Out of Gas - Hurst Equipped

gtownv6 · Post by **gtownv6** » Tue Aug 16, 2011 2:04 am

A leak down test will NOT show bad valve stem seals. A leakdown test is performed with the cylinder at TDC so both the valves would be closed.

DetergentCandy · Post by **DetergentCandy** » Tue Aug 16, 2011 12:57 pm

I understand that. But i'm still confused. How can a compression test show good cylinders, but a leakdown test show bad cylinders?

I'm confused.
Good compression test = Yay! Good piston rings!
Bad leak down test = Just kidding! Bad piston rings!

Am I wrong? The leak down test found a leak in the valve cover breather.
A big leak, according to the shop.
So that means air has to be passing by the rings, going into the crank case, and coming back up out the breather?
What am I missing? How can one test tell me the rings are fine and the other test tell me they're bad?

caustic neon · Post by **caustic neon** » Tue Aug 16, 2011 4:53 pm

If I'm correct a leak down test is how quickly the compression is lost on the compression stroke.

compression test checks how much compression is being made in each cylinder but not how long it will hold that compression, that's what a leak down test does

DetergentCandy · Post by **DetergentCandy** » Tue Aug 16, 2011 5:24 pm

I see.... :/
Someone on the SRT forums suggested oil control rings.
Those can be bad and not show up in a compression test. But they will show up in a leak down test, right?

I'm just tossing thoughts out there...cause I don't want to have to rebuild or replace my engine if I don't have it. If i can just drop the oil pan and pull the pistons and re ring them i'll be fine.

LilSparkPlug · Post by **LilSparkPlug** » Sat Aug 20, 2011 7:51 am

The misinformation in this thread is abundant.

Compression test: Measures how much compression each individual cylinder can make not how long they can hold this compression.

Leakdown test: Polar opposite of a compression test. With the engine at TDC you push air into the cylinders through the spark plug hole, measuring how long they hold this compression. 0-10% loss is normal anything above that is cause for concern.

A leakdown test is essentially measuring cylinder wall, piston ring and valve issues. Listening for where the air is coming from tells you almost exactly what is leaking.

i.e. whistling through the turbo, exhaust, etc. = exhaust valve(s), whistling out of the air intake or TB = intake valve(s), whistling past the PCV valve indicates air is getting past the rings = cylinder wall damage and/or bad rings, if there are air bubbles in the coolant during the test = bad HG and this can also indicate a cracked cylinder head.

Hopefully that clears up some of your confusion for you.

DetergentCandy · Post by **DetergentCandy** » Sat Aug 20, 2011 4:19 pm

It does!

Thanks.

Alright. We did another leakdown test.
Like I thought, the shop I took it to the first time was a joke.
Cylinders 2,3,4 were good on the leak down. Cylinder 1 had...like a 60% leak. Maybe 70%. The other three were less than 10%. Maybe 6%...maybe 7%. I dunno. Less than 10%
Compression test was good across all cylinders again. I cranked this time and he took down the numbers. HE said it was 145-150 across all 4. Which seems kinda low compared to my 150-160 I got the first time. But it could be a discrepancy in gauges.

Anyways, he believes piston 1 is either cracked or has a broken ring land.
We disconnected injector 1, so i'm only running on 3 cylinders right now.
Drove it from his house back to my parents, up and down the street a few times, and it's still smoking a little...but not nearly as much. I wanna drive it a little more like this to see if it just needs to clear out any old oil that may have still been...trapped somewhere? I dunno. I just wanna see if the smoking will go away completely. And driving it is the only way to do that.

So now I get to talk about pulling the head and pistons and...all sorts of stuff. I need to pull the intercooler anyways so I can drain it. It's definitely got some oil in it.

He's going out of town again on Tuesday, and is busy putting an engine in another car until then. Then he's back on the 31st. Then he leaves again on the 13th.
Heh. So he's not going to be able to help for a month.

How long should I expect the job to take? A day? Two? A whole weekend?
What's the process of pulling the pistons? He said i'll want to hone the cylinder for sure...which makes sense. He said I can do it in the car, so does that mean I only have to drop the oil pan and pull the head?
He has all the tools to help, but no free time for about a month :/
And I can't keep driving on 3 cylinders, can I? XD
I can definitely do it. But never having done it before, some guidance would be nice. Or another helping hand XD

gtownv6 · Post by **gtownv6** » Sat Aug 20, 2011 8:45 pm

You can swap pistons with the motor still in the car but honestly if it was me I'd pull the motor and do it on a stand

Post by **occasional demons** » Sat Aug 20, 2011 9:41 pm

Hopefully it is not a cracked ring. If it is, then the ring can tear hell out of the cylinder wall. Honing will not help if it has gone long enough.

