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Cadillac Repair/engine change 1987 v8-252, 4.1L


can I put a 1988 v-273,4.5L engine into my 1987 Cadillac sedan deville...will this work? I'm having problems with oil in my coolant system...sure the head gaskets are the problem. I can't get anyone to change head gaskets on my 1987 v8-272, 4.1L.  Is this engine switch possible?


This is a frying pan into the fire situation. Same issues and most of those engies are junk because they too have been overheated. this is the problem when dealing with aluminum engines. I doubt if you will find an interchange book to see if the engine is a go for a replacement, but before going to the work to find out the 4.5 is bad, you need to run a cooling system pressure check. If not in the car, stay away from it!You will have to change computers. You will also need the ignition lock and key r column from the car if from a 1990his creates another issue because the lock cylinder for the VATS was problematic. If you are getting the 4.5 from a 1990 you need to change the engine harness as well as the under dash harness at the firewall.
Unfortunately, even if the engine bolts up, the computer system and associated wiring needs to be considered.
This is an issue many don't consider, swap the engine and find it won't run. I have never found a good used Cadillac engine.

If your 4.1 needs head gaskets, that is not the cause of overheating, but the effect. There is an issue in the cooling system that caused the engine to overheat in the first place. A plugged radiator, cooling fans not functioning at low speeds as well as many more issues. The 4.1 had other problems as well like many with an annoying built in wrist pin slap straight from the factory.
I have been very fortunate with the 4.1s and never overheated one. A factory crate engine is $4k if one is still available which is more money than the car is worth.
I do not know if a rebuilt is available, but you can check with Jasper engines on the web. You might find that getting a rebuilt with a guaranty might be less of a headache than converting to the 4.5.
If you go that route, you must make sure the over heating issue was caused because of your current engine.
Many (like me) shied away from replacing head gaskets on the Cadillac engine because they were just doomed to be a comeback where the tech would marry the car and live with problems for live. Depending on the overheating the damage can be more severe than head gaskets. I have seen where the block has cracked, pistons have melted. The over heated 4.1, 4.5, 4.9, north star are all categorized by us techs as a "pig in a