Repost from a past tread, this time with video!

I am having a weird problem with one of our LNF's

At first the car would not boost except on 4th or 5th gear it will give me a little bit of boost (2 to 5psi) but if you would turn off and then back on, you would have full boost for a few moments before going back to the same. I went to the shop to diagnose the problem with the code scanner and had the following codes:

P0101
P2187
P0017

I decided to erase all the codes to see witch one would pop up first but when I erased the codes to turn the car back on again, the car turns on only to find that the car turn back off. I tried the gas pedal and the car miss fires a lot, like it has too much fuel and once I let go, the car dies. I also tried turning the car on for a few times to see if the codes come back but no code comes back after several starts.

Cobalt Fails - YouTube


I forgot to mention something very important. Before erasing the codes, 2 days before, my intercooler broke and I had install a pipe to bypass the intercooler while the shop fixes the intercooler. When I erased the codes the bypass was already installed and the car was running with the same problem above, note that I never went full throttle while this bypass was installed and was only used to be able to move the car to the shop

 

Oyeme! Thats bad bro. P0017 is timing related(Crankshaft correlation to camshaft) Sounds like it may have skipped a few teeth on the sprocket. The other two codes, one is related to the purge solenoids and the other is the MAF code. Id try another MAF and see if the MAF code goes away and replace both purge solenoids. The one on the intake mani and the one on the canister in the back next to the fuel tank. But that crank correlation thing...no se, both times I had that happen to me it was my timing had skipped a tooth and I had to reset the timing. Long story.

 

Jesus that's the worst i have ever heard.

Jump teeth then bend a valve or something.

Sounds like a damn lawn mower.

 

 

the very odd thing is that this happened AFTER I erased the codes to start diagnosis. Can our cars bend valves if the engine skips a teeth?

I am a very sad panda if my car bend my valves because that would mean a lot of $ to fix him!

 

Have you messed with anything as far as the engine?

Crank sensor could definetely be the cause of this.

https://www.cobaltss.net/forums/2-0l...-p0017-247414/

This guy had the P0017 and fixed vacuum leak and crank sensor.

 

yes .. lol if it actually skipped a tooth you're pretty guaranteed to have a bent valve

i hope not man good luck

 

No no. If it only skipped ONE or TWO teeth then your okay. The LNF ECU will dissable the VVT which eliminates CAM phasing altogether. Its the engines way of saving itself from tapping a valve. Now, if it skipped like a crazy amount of teeth and its seriously out of time, then yeah, it will tap a valve. The funny thing is that if thats the case then it would be registering missfires too. Ive not heard of too many LNF crank sensors going bad but if that is the case then yeah, it would cause this issue like the other members problem. Sensor bad, so the ECU dont know if the crank is in time with the cams or not, even if timing is correct, it will run like **** and shut off.

 

Id say make sure the crank position sensor is good first. Then check timing. Oh and get a intercooler on there too.

 

We tested the sensor and it seems to be working, will check for leaks when I install the new MPx intercooler, will let you know how it turned out!

Gracias mi hermanito! that really makes sense!, we checked the sensor and that seems to be ok so we are getting to the timing this Saturday if we have the time. I will update my status as soon as I get to it.

 

No no, sin pena. Dale meng. Esos simptomas son clasicos si esta fuera de tiempo. Cuando le hagan el chequeo del tiempo, be sure to inspect the VVT sprockets inside to see if the little dowel is loose or firmly seated in its hole. Also, check the cams to make sure that the keyhole where the dowel in the sprocket fits into on the cam is not misshaped or warped. Thats what happened to me. No se como, pero eso fue lo que me sucedio a mi brode. Cuando el motor estaba apaguado aperecia que estaba en tiempo. Lo que sucedia era que como el VVT sprocket no estaba firme, se movia tan solo un chililin, it would appear to the ECU that the timing was off when the engine was on. I had to replace the cams and sprockets LOL

 

tremendo spanglish broder!!!!

 

No no, no penalty. Dale meng. These are classic simptomas if outside time. When you get the time check, be sure to inspect the inside to see VVT sprockets if the little dowel is loose or firmly seated in STI hole. Also, check to make sure the cams That the keyhole Where the dowel in the sprocket on the cam fits Into is not warped or misshaped. Thats what Happened to me. Do not know how, but that's what happened to me brode. When the engine was Apagua aperecia was in time. What happened was that as the VVT sprocket was not final, it moved only a chililin, It Would Appear That to the ECU off the timing WAS WAS When the engine on. I Had to replace the cams and sprockets LOL

Here is broken ass English translation.

 

Oyeme! De verda' que si! Tremendo arroz con mango LOL
If you saw what I look like youd never think I was cuban! Well, Im half cuban. My dad is american but I grew up with the cuban side of my family, asi que imaginate meng LOL
Been to cuba to visit family over there en Cienfuegos, Las Villas a few times. Anyways, sorry for the thread jack!

Keep us informed OP. Im interested in finding out what the issue was. Oh! Dunno if youve ever done the timing on an LNF before but just in case, the timing mark on the crank down below is behind a thin metal shim. It is NOT the mark that is visible on the sprocket, again, its BEHIND the thin metal shim. I learned that one the hard way LOL

 

OMG that EPIC lol Sorry for posting in spanish

 

no te procupes hermano, estos gringos no entienden lo que estamos diciendo!

 

Haha! OP is from PR
uh ohhhh...Se 'sta formando la cosa aqui! lol

 

True true. By the time the OP comes back this thread will be like 10 pages long LOL

 

sounds like cam and rockers, when i blew mine it sounded like that, it should shut down 2 cylinders, i miss shifted mine

 

Def could be this too.

 

I wish we could have a beer or two one day, if you visit PR sometime let me know!

we have the engine out already and hopefully we will get to it this week if we menage to finish some other cars that where before mine came in, I will be posting pictures with results very soon

Thank you for your additional insight on the timing!

LFMAO

 

This thread makes me laugh. Not at the OP's situation, just at the Spanish.

 

epicness

 

LOL No problem. You got a lot of good suggestions to check on from all of us. Ill make it out to PR one of these days. My uncles wife is from PR. They go visit all the time. Uno de estos dias les pido que me metan en un maletin cuando viajen pa'ya otra vez and we'll have that beer bro

Good luck, let us know what you find.

 

HE LIVES!!

I just have been told the car is fixed! It skipped 1 teeth! the amazing thing is that there was no other damage! the only thing I might need is new spark plugs! the hypothesis is that the Timing Chain Tensioner had no enough oil pressure during a dry start and because of this the tensioner did not apply the correct pressure to the chain when it needed it and the darn thing skipped a teeth. We wen to the highway and did a decent 138mph in no time so The thing is officially fixed! Now to make a header manifold for this sucker!


Will post more pictures as more develops! thank you all!!