The 4.1 holds the dubious title of “Only engine I have ever seen that had a headgasket fail due to rusted out head bolts”.....
I appraised a Caddy trade-in that had steam leaking from the head....put it in the air and I found an external head bolt had failed due to road salt. Rusted right thru where it entered the block.
Cadillac small V-8 engine
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Re: Cadillac small V-8 engine
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Re: Cadillac small V-8 engine
The part that I like about them is that they use a very small area for the oil return from the heads. I think small drillings that lead to the area around the upper head bolts. These plug up with gunk because it's a 1980s all aluminum engine, and then if you thought the low mounted valve cover gaskets leaked before, you ain't seen nothin' yet.
One fix that I thought was entertaining was to tap the passage for a grease fitting and use a high pressure grease gun to force the sludge through. If 2500+psi can't get the sludge out, nothing will.
The cylinders are wet sleeves with O-rings on the bottom. Predictably, the block corrodes down there, and they leak coolant into the oil. The only real fix is to replace the block. The liners can also leak just from removing the heads and re-installing them. Most people who have replaced head gaskets on one of these engines only have done it once, because they got burned by the experience.
I think the Cadillac engineers threw a party where all of the 1970s drugs were involved, and game up with a game to see how many bad ideas they could incorporate into a single engine. The drawings from that party accidentally got in the hands of management and it got approved by mistake.
One fix that I thought was entertaining was to tap the passage for a grease fitting and use a high pressure grease gun to force the sludge through. If 2500+psi can't get the sludge out, nothing will.
The cylinders are wet sleeves with O-rings on the bottom. Predictably, the block corrodes down there, and they leak coolant into the oil. The only real fix is to replace the block. The liners can also leak just from removing the heads and re-installing them. Most people who have replaced head gaskets on one of these engines only have done it once, because they got burned by the experience.
I think the Cadillac engineers threw a party where all of the 1970s drugs were involved, and game up with a game to see how many bad ideas they could incorporate into a single engine. The drawings from that party accidentally got in the hands of management and it got approved by mistake.