Compression Test

pdsman53 · Postby **pdsman53** » Sat Oct 10, 2020 5:05 pm

Hi guys,
I did a compression test on my 10AE with 180k km and cylinders 2&3 we're well down.

Hot.......190 165 150 185

I got interrupted....went back when in it was still warm.

Warm...180 145 135 170

Then did a wet test.

Wet.......210 165 150 200

This appears to indicate worn rings or cylinder bore scoring/wear.

I did a Leakdown test....I thought that there may have been a very slight leak through the Inlet manifold, but wouldn't like to order the Valves etc parts and rip the head off for a rebuild...on a "I'm not 100% sure" basis.

I'm considering using a Rislone Compression Repair additive...to confirm the diagnosis.

I'm reluctant to use some of these additives.....
Has anyone had any experience with this issue and Resolved it with Rislone or similar product.

Cheers...Jim

Ned Loh · Postby **Ned Loh** » Sun Oct 11, 2020 6:20 am

What are the percentages for each cylinder on the leak down test?

Never used that sort of additive, sorry.

rascal · Postby **rascal** » Sun Oct 11, 2020 8:45 am

I don’t think I’d bother with the additive. Those numbers are pretty conclusive.

I’d suggest you’re up for bottom end work at least.

track_addict · Postby **track_addict** » Sun Oct 11, 2020 9:22 am

Do a leak down test and try to listen for where the air is escaping. Pressurise the cylinder, put your ear to the dipstick, then the intake, then the exhaust to hopefully hear where it’s coming from. That will help you diagnose what’s gone to sh*t.

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greenMachine · Postby **greenMachine** » Sun Oct 11, 2020 10:23 am

One cylinder down, could be a leaking valve or broken ring. Two, that speaks of more serious/widespread trouble. Interestingly, No4 not one of the problem cylinders.

I'd run it for a while, while I was prepping a spare bottom end. Then pull the head and look at the valves/seats, a quick re-seat if OK, skim and fit to the new rebuilt bottom end. If you can find a cheap complete engine to rebuild get that, but be sure it hasn't overheated - this is a quick way to kill the head.

:mrgreen:

pdsman53 · Postby **pdsman53** » Sun Oct 11, 2020 11:24 am

Yeah thanks guys.
As I indicated in the initial query...I did a Leakdown.
There were no leaks other than a very slight feel of air on the Inlet m'fold for 2 & 3....but wouldn't like to bet on the results....that's why I wanted to test the Rislone additive.
Just to confirm 100% that it is rings....and not a 2 cylinder to 3 cylinder...head gasket failure.
If I can confirm it's just the Gasket, it will save the bottom end work.
Cheers,
Jim

ricky-pinky · Postby **ricky-pinky** » Sun Oct 11, 2020 2:33 pm

If the pressures don't increase when you do a wet test, I understand that to indicate valve seating issues.

Check valve/cam clearances on numbers 2 and 3.

I would guess the rings may be okay.

pdsman53 · Postby **pdsman53** » Sun Oct 11, 2020 3:36 pm

Hi Ricky,
My 'wet' results increased...so indicates rings.
Cheers,
Jim

lonesailor · Postby **lonesailor** » Wed Apr 14, 2021 4:29 pm

I would have thought that rings should last more than 180K It possibly could be a head gasket leaking between cylinders 2&3. If it were me, I would consider pulling the head initially to check, it's easier than the engine. If you find the gasket is intact, then the rest of the engine could come out. If it is the rings the head has to come off anyway, you may have to replace it temporarily to make use of the lifting hooks but that should be no problem.