I'm new here, but I do know enough to be dangerous. I read a few posts about running problems with no engine codes. I was wondering if anyone had herd about the ground on the front side of the engine, down around the front engine mount causing problems. I'm no expert, but was told about it on 4.5 Deville that ran bad after new plugs, wires, cap, rotor, coil, and I can't remeber what all else. This car blew the muffler apart from backfiring. I can't remember what all else, but do remember that. Seems like it had a 15mm nut, then a double sided stud. All I did was take everything apart and clean it so it had a good connection, and that fixed it. Some thing about the bolt being steal, the block being alm, and the connector being copper made them oxidize over time and not make a good connection. Just throwing that out there. Thoght it might be helpful to somebody, and was wondering if anyone else had heard of anything like that before. One other question. Every once in a while my 95 Eldo will set a PO39 torque converter clutch code. I would say "random" but I can almost make it set the code. The TCC solenoid has been replaced, and it seems that it only does it with real light load, like 45 mph in 4 gear. Do you all think a rebuilt converter will make the code go away? Car has 112,XXX miles.
Performance and Driveablity ? for the experts
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Probably. This pertains to OBDII codes, but the basics are the same. You have already eliminated the solenoid.
http://www.cadillacforums.com/forum...on/149834-information-p0741-p1860-1998-a.html
http://www.cadillacforums.com/forum...on/149834-information-p0741-p1860-1998-a.html
Thanks for the reply. A GM tech that I trust said that it would most likely fix it, but that he had seen cars run a long time with that code and not have a problem. My car uses about 2 to 3 qts of oil between changes, and looks like it's coming from where the block splits above the oil pan. If it gets much worse I guess I will have to pull it to fix that, and that would be the time to change my converter. Do the N* engine head gaskets fail over time for no reason? If I pull the motor for the oil leak, change the converter, wonder if I should change them at the same time? On second thought, oil is still cheaper. Its amazing how it can snow ball out of control.
I know these grounds are for critical electronics & are somewhat vulnerable to the elements on the front of the block. A connection problem there would have high potential of signaling many DTC's.
You locate in GA so I believe the weather element(road chemicals)is lessened a bit more than if you lived in the rust belt states.
You locate in GA so I believe the weather element(road chemicals)is lessened a bit more than if you lived in the rust belt states.
The tech that told me about the grounds said they develop the resitance over time because of the dissimalar metals touching each other, not so much elements. I don't really know, he made it sound like a common problem at the time when I was working on that car. I thoguht maybe it would be something that didn't cost anything to atleast try.
Sometimes the different metals do chemically react, especially if a current flows though them. I'm not going to pretend I know spit about chemistry.
Zinc & aluminum will. Galvanic reaction doesn't always happen severely. It's not hard to inspect grounds if you know where they are. Steps have been taken in the engineering process to minimize these reactions usually.
Your mechanic seems be just itching to sell you some electrical labor.
To seal up the half block is quite costly, you absolutely need to know this mechanic has experience with these cars.
Head gaskets don't fail usually, threaded head bolt holes fail & that's what causes head gasket failure.
Zinc & aluminum will. Galvanic reaction doesn't always happen severely. It's not hard to inspect grounds if you know where they are. Steps have been taken in the engineering process to minimize these reactions usually.
Your mechanic seems be just itching to sell you some electrical labor.
To seal up the half block is quite costly, you absolutely need to know this mechanic has experience with these cars.
Head gaskets don't fail usually, threaded head bolt holes fail & that's what causes head gasket failure.
I'm no chemist either, but this was years ago when I worked at a used car lot and replaced a bunch of parts for nothing. He just told me to try it and it worked for me. Just thought I would tell others of my own experanice. My car is setting a PO39 code, but intermittently. The only way I see to reseal the block halves is to remove the engine, thats why I was wondering if anyone thought a converter would fix it. If I went that far, I think I would want to replace the head gaskets and rod and main bearings at the same time. Someone else also warned me of the threads failing in the block, but when I would try to remove the bolts. Is there any kind of "rule of thumb" when they fail in miles? I do as much of my own labor as I can, so I would try this.
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