Engine advice—How screwed am I (pics)

[Erik the Awful]

You're right, they should just stop selling individual head gaskets for these engines and only make them available in rebuild kits.

While the top end and bottom end are in the same engine, the only time a blown head gasket correlates with a bad bottom end is if you ran it with water in the oil too long. The excuse that a new head gasket will cause the bottom end to go bad is dead wrong. If the bottom end starts knocking after replacing the head gasket, the bottom end was already bad and the head gasket was bleeding off pressure, hiding it.

It's also incumbent on the shop to perform a diagnosis. What's the oil pressure? If the oil pressure's 5 psi at 3000 rpm, then it's time for an engine. If it's 35 psi with the blown head gasket, the bottom end isn't going to knock just because you put a new gasket on it.

The shop needs to make the customer aware that it's an old engine, but they also need to lay out the evidence. At the end of the day, it's the customer's risk. Have them sign paperwork explaining that they took the path you didn't advise. If they choose the risk, get burned, and then come back whining, get a backbone. Tell them how much it will cost for an engine replacement and show them where they signed to take on the risk.

 

[RoyBob]

run the piston to the top, spray a little Yellow can easyoff on the top wire brush it and see how it looks,

 

[movietvet]

Besides pressure bleed off at head gaskets hiding a possible rod knock, I also worry about damage to rings from the coolant/oil mixture being ran too long before shut down. Sometimes there are days that go by, with coolant loss that is never discovered till it is too late. Especially with high mileage engines also having coolant mixed in the oil circulating thru the oiling system. I personally had head gaskets go on a GMT 400, that became very noticeable coming home from work one day. I crossed fingers and just did head gaskets on a 140k miles engine and it came out just fine BUT, I did worry about it for about 2 weeks after the head gasket work. I had the heads reworked and the manifolds checked and surfaced as needed. While I do like my 2005 Tahoe Z71, I miss that 95 K1500 extended cab.

 

[Schurkey]

Thousands of years ago, when I was actually working for a living, I saw and heard about two types of "failures after new head gaskets/new valve job".

1. The cylinder heads or head gaskets were so bad that they covered-up worn-out/damaged rings. The engine smoked, burned oil, and "somebody" decided that the heads were to blame. So the heads were rebuilt, the engine runs "better"...and now the worn rings were easily diagnosed. Of course, in the customer's mind the mechanic must have caused the rings to go bad. "Ever since you worked on my head gaskets, the tail lights don't work, the brakes squeak, and the engine smokes. It's your fault..." From a certain perspective, this really was the shop's fault--INCOMPLETE DIAGNOSIS, especially in the case of sudden water-in-the-cylinder problems where broken rings/bent rods due to hydrolock should have been considered.

2. The engine ran so bad for so long, and then FINALLY got some attention. The burned valves were replaced, the failed head gasket was replaced. Dead cylinders that were producing little or no combustion heat are now running good...and now instead of making 1/2 it's rated horsepower, it's making ALL the ponies it's supposed to. So the clogged radiator that was able to reject the heat of half the horsepower is now overwhelmed trying to cool off a fully-functional engine. "Ever since you worked on my car, it's overheated. You did something wrong. It's your fault..." From a certain perspective, this is the shop's fault, for INCOMPLETE DIAGNOSIS, they should have at least checked the radiator...hoses...belts...and a dozen other things when performing major engine work.


There is a third failure mode, which I don't see any more--I'm out of the business, AND I think service shops have kinda wised-up. When I was service-advisor in a Chevy dealership in '84/'85, all the techs were using brown 3M "surface conditioning discs" ("cookies") to clean gasket surfaces. I watched them, and learned. That's when I bought my first die-grinder and Velcro mandrel, so when I worked on my own stuff, I could buzz the gaskets off as easily and effectively as they were. Holy carp, they left a beautiful-looking gasket surface.

There are multiple problems, though. The silicon dioxide embedded in the fiber pads goes EVERYWHERE, thrown out by the centrifugal force of the die grinder, blown around by die grinder exhaust and ambient air currents, and that abrasive--and the fiber of the "cookie"--are ripped away by the abrasive action against the gasket surface and the other metal bits near the gasket surface. In short, the abrasive ends up in your lungs, in the engine, and in whatever is being taken apart in the next stall...or two...or three... The abrasive dust contaminates EVERYTHING it touches and when the engine runs again, the abrasive dust is carried by the oil to every lubricated part inside the supposedly-"fixed" engine.

I quit using them when the local machinist that was resurfacing parts for the shop, told me that he could tell when someone cleaned gaskets with "cookies", because the gasket surface even on iron parts became wavy. Wherever the gasket material was stubborn, there'd be a low spot on the casting where the abrasive had worn-away the metal. Aluminum was horrible for that, iron was merely "bad". The first pass with the surface grinder would show all the low spots; which hopefully would be cleaned up with the finish pass.

Wasn't until later I figured-out that the techs had been contaminating each-other's work--a head gasket job in one stall would drop abrasive all over the disassembled valve-body of an auto transmission two stalls over.

 

[movietvet]

Saw, and even used "cookies" myself and then stopped when I heard it described to me what the ramifications were. I don't see them any more but you can bet someone is still a "cookie monster".

 

[Erik the Awful]

We used roloc "cookies" all the time at the dealership, but we were very mindful of which abrasiveness we used. That said, because of the discussions here I have reconsidered my use of them, and now I try to clean surfaces without them.

True story, I was on the promos for an episode of Street Outlaws, wearing a Cookie Monster costume while waving the green flag for a Lemons race and brandishing a toy AK. Then I think they got a cease-and-desist letter from Sesame Street and I was cut out of the episode.

 

[98_SLE_98]

Nothing has changed all these years later. It is still covered in psb #00-06-01-012N. Schurkey nailed it. The amount of airborn particles in the shop even without using them is nuts. Get the sun shining at the right angle and you can see all of it. Have worked in the past with people that didn't understand the imporance of separate areas for transmission work, engine work, etc, Don't wanna be next to the guy getting rotors ready to cut as your in the middle of a 10spd rebuild

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[Scooterwrench]

The guy that came up with the idea of grinding gaskets off should be hanged by his skadeechies. I've got three wood chisels that I keep razor sharp just for scraping gaskets and still have to damned careful with those not to gouge the gasket surface.