Re: 90 ZR1: Oh crud, did I break it?
 

I"ve got a Universal Block Tester Kit I bought to use on my old LT-1 after I thought I blew a head gasket. there is approx a half bottle left of the testing fluid. It has all the instructions on how to test (really simple) for a head gasket leaking, cracked block etc. A simple matter of watching the fluid turning form blue to yellow is a leak is present.

If you want the kit I"ll send it to you for nothing but I"d like to get the postage back. If your interested, drop me a PM...

Re: 90 ZR1: Oh crud, did I break it?
 

from page 2
http://i13.photobucket.com/albums/a2...oprearview.jpg

you may have to pull the plenum to check the bottom side of it but that's an easy job.

Re: 90 ZR1: Oh crud, did I break it?
 

Geezzz... you guys can scare the new guys half to death with this head gasket talk. While I agree that the stated symptoms may point in that direction there are other possible causes. There is a simple and quick way to check for a blown head gasket. Go down to your local Autozone or Kragen and rent a cooling system pressure tester. Hook it up, follow the directions (important) if it holds pressure you don't have a blown head gasket, if the pressure won't hold and there's no puddle of coolant under the car you have either a blown headgasket or a blown IH gasket. Once you've done that we'll talk.
H
:cheers:

Re: 90 ZR1: Oh crud, did I break it?
 

I had the same thing happen 4 years ago. It was two bad injectors and an intermitten problem. Like you at the time I didn't know squat about the car (of course all of that's changed now). Took it to corey Henderson. Took him no time to chase down and fix what was wrong. But again it was to bad injectors. Running great and in a split sec ran like it was gonna self distruct.

Re: 90 ZR1: Oh crud, did I break it?
 

I'm on board 110% with Hans here. Save yourself a lot of time and get the cooling system tester. I'll never troubleshoot a cooling system again without using one of these. I had a leak in BG this year, once I got home I replaced the water pump (I was positive it was the pump as I saw fluif dripping off a lower pump bolt) before testing the system. After I replaced the pump there was still a leak so I decided to get the tester. Found a leaking hose. It was brand new set of Samco's and the hose going to the upper radiator had a small slit in it. I used the original clamps (spring type) and think they caused the problem. Don't know how the fluid got down on the pump bolt (if it did). There was a puddle of fluid right under the hose on the frame now. Samco replaced the hose and I used their clamps this time. Problem solved. But...now I have a water pump that may or may not be bad because I didn't test the system.

Hope that helps a little. The tester will absolutely tell you if you have a coolant leak. If you do this, pull the plugs first.

GL

Re: 90 ZR1: Oh crud, did I break it?
 

I am just curious if the car ran the same with the power key on as it did with it off. I had some secondary injectors go bad and the car ran rough with the key on, but ran OK with it off.

Ron

Re: 90 ZR1: Oh crud, did I break it?
 

I emailed you GTO but have not heard back from you.

Jim

Re: 90 ZR1: Oh crud, did I break it?
 

Hello there Jimbo :wave:

Re: 90 ZR1: Oh crud, did I break it?
 

OK, Update.... first of all, thank you for all the follow-ups and it's not that I've been ignoring you, but I got nasty sick on Friday and was down for most of the weekend. I dragged my sniffling self to work this morning just 'cause I didn't really have a choice. Now I'm feeling better so it's time to get the ZR1 feeling better!

NOW... for the excitement... This morning I came downstairs after getting ready for work and the wife says "it smells like gasoline down here". Being stuffed up still, I took her word for it. Until I got to the back hall and sure enough that was gasoline I smelled. I opened the garage door and it was really strong. Looked around under the car and found no puddles. Had to go to work.

Came home tonight & I managed to get all the plugs out except for 8. I'll go back and search for all the tips on how to get at 8, but what was GM thinking there?! :icon_scra

I compared all the plugs and they appear original (almost 28k miles on the car). #5 looks very fouled.

I bumped the starter a few times and watched for water to burble out one of the cylinders. When it hit #5, a geyser shot from the engine to the garage wall... on the far side of a 3 car garage! And it was gasoline.

I made another revolution with the starter and got the same result with slightly less gasoline bursting out. I got little "poofs" out of the others.

So now I'm thinking it's probably NOT water in there, but unburned fuel making its way out the exhaust valves and burning/evaporating off the inside of the hot exhaust, and that was the smoke I was seeing. Wouldn't that say "bad injector" to you? In which case, isn't that a big relief vs. it being a head gasket?

Whadya think?

Re: 90 ZR1: Oh crud, did I break it?
 

Appears you have found the problem.
Time to pull the plenum and replace the injectors