I have seen it happen with two engines I have torn down. A Datsun 2.0 and a Chevy 350. The 350 looked like someone shoved a shamrock into the bores. It came in for a valve job. The heads were about all they kept.

Oil control rings are the bottom rings on the piston. Their only purpose is to scrap excess oil from the cylinder wall. They will not help much with compression. That's what the top and second rings are for.

If the rings are bad enough, or broken, driving it even with no fuel isn't doing it any favors. It is still making compression. The smoking won't go away if the oil is getting into that cylinder via the rings/cyl. walls, or crack in the piston. It will still be pushed out the exhaust valve to the hot manifold.

If you truly wanted to limp it on three cylinders, remove the intake/exhaust rockers. It still isn't perfect but it won't build as much compression. If the ring is broke, it is still going to do damage. That is the bitch: You don't know until it is taken apart.

Edit: If you do remove the "Rockers" you may need something to hold the lash adjusters in their bores. You don't want oil squirting freely after they pop out and are playing hopscotch with the cam lobes.

If it was my car, I would borrow someone's, if at all possible to get you by until it is figured out. Not sure if your insurance would cover a rental until it is repaired. Something to check, if you have full coverage.

DetergentCandy · Post by **DetergentCandy** » Sat Aug 20, 2011 10:31 pm

Hmm, well i'm just going to have to tear into it and see what the damage is. I guess there's no way to tell until I do!
Hoping it hasn't caused any damage.

Would removing the engine be that much easier? After you factor in the time to remove it and put it back in of course.

I have the space to work on it. Parent's have lots of concrete space in their backyard. Aaaand, neighbor has any tools I may need that my father doesn't have.
It's just going to be a full weekend of...pain and sweat x.x

I'm pretty screwed right now to be honest. I'm bumming rides off friends, and borrowing my mother's car when I can. This car has turned my life into a nightmare. I just want to get rid of it, but I don't think I can with the way it sits right now.

alsey_seven · Post by **alsey_seven** » Sun Aug 21, 2011 1:07 am

wait what?????? want to trade?????

SC62391 · Post by **SC62391** » Sun Aug 21, 2011 3:28 am

If you need a hand just give me a ring man

I wont be much help when it comes to knowledge but i have 2 hands!

Also wouldn't hurt to post it on craigslist. Worst that could happen is you'll get low offers :/

gtownv6 · Post by **gtownv6** » Sun Aug 21, 2011 3:37 am

Ill trade ya for my acr lol

NEON PARABOLA · Post by **NEON PARABOLA** » Sun Aug 21, 2011 9:47 am

This car has turned my life into a nightmare. I just want to get rid of it, but I don't think I can with the way it sits right now.

That sucks so bad man, I'm really sorry. Dont Give up!

DetergentCandy · Post by **DetergentCandy** » Mon Aug 22, 2011 4:17 am

Hehe, sorry guys. I'm keeping the car.
As much of a nightmare as it is right now, it'll be purring in no time

I'm not giving up yet!

So, in all seriousness, would it be easier to pull the engine to do the repairs? I know the turbo and the exhaust manifold are a pain in the ass to get to with the engine in the car. I had to be on my back under the car for a long time trying to wrench all the lines off the turbo the first time I took it off.

My father has an engine hoist, and i'm sure I can get my hands on an engine stand.
Can I remove the engine...as is? Like, I just have to unhook the lines and the wiring harness, unbolt the motormounts and the engine is free to pull? Do I need to remove the tranny? Or can I leave that in the car?

If it's easier to do this job with the engine out of the car, what's the proper/best way to remove the engine?

Midnight_Rider · Post by **Midnight_Rider** » Mon Aug 22, 2011 8:42 am

DetergentCandy wrote:Hehe, sorry guys. I'm keeping the car.
As much of a nightmare as it is right now, it'll be purring in no time
I'm not giving up yet!

I can't help you with any mechanical suggestions but I will say that I am relieved to read that you've decided to work on it and keep it. It may be a pain in the patootie now but you wouldn't want the possiblity of some punk kid getting it and ruining it, right?

theColonel · Post by **theColonel** » Mon Aug 22, 2011 8:49 am

Midnight_Rider wrote:
DetergentCandy wrote:Hehe, sorry guys. I'm keeping the car.
As much of a nightmare as it is right now, it'll be purring in no time
I'm not giving up yet!
I can't help you with any mechanical suggestions but I will say that I am relieved to read that you've decided to work on it and keep it. It may be a pain in the patootie now but you wouldn't want the possiblity of some punk kid getting it and ruining it, right?

x2 ... mine is a hemorrhoid too

LilSparkPlug · Post by **LilSparkPlug** » Mon Aug 22, 2011 11:06 am

Pull the motor out, inspect everything and do it the right way. It's much easier to replace pistons with the motor out of the car. I wouldn't continue driving it in the condition that it's in, you're only doing more harm than good. Plus with the motor out of the car, if you need to hone the cylinder at that point all you need to do is load it up in a truck and take it to a reputable local engine shop.

