Engine using oil

[stkelly]

After a shop had to rebuild the heads and timing area on my engine due to a bad repair job (see link below if you'd like to read more) it seems I'm using quite a bit of oil. My engine seems to be using about 1.5 quart of oil within ~4500 miles. Before the rebuild I used no oil between 5K mile oil changes. The truck has about 83K miles.

I've already taken it back to the shop and they keep saying nothing is wrong.. Of course nothing is wrong to them!
There are no obvious leaks. Any suggestions as to what to look for when trying to find what's causing the oil use? It seems I can perform a pressure test and that should tell me if the piston rings are ok. But how can I test the rebuilt heads? Also, is there a chance that this much oil use could be due to breaking in the heads?

Thanks in advance!

Link to thread about shop damage:
http://www.explorerforum.com/forums/showthread.php?t=390513

 

[Flag Gibby]

Proper break in should have been done with a 30w oil so that the rings don't glaze over causing improper seating/sealing. going with the 5-20w motorcraft oil right off the get go is a big mistake in my mind. However, there is only maybe 5% synthetic stock in it so not as bad as using a full/higher percentage synthetic mix but still too light of an oil and too many additives to allow proper seating of the new metal components.
You might be able to go through a fast/hard break in sequence and be okay at this point by getting some Valvoline 30w and a cheap walmart filter and doing a 500 mile break in procedure (lots of stop and go traffic with a couple of 4000 RPM runs once it is hot) to see if you can help stop the burning/loss of oil.

 

[stkelly]

Thanks for the feedback.

When they finished the job they used Castrol Syntec 5W/20. So it wasn't even the Motorcraft 5/20 I usually use. So now that it's about 14K miles after the change is there any hope in breaking in the engine properly? I really don't want to go from having an engine that used no oil to one that uses 1.5 quarts by the time the oil needs to be changed. Esp since it was from the shops mistake. I wish the shop would have said something, I didn't even think to ask them to put in a heaver weight oil.

I had an oil analysis done and I had higher than standard numbers for aluminum, chromium, iron (biggest increase), zinc and silicon (from sealers). Blackstone labs said this was fairly normal bump on metals due to the rebuild, but they should go down with each change. I'm about to do another oil change and send it off to be analyzed again.

Do you think there is anything else I can do to determine what part of the engine is using the oil or should I just assume it's the heads since that's what was rebuilt?

Also, should I just use a straight 30 weight oil and not a 5W-30 for the break in?

Thanks again!

 

[Flag Gibby]

Yes, a straight 30 wt on the oil so it doesn't have all of the extra additives to get the lower wt cold rating. I think that the best thing you can do to help seat things is to go ahead and run a 500 mile fast break in procedure on the motor to see if it helps with the oil consumption. Don't know what to tell you other than if there is no oil in the coolant, and there is no signs of a leak under the car, then it is getting burned in the combustion chamber and that is not easy on the catalytic converters.

 

[tripplec]

Being engine rebuilders they should know what oil to use etc. There had to be some warranty. If its still consuming oil after a good amount of miles I guess you have to take it back again.

 

[matsavol]

Correct me if I'm wrong but only thing that were removed were cylinder heads. Valves were not removed from heads other than on the cylinder #4 which had the bent valve? That valve must have been replaced with new valve stem seal.

I'd first suspect the valve stem seal leaking. This is quite common reason for oil consumption in older cars. Possibly the valve steam seal was not properly installed or damaged during install causing the leakage? Might be worth pulling the spark plug to see if there is even more carbon deposits in cylinder #4 to confirm this.

 

[tripplec]

Well it does not sound like a breakin is required to me. No rings or pistons to work in which would be the only reason for breakin oil.

 

[stkelly]

You're correct, cylinder #4 had the valve that hit the piston. The valve was slightly bent according to the shop.

Supposedly both heads were sent out to be machined and all new valve seats were installed. New valves were used in cylinder 4 and no where else.

The shop is being a real pain now. They keep giving the me the run around. They first said I needed to let the engine break in and it'll stop using oil. Now they're saying all cars use oil and that 1.5 quarts in 4500-5000 miles is perfectly normal. I feel like it's going to be a real battle from this point on. It seems they're just trying to get me to 24K miles so they can say the repair is out of warranty.

I agree I think the valve steam seals are leaking. Would symptoms of an incorrectly rebuilt head show up in a Blackstone oil report?

Thanks again!

 

[colintrax]

You're correct, cylinder #4 had the valve that hit the piston. The valve was slightly bent according to the shop.

