Ok so About 4,000 miles ago I had my engine rebuilt. Now it leaks a little oil, not much but enough to leave a spot on the driveway.

When you take the oil cap off while the engine is running it pumps out oil mist. Enough to make your hand covered if you hold it over.

I did a compresion test and all the cylinders are at about 140 PSI, not great for a rebuilt.

Also there is oil soot around the exhaust pipe and if you take a rag and wipe around inside you will get a little oil on it.

Just by guess, does anyone know what it could be?

 

Yep....140 is rather poor. How does it run? Does the vehicle smoke at all? You can tell a lot by the color of the exhaust....if it is. Look for blow-by in your breather and PCV lines going to the plenum. That will also tell you a lot. I mean the carbon in your tailpipe could just be from running rich in fuel.

 

It runns OK, never a race machine, but it does alright. The exhaust is normal looking/smelling. I had a friend flolow me in his car to look at the exhaust and it is normal color. It doesn't smoke. For a short period I did switch to synthetic oil and thats when I seemed to have my problems. I now run a thicker oil with the resotre aditive.

 

If you just had the motor rebuilt, you need to take it back. 140 is below service limit even. Something's wrong. Do all cylinders show about the same compression? Are you losing any coolant that you've noticed?

 

The coolant level is fine and all the cylinders are about the same presure. I would take it back, but I had it re-built in MI and I now live in CO. Bummer!

 

Well, if you have a compression tester, put a teaspoon of oil in the cylinders and retry the test. They say that this will seal up the rings and bring your compression up during the test. If it helps, you can be more sure it's the rings that are the problem. If it doesn't help, you can bank on it being the valves.

 

Oil leak, where's it coming from on the engine? Front seal, rear seal, head gasket, V/C gasket, PCV valve, etc..
From the way you describe the the "oil mist" thing, it could be that the piston rings havent seated yet. That would explain the lower compression and what sounds like "blow-by". Do you know what type/make of rings went into the engine in the rebuild.
Was the compression test a dry or wet one?

 

All the parts that went into the rebuild were from Engbldr. The test was done dry with now added oil to the cylinders. Could the rings not seated in 4,000 miles of driving? I thought they would seat within the first 500 miles or so. Thanks for the tip on using oil when I do the compresion test. I will try that and see what happens.

Oh, and I think the oil leak is coming from the back of the head. There is a plate back there for something. I really havent pinned the spot down where it is leaking from yet. I think the high crank case pressure in the head must have blown a coulple gaskets.

When I had the engine re-built I did not rebuild the head. Only laped the valves and put all new valve seals/gaskets in.

 

If I were you i would wait and see if it breaks in but...

If you continue to have concerns do a differential pressure compression test and while doing the test remove the intake, open the throttle valve and listen for a hissing noise....do the same at the exhaust listening for hissing, then remove the oil filler cap and listen there for blow by.

By checking these three points you should be able to hear the hissing somewhere and marrow down your problem. hope you find it.

But like stated above it is more than likely the engine has not broken in yet.

 

How do I insure that the engine does break in?

 

Take close notice of your temp gage.....It should be running a bit hotter than it could be if it were broke in. Typically they shouldn't take more than 500 to brake in but I must tell you I have never owned a new engine in my life...hahah

 

If the engine rebuilder use "hard" piston rings, it could take many mile to seat them in. LOTS of variables there[ cross hatch on cyl walls, cyl spec, type of rings, ring tension, oil your running,etc] Only reason I bring it up is years ago I built up a engine using some hardened rings. It burned oil at first, I thought I had made a fauxpas in my build-up/assembly. I checked back with the "ring" manufacturer and was told "break-in" of the rings would be longer than normal and NOT to use synthetic oil jurying the break-in period[syn oil was just to "slippery"]. It burnt/used oil for about the first 10,000 km, but did seal up and stop using oil. Ran it for another 80,000km[until i sold it] and it never used a drop after that.
Options
You could try taking it back and see if the shop would warrenty it[long distance thing now from the sounds of it].
You can just drive it and see if it seals up[use conventional oil for a while to aid break in.]
You could run a few more checks/test, find out whats "not to spec", bite the bullet and spend $$ and fix it right like it should have been done the first time.
Just my .03 cents.
Good luck, keep us posted.

 

Synthetic oils should not be used on rebuilt engines until oil consumption drops to normal.

