97 Eldorado ETC History

[BodybyFisher]

This is a work in progress. I will correct details and embellish with photos and scans. It is by no means considered finished, accurate or quotable or taken out of context till I have completed my writing. I have taken the engine apart and the results of my inspection will be posted along with photos. The engine suffered an internal failure that along with other issues caused a domino effect of problems. I can say that I have spoken many mechanics and this is a rare thing to happen. I am using this analysis and engine swap as an extreme learning experience and have taken hundreds of photos. I am pedal to the metal now in completing this job and will attempt to reconstruct the sequence of events as best I can.

I purchased this Eldorado in 2013 from a member on this board. He had just invested a lot of money into it for rotors, brakes, bushings, struts, stabilizer links, stabilizer bar bushings, EBTCM intermittent code diagnostics, the hub bearings and the heater pipes are new. The car is beautiful and has been well cared for.

• In 2006 the engine was replaced with a Jasper remanufactured engine, and installed by a Jasper certified installer. The engine had a 3 year/100,000 mile warranty, but in reality since no one drives 33,000 per year, it was effectively a 3 year warranty. Average miles per year I find is 12K to 15K per year which would amount to 36,000 to 45,000 miles over 3 years.
• From the beginning the owner swore by and used 5w30 Mobil 1 fully synthetic oil. As a matter of fact, the dealer once put 10W30 into it and the owner made him change it to 5W30 as he said he could feel the difference in the seat of his pants, and he felt with synthetic he gained 5 HP. (I have confirmed that it is true that there is a HP gain with thinner oils and will post a reference to my research).
• The engine developed a misfire in the #8 cylinder that occurred at idle and went away at higher RPMs, and he changed plugs, ignition wires, checked the injectors, etc with no success. This code was enough to cause the car to fail the NYS emissions test.
• He had his shop do both a wet and dry compression test and cylinder leakdown test to determine is the problem was bad rings or valves. His shop and he determined that it was a bad intake valve on the #8 cylinder and they claimed they heard air coming through the throttle body. Seemed like a slam dunk.