Help with possible bad piston rings

[itSSlow98]

Pop the PCV valve out of the drivers side valve cover. Wipe it off and blow straight into the end that the hose plugs in to. If you can blow with no restriction then the PCV is failed, if its hard as hell to blow and only a TINY amount goes through its fine. Then try blowing thrugh the other side and there should be no restriction there.

How is your system routed?

 

[333arod333]

I'll definitely do that tomorrow. Thanks Slow98. It's stock routing in the pcv system. Hopefully it has failed.

 

[MoKo_03SVT]

Yes moko I agree. But like I said it burns oil on startup and some said that might b a pcv problem. So now I'm hoping the pcv or sc is just sucking in too much oil and that's where the plume on startup comes from, but the more I look this up the less I know. Looks like I'm definitely making time for the comp test real soon. O n btw if these cobras running right burned ZERO oil, then no one would b buying catch cans to catch intake oil. So with no catch can, in the intake the oil goes, n then the cylinder. Sorry if I'm making this point if u actually have a catch can I'm just saying these cars must burn a LITTLE oil.

lol you can rationalize it however you see fit, but rest assured, most peoples cobras do NOT burn oil. yes they occasionally get BLOW-BY (oil in the intake), but this is normal on just about all forced induction cars. i certainly would not call a forced induction vehicle that is getting a little bit of blow-by a "car that burns oil".
anytime/everytime i have done an oil change, in the several years of owning my car, not ONCE has it been low on oil ( or missing any)...or even below the "full" line on the dipstick. nor does it smoke on start-up, or smoke at ALL for that matter....and guess what? NO CATCH CAN.

edit: by the way....a car that "burns oil", and a car that gets a little bit of blow-by, is two ENTIRELY DIFFERENT things. dont get confused....YES...a car that gets A LOT of blow-by, COULD end up blowing smoke out of the pipes, due to some of that oil getting burned, and technically that would be "burning oil"....but this is very different than a car that actually burns a quart of oil, every 2 months (unless your car is burning a quart of oil every 2 months, strictly from blow-by....which i strongly doubt that is happening....getting THAT much blow-by. it could be possible though, i guess.. obviously this would definitely mean something isnt right, and needs fixed/looked into ASAP, if it IS that much blow-by)

 

[Hangman]

I agree about checking the small stuff first. Of course I've done the things u mentioned before jumping to the rings lol. I just wanted to see if anyone else thought it might b the pcv or something else like that before I just replace it for no reason. I've been told it might b the valve guides which is ok with me it's the rings that I want to b sure r ok. I'm in broward county and asking gear heads around here what shop to go to is like asking if there is a god lol. Thanks guys.

I have been taking my car to torq recently in Miramar, the guy does good work, and will tell you straight up when it comes to your car. Paul knows the 03-04s. There is blow by racing a little farther north, those would be the only two i would recommend, i would call torq first, they get my :thumbsup:

Heres there website:
South Florida Dyno Tuning and Performance Shop. Specializing in SCT, Diablo and Standalone Tuning for Diesel, Mustang, Camaro, Corvette, Charger, Challenger, SRT, Viper. Professional Installation of aftermarket performance products - Torq

When i talked to them yesterday they had a guy going who just bought his new car, and was going on a long road trip in his bolt on terminator and he had them dyno it and make sure it was ready to go.

They will take care of you.

 

[333arod333]

Thanks hangman I'll probably visit torq for a retune in the near future. I'm not trying to start a quarrel here moko just tryin to get my cobra running right.

 

[333arod333]

Ok gents I can blow into the pcv valve at a little more flow/rate than blowing through a drinking straw. I'll pick up a new pcv wen I pass by a parts store later today. It's. Motorcraft ev-153. Should I replace with the same? Thanks guys!

 

[MoKo_03SVT]

Thanks hangman I'll probably visit torq for a retune in the near future. I'm not trying to start a quarrel here moko just tryin to get my cobra running right.

understood. these guys will get you on the right track...just keep hangin in there!

:rockon:

 

[Demonio]

let us know the outcome....

