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91 Eldorado #1 main bearing thump


skyman

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After several years of driving my 91 Eldorado with the #1 main bearing thump. I finally talked my back yard mechanic friend into doing the job. He was hesitant in starting it as he had never opened up an Eldo before and they are a bit tight to work on. I ordered the special service bearing from GM and brought it up to him along with all the info and help that I printed out from this discussion group.

Well he put her up on the lift and found that the job was much easier than expected. He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

The engine sounds great. NO KNOCKS.

The only problem I have now is that for the last year or so, the engine seem to be running 5 to 10 degrees hotter than it used to. I always ran at 192 degrees before. Performance is good though and I still get over 31 mpg on the highway.

Does anyone here know how to access the pictures of members cars on here. Can't seem to figure out how to get a thumnail pic of my car on my posts here.

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After several years of driving my 91 Eldorado with the #1 main bearing thump. I finally talked my back yard mechanic friend into doing the job. He was hesitant in starting it as he had never opened up an Eldo before and they are a bit tight to work on. I ordered the special service bearing from GM and brought it up to him along with all the info and help that I printed out from this discussion group.

Well he put her up on the lift and found that the job was much easier than expected. He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

The engine sounds great. NO KNOCKS.

The only problem I have now is that for the last year or so, the engine seem to be running 5 to 10 degrees hotter than it used to. I always ran at 192 degrees before. Performance is good though and I still get over 31 mpg on the highway.

Does anyone here know how to access the pictures of members cars on here. Can't seem to figure out how to get a thumnail pic of my car on my posts here.

Probably crank was just in the position that allowes to remove the oil pan. BTW, 192F is perfect for 4.9 engine. 31 PMG! Unbelivable! Did you try to compare that data to one based on the actual fuel used from pump?

The saddest thing in life is wasted talent

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...

The only problem I have now is that for the last year or so, the engine seem to be running 5 to 10 degrees hotter than it used to. I always ran at 192 degrees before. Performance is good though and I still get over 31 mpg on the highway.

...

Have you changed the coolant in the last two years? If not, you should ASAP. The extra few degrees could be a lot of things; I would drain and refill the coolant with 50-50 antifreeze and distilled water (I've seen 50-50 coolant sold in the bottle in auto parts stores). If the temperature doesn't go back to noraml, I would have a pressure check.

...

Does anyone here know how to access the pictures of members cars on here. Can't seem to figure out how to get a thumnail pic of my car on my posts here.

First, make a photo that you want to use, and resize it to 64 X 64 pixels. Then, at the top of the forum screen, click the link "My Controls." This will bring up your forum options. On the left you will have a column of links, several under each of four headings. Under the heading "Personal Profile" you will see the "Edit Avatar Settings." Click that and follow the directions to upload your 64 X 64 picture.

There's an option to scale the picture for you. If you use it, you can just use a larger picture. I haven't tried it.

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Great job on the #1 bearing knock! My 91 had it but I found that I could minimize it most of the time using 10W40.... In very hot weather however when the oil was very hot and thin it was more pronounced.

Change your thermostat it could be hanging up... My 91 went through stats quite often. They should be changed if you ever overheat badly and they wear. The spring cocks and they bind you will see wear marks on the brass part on the spring side of it that moves through a hole in the frame. There is no reason you should be running hotter. Pressure test your cooling system, the end tanks crack and leak pressure. Check for codes for the hell of it. Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

Did he have to remove the exhaust crossover pipe to drop the pan ?

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After several years of driving my 91 Eldorado with the #1 main bearing thump. I finally talked my back yard mechanic friend into doing the job. He was hesitant in starting it as he had never opened up an Eldo before and they are a bit tight to work on. I ordered the special service bearing from GM and brought it up to him along with all the info and help that I printed out from this discussion group.

Well he put her up on the lift and found that the job was much easier than expected. He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

The engine sounds great. NO KNOCKS.

The only problem I have now is that for the last year or so, the engine seem to be running 5 to 10 degrees hotter than it used to. I always ran at 192 degrees before. Performance is good though and I still get over 31 mpg on the highway.

Does anyone here know how to access the pictures of members cars on here. Can't seem to figure out how to get a thumnail pic of my car on my posts here.

Probably crank was just in the position that allowes to remove the oil pan. BTW, 192F is perfect for 4.9 engine. 31 PMG! Unbelivable! Did you try to compare that data to one based on the actual fuel used from pump?

Yes I've checked it against actual miles used from pump and from fuel used on the computer. I keep it on ave MPG while on the highway. I make trips from my home in CT yo my home up west of the Catskills. Its about 225 miles one way. I keep the speed between 60-65 and I'm easy on the pedals. I actually get reading of up to 34.3 untill I get to the hills. Sometimes I've only gotten 29 mpg I guess depending on the gas I put in don't know but usually it's around 31.

He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

Did he have to remove the exhaust crossover pipe to drop the pan ?

After several years of driving my 91 Eldorado with the #1 main bearing thump. I finally talked my back yard mechanic friend into doing the job. He was hesitant in starting it as he had never opened up an Eldo before and they are a bit tight to work on. I ordered the special service bearing from GM and brought it up to him along with all the info and help that I printed out from this discussion group.

Well he put her up on the lift and found that the job was much easier than expected. He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

The engine sounds great. NO KNOCKS.

The only problem I have now is that for the last year or so, the engine seem to be running 5 to 10 degrees hotter than it used to. I always ran at 192 degrees before. Performance is good though and I still get over 31 mpg on the highway.

Does anyone here know how to access the pictures of members cars on here. Can't seem to figure out how to get a thumnail pic of my car on my posts here.

Probably crank was just in the position that allowes to remove the oil pan. BTW, 192F is perfect for 4.9 engine. 31 PMG! Unbelivable! Did you try to compare that data to one based on the actual fuel used from pump?

Yes I've checked it against actual miles used from pump and from fuel used on the computer. I keep it on ave MPG while on the highway. I make trips from my home in CT yo my home up west of the Catskills. Its about 225 miles one way. I keep the speed between 60-65 and I'm easy on the pedals. I actually get reading of up to 34.3 untill I get to the hills. Sometimes I've only gotten 29 mpg I guess depending on the gas I put in don't know but usually it's around 31.

He had no problem getting the pan off and said he didn't need to rotate the crank to clear the counter wieghts on the crank.

Did he have to remove the exhaust crossover pipe to drop the pan ?

Yes the crossover pipe had to be removed.

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