Hello all,
I need to vent. I recently brought my 92 LT1 to my mechanic because I had a slight stumble or miss when idling at light or stopped in gear. (automatic) When driving or highway seemed fine. Right before I brought him the car it gave me a little hard time starting. So, Mechanic has car calls me tells me the intake manifold is leaking and dripping to Optispark (which I had changed in 2013 to MSD) could be causing the stumble needs to take off water pump, take apart Optispark check it out see if oil in there then go further and change seal in water pump and Optispark. Could not get crankshaft hub off so we skipped doing timing cover. Changed the gaskets on Intake manifold and used TRS on China Wall. Changed gaskets on Water Pump. Also installed new Serpentine Belt. Assuming he added coolant. Calls me car won't start. Gets computer program finds he needs to move opti in different position. Gets car started now he calls me tells me water is bubbling in reservoir car overheating quickly says I need Head Gasket. What the F@#k. The car was not over heating when I was driving it. BTW car has low milage It's not a daily driver we are talking under 30,000 miles.
Can anyone tell me how a Head Gasket is possible I am beside myself.
Thanks for listening

 

Would seriously look at the intake manifold gasket replacement servicing
History shows gaskets can be/have been installed incorrectly
Many articles written which describe overheating by incorrect installation of intake manifold gaskets--"Google Search Time"

 

does an lt-1 have coolant in the intake manifold? never owned one.

 

No. The intake does not have coolant passages.

 

It's a 30 year old car - almost anything is "possible".

You have several options. Much depends on how much you trust your mechanic, and how much you feel you yourself can do on your car.

If the head gasket is in fact bad - it will show up on either a leakdown test OR a cooling system pressure test.


If I were you - I'd talk to the mechanic and ask him what makes him believe the head gasket is bad. Water bubbling in the reservoir tank could be any number of things - including air that got in during the water pump removal, being purged. If you're not happy with the answer - get the car out of there and into another place. Post the answer you get here if you want other opinions. If you don't trust the mechanic - just get the car out of there to another place.

 

^^

if the car did not have a blown head gasket before the work was done it certainly did not miraculously happen while getting work done. if the system was opened my guess is that the cooling system is not purged like the previous member suggested. ^^

note, if your cooling system is sealed properly, then as the pressure escapes out the coolant overflow, and if you have filled the overflow tank yourself, it will “vacuum” it back in as it cools. but i dont want to drive around with it boiling. you can “boil” it a bit at a time and it will suckback as it cools.

or if u know what u r doing which i didnt many years ago, u can just purge it properly the first time


i experienced this exact thing and i must have been sick and really low energy when i recorded this years ago

https://m.youtube.com/watch?v=1a5XCE0fv18

 

I'm calling BS on this mechanic. The opti pin only installs in one position. The pin has maybe 64 teeth (no idea on the exact count) and there is only one spot on the pin where the teeth are squared off to fit. I just did my timing chain on my 92. I used an inspection mirror to tell where the groove was to be sure I installed the opti easily. It is not like a regular distributor where you have endless possibilities of it being off. As for not being able to get the balancer off, I used a regular old puller. Just had to loosen the PS line that is in the way. If this mechanic couldn't figure out getting the balancer off I would not trust him to do a head gasket job. Too many mechanics out there are only competent to do basic maintenance, then they take on jobs they are not skilled to do. Then they make up BS stories to cover up their failures. I'm curious what computer program he used to tell all this. Sounds like more BS to me as the diagnostic computer equipment on this car isn't common.

 

yes!!!!!

i always feel badly for members who post these situations. last thing they want to read is this.

to the OP, where do you live? is there maybe a local member who can help get this train back on the rails by either buttoning it all back properly or by recommending an experienced and informed mechanic?

 

The right thing to do when the had the water pump off was to install a drain line in the weep hole .
The weep hole has taken out the best of optispark units
Changing the gasket was shooting from the hip.
I they didn't drain the block before removing the water pump , chances are good that there is now coolant in the optispark and rendered it useless .
Sorry to hear you are getting the run around with this guy .Inexperienced technicians are a major cause of enthusiastic Corvette owners to leave the hobby

 

You definitely need a new mechanic.

 

Reason 99,954 why I'm glad I can work on my own stuff!

 

Water bubbling and overheating is caused by air trapped in the cooling system!

 

There is a chemical test you can use to see if combustion gasses are in the cooling system, used to be about $20. If it's bubbling in the coolant tank though you can simply give it a sniff yourself, you'll know.

 

I'm not a fan of HF tools, but I bought this combustion leak tester a few months ago, as it was the only one I could find locally.
Combustion Leak Detector (harborfreight.com)

It was fairly easy to use, and luckily, I did not have a head gasket leak, I had some hoses that were loose enough to suck in air, but not loose enough to leak coolant.

 

I apologize for not getting back to the forum on progress of my Vette. After the Intake Manifold gasket was replaced and had the cooling system issue resolved. I indeed had a head gasket leak on the passenger side of engine. So, we had to do this all over again... fun right. Off came the water pump Intake Manifold etc. Drain Coolant, Drain Oil you know the drill. Replaced Head Gaskets replaced everything in reverse order. Installed new plugs and wires. Started car and was idling a little rough drove it and wasn't quite right. Jumped the ALDL to get codes ... no codes. Disconnected battery reset computer. The Opti is MSD and it has an adjustment screw +5 -5 not sure which direction he went. Car is running well so far. What a freakin journey.
Side note I've had an oil leak forever it seems. Always had a cardboard mat under car in garage, So far, no leak on new cardboard. I'm guessing I really did need that head gasket. Fingers crossed.
I want to thank you all for your advice and your knowledge it helped me a great deal.

 

Nope

 

I was working on my LT4 recently and noticed that one of the intake manifold bolts was loose. I re-torqued all of the starting at 10 ft-lbs then 35. Every damn one moved at 10 ft-lbs. Everyone with an LT1/LT4 should check the bolts.

I don't see how working on the manifold could cause a head gasket issue OP. Unless it's possible for head bolts to loosen over time like the manifold bolts I just mentioned.