99 cobra smoking bad ...help!

[nitrous408]

when i hold my motor at 4000 rpms for 20 seconds it starts smoking relly bad blue you can smell oil ..then if i blip the gas to 6000 rpms it really smokes ,car as 57,000 miles on it ,compression is 170 to 175 psi ,,any thoughts? before i pull it out.

 

[midlifecrisis99cobra]

It's the 20 seconds that has me bugged. If the wiper rings were gone, why would it wait 20 seconds? Is it possible that oil is being pumped into the top end of the motor and finding it's way into the cylinders? It would be real messy to try to figure out if the oil is draining properly. At least any way I know to look. Nothing else pops into my head right now. Did this problem just pop up or has it been creeping up for a while?

 

[nitrous408]

It's the 20 seconds that has me bugged. If the wiper rings were gone, why would it wait 20 seconds? Is it possible that oil is being pumped into the top end of the motor and finding it's way into the cylinders? It would be real messy to try to figure out if the oil is draining properly. At least any way I know to look. Nothing else pops into my head right now. Did this problem just pop up or has it been creeping up for a while?

it just been getting worst ..to the point i cant even sell it for cheap to buy a 03/04 cobra..?if i hold it for 1 min at 4000 boy its like james bonds car. i heard they had the wrong v/seals on them ,on a google seach i do ..but dunno ..i dont want to pull motor if i dont have to .but i can even get the v/ cover off.

 

[COBRA90GT]

What are all of your car's modifications?

Wouldn't happen to have a set of MAC longtube headers installed, would you?

 

[nitrous408]

What are all of your car's modifications?

Wouldn't happen to have a set of MAC longtube headers installed, would you?

matter of fact i do....i heard it all. i've heard from numous engine builders ..they said i header wont make your car smoke.even paul form pauls hi po in MI. said so..i did a search long times ago..i dont know what to belive? i heard it was the coating or something in the headder? going though egr vavle..i got car used with 47,000 k on it wreaked in ft. end when i fixed it i put the headders on it at the same time. so i dont know if it smoked before the headders? i heard 99 had v/ guide problem that people just thought it was a mac problem?

 

[COBRA90GT]

matter of fact i do....i heard it all. i've heard from numous engine builders ..they said i header wont make your car smoke.even paul form pauls hi po in MI. said so..i did a search long times ago..i dont know what to belive? i heard it was the coating or something in the headder? going though egr vavle..i got car used with 47,000 k on it wreaked in ft. end when i fixed it i put the headders on it at the same time. so i dont know if it smoked before the headders? i heard 99 had v/ guide problem that people just thought it was a mac problem?

Sounds like it's time to tear into that engine.

Did you clean up the insides of the headers (welding slag) prior to installing them? That would have been good preventative maintenance...

The MAC longtubes are probably the culprit (uncleaned MAC longtubes prior to installation on cobra engines = recipe for trouble). It's been documented by numerous owners in the past; further reading:

http://www.corral.net/forums/showthread.php?t=167953

 

[86bluecobra]

no chance that you are sucking a bunch of oil in through the pcv? can you look where the pcv enters intake to see if there is excessive oil slug there? I'm not completely fimilar with the modular motor but i know this can be a problem on the 302's. I would rule it out before i ripped engine out. See i suspect it because maybe in the 20 seconds you are building the crank pressures up and they along with oil are being sucked by the pcv.

 

[nitrous408]

no chance that you are sucking a bunch of oil in through the pcv? can you look where the pcv enters intake to see if there is excessive oil slug there? I'm not completely fimilar with the modular motor but i know this can be a problem on the 302's. I would rule it out before i ripped engine out. See i suspect it because maybe in the 20 seconds you are building the crank pressures up and they along with oil are being sucked by the pcv.

well here what i dont while back i disconnected the pcv pluged the vac souce and put a breather in the driver side v cover still does the same thing ?? heres where im at .....i took off intake.it seems to be alot of oil on top of the vavles..all the ones that are closed have oil pullded aroung them?? what you think if the heads come off stock manifolds are going back on ...feed back please ...also now that my car is torn apart,i found a 03 cobra vert ..i knoew this was going to happen..should i put v seals on my 99 than sell it ?

 

[MrCleanCoupe]

I would pull the heads off and have them checked at a shop. I think its the head gaskets. You ight even be able to just replace those.

 

[midlifecrisis99cobra]

well here what i dont while back i disconnected the pcv pluged the vac souce and put a breather in the driver side v cover still does the same thing ?? heres where im at .....i took off intake.it seems to be alot of oil on top of the vavles..all the ones that are closed have oil pullded aroung them?? what you think if the heads come off stock manifolds are going back on ...feed back please ...also now that my car is torn apart,i found a 03 cobra vert ..i knoew this was going to happen..should i put v seals on my 99 than sell it ?

Try hooking the PVC back up and see if you get the same problem. Doesn't sound like a problem in the bottom end. You could keep tearing into it, but I don't think a head gasket problem is going to give you oil where you have it. You might try opening a thread at modular depot. Those guys are pretty sharp.

 

[nitrous408]

my pistons and bore are wasted...its not mac long tubes...v guides are bad too.

 

[BurningRubber]

Dont mean to resurrect the thread, but why are you holding the engine at 4k for a minute?

That kind of abuse will waste an engine even at low miles if done enough. Holding at those RPM's, or constantly being revved out is hell on rings, and other seals.

 

[nitrous408]

Dont mean to resurrect the thread, but why are you holding the engine at 4k for a minute?

That kind of abuse will waste an engine even at low miles if done enough. Holding at those RPM's, or constantly being revved out is hell on rings, and other seals.

25 to 30 seconds ass munch not a minute.motoe rebuilt in doing good 80 so far.going to put some more miles rightnow before i sell it .