I was noticing some coolant loss and wanted to see what was going on. I did an oil change it it looked like straight oil. After removing the air filter today I saw what looks like some dried coolant on top of the engine and you can see in one of the images there is a plug with 2 plastic holes where two hoses would hook up to. Maybe going to the AC that was ripped out? Also there is no coolant reservoir.
The intake manifold gasket looks like it is leaking as well as the valve cover gaskets. I have never done this type of job but I am thinking I could follow a few tutorials and get it done. Should I also replace the exhaust manifold gasket and what other ones should I be looking at doing?
If I open it up what would I be looking for with cylinder 7?
Also I included a picture of the transmission and I am assuming this was a rebuilt one installed at one time?
What did #7 spark plug look like compared to the rest? If a cylinder is leaking water it will flash to steam during combustion. This will cause that plug to look like it's been steam-cleaned (which it has sorta).
I've never cared that much for compression test. A cylinder leakage test and a good plug read speaks volumes.
That "plug" on top of the thermostat housing with the broken hose connections is a thermostatic valve and was part of the old vacuum advance.
The exhaust manifolds don't have gaskets at the heads.
What did #7 spark plug look like compared to the rest? If a cylinder is leaking water it will flash to steam during combustion. This will cause that plug to look like it's been steam-cleaned (which it has sorta).
I've never cared that much for compression test. A cylinder leakage test and a good plug read speaks volumes.
That "plug" on top of the thermostat housing with the broken hose connections is a thermostatic valve and was part of the old vacuum advance.
The exhaust manifolds don't have gaskets at the heads.
Here are the pictures of the spark plugs. The previous owner changed them about 500-1000 miles ago so they are relatively new. The gap looks high and some are grey and some have an oil build up?
I can grab a leak down test kit from autozone tonight.
Was the thermostatic valve for the AC?
Basically seeing if I should move forward with gaskets in this engine or if a new crate engine sometime this year will be a better move.
A new spark plug in cylinder that's consuming water will still look almost new at only 500 to a 1000 miles. You'll need an air compressor for a cylinder leakage test. If you can rent a coolant system pressure test kit you can pump the system up to operating pressure and look for water in #7 (and elsewhere) You might try that first as it will be easier and quicker and it's a hand pump operation. You can also leave the coolant system pumped up for a couple of hours if you don't see any water at first
Do you think the spark plug looks like it has extra oil?
I have an air compressor for my nail gun that should be able to hook up to the unit. Do you know how to find 'top dead center' for each cylinder on the 350? That is one thing on these leak down tutorials that I am not sure about.
The spark plugs look a little dark but it's hard to tell if it's oil, running rich or just a cold plug. For cylinder TDC: Pull the valve cover so you can watch the rocker arms. With both valves closed the cylinder is as closed up as it's gonna get. The valves and the distributor rotor button will tell you when you are close to TDC on whichever cylinder you're checking.
The 350 is a good motor … if you get a new crate its the same block you have now with new gaskets...… I don't believe the motor is bad it just needs some lovin …
maintenance is always better than a catstroific failure ...
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB
These engines were prone to cam lobe wear. When you pull the valve covers you can measure and compare the rocker arm movement for a idea of how much lobe wear you have. I've seen guys crank down on the rocker arm adjustment on a cylinder with a bad lobe just to get it quiet enough to sell the vehicle. If the cam is worn, or if the rings and valves leak you'll have a better idea of the condition and past life of the engine and can make an informed decision on the next step. JustMy2%. Replacement would depend on how long I was gonna keep it and the condition of the rest of the van. That would be a personal choice. We have a '94 GMC with well over 300K and it's part of the family. In fact I believe, sometimes, the wife likes it better than she does me. If it needs anything it gets it. Same with our '95 G20 but it just turned 65K.
The 350 is a good motor … if you get a new crate its the same block you have now with new gaskets...… I don't believe the motor is bad it just needs some lovin …
maintenance is always better than a catstroific failure ...
If you were going to open this up and replace gaskets/seals/clean what would you be looking to do? I am new to this and looking to learn.
Originally Posted by CatFish
These engines were prone to cam lobe wear. When you pull the valve covers you can measure and compare the rocker arm movement for a idea of how much lobe wear you have. I've seen guys crank down on the rocker arm adjustment on a cylinder with a bad lobe just to get it quiet enough to sell the vehicle. If the cam is worn, or if the rings and valves leak you'll have a better idea of the condition and past life of the engine and can make an informed decision on the next step. JustMy2%. Replacement would depend on how long I was gonna keep it and the condition of the rest of the van. That would be a personal choice. We have a '94 GMC with well over 300K and it's part of the family. In fact I believe, sometimes, the wife likes it better than she does me. If it needs anything it gets it. Same with our '95 G20 but it just turned 65K.
If you were going to open this up and replace gaskets/seals/clean what would you be looking to do? I am new to this and looking to learn.
What would I be lookin for ? The number to my mechanic as I am not. You know Or will know whats wrong and whats been fixed with this one … getting a new one you start over. New isn't always better. I had bad parts right out of a new box.
Ive had both of my 454's refreshed .
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB
The engine I pulled out of the Queen Anne's Revenge had a blown head gasket and cylinder #7 was filling with coolant.
Replacing the gaskets isn't really a huge task, but it is time consuming. There are a ton of great videos on YouTube about SBC repair. I've always left out the front and rear parts of the intake gaskets and used RTV instead. The front and rear pieces they give you in the gasket kit always seem to leak on me.
I also prefer the thick aluminum exhaust manifold gaskets where the manifolds bolt to the heads, but the paper style gaskets aren't too bad either.
We decided to pull the 350 with blown head gasket and throw in a temporary 305 just to get us on the road until we get the time and money to rebuild the 350.