fixing a 1986 HT4100 in a Sedan Deville

[fvendbrr]

Hello everyone, I am new here and have read with interest all of the good information. I would like some suggestions / info on if I am wasting my time. I have a 1986 sedan deville that I obtained for virutally nothing at a local police auction with 170k miles. I bought the car because it looked brand new inside and out, even the tires. Problem was it was leaking oil from everywhere and had a miss, but no smoke out the exhaust. So, being the dummy I am, I dismantled the engine down to the long block, cleaned everything and have been replacing all of the gaskets, o-rings, hoses, etc, and water pump. The reason for the miss became apparrent when I pulled one of the valve covers, one of the aluminum keepers (that tie 2 rocker arms together on the cyclinder) was broken and the valves were not working. easy enough to fix.

Also, there was no antifreeze, etc.. in the oil when I drained it but the radiator fluid was a very thick milky color, which I have tried to clean out of the block also. Is this normal with the additive Cadillac says you need for sealing, or was it something like Bars leak added.?

Am I wasting my time and any suggestions on what to look for, and do, while putting it back together will be welcome. When I finish, I will post my results.

[Ed Hall]

Hi,

Sounds like you found a nice car and you're willing to spend some time to get it working good rather than spend money on monthly car payments like what most people do. If it were my car, I would not mess around with the 4.1 but rather, I would find a 4.5L Cadillac engine out of a 88 or 89 Cadillac to put in your car. They can be found for around $200 and many improvements were made including roller lifters, roller cams, more power, etc. I've driven both 4.1 and 4.5 cars and even though the 4.5 has only 25 more hp, it feels a more than that. Try to find an engine with not to many miles like under 120k miles. They are long lasting engines but if it has too many miles, you need to replace the rings since those tend to wear out at around 250k miles.

If you do plan to rebuild your 4.1 L, I urge you to read the following PDF article in the link. Pay particular attention to the fasteners used to bolt down the intake manifold.

http://www.sendthisfile.com/myfiles/filede...QVh3olJHEHWgyce

Also, since you have the engine out, you might want to freshen up the transmission. I would buy an $80 rebuild kit and rebuild that transmission so that it goes another 150k miles. I would also install a trans-go shift correction package to make this transmission a lot more robust. I would also buy a new Viscous Convertor. They run about $90.

Good luck

[KHE]

I'm not sure how the electrical portion of the 4.5 engine would work in the HT-4100 car.

The bars that hold the rockers together need to be tightened per the sequence in the service manual or they will be damaged. It's possible that someone was inside the engine and improperly assembled the valve train. If you haven't already done so, get a factory service manual (not a Chiltons or Haynes) and read up on the correct assembly method.

Not sure what the mikly substance was in the coolant - it does not sound like the bars leaks powder - that is a brown color. Does the car have an engine oil cooler in the radiator tank? By the way, it is imperative that the Bars Leaks sealer be used in the coolant for the 4.1/4.5/4.9 engines.

[Ed Hall]

I'm not sure how the electrical portion of the 4.5 engine would work in the HT-4100 car.

.

The electrical portion of the 4.1 works fine on the 4.5 for 88/89. Both engines were TBI and lower compression. What works best is to transplant the whole 4.5 including the TBI from the 4.5. There have been others who have transplanted 4.9's and they usually have to use an adjustable FPR since the electronics on the 4.1 don't compensate enough for the extra cubic inches.