How many miles on your engine when you put syth oil in, and how many miles did you drive it for with the synthetic oil in it?

Your best bet at this point is to use normal 10w30 oil and a genuine Toyota oil filter. Any non-synthetic oil other than recycled/reclaimed oil. Any additives are NOT a good idea. Drain your oil out to get rid of them.

Warm the engine up by driving it gently, then go find a BIG mountain highway and drive up full throttle, top gear. This will put full load on your rings and help seat them. Keep an eye on the temperature gauge and don't overheat your engine. If the temp gauge creeps up, you have a cooling system problem that should be repaired.

Once the engine is at operating temperature, it is permissable to drive at full load, full throttle. Doing so is a GOOD THING.

After 20-30 minutes of full load driving, check your oil levels, and top up if required. Then go do it again.

This is how we seat the rings on freshly rebuilt engines. Done it to dozens of them. Once the rings are seated, your oil consumption issues will disappear, and your compression readings should increase. Note that I'm at sea level, and in CO your altitude will affect power and compression gauge readings.

 

I agree

Do not use synthetic oil during the break in process!!!!!

Use mineral based oil Helps seat the rings If you have been using synthetic oil since the rebuild then the chances of you engine being broken in are very low.

 

I agree. Go take the thing up a good big hill and get on it. If you want load it up with gear in the back to make it harder on it. Doing this forces the rings into the cylinder walls and helps break in. Not good to baby them when breaking them in as the cylinders will glaze over and then you need to run them hard to get it broken in. Which is pretty much what your case sounds like. I rebuilt my 22R with an Engnbldr kit and it has 160 PSI on all 4 and run fine. Leaks a bit of oil but not very much. One thing about the kit is with the pistons they are not as high a compression as stock ones so that will lower it a bit. I wish I would have used my stock pistons as before the rebuild I was getting 180 psi on a few cylinders. Reason for rebuilding was a bit of knocking and it was using oil due to stuck oil control rings. Really wish I would have used the stock pistons.

 

A leak down test would tell you where you're leaking, but with 140psi and a stock-ish cam, I think rings are the most likely suspect also.

Buying good parts is part of the formula. Good parts and crappy machine work..well, doesn't matter how good the parts are.

When you had it rebuilt, what size were the pistons? Putting back standard pistons in well used bores - after honing, you can see this sort of thing. Ideally, the machinist checks out the block, you'll bore it to the next size (after being checked out) - final hone is done with the pistons in the machinist hands, as piston size can vary one to another....

Other likely causes - improperly installed rings (installed upside down).


Some blow-by is normal. 140 psi compression is not normal.
A leak down might tell you more.. the rest of my comments are guesses, based on the normal quality of "rebuild" I see in my area.

 

Hmmm, this makes me think. When the engine was rebuilt the cyliner walls were measured and found to be within tollerance. Stock piston size was used. The cylinder walls were not bored out. they were honed out.

I only ran synthetic after I had 3,000 miles on the engine. Than after 3,000 I switched over only for about 500 miles until I realized it was leaking bad. I did the compresion test with the synthetic oil stil in it. Right now I am running dyno oil (10W40 with a quart of Lucas).

 

well broski. I hear ya. I just got done chasing an impossible problem with good compression fouling plugs and soot out the tail pipe. First, like every 1 said, your compression is low. Check that out with a leak down if you get the chance. Dont have the tools, no worry there are ways round that too. Any case, are your plugs fouling? all cyllinders just one? Mine was just one in #3 and only half the plug fouled. Turns out it was a broken valve guide. So check your plugs, check ur compression, and drive it hard if you haven't already.

 

I don't know what stock 22RE's do at sea level but 140psi sounds about right for 1 mile+ above sea level. Altitude makes a huge difference.

Here's a post on another forum that shows the math:
http://www.eng-tips.com/viewthread.c...169417&page=15

It basically shows that a reading of 160psi @ sea level is about 113psi @ 7800 feet.

That's where turbo's come in handy..

 

Thanks for the knowlede. I havent checked the plugs to see if they are fouled. I have noticed that when I gently step on the gas from idle the truck shakes up to 1800 RPM. After 1800 it runns fine. Would that be an example of a fouled plug?

And the other thing that is very intersting is compresion at sea level vs. 1 mile altitude. I never thought about that before.