 

[333arod333]

Ok so I got around to doin the compression test today. Cylinders read as follows, starting from front drivers side moving back and then passenger side moving back: 180 190 185 157 185 183 182 183. So the cylinder nearest the brake booster/steering wheel reads lowest. My range is 33 so that cylinder is like 17% lower in compression. Also has some slight corrosion around the coil and spark plug shaft but looks very minuscule. So what do you guys think? What now? I put new spark plugs in and will very soon go to torque for a retune. Also put in a new pcv and it had no effect on the startup smoke.*

 

[333arod333]

Can anyone chime in about these compression numbers? Is that one low cylinder too low? Is it a serious discrepancy?

 

[SVT_Troy]

All cylinders are good except the low one according to your #'s. depending on what's actually failing determines how long you can just ride it out with adding oil all the time. If it where me id get it fixed now before it gets worse. People have gone years on bad valve seals.

 

[333arod333]

Yes if it's the valve guides I don't really care but what about those piston rings? It won't smoke as much on startup if it's only been sitting for a couple hours or if under 4500 rpm under throttle at normal temp, but that compression is worrying me on that one low cylinder. If it is indeed the rings what do I do? Is it that serious or can I wait on it until its way worse? I do want to take care ASAP but don't hav too many $ to spend. Oh man such bad news!

 

[Hangman]

Yes if it's the valve guides I don't really care but what about those piston rings? It won't smoke as much on startup if it's only been sitting for a couple hours or if under 4500 rpm under throttle at normal temp, but that compression is worrying me on that one low cylinder. If it is indeed the rings what do I do? Is it that serious or can I wait on it until its way worse? I do want to take care ASAP but don't hav too many $ to spend. Oh man such bad news!

If the pistons have to come out, that is some serious work, paying a shop would be costly, if you are comfortable with working on your car then you can do it, otherwise I would ride it out, but definitely have a good shop take a look at it, get there .02 on the whole situation and report back. Labor would be $2,000 + from start to finish plus parts. Then while the pistons are out, hmmm...maybe diamond pistons, new valve guides, etc etc, see what happens?

Good luck with this bud, that low compression in that one cylinder would bother me as well. It will work out, just take your time and don't let it stress you, spend all that time worrying and make more money so you can invest in better upgrades for your car.

 

[333arod333]

Thanks for the sympathy hangman I'm a perfectionist when it comes to my ride so that low compression will me killing me on the inside. I hope when I go to torque they won't rate it at 400/420 even though I think they use a mustang dyno. Dynos don't mean Anything but if they notice something wrong in the obd2 sensor reads or too much smoke at wot then I guess I hav to take it from there. Damn!!!!! I will b getting on talking to someone I know that builds these engines in his sleep and used to build NASCAR engines or was in that build team. Man this sucks though!

 

[333arod333]

Oh and I would b more than ecstatic working on my own engine but I don't have all the lifts and overall 100% guarantee in myself that I'll get it all right. Maybe with some reading, determination, and help though.

 

[Qwk GT]

Thought I've read something where guys who have a hurt cylinder will pull that piston out only, put some kind of sleeve in it and replace the piston and rings.....'

Never done it but read/heard about that being a cheap alternative....

 

[Quick Strike]

Re-test the low cylinder. Then add a squirt of oil to the low cylinder and see if the compression comes up. It is the rings if the pressure increases adding oil.

 

[SVT_Troy]

Re-test the low cylinder. Then add a squirt of oil to the low cylinder and see if the compression comes up. It is the rings if the pressure increases adding oil.

+1 this is correct

After that I'd get that's cylinder borescoped so you can see how bad that cylinder looks

 

[333arod333]

Cool thanks guys I'll try that. Should I pull all the plugs out again, that's kind of a pain. I did retry that cylinder a couple times I can get it to read 160 165 after 7 cranks when the others only took 5. I'll look into that cheaper alternative too.

 

[333arod333]

Can anyone tell me why the squirt of oil in the cylinder will increase compression? Is it just acting as a sealer basically? If I do that and the compression doesn't go up then what does that mean? God I hope it's just valve guides....