Ive been on this board for about 7 or 8 years and have had 4 f-bodies and i have read up about how all lt1s run horrible and idle rough when they get some miles on them. Well about 2 months ago i noticed my car had a slight miss to it. I DO NOT drive the car much at all. Since the first time i noticed the miss i have driven it all of 5 times. Each time it gets progressively worse, it is now to the point it is undriveable. I DO NOT have a check engine light. Before i touched the car i decided to take it to the Pontiac STEALership to have them put it on the computer and pinpoint the problem before i THREW parts at it. They wanted to THROW plugs, wire, and an OPTI on it. I OPTED to put it some TR55s and new wires myself. It did nothing. I put on an ACDelco Opti, It did nothing. It runs ****ty at all rpms. In the high RPM range it blows a little white smoke and smells horrible. It surges and idles rough What is the next step here? I am about to take it to the CHEVY STEALership and demand they pinpoint the problem BEFORE spending a dime on another part! Any suggestions? Thanks all

 

Blown head gasket?

 

white smoke is steam... so sounds like you may have a mild head gasket leak.... My car was the same way for a while then after a few passes at the track it tossed a code... kept driving it till one night no water... got it hot, filled it up and got hot 1 more time on the way home. next day tried to start it and it was hydrolocked. if i pull #2 plug it will let the water out and fire right up. Obviously mine got bad and probally did some or most of teh damage when it got hot. but it did have a very slow leak before as the coolant would slowly go down over a few thousand miles and i had white steam out the tail pipe.

 

Would that make it run so terribly though? I did not get any water out of the plug holes and the oil looks fine. The smoke smells like its not burning all the gas.

 

do you still have the EGR system, could be a stiking EGR valve?

 

yea i have egr system but even when i pull the vacuum line off it doesn change anything. i also have a gutted cat and !air pump.

 

hell yea it would make it run like complete and total crap. its water... it doesnt combust and will cause a missfire once it gets bad enough to trigger it.

If you have water coming out of the plug holes then it would be hydrolocked.
Just cause a headgasket is blow does not mean water will be in your oil or oil in your water. and it also doesnt mean you will see it coming out of teh plug holes. chances are you wouldnt unless half the gasket was missing... just a tiny bit of water can make it run horrible, and it can also go on w/o showing any signs of it too (not over heating, no noticable coolant loss ect.) go to NAPA and buy you a block tester kit. Read the directions Its stupid easy to use and will tell you what you need to know. If no directions are provided or you cant figure it out i can explain it in detail.

the kit cost all of 30 bux and is re usable many times over. its worth having IMOP.

 

could it be intake gasket? How can i detemine exactly where coolant is getting into cylinder?

 

correct me if I'm wrong but I thought we had dry intake manifolds, no coolant runs through them so it cant be an intake gasket

 

yes you are right. i was half asleep thinking that. i also forgot that i have the coolant tb bypass done.
btw the driver side plugs looked good and the pass side were kinda black.

 

black typically means rich/oil/leaky valve seals. If it smokes a little upon startup then stops could be valve seals. A head gasket would make a plug look really white and clean.

 

it doesnt smoke at startup, only when high rpms. so along with the smoke and dry black plugs it sounds like running way rich not blown head gasket? what does everyone think?

 

black plugs are oil/rich like stated above. We really need to know if the smoke is white, black, or blue... White is water/ coolant, black is excess unburnt fuel, blue is oil.

If only on one side and it is all 4 of em it could be a bad 02 sensor getting a bad reading thus sending the computer data to make it run a little richer on that side till it THINKS it has the right readings.... If your fuel miledge has gone down that could also be another sign of a bad o2 sensor.

Also do you have cats? or a cat (being a 95 i think you only have 1 cat since it is a OBD1 system) if teh cat is clogged on a PRE OBD2 vehicle it will not thorw a code as the catalyst is NOT monitored. If the cat is clogged It will choke down the engine (rougher then normal idle), and Make it smell like unburned fuel (since its no longer doing its job to burn up the excess unburnt fuel)
Also it could be a combo blugs black from bad 02 and rough idle from bad cat.

So what say ye?

 

gutted cat. i dont drive it much to know if mileage has gone down but it seems that it has. i really cant tell what color the smoke is because there isnt that much of it. the plugs were black and dry on that side. how can i tell if it is o2 for sure?

also would it run horrible hot and cold if it is o2?

 

yea 02 would be pretty much all the time. only way to know for sure is to check the voltage it is sending either using a scanner (but your OBD1 so finding a good scanner to do this is a little harder than OBD2) and another option is i think you can use a fluke or a multimeter on it to check it but im not sure how.

pull it out and see what it looks like...

they can be had for $42.99 and up from oreily's, $52.99 and up from Auto Zone, $58.99 and up from Napa Auto Parts, and $52.98 and up form Advance Auto Parts