Best of luck with it

*edit* Going back through your thread and reading a few results from tests that you posted and tidbits of information I have a few other ideas. When you posted the wet and dry compression test results are you 100% sure that you did the test properly? Reason being, is that if you had a bad piston or ring(s) the wet test would jump up dramatically from the numbers in the dry test in that specific cylinder. If the numbers don't change much between the wet and dry tests chances that it is a piston or ring issue are slim.

The other thing you stated that struck me was that when you took the PCV valve off you had a silly amount of air (blowby which occurs when compression is leaking down into the crankcase) rushing through it, this right here showed a leak before anything else. This is also the reason that you continue to build up excessive amounts of oil in your intercooler. Now that I read it again, no catch can will fix that.

Also, the fact that the smoke doesn't start immediately on start up leads me to believe the leak may be in the top of the engine rather than the cylinder itself. Once the oil gets up to the head, and oil pools in the intake ports getting by the valve guides, then smoking is seen on acceleration which is preceded by deceleration. Are you sure all four valves are closed during these tests??

The injector situation that you have still is not normal, those ports are precision machined and there should be no gouging or any other markings, dents, etc. on them because that will mess with fuel distribution/atomization in the cylinder. That's definitely a cause for alarm.

When you have oil burning there are only two possible issues (outside of a turbo) it's either valves...or rings....and looking at all of it again I really don't think it's rings but I can't be sure without seeing it in person.

gtownv6 · Post by **gtownv6** » Mon Aug 22, 2011 3:07 pm

LilSparkPlug wrote: Also, the fact that the smoke doesn't start immediately on start up leads me to believe the leak may be in the top of the engine rather than the cylinder itself. Once the oil gets up to the head, and oil pools in the intake ports getting by the valve guides, then smoking is seen on acceleration which is preceded by deceleration. Are you sure all four valves are closed during these tests??

This is a great point. If you decide to pull the engine, it may not be a bad idea to take the head and valvetrain in to be checked before you start tearing in to the rotating assembly.

DetergentCandy · Post by **DetergentCandy** » Tue Aug 23, 2011 12:14 am

Very good points, Crystal.

I'm positive we did the tests correctly. We did two different compression tests. And had a leak down test performed correctly. He was a Chrysler mechanic after-all so i'm trusting his judgement. I was there as well and it looks to me like the test was done spot on.

However, considering i'd have to remove the head either way, i'll make sure I inspect the valves and the guides and seals before moving on to the pistons and the crank shaft.

He suggested I do the work with the engine in the car, because he has a car lift so we can easily get to the oil pan/pistons etc. Is it still a better route removing the engine? I don't think he'll care either way...considering he's only going to be overseeing the piston/oil pan removal. The rest of the work will be on me. He was pretty confident that doing the work in the car would be alright. But...I don't think he has much experience with SRT-4s. He may be a Chrysler mechanic, but that doesn't mean he's worked on a lot of turbo 2.4s.

gtownv6 · Post by **gtownv6** » Tue Aug 23, 2011 1:55 am

Well youre going to have o remove the timing components and reset the timing, to do that the engines halfway out anyway. Take a little more time to pull the motor and it wiill make setting timing and taking the head on and off alot easier.

LilSparkPlug · Post by **LilSparkPlug** » Tue Aug 23, 2011 8:37 am

I would personally pull it out and go through it with a fine toothed comb. There isn't much room to work in these bays with the 2.4L crammed in there. If you think you can get it done with it still in the car by all means do it that way.

If all the tests were done right then my opinion about the piston/rings not being the issue still stands. The only other idea I came up with was that if he didn't drive the car often and only drove it on short trips it could be a coking issue, but that wouldn't cause lost compression during a leak down test in the manner in which you are describing.

DetergentCandy · Post by **DetergentCandy** » Wed Aug 24, 2011 3:22 am

Ya, i'll definitely pull the engine. I don't want to be hunched over the engine bay or crawling under the car for several hours trying to unbolt everything.

What's coking? O.o Sounds...dangerous

But, i'm pretty damn sure we did the tests right. 1 had a massive leak. We did 2,3,4 and there was very minimal leakage. So we retested 1 thinking we did it wrong the first time, and we got the same result.

I'll be pulling the head. Neighbor is going to help with the pistons. So before we hit the bottom end, i'll make sure to go over the head very carefully.

I haven't had time to touch the car yet. But tomorrow or Friday, at some point, i'll start unhooking stuff to get ready to pull the engine.

Do I need to take any special precautions while pulling the motor?
I figure as long as I tag and mark every line I disconnect so I can reconnect it again, I should be safe.
Since i'll be pulling the engine, is there anything I should do while it's out of the car? Other than taking the engine apart of course

I mean, tucking any lines in the engine bay? Painting the engine block(Mopar blue or Hemi orange maybe) or...vacuum line clean up?

