92 Corsica lost power
June 26th, 2012, 1:00 AM
#1
CF Beginner
Thread Starter
Join Date: Jun 2012
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
92 Corsica lost power
I have a 92 Corsica with a 3.1L V6 that has about 151k miles on it.
It had some issues before (overheating, minor coolant leak, rough idle in gear) but it became much worse over the last couple of weeks. Now, even in the slightest uphill the engine will lug and I'm happy if I can go 55, or it will shift down. (previously, it could do 75 - 80 uphill with some power left) The sound of the engine has changed a lot, too. I got the car about 6 months ago with ~143k on the odo, and I know that it is significantly worse in most respects. The only better thing is that it no longer overheats. I also had the "Service Engine Soon" lights come in several times in the last week -- that always happened on a freeway around 55 - 65 and turned off itself when I got to side streets.
I checked the front 3 spark plugs -- looks to me they've been there for a long time (visible wear and one had some minor cracks) but otherwise they didn't look really bad. I'll be getting a set of new spark plugs and wires, even though I don't think they are the root cause.
Initially, I got 30+ mpg on freeway, but I think it's well below 20 now (mixed driving, though)
Questions:
a) any idea on what can be the root cause?
b) what is the easiest way to remove the rear 3 spark plugs?
c) what needs to be removed so I can check the coils?
d) how much work would be to replace the intake manifold gasket?
e) is there a way I can test to see if the head gaskets are good?
TIA
It had some issues before (overheating, minor coolant leak, rough idle in gear) but it became much worse over the last couple of weeks. Now, even in the slightest uphill the engine will lug and I'm happy if I can go 55, or it will shift down. (previously, it could do 75 - 80 uphill with some power left) The sound of the engine has changed a lot, too. I got the car about 6 months ago with ~143k on the odo, and I know that it is significantly worse in most respects. The only better thing is that it no longer overheats. I also had the "Service Engine Soon" lights come in several times in the last week -- that always happened on a freeway around 55 - 65 and turned off itself when I got to side streets.
I checked the front 3 spark plugs -- looks to me they've been there for a long time (visible wear and one had some minor cracks) but otherwise they didn't look really bad. I'll be getting a set of new spark plugs and wires, even though I don't think they are the root cause.
Initially, I got 30+ mpg on freeway, but I think it's well below 20 now (mixed driving, though)
Questions:
a) any idea on what can be the root cause?
b) what is the easiest way to remove the rear 3 spark plugs?
c) what needs to be removed so I can check the coils?
d) how much work would be to replace the intake manifold gasket?
e) is there a way I can test to see if the head gaskets are good?
TIA
October 27th, 2012, 2:54 PM
#3
CF Active Member
Join Date: Oct 2012
Posts: 111
Likes: 0
Received 0 Likes
on
0 Posts
old spark plugs and cracked plugs are a BIG problem...
Causes weak or no spark which means fouling, and that means lack of power. Especially when the engine heats up...
The 3 rear plugs will take time to remove, be careful you do not break any vacuum lines/wires. it just takes a little longer than the front three...
Try smaller ratchet, some different extensions, universal... Just do not strip them.
-------------
I'm assuming you have the 3.1L MPFI v6, to remove the ICM & coils you will have to remove the radiator fan.
Unless its the 3100 SFI v6, then the coils are on the top of the engine by the firewall. they should come off easily.
To replace the intake manifold gasket, you will want to make sure you have a day or two to work on it. Sometimes it takes time...
If you remove the plenum on the 3.1L MPFI engine, there is a rubber hose under it which will probably be brittle and break, its shaped link the letter S. It can be found at advanced auto parts or auto zone.
The 3100 SFI v6 needs to remove the alternator first before the plenum comes off...
The head gaskets should be fine, as long as coolant isnt leaking into the cylinders it should be fine... There is no real way to check them other than that...
Hope this helps.
Just ask if you want to know more.
Causes weak or no spark which means fouling, and that means lack of power. Especially when the engine heats up...
The 3 rear plugs will take time to remove, be careful you do not break any vacuum lines/wires. it just takes a little longer than the front three...
Try smaller ratchet, some different extensions, universal... Just do not strip them.
-------------
I'm assuming you have the 3.1L MPFI v6, to remove the ICM & coils you will have to remove the radiator fan.
Unless its the 3100 SFI v6, then the coils are on the top of the engine by the firewall. they should come off easily.
To replace the intake manifold gasket, you will want to make sure you have a day or two to work on it. Sometimes it takes time...
If you remove the plenum on the 3.1L MPFI engine, there is a rubber hose under it which will probably be brittle and break, its shaped link the letter S. It can be found at advanced auto parts or auto zone.
The 3100 SFI v6 needs to remove the alternator first before the plenum comes off...
The head gaskets should be fine, as long as coolant isnt leaking into the cylinders it should be fine... There is no real way to check them other than that...
Hope this helps.
Just ask if you want to know more.
Thread
Thread Starter
Forum
Replies
Last Post
