1993 4x4 truck 22re manual 187,000 miles original engine. I've owned this truck since it was new and did a top end chain job around 15 years ago (~100k miles). At that time, my chain guides went and I installed DOA Racing metal guides and used Toyota parts elsewhere (chain, thermostat, etc.). The bottom end looked good so I didn't mess with it. I also had a reputable machine shop re-mill the head but I can't remember if they pressed in new valve seals at that time - pretty sure they did. Recently, I have noticed that my truck is losing oil - around a 1/2 qt every 200 miles or so and I have done the following to try and figure out what's going on (based on similar posts on this forum):

1) No leaks. I keep the engine very clean and it doesn't leak anywhere
2) No oil on the air filter
3) No smoke on startup that I can see
4) The tailpipe has some black oil residue on the inside of the pipe but it is not caked on there and even the residue is thin. I can rub my finger across it and it leaves a black oily smudge.
5) The PCV valve was installed about 5000 miles ago and still looks new with no leaking around it
6) Checked coolant - no milkshake; the Toyota red looks brand new.

I haven't pulled the spark plugs yet or done a compression test. Is this the next step?

Thanks,
JARED

 

Leakdown test. You can borrow the tool from a parts store.
Watching a few videos on Youtube first will be helpful.

 

Thanks....I found a good video of someone doing a leak down on a 90 22re. But do I perform the test on a warm or cold engine (or both) and if warm, would less than 20% loss be acceptable?

Thanks!

 

Warm will give you the most realistic numbers.
Leakdown test is a lot like a compression test in terms on the results.
Ideally all the cylinders are close to each other in terms of psi. Within 10%
None of the cylinders should be over 20%. That's the red line in the sand. Techs typically like seeing the numbers under 10%. 11-15% they raise eyebrows. 16-19% they start getting squimish and warning the customer that things are trending the wrong way.

For a comparison, a new Toyota is usually under 2%

 

Good to know. I'll give it a whirl and see how it goes. Thanks again.

 

Hey, how is everything going?


 

I ordered a leak down tester (OTC) - hopefully that comes in soon and I will provide the numbers. I also checked the spark plugs and they are evenly clean. And I adjusted the valves with only two of the exhaust-side ones being a little tight.

Thanks,
JARED

 

2.5 quarts per 1,000 miles is a lot of oil.
Barring external leaks, it comes down to top end (valve stem seals) or bottom end(rings). Head gasket is a possibility, but that's awfully remote.
I doubt THAT much oil is going down the valve stem seals, so while the leakdown test doesn't play favorites, I'd expect the rings to be the likely culprit.

That was one of the drawbacks to doing head work, and especially on a higher mileage 22R. It wasn't that uncommon to see oil consumption soon after top end/timing chain work, and even moreso if the head was decked. Compression is always looking for the easiest path to escape, and with the top end now like new it goes after the older, weaker rings.

If it does come down to rings you could try an oil cleaner to free up the oil rings on the pistons if they're grunged up. I have had it work. The two different products I've used is BG MOA (they make 44K), and Rislone. Rislone is the easiest to come by. I'd do a oil and filter change, substituting the Rislone for 1qt of oil. Drive it for 500 miles(checking oil level all the time) and then change it out with new oil and filter. Sometimes I'd see improvement and do a second round. I've never had a third round change much. good luck!

 

Thanks Jimkola for the advice - especially on using an oil cleaner. I am very religious on changing the oil every 2-3k miles (never going over 3k), use only Castrol GTX 10w-30 non-synthetic and Toyota filters - so I would be very surprised if the rings were all that grungy. And with the spark plugs being so clean - that also has me scratching my head. I'm not much for additives but if I am facing a rebuild, might as well try the oil cleaner and cross my fingers. I'll post the PSI loss ratios once I get the leak down tester. I assume if my rings were going, the leak down test would reveal that?

Thanks,
JARED

 

The leakdown test probably gives the most useful data prior to anything coming apart. Much more focused than a block check or compression test.
Fwiw, i typically hate additives, especially those that merely increase oil viscosity, or you dump in a radiator to stop a coolant leak. But I think the oil cleaners, on a limited scope, are worth a shot. Especially considering the alternative.

