Compression Test Results

[chasman]

Hi All,

Background:
Back in 8/05 at ~184k our car was knocking under load despite relatively new spark plugs & correct timing. Our mechanic suspected carbon deposits and suggested a can of BG 44k fuel additive, which solved the problem.

Recently, we noticed a new oil leak. Diagnosis: oil seals on the front of the engine and a small leak at the rear main seal. However, we had changed the front seals when we last changed the timing belt at 150k miles - only 40 k miles ago! Our mechanic thought the premature failure of the seals might be due to blow-by contaminating the oil. So we had him perform a compression test.

Test Results:
- 175 lbs. dry
- 195 lbs. wet

Diagnosis:
Engine has moderate blow-by (probably caused sticking rings due to carbon build-up) causing premature seal failure. Does this diagnosis sound correct?

How to Proceed?

• Would any other tests be helpful?
• Drive the car as is and closely monitor oil level
• Replace all seals on the front of the engine, all belts, & the water pump and hope the new seals last another 40k miles & monitor rear main seal.
• Rebuild the engine with genuine Toyota parts
• Install an ATK or Jasper reman.
• Replace the car / Buy a used Gen3 wagon
• Something else?

One-owner car, well maintained, just overhauled the suspension. Any recommendations would be greatly appreciated!

Thanks!

[88 LE]

Compression readings look good.

Considering the motor has almost 200,000 miles on it, I'd say a little bit of blowby is normal.


For other tests, you can do a leakdown test.


As for what to do, are you going to keep the car? If so, I'd fix it.

An option you didn't list, is a used Japanese motor. I've seen 3S-FEs for around $200.

[Gary_602Z]

I would say your compression is good. A leak down test may help to determine if you are getting some blowby past the rings. As far as a used motor you don't really know what you are getting. Also have you checked your PCV valve as it maybe giving you a little extra crankcase pressure.

Gary

[88 LE]

^ No PCV valve on a 3S-FE. Theres just a hose from the valve cover to throttle body.

2VZ-FE has one, IIRC.

[JetspeedCamry]

Originally Posted by 88 LE

2VZ-FE has one, IIRC.

Indeed it does Positioned on the rear bank. It also has a breather like the 3SFE on the front bank.

[chasman]

Originally Posted by 88 LE

Compression readings look good.

Considering the motor has almost 200,000 miles on it, I'd say a little bit of blowby is normal.

For other tests, you can do a leakdown test.

As for what to do, are you going to keep the car? If so, I'd fix it.

An option you didn't list, is a used Japanese motor. I've seen 3S-FEs for around $200.

I'm not familiar with a leakdown test. What is the advantage of it?

Yes, our hope is to not have to replace the car especially since the Camry wagon no longer exists. It runs well especially for its age & mileage. We still average 30 MPG on interstate trips at "go-with-the-flow" speeds.

I didn't list a used engine as an option due to the age of the car. A used high-mileage engine obviously would only be a short-term solution.

A used Japanese 3S-FE motor? Please tell me more. With typically how many miles? Is there a recommended supplier for such motors? Do they come with an oil change history?

Are there any proven chemicals that would solve or improve this issue without negative side effects?

Thanks!!

[marc780]

Regarding a used japanese engine option. I think that in comparison to the work involved in ripping out the trans to fix the rear seal, and taking apart the front, timing belt, oil pump etc. to get at the front seal to change, a used japanese engine MIGHT be a good solution.

But if anyone wants to learn from my experience, i did change the engine (in my old 85 Nissan 200SX) for a used japanese engine. The cost was $1000 and ultimatley no bargain.
I rented a hoist and engine lift and started to do it myself, in a closed garage in summertime no less. And got the engine out, the manifolds and acesories off and as far as changing the intake manifold when it turned out the manifold wouldnt fit, it was blocked by a cooling pipe from the engine, that was different on the new one! Not only this, the intake ports did not match, my old ports were oval and the ones on the new cylinder head were round. But they told me it would still work, and finally after having the car towed back to the place and having their mechanics finish the job it did work, sort of. it ran but never as well as the engine it replaced (i had overheated the old one and broken a piston).

A used japanese engine can sometimes be a really good deal - nothing wrong with most of them. You've probably heard they come from japan where the smog laws are insanely strict, so alot of perfectly good engines get changed with only 35,000 - 40,000 miles on them.
If you do go for a used japanese engine, they CAN be good deals, but id never buy any engine sight unseen. I'd want to have a real good inspection of my old engine first, maybe even take some digital pictures and then COMPARE the old engine to the replacement engine to make sure it matches EXACTLY. And not take the engine shop's word for it lol

[88 LE]

Originally Posted by chasman

I'm not familiar with a leakdown test. What is the advantage of it?

A compression test tells you how much pressure (psi) a cylinder is capable of making.

Leakdown test tells you if theres leakage past the rings and how much leakage.


Leakdown tester has 2 gauges on it. One gauge connects to a air source (air compressor) and the other gauge to the cylinder your testing. The gauge connected to the air source has a dial on it to adjust/set the pressure. Theres a hose that attaches to the 2nd gauge that screws into the cylinder. The hose screws in just like the hose on a compression tester.

You screw the tester into the cylinder your testing. Turn the dial to set the pressure. Say you set it at 80 psi., this pressurizes the cylinder to 80 psi.

Then compare the readings on the 2 gauges to see if theres any leakage. The reading on the gauge connected to the compressor shouldn't change. IIRC their should be a chart that comes with the leakdown tester, says something like this amount of leakage over this period of time.

