Water running down back of engine block, drivers side.

Hello everyone! Truckie suddenly dropped low in water and I couldn't find any leaks underneath the hood or see water underneath the truck at the time. The oil appears clean. and no steam. Today I was working on the brakes and spied water running down the side of the transmission on the drivers side. I can see the back of the engine block is wet, but I can't tell if it is the head or the intake. Is this a typical intake gasket failure?

Typical intake gasket failure. When you replace it, change out the coolant to green, yes green. The dexcool eats the gaskets. Put a pressure test on it to make sure and you will see it leak.

Check the heater hose quick connector.

Wife's 99 burb did the same thing,leaking from the crossover where the head meets intake.

Replace the gaskets with a quality set. I believe the better ones will run ~$50 or so, e.g., FEL-PRO MIK98000T.

Stick with the long-life antifreeze, it'll do you well; mix concentrate with distilled water. We ran Dex or its equivalent (Prestone Dex) in my 1998 'burb since new, for about 20yrs. Changed it a couple times over that period. Eventually an intake gasket started to leak around 2017, as many do. Replaced the gaskets with a FelPro set and backfilled w/ Prestone Dex.

Newer gaskets have overcome the issues of the antifreeze additive 2-ethylhexanoate (2-EHA) which, when introduced in the early 90s in Dex and other compositions (Prestone Long Life, et al.), did so much damage to the gaskets of that time. 2-EHA is still commonly used, today.

See also https://www.gmt400.com/threads/orange-coolant-in-radiator.56832/post-1222252

1998_K1500_Sub said:

Replace the gaskets with a quality set. I believe the better ones will run ~$50 or so.

Stick with the long-life antifreeze, it'll do you well; mix concentrate with distilled water. We ran Dex or its equivalent (Prestone Dex) in 1998 'burb since new, for about 20yrs. Changed it a couple times over that period. Eventually an intake gasket started to leak around 2017, as many do. Replaced the gaskets with a FelPro set and backfilled w/ Prestone Dex.

Newer gaskets have overcome the issues of the antifreeze additive 2-ethylhexanoate (2-EHA) which, when introduced in the early 90s in Dex and other compositions (Prestone Long Life, et al.), did so much damage to the gaskets of that time.

See also https://www.gmt400.com/threads/orange-coolant-in-radiator.56832/post-1222252

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Agree

Thank you all so much for the replies. I was just in there replacing the spider injector and am not looking forward to sitting under the hood even more. I have had it for 18 years, and she has 249k on er now. I am debating on whether this is a good time to pull it out and refresh the engine, possibly convert it to a 383. I believe I could swing the engine about as quickly as I could change the intake.

I once found a post about camshafts, I believe it was on here. Is there a preferred one for the vortec for just plain acceleration perhaps with a mild lope? I do little towing, but I do like to get out in traffic.

383Dreams said:

Thank you all so much for the replies. I was just in there replacing the spider injector and am not looking forward to sitting under the hood even more. I have had it for 18 years, and she has 249k on er now. I am debating on whether this is a good time to pull it out and refresh the engine, possibly convert it to a 383. I believe I could swing the engine about as quickly as I could change the intake.

I once found a post about camshafts, I believe it was on here. Is there a preferred one for the vortec for just plain acceleration perhaps with a mild lope? I do little towing, but I do like to get out in traffic.

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If the funds and time allow yes

383Dreams said:

I was just in there replacing the spider injector and am not looking forward to sitting under the hood even more.

Click to expand...

I won't discourage you from making cam / engine changes. You might want to run a compression check first just to gauge the engine condition. The ol' L31 might be better (or worse) than you think and sway your decision, for good reason.

I will say that the intake gasket job isn't horrible, it's mostly rote. Getting the distributor back in is straight-forward and the engine will start and run quite well, but the distributor needs to be "dialed-in" with a scan tool at some time (could be a day or weeks later, just sometime) so that the camshaft sensor (@ distributor) jibes with the crankshaft sensor (@ timing cover) nuts-on... others here can tell you how this is done, I can't regurgitate the process from memory like some can (@Schurkey et al.). The reason: See here and perhaps elsewhere https://www.gmt400.com/threads/cam-sensor.38782/post-970165



One thing: When the intake is off, do something (anything!) to block the distributor hole in the engine so that if you drop something (like a tap) it doesn't fall all the way down into the oil pan. If that happens it will add a whole new dimension to the job and expand your vocabulary greatly. Ask me how I know.