Supposedly both heads were sent out to be machined and all new valve seats were installed. New valves were used in cylinder 4 and no where else.

The shop is being a real pain now. They keep giving the me the run around. They first said I needed to let the engine break in and it'll stop using oil. Now they're saying all cars use oil and that 1.5 quarts in 4500-5000 miles is perfectly normal. I feel like it's going to be a real battle from this point on. It seems they're just trying to get me to 24K miles so they can say the repair is out of warranty.

I agree I think the valve steam seals are leaking. Would symptoms of an incorrectly rebuilt head show up in a Blackstone oil report?

Thanks again!

First off, all the info in this thread as far as breaking in are wrong. 2nd, there's no need to break in an engine that only got a new valve.
What matsavol said, pull the spark plug and check. I'm betting he's right.

 

[Flag Gibby]

First off, all the info in this thread as far as breaking in are wrong. 2nd, there's no need to break in an engine that only got a new valve.
What matsavol said, pull the spark plug and check. I'm betting he's right.

I agree, lost track of everything that was done starting with a timing chain and pieces of metal everywhere and last thing I recalled was a valve hitting a piston so naturally I had assumed that they went all out on the motor since they were already there and redoing the head/heads.
However, for the shop to have no clue where the issue is that is something that puzzles me unless they just don't want to have to do the work to fix it.

 

[colintrax]

I agree, lost track of everything that was done starting with a timing chain and pieces of metal everywhere and last thing I recalled was a valve hitting a piston so naturally I had assumed that they went all out on the motor since they were already there and redoing the head/heads.
However, for the shop to have no clue where the issue is that is something that puzzles me unless they just don't want to have to do the work to fix it.

If they're intelligent enough to rebuild the heads, I'd assume they know what the problem is. They just don't wanna have to fix it for free. That's lots of lost time

 

[stkelly]

Yeah, they don't even want to look at it. I'm going to try and catch the owner on Monday. Sounds like they just need to open the engine up again to find the problem.

What is the difference between the min and max in quarts? I thought it was 1 quart but I've also heard 1.5 to 2 quarts.

Thanks again.

 

[tripplec]

Should not use anywhere near that. I have leaking rocker cover gasket on my Jeep and it does not affect the level between changes. You're approaching being a 2 cycle engine if you were to use any more oil. LOL

I expect people behind could see you're using oil and not gas at times.

 

[colintrax]

Yeah, they don't even want to look at it. I'm going to try and catch the owner on Monday. Sounds like they just need to open the engine up again to find the problem.

What is the difference between the min and max in quarts? I thought it was 1 quart but I've also heard 1.5 to 2 quarts.

Thanks again.

Should be 1 quart between min and max.

 

[tripplec]

You're not clear but it can vary if you're on about the dipstick marks. No more than a quart for sure if that between add and full. Your gauge is starting full. When you need to add see how much you put in to bring it back. Simple....

 

[wsar10]

Am I missing what engine you have ??
I do not see any reference to a 6 or 8.....

My first question would be why are you using or even considering a 20wt oil in a 4.0 (if its the 6) ?

My next question is can you post the UOA ?

 

[stkelly]

It's the 8. I'll have the oil report posted shortly.

Thanks again!

 

[joecrna]

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.

 

[stkelly]

I finally talked to the shop owner. He agreed to do a pressure and leakdown test. He says these two tests will tell them if there are any internal leaks. Reading online I'm not sure it'll tell me the true story on the valve seals.

Will these two tests tell the full story? Or are there any other tests I should ask him to perform. I want to ask everything while they have the truck.

Thanks again in advance, everyone has been extremely helpful through this mess.

 

[stkelly]

Also, I forgot to include that the oil consumption seems to have picked up. Right after the rebuild job it took about 7,500 miles to lose 1.5 quarts. It's my wife's truck and she just tells me when "Oil Change Required" gets displayed. Usually I drive the truck more and catch it at 5,000 miles but didn't this time.

I went to change the oil when I noticed there was hardly any oil on the dip stick. So I took it to the shop and they added 1.5 quarts to get back to full and told me to drive another 1,000 or so miles and bring it back. I brought it back after about 1,500 miles and it didn't look like it used much. That's when they told me the engine just needed to be broken in after the repair. I sort of bought it and changed the oil. This oil change is what I sent away to be analyzed at Blackstone Labs. It shows all the elevated levels of the various metals and silicone sealers.

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.