You have to make sure the valves (intake and exhaust) are closed on whatever cylinder your testing. Otherwise you'll have air leaking past the valves into the cylinder head.


In the pic below, the gauge on the left connects to a air source. And the gauge on the right connects to the cylinder your testing.

Is there a recommended supplier for such motors?

Only one I can recommend is Attarco. Some of my friends have bought motors from them. I don't know where your at, but Attarco is in California.

http://attarco.com

Are there any proven chemicals that would solve or improve this issue without negative side effects?

Nope. And I don't recommend additives.

If an engine is worn its worn. Theres no additive that'll fix it, other then another engine or a rebuild.

[chasman]

Originally Posted by 88 LE

A compression test tells you how much pressure (psi) a cylinder is capable of making.

Leakdown test tells you if theres leakage past the rings and how much leakage.

Since the wet compression values are higher than the dry, does this indicate that there is leakdown/blow-by?

Only one I can recommend is Attarco. Some of my friends have bought motors from them. I don't know where your at, but Attarco is in California.

Any recommendations for the Mid-Atlantic area? If no, would you recommend reman. or rebuild?

Nope. And I don't recommend additives.

If an engine is worn its worn. Theres no additive that'll fix it, other then another engine or a rebuild.

The reason I asked about chemicals is I have seen that Seafoam has been discussed on this forum. Seafoam claims to remove carbon deposits around rings. Any thoughts?

Thanks again!

[chasman]

A used Japanese 3S-FE motor sounds like a potential solution. Is there a recommended supplier for such motors in the Mid-Atlantic region?

Thanks!

[white90dx]

My opinion:

Your motor is still good. 40k miles for new seals isn't great, but not totally out of wack (maybe there was some contamination that caused it to fail early). 175psi dry compression on a 9.3:1 compression motor is reasonable (I got 180 out of a recently rebuilt 3s-fe).

Japanse motors are somewhat of a gamble. Make sure you get a decent warranty if you go that route.

-Charlie

[Gary_602Z]

A leakdown test will also tell you if you are having valve problems. But from what you are saying 30 mpg and running good I would just fix the seals and run it! SeaFoam is a good product, would it help your compression?,doubtful. But for 5 bucks buy a can an run it thru.

Gary

[chasman]

Originally Posted by white90dx

My opinion:

Your motor is still good. 40k miles for new seals isn't great, but not totally out of wack (maybe there was some contamination that caused it to fail early). 175psi dry compression on a 9.3:1 compression motor is reasonable (I got 180 out of a recently rebuilt 3s-fe).

Japanse motors are somewhat of a gamble. Make sure you get a decent warranty if you go that route.

-Charlie

Originally Posted by Gary_602Z

I would say your compression is good.

Originally Posted by 88 LE

Compression readings look good.

Sounds like their may be some life left in our original ~20 yr old 189k 3SFE engine. The questions become:

• How to determine the most likely cause of the premature seal failure?
• If we replace all the leaking seals, how long will the next set last?
• How much should we invest in repairing versus rebuilding such an old engine? - (Replace all seals on the front of the engine, all belts, water pump, & rear main seal.)
• How much longer is the engine likely to last?
• At what point is it better to invest in a used/reman/rebuilt engine?

Thanks!

[88 LE]

Originally Posted by chasman

Since the wet compression values are higher than the dry, does this indicate that there is leakdown/blow-by?

Not necessarily.

Wet compression test involves pouring some oil (teaspoon or so) into the cylinder then doing a compression test. Oil does not compress.

I would be concerned if the compression readings were low or compression on some cylinders are higher then others. But thats not the case here as your compression readings are good.


If your concerned about leakdown/blowby, do a leakdown test on the motor.

Any recommendations for the Mid-Atlantic area? If no, would you recommend reman. or rebuild?

I don't know of any places in the mid-atlantic area. Maybe some other members can suggest some place.

Reman. is a rebuilt motor. If you go that route, buy from a reputable place and check the warranty on the motor.

If we replace all the leaking seals, how long will the next set last?

Hard to say.

It could last another 40,000 miles like the previous set or for the rest of the life of the motor.

How much should we invest in repairing versus rebuilding such an old engine? - (Replace all seals on the front of the engine, all belts, water pump, & rear main seal.)

The parts aren't that expensive, its the labor.

How much longer is the engine likely to last?

Thats hard to say, but I have seen 3S-FEs with 300,000+ miles.

From what you've said so far, the engine runs fine except for the leaky seals and some blowby.

At what point is it better to invest in a used/reman/rebuilt engine?

When it costs to much to repair or your engine is just tired/worn out.

[chasman]

Originally Posted by 88 LE

Not necessarily.

Wet compression test involves pouring some oil (teaspoon or so) into the cylinder then doing a compression test. Oil does not compress.

So what is the purpose of the wet compression test?

If your concerned about leakdown/blowby, do a leakdown test on the motor.

That will be our next step as we really would like to know the reason for the premature seal failure. I'll let you know what we find.

Reman. is a rebuilt motor.

Yes I'm aware. I was trying to differentiate between buying a reman. or having our motor rebuilt.

The parts aren't that expensive, its the labor.

Agreed.

Thats hard to say, but I have seen 3S-FEs with 300,000+ miles.

Sounds encouraging. Is that the exception or typically how long they'll last with regular oil changes?