposits then the plug next to it.

The head itself should be fine unless they reamed out the hole the guide goes through to fit the new guide. In which case thats your likely culprite. If thats all they did (no cam, lifters, pistons/rings, rods or bearings) no breakin was really needed. Even then they should complete that in the shop. At any rate, you have put some many miles on the engine since then that its a moot point.

Personally, if I had an engine that had a valve contact the piston, i would have done a bit more. Minimum of replacing the contacted piston, honing that cylinder, new piston and new rings, new valve and new valve guide. If the heads went out to a machine shop it was damaged. Meaning that combustion chamber needed "cleaned up". So a valve job on at least that cylinder. This in turn means two valves (one intake and one exhaust) needs replaced along with their guides.

If both heads were machined, I ask why. Regardless, they now both were hot tanked to remove all crud (thats the scientific term). You now need a vavle job all around, which in turn needs new valves to seat properly (they must be mated to eachother correctly) which in turn needs all new valve guides. This is the minimum to do it properly. If it's a quicky fix, just do the same but only to the one cylinder. The head on the other side needed nothing.

Either way a compression test and a leak down test if still needed should demonstrate any needed repair. If they look fine, then you are in a loosing battle. I'd just live with it at that point. Having said ALL of the above, sorry so long, I would not accept that rate of "normal" oil consumption on any of my cars.

joecrna,

It's funny you ask about the other head. I asked at the time why they were sending both heads if only cylinder 4 hit the valve. They said it was to clean everything up since they were in there. But they assured me the other head didn't have any damage.

I don't think they used new valves or valve parts, the tech was saying he reused everything from the old head except items in cylinder 4. I also asked about the #4 piston at the time, they said the walls looked fine and nothing needed to be done to the block. I should have pushed for more at the time but figured they were being honest up to that point. Should have trusted my gut more.

On the oil use, I do all the oil changes so I know that the engine didn't use very much oil between changes. If it did, it was still on the upper end of the dip stick so I didn't notice. Because like you said and I agree, they all use oil but it definitely didn't use 1.5 quarts after 5K miles. I would be fine with some use but not all the way to the bottom of the stick, especially since it seems like the use may be increasing.

Thanks for the information, seems like you're dead on with the leakdown test. Hopefully that'll find the issue. I really, hope they're honest with the results. Short of me sitting there while they're doing the tests I'm not sure how to make sure they don't fudge numbers. I just may ask to do that!

Thanks again.

 

[Bobmbx]

This time I've been trying to keep a better eye on the dip stick. I'm at the same spot on the dip stick at 5,000 miles. So I'm figuring I burned the 1.5 quarts around the 4,500-5,000 mile range.

Thanks again.

I'm just wondering why so much effort is being expended here. The OP says there are no leaks and it isn't smoking. Both are good things. The issue seems to be that oil, which is a consumable on internal combustion engines, is being consumed.

I gotta tell ya, 1.5 quarts in 4-5k miles isn't an issue. My 99 Mounty has ~270k on an original motor, untouched motor, and it burns about the same amount of oil. No smoke, no leaks.

I'm pretty damn happy about that.

If you're so concerned about your oil consumption, here's the advice you need to hear: Get a new engine, or overhaul the one you have.

There are no fixes or magic potions that will cure it. An engine restorer will work temporarily, like Slick 50, but I'd never put that stuff in my engines.

 

[matsavol]

I might add that if the valve stem seals were leaking oil it normally causes a blue cloud of smoke when engine is started. This is because the oil slowly seeps down the valve guide, getting burned at once when engine is started. Have you seen this happening?

 

[stkelly]

Here's the oil report from blackstone:

 

[stkelly]

I might add that if the valve stem seals were leaking oil it normally causes a blue cloud of smoke when engine is started. This is because the oil slowly seeps down the valve guide, getting burned at once when engine is started. Have you seen this happening?

While driving I haven't noticed any blue smoke. I'll have my wife start the truck tomorrow and rev it while I look from behind. I haven't noticed any burning smells either.

 

[wsar10]

Here's the oil report from blackstone:

Its hard to believe that this oil did not shear more @ 9k mi. it's still a heavy 20wt.

That being said IMO that iron number is VERY high for an engine that "really" did not have a complete rebuild done......... does the 4.6 have a CI block ?
Scored cylinder walls could cause this FE number and worn rings with that could cause oil consumption....... FE could be a bit higher due to the 9k mi OCI, this can also come from cam lobes and crank journals. Usually with excessive ring wear you will see elevated chromium, yours is a bit higher but not alarming. I could see higher chromium, Aluminum and tin with the work you had done.

 

[stkelly]

It does have a cast iron block. I thought the same thing about the iron. Makes me think there was damage to the block and not just the heads. I called Blackstone about it, the guy said it is possible but to see if the oil consumption and iron goes down on the next oil change. However the consumption is going up and we'll see the iron levels after I test again.

I'm wondering if the shop added an additive when I brought it back at 7,500 miles. Or did they change the oil. It was golden after I brought got it back. That would really throw off the Blackstone numbers. It's hard to know because I'm not there and they knew I was going to have the oil tested. Due to the fact I was sending it out, I requested they not change the oil or add anything. Maybe that backfired.

 

[wsar10]

It does have a cast iron block. I thought the same thing about the iron. Makes me think there was damage to the block and not just the heads. I called Blackstone about it, the guy said it is possible but to see if the oil consumption and iron goes down on the next oil change. However the consumption is going up and we'll see the iron levels after I test again.

I'm wondering if the shop added an additive when I brought it back at 7,500 miles. Or did they change the oil. It was golden after I brought got it back. That would really throw off the Blackstone numbers. It's hard to know because I'm not there and they knew I was going to have the oil tested. Due to the fact I was sending it out, I requested they not change the oil or add anything. Maybe that backfired.

It would DEFINITELY make sense that they added "something, I cant believe that a 20wt did not shear AT ALL on a 9k mi OCI, with higher wear metals, I would think there would be at least a little more fuel dilution, none at all would mean you started it @ operating temperature EVERY TIME and NEVER idled. That being said the thought of "ring wear" is not possible with out ANY fuel dilution.....(I would think)