I agree, though, with that kinda of oil consumption I'd think the sparkplgs would be starting to foul.

 

Ok, did a leak down test @100 psi and definitely something is going on with cylinders 2&3

Cyl 1: 99 psi
Cyl 2: 20 psi
Cyl3: 20 psi
Cyl 4: 96 psi

I had the radiator and oil fill caps off. I also took off the air filer lid. When cylinder 2 & 3 were under pressure, I heard an air leaking sound from the exhaust manifold. I'm thinking I have leaking exhaust valves on these 2 cylinders.

 

Head gasket failure between #2 and #3 cylinders??

 

Run a Leakdown test

 

for useful data prior to anything coming apart*

 

I assume the leakdown tester you got was dual gauge. What were the percentages of each cylinder?
20 psi is awfully low. Might be worth doing a block test and check for a headgasket leak.
Your engine should be running fairly bad, I'd think

 

Yeah, it's a dual gauge OTC leak Down tester. I ran the first gauge at 100 psi and the second gauge showed 20 psi for cylinders 2 & 3. Ran the test for cylinders 1 & 3 at TDC with rotor pointed at cylinder #1. Turned the crank 360 degrees at TDC again for cylinders 4 and 2. It's not running very crappy - just the unusual oil leak. Wouldn't a leaking head gasket have oil mixed in with coolant, external leaking or white smoke from the exhaust? None of this is occurring. I'm going to tighten the exhaust manifold bolts....hope maybe that is the issue??

 

Forgot to mention that I pulled all spark plugs and ran the test. Should I do one at a time?

 

Pulling all the plugs wouldn’t matter.
If a headgasket was failing the most common symptom is exhaust gas in the cooling system. The block test is pretty good at detecting this. It’s very rare that oil enters the cooling system. Oil in the cooling system is a bit of a disaster when it does happen, as it tends to just ruin all the various coolant hoses.
Tightening the exhaust manifold nuts won’t help the leak down numbers.
A Leakdown test generally focuses on four things. Rings, headgasket, intake and exhaust valves.

I’d still like to the % of each cylinder, with its respective compression psi.

 

Thanks again Jimkola. I did re-tighten the 8 exhaust manifold bolts to 33 ft lbs just for the heck of it. They were all tight to spec. Everything looked good on that side of the engine - no leaks or anything. I'm not seeing bubbles in the coolant either. I also drove the truck lightly for 20 miles and let it run for about 45 minutes parked and was surprised that the oil is still at fill. I'll take it for a longer drive and see how that goes. I mean, there's no way that this thing fixed itself after just adjusting the valve clearance. Plus with the 20 psi readings for cylinders 2 & 3....I would think there would be some other tell-tail sign of failure elsewhere. Maybe I'll run the leak down test again and get you percentages. Although, if I am porting in 100psi of air and the other gauge is reading only 20 psi with a lot of air going somewhere, wouldn't that be an 80% loss? As the air escapes, I am going to listen to it more clearly and see exactly where it is going. Thanks again for your insight and help. Much appreciated. BTW, I just noticed you're location is CA....I hope you are not affected by the fires happening over there. Stay safe.

 

Might be worth running the test one last time.
1) pull all the plugs
2)get the cylinder to be tested at top dead center on the compression stroke so both valves are closed.You can always check that the valves are closed by pulling the valve cover and seeing if the rockers are loose. But set it back on once you start the test so you can listen for leaks.
3) connect the tester to the cylinder.
4) open the valve to let air in. Watch the left gauge, this shows the psi you let in. Most go to 100 psi for easy math.You don't have to use 100psi on the left, 80psi or 90psi works, too.. Just whatever you decide on do the other three the same.
5) once the left gauge shows 100psi see whats on the right gauge. This shows what the cylinder is holding. the difference between left and right will be the % that leaked out(100 psi makes it easy to calculate)
so if you test #1 cylinder at a 100psi on the left gauge, and the right gauge reads 93psi that cylinder has a 7% leakdown.

record everything. left gauge and right gauge for each cylinder