jeff105

Hey guys, first post here.
My 94 LT1 T/A recently wouldn't start after shutting it off . I had made a few short trips around town,I cut if off to go into get a bite to eat and when I got ready to go, the starter would turn over fine but it would not fire up.

I had the car towed in and they said the opti was bad. OK, they replace that and they also told me they replaced the ICM as well. I hadn't expected them to replace the ICM but neither did the mechanic,originally. I totally trust the shop so if they it also needed the ICM, I'm feel sure it did.

I go to pick the car up today. The mechanic told me that it was idling rough but they were hoping it was a just a fouled out plug that would straighten out in a few miles. If it didn't bring it back and they would change that plug. (# 4 I think)

I leave with the car just to have it continue to run rougher and then overheat and die in the middle of the street.


New opti and ICM (GM parts) plugs have 15 or 20k miles.
Any ideas ? Head gasket ?

Thanks for any input.

FAD2BLK93

Sounds like they may not have purged all the air from the cooling system, or possible thermostat? Is the rough running a miss fire problem? Bring it back and tell them to make it right at their expense! U pay that kind of money...u expect a running car!!!!

Speedy

Did the mechanic install the plug wires the right way?

jeff105

Thanks guys.
I had the car towed back to the mechanic shop. The car made it all of maybe 3 miles before it quit.
Maybe they will get it straightened out tomorrow. I hope so anyway.
I posted the question on here because you guys seem to have a tremendous amount of knowledge. I only wish I knew half of what you know.

F0x Slaughter

Then read read read read read. Never go to shops they are rip offs. I knew for a face my sisters car the just needed something (forgot what is was and I was to busy to do it) so I told her take it to a shop, she ended up paying like 300 dollars for a 20 dollar part because they kept saying this was bad this was bad.

I know people who work at shops and the shady work and things they do is disgusting. I never ever take my car to a shop.

Just read and learn how to do things. Working on a car is a simple thing. Go to Sears and pick up like 150 piece mechanics tool set and some jack stands from Harbor Freight.

Look at the engine coolant temperature sensor. The one in the water pump is the one the PCM uses and the one in the driverside head is the one the gauge uses.

jeff105

I agree that there are some shady shops but the shop I use is a family run garage that has been around for a very long time and have an excellent reputation.
Hopefully they will have good news for me tomorrow.

FAD2BLK93

Well just come back and let us now what it was, alot...alot of threads get started and people dont come to tell what fixed it. That is what people are looking for in this community. Thanks besides i want that 100 bucks...lol...

jeff105

I will let you guys know what I find out.
I absolutely hate whenever I stumble upon an interesting thread that just leaves you hanging.
I won't make that mistake.

Fast94CamaroZ28

We had almost the very same thing happen to our 94 Camaro Z28 and we spent all kinds of money to fix it. All you could smell was gas from the exhaust. We took it to a high performance shop. They took out the plugs to do a compression test and found out that they had rust on them. They found out it was the head gaskets but the water wasn't going in to the oil. It was going into the cylinders! Plus #3 & #7 plug wires were crossed. Hope this helps narrow down your problem.

jeff105

As it turns out, the shop informed me today that I have a leaky head gasket. It takes a while but he said the temp would start to climb after driving ?? miles.
He did go onto say that it wasn't leaking bad and that it would be worth a try to put put some Bar's Leak Head Gasket product to see if it would seal it off.
If this doesn't work, I guess we'll just go ahead remove the heads and replace the gaskets,mill the heads,etc.
I really wasn't wanting to spend that kind of dough but I do know the car very well because I bought the car brand new. It has 120K miles and has always been pampered,garaged,never wrecked,etc,etc.

They also replaced the thermostat (GM) and also found a plug fouled.

Speedy

Take a pass on the Barr's Leaks. I recommend getting the head gasket replaced. It beats having to rebuild the engine, and that's just what you risk doing if (when) the rest of the gasket blows.

Headgaskets often go if an LT1 has overheated (bad rad cap, not enough coolant, faulty water pump, etc.). The aluminum head expands (aluminum expands at 4x the rate of iron) and tears the gasket. If you get it in time, you're lucky.

93 LT1 Vette

No such thing as "not a bad leaking head gasket". Especially when the car overheats and leaves you stranded and a salvageable motor is now a boat anchor.

Now did they determine that the head gasket is leaking.

Is the fouled plug because of water and antifreeze leaking into the cylinder from the popped gasket.

They change the opti and ICM and suddenly it has a head gasket and overheating problem.

Like it was said above. Did they improperly bleed the air out of the coolant system which overheated the car and that's what popped the head gasket.

You should ask some serious questions because something ain't adding up.

Unless the car had a prior history of overheating and stalling after being driven 3 miles or so then your stuck. Good luck