The news is not good.

The front rotor posted nice even compression pules as the engine was turning over. The compression wasn't too high, but that's expected with the bores being washed of oil from all the petrol trying to start it.

However the aft rotor is very inconsistent. Sometimes it gets a pules, then it misses a few then it gets another. Looks like a tear down is in order.

 

Well, looks like no one is getting Christmas presents from you this year . Sorry to hear... most of us have been there ... it's a dark, expensive place. Good luck. Keep us updated!

Question:

Are you getting one jump and two misses on the rear rotor?(Could be broken apex, could be stuck)
Or Two jumps one miss?(broken, stuck side seal(rarer))

 

It appears I'm getting 2 misses and 1 jump.

Well its the reason I needed to pull my finger out and get cracking on with restoring my other shell. When it goes back together I think I'll be running it with a standalone.

 

Wonder if you have a stuck side seal...

 

Side seal would be Two jumps one miss. Definitely stuck or broken apex. When an apex breaks you may not even notice it... you'll just stall. You won't hear anything and there will be no warning signs. You'll just be like, "where did the power go?" and then you'll stall at the next stop.

The one thing you will notice is the engine will sing a different tune when attmepting to start. It will have a strange rhythm to it.... not YIN YIN YIN YIN YIN... more like YIN YIN yin YIN yin YIN YIN. It's good to know though... cuz if you hear it you don't even need a compression tester, you'll just know.

The one upside to blowing an apex is that you usually make it home... unlike spun bearings.... that was the worst day of my life.

 

This appears to be the sound I get.

Looks like I get to do a full rebuild then. Hopefully the housings are good.

 

I must have misread. I thought he said only 1 rotor face didnt have compression.

 

You have one final avenue to travel down before you jump into the rabbit hole. Do this:

Get your exhaust manifold off.

Turn the engine by hand until you see the apex cross the port half way.

Now take a flathead screwdriver and push on the apex seal. You should feel movement and it should spring back against the wall.

EDIT: Push the apex in different places to get a better idea of how free moving it is. Like, push farthest left then mid-side, middle, mid-side, right side... do this for all three apexs on your rear rotor.

You may find that one of them is stuck and you might just have to free it up somehow(research mystery oil).

If they all move then as unfortunate as it is you'll have to tear 'er down ;( but we have to stay positive to the bitter end! haha

 

id pump in a crapload of MMO and get it running then do a water treatment on it to blow out the carbon that caused it. or you could rebuild it, if your set on it. doesnt hurt to refresh an old tired engine before it really lets go.

 

Mmo?

 

Marvel Mystery Oil, it works great at loosening carbon buildup and helping it burn off

Idk how fortunate you’ll be finding it over seas though

DO NOT USE ATF

 

Considering the car will start and idle, you can also try the water treatment if you can't find MMO near you.

 

Facts: Compression test revealed issue with one apex seal.

Causes: Broken seal or seal is stuck.

Coarse of action: Find out if seal is broken or stuck.

Method: Check seals via exhaust port.

Possible outcomes: Seal is stuck, Seal is not stuck(meaning one is broken)

If you do this you will know what to do next.
Assuming is the worst habit ever. Why spend money on oil that you will undoubtedly have to order and wait forever -only to find out that your apex seal is indeed broken?

 

you can view the seals through the lead plug holes without spending hours dicking with the exhaust.

if a seal is broken, the result is almost always a flat 0 compression on all faces. its rather rare that one face will give compression and the others won't unless a seal is merely jammed into the rotor, as a broken seal almost always trashes the housing which compromises the rotor, housing and all the other seals which kills the compression all around.

but care must also be used when trying to free a stuck seal, letting the engine try to unstick it sometimes can cause the seal to break. so trying to unstick it without using the centrifugal force of the engine is always best.

 

I disagree. In many cases the debris will get swiped out the exhaust port during the actual revolution it failed or it will be pulverized. In many cases you will have a jump and two misses if an apex seal fails. The fact that he is experiencing one jump and two misses embraces this.

Also you can't articulate the apex seal well from the spark plug hole. There is much more surface exposed at the exhaust port allowing you to free it up if it is indeed stuck.

 

you can disagree all you want, but of all the engines i tore apart with apex seal failures, about maybe 5% would result in no damage to the rotor housing and subsequent low compression on the 1 good chamber. those aren't very good of odds.

what i meant by viewing the seal from the plug hole is that, i didn't mean trying to work it loose. MMO will do that by letting it soak and then starting the engine and letting it idle for a bit.

but the main problem is that a stuck seal is a sign of other problems, problems that might warrant just rebuilding the engine anyways.

 

I didn't say there would be no damage to the housing. There is a reason why people diagnose it with the pulse check.

I do agree that it should be overhauled.

 

shrugs, damage is pretty universal. if i get a rotor that has 0/0/30 then i know one seal let go and the housing is in bad shape so half the engine is probably toast.

if i have a rotor that has 15/15/90 then i am pretty sure that there is a semi jammed apex seal causing a bleedover of compression between 2 chambers.

 

Maybe you and I know that but we're trying to help someone out and you only have to get as technical as you need to be. He experienced one jump two misses. He didn't give us numbers.

Tone 'er down or I'm coming down to your Mother's and unplugging your PS4.

 

Guys, chill! I appreciate all the help.

The engine does have to come out the car eventually as its getting swapped into my better shell, a rebuild was always on the cards, but ideally I wanted to put it off a year, this just means I have to do it sooner than planned.

I'll have a go at seeing if I can get some photos of the apex seals through the spark plug holes and failing that I'll go and buy a mirror on a stick so I can get in there.

 

you could buy a cheap bendable camera too and look in there that way

 

I just looked them up.
Never imagined they were so cheap!

 

yeah they used to be quite expensive but now you can get one that fits inside the plug holes for about 50 bucks.

 

Sucks that you are having Apex Seal issues. I have been lucky with my barn find car that the N/A engine seems to be pretty strong.

 

Look on the bright side,