Okay first of all i know that temp. plays a big role on how a car runs, but my car feels like it runs diffrent almost each time i drive it.......i mean sometimes the car just PULLS like a ****!, but most of the time the car feels like it doesnt want to go anywhere, like there is pretty much no pull at all (and this is in the same type of weather) ....it could be carbed up but i dont know........its really pissing me off ....also the car doesnt sound as strong and smooth as it does when ever it decides to run good........WHAT CAN IT BE!!!!!

 

Well, some morning my car starts right up with a bump of the ignition switch.. Then other times it takes acouple of turns....

Tempermental I guess.....

 

so thats normal, .......that suxs if thats true

 

Mines the same way, except its not just the engine. Sometimes all the creaks and rattles disappear, the tranny shifts smoothly, and the engine pull to no end. Other times the car feels like its going to shake itself apart, the tranny is notchy, and it just doesn't pull as hard as I'd like. I have accepted it and have moved on.

 

someone needs to investigate this or figure this out, or something.....then only thing my car varies on is torque, but it's a BIG difference! it's always low end torque...sometimes i can stomp and it'll leisurely shift through the gears, only getting up to its standard rpm shiftpoint (mid 3's? on an A4) but to confirm that i'm not insane, last night it took off like it shouldve, hitting high 5k rpms before shifting. ARGH! i haven't been able to pinpoint any kind of variant that could have this effect, but i'm hoping its the plugs and wires. (desperately hoping) i'm having them replaced in the next week or 2, maybe tomorrow even. if anyone has a clue, clue me in!

 

DOES ANYONE HAVE AN ANSWER TO WHY THIS IS ON LT1s?

 

oh jesus, Ive had my car 2 years.. NO noises, sounded like an LS1 then all the sudden winter hits.. and BOOM - every freaking thing inside rattles, squeaks.. ugh

and yes these cars are tempermental as hell

 

Same here sometimes runs great,sometimes it's on vacation,I still love my car.



NICK

 

Like Forest Gump's mama would say "LT1's are like a box of chocolates you never know what your going to get"


I figure after i replace every part on my car........the problems will be gone

 

i agree, fbodies are tempermental, and we still love them, but there remains the UNSOLVED PROBLEM! glad to know i'm not alone, but we still need real info here.

 

Put a 160* thermostat & program the fans to come on sooner, then this whole tempermental issue will be solved, don't know about body stuff though

 

Well, there are really only two main things that make the LT1 different from all the other engines out there, optispark and reverse flow cooling.

As for the optispark, I would think that it wouldn't be much of a problem. It offers very accurate timing, which should help the engine run smoother. However, GM took an old design and tried to make it last ten times longer than it should. I know if I had vehicle with a regular distributor, I would probably change the cap & rotor every 10k miles. Some people that have switched to coil per cylinder ignition systems (mainly LTCC) have complemented the system on how the engine feels smoother at idle, and how there is better spark delivery on the top-end. Every time I think about a metal tipped plastic rotor sitting right underneath the water pump spinning at 6k rpms, I cringe.

The other issue would be reverse flow cooling. One would think it would work just fine, and it seems to, considering there's plenty of people well over the 100k mile mark. However, I have read that the reverse flow cooling has the tendency to make hot spots in the cylinders, which would be the reason GM went back to the standard way. Hot spots could be a starting point for some instability in the system.

And as a result of the reverse flow cooling system, GM had the compression raised to 10.5:1, which is high, even for today's standards. The LT1 is basically just a tweaked SBC, so who knows if it was really designed to run this way all the time. It's possible that this could also be a factor. High compression engines don't have quite the same smoothness that the lower compression engines do. If you've ever driven a 74 Caddy with 8.25:1 compression, you'll understand. That thing is so smooth, it's more like riding on a train than in a car.

And finally, the tuning could also play a factor. GM designed these engines with performance in mind, so they run pretty close to their limits from the factory, although you can still get 10-15 at the wheels from a mail order tune, maybe more on a dyno, but I think that has more to do with adjusting the fans and the a/f ratio than the timing, I doubt more than a couple of degrees

Basically, high performance engines are always finicky, and it takes a lot of work to get them to run right all the time. Since the LT1 is a 55 SBC "second edition", unlike the truly new LS1s, I see no reason it shouldn't be finicky. There are always ways to improve upon the LT1 and make it less prone to strange occurences, but good luck getting rid of it completely. In fact, I bet there's only one way: back off the timing, reverse the impeller in the water pump, and do a little carving on your combustion chambers. But I don't think you want to do that.

 

Yeah i bought my car with a Hypertech 160* and manual fans, and its never bogged down or anything in any weather, and after i did the TB Bypass, its been even better. Always shifts right, though sometimes (RARELY) a little soft. The only time it ever bogged down was when i had a clogged cat. Replaced it with a high flow and been golden ever since.

 

so i need a tune and a manual fan (is the hypertech fine)

 

It would certainly help. You can go with either a hypertech or an SLP, it doesn't really matter, just a spring that expands when it gets hot (160*)