High rpm problem.. Help
#1
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
High rpm problem.. Help
Hi , i will start off by saying i am new , since i just bought my cobalt a week ago.
So here's my mods: gm stage 2 tuned by gm and injen cai , thats it everything else is stock
Here's my problem : while racing with an acura rsx-s in 3rd gear at about 5,5k rpms it felt like if i hitted the rev limiter which i know i didnt cos its at 7k , then for like 5 minutes the car had less power and was stiff. EX : i would floor it at 2k and i would get full boost instantly which is uncommon, and when i release the gas it jerks alot just like if i were in 1st even though im in 5th at 2k rpms , its kinda hard to explain ... Anyways im not a mechanic but could this be misfires in a cylinder or too much gas so it cant ignite. Thanks!
Jeremy
So here's my mods: gm stage 2 tuned by gm and injen cai , thats it everything else is stock
Here's my problem : while racing with an acura rsx-s in 3rd gear at about 5,5k rpms it felt like if i hitted the rev limiter which i know i didnt cos its at 7k , then for like 5 minutes the car had less power and was stiff. EX : i would floor it at 2k and i would get full boost instantly which is uncommon, and when i release the gas it jerks alot just like if i were in 1st even though im in 5th at 2k rpms , its kinda hard to explain ... Anyways im not a mechanic but could this be misfires in a cylinder or too much gas so it cant ignite. Thanks!
Jeremy
#3
Member
Join Date: 01-05-12
Location: Joplin Missouri
Posts: 280
Likes: 0
Received 0 Likes
on
0 Posts
I would say first off is there a check engine light? Did you notice the check engine light come on while racing? Also if you have a chevy tune for the GM Stage II kit I would assume there might be something off on the tune. Wouldn't be a terrible idea to have someone check it out for you. How much vacuum are you you pulling when you are off the gas coasting down the road? If you don't pull very much then I would say clogged cat. Could be spark blow out from plugs that are gapped to wide or you may try to run cooler plugs. Another thing would possibly be your IC pump stopped working and your IAT2 temps got too high. There's a lot of things that could be going on causing that.
#5
Member
Join Date: 01-05-12
Location: Joplin Missouri
Posts: 280
Likes: 0
Received 0 Likes
on
0 Posts
take it in to any reputable muffler/exhaust shop and have them check it for you. Oh and try not to drive it a lot or put in under a lot of strain. If you do have a clogged cat then you could be putting too much pressure in the cylinders and would do terrible things.
#6
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
First off , Thanks everyone who answered.
Yes i do have a CEL light , my friend thats works at gm did the test for me and it sent a cat malfunction , he checked and it is completely clogged, so he said there is a recall on that should i get a new stock one or choose to go with a downpipe/exhaust system , i think the more air flow the better , what do you guys think about that?
BTW, the new cat + installing is free
Yes i do have a CEL light , my friend thats works at gm did the test for me and it sent a cat malfunction , he checked and it is completely clogged, so he said there is a recall on that should i get a new stock one or choose to go with a downpipe/exhaust system , i think the more air flow the better , what do you guys think about that?
BTW, the new cat + installing is free
#8
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Yeah ill probably do that since its free so why not, then ill look for something a little better. I just hope that was the problem and nothing else is wrong...
#12
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Yup boost is back to normal but power loss is severe right now and the car feels like if its missing gas or fire. This is what i tried so far : new cat , new maf sensor , new cam positioning sensors. Im tired of putting money on the car since i just bought it ! Damn
#13
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
And i forgot to say that most of the time the car is fine but once it egts the first power loss around 120kmh(70mph approx) it stays like that until i shut it off wait 5 sec then restart the car , if i do that hes fine again , so weird
#18
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Ok, so i checked my injectors they are good , checked my spark plugs they are good , not burned or oily and the gap is 0.035, tomorow i will check the fuel filter. Oh and i forgot to say that when the tanks gets lower to 1/4 the power loss seems to happen more frequently and after 1/8 its all the time, just saying maybe it has something to do with the problem ?...
#20
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Found out the problem, After wasting 3500$$ in repairs and work, we finally found the only problem my car has is the engine is going bad. 70/100 blowby , 50PSI on 1 and 3, 125 PSI on 4 and 2 seems normal.. Anyways the oil is pouring out of the dipstick. If anyone has an idea where to get a good engine with 100k km/60k miles or less , Please PM me. By the way i live in new-brunswick canada, so id prefer to get an engine from canada..
Thanks,
Thanks,
#21
Senior Member
iTrader: (6)
Found out the problem, After wasting 3500$$ in repairs and work, we finally found the only problem my car has is the engine is going bad. 70/100 blowby , 50PSI on 1 and 3, 125 PSI on 4 and 2 seems normal.. Anyways the oil is pouring out of the dipstick. If anyone has an idea where to get a good engine with 100k km/60k miles or less , Please PM me. By the way i live in new-brunswick canada, so id prefer to get an engine from canada..
Thanks,
Thanks,
#23
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
No actually i changed : Spark plugs, fuel filter, air filter, compression leak test, MAF, Cat, Many sensors including O2, Crank position and a few other sensors plus GM did a good 10 hours on it so yea roughly 3500$$
#24
New Member
Thread Starter
Join Date: 07-09-13
Location: Canada
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
No, when i bought the car the guy said it was the MAF, the car had a wierd idle so it could be a maf ... turned out it was not the maf at all , and i did nothing wrong with the car, really .. He knew the engine was totalled when he sold it, bad trade for me
Thread
Thread Starter
Forum
Replies
Last Post