I'll have an empty bay for a few days after all.

LilSparkPlug · Post by **LilSparkPlug** » Wed Aug 24, 2011 7:46 am

You could do any of the above while you have the motor out, obviously you'll be doing a coolant flush and other fluids which never hurts. Make sure you use the Mopar coolant that is made for the engine, no green stuff.

This is coking.....

It's pretty common in the turbo's oil lines if they're factory. But not so common on the pistons themselves if the car has been treated right.

DetergentCandy · Post by **DetergentCandy** » Wed Aug 24, 2011 4:46 pm

Eeeeeew :/ Okay.
Well, I guess i'll find out once the head's off.
I'll pull the engine. Remove the head. And inspect the head inside and out before pulling the oil pan.

gtownv6 · Post by **gtownv6** » Wed Aug 24, 2011 6:48 pm

coking usually occurs when the car is run hard the the turbo gets excessively hot and isn't given sufficient cool down time before being turned off. Basically the point of a turbo timer, but coking is alot less common on stock setups because the water cooling helps to dissapate the heat when you shut the car off.

BlackRoseRacing · Post by **BlackRoseRacing** » Wed Aug 24, 2011 8:47 pm

gtownv6 wrote:coking usually occurs when the car is run hard the the turbo gets excessively hot and isn't given sufficient cool down time before being turned off. Basically the point of a turbo timer, but coking is alot less common on stock setups because the water cooling helps to dissapate the heat when you shut the car off.

agreed

bone-yard-racing · Post by **bone-yard-racing** » Wed Aug 24, 2011 9:27 pm

Your o2 sensor is melted I think that may be the damage to the injectors as well. Most likely from detionation. Decent compression with high leakage leads me to again a headgasket or valve seal issue. Pull the valve cover and coolant pressure cap then pressurize the cylinder if you see bubbles in the coolant probably a headgasket.

It seems you have had awhile of running on a bad tune or misadjusted cam timing. Id suggest starting with a headgasket job the mopar set comes with valve seals. You can do it with the engine in no problem. Set aside a full weekend get to in early Saturday morning get everything torn down, take the bare head inside with you Saturday night you can clean and change valve seals. Make sure to check for flatness of the head and deck surface. Take a good look at the piston tops and valves make sure they are not burnt.

Are you sure you have no oil leaks?

Also when engines get old they become looser and will smoke slightly usually its not a big deal and the only way to get rid of the smoke is with a full rebuild however you are using way too much oid for this to be normal wear.

DetergentCandy · Post by **DetergentCandy** » Wed Aug 24, 2011 9:48 pm

Doesn't smell like burning coolant though.
It's definitely burning oil.
And when I pulled the injector from cylinder 1 and had it running on only 3 cylinders, the exhaust smelled clean, cept for being a bit rich.

However, with the head off, i'll be able to inspect it top to bottom. And I may as well do seals while it's out of the car. Might take a couple more hours, but i'll already have it on a workbench so I guess I should do everything right the first time.

For all I know, it only started running poorly after the spark plug got fouled with oil. Which would explain the running right part. Which would explain the detonation. Which would explain the burned/damaged o2 sensor.

But I won't be able to track down why it's running rich until I solve the oil problem. Otherwise the spark plug is just going to keep fouling.

Guess I should start looking for some new injectors though, huh? :/
Local guy has some clean Stage 2 injectors he's willing to sell me for $100. Can I run those with the stock PCM? Or will I need to pick up a DSP and do some tuning?

Also, positive I have no oil leaks. It's definitely going out my exhaust. The rest of the car is clean and the ground beneath the car is always clean.

bone-yard-racing · Post by **bone-yard-racing** » Wed Aug 24, 2011 9:57 pm

Neon head design is pretty interesting failed headgasket rarely means mixing or coolant and oil leaks.

Oil in the combustion chamber will not cause detionation. Too lean a fuel mixture, agressive timing, and, high intake temperatures can. Have you tried new plugs? What PCV valve are you using? Replace it with a new stock one and install a PC275 (93+ Supra Turbo ) PCV inline with the stock SRT.

Everything you describe except the cylinder leakage sould like a turbo oil seal I saw you pulled the turbo how did you check the seal. The exhaust is hot enough to burn oil if you are looking for liquid in the exhaust you probably wont find any

DetergentCandy · Post by **DetergentCandy** » Thu Aug 25, 2011 3:59 am

Haven't tried new plugs cause they'll just foul with oil

PCV valve is new OEM.

Checked the seal by testing the shaft play. I was under the impression that's how you can tell if the seal is good or bad.
There was zero shaft play. Wheels04SXT can vouch for that cause we inspected it together.
Not to mention, there's zero oil in the charge pipe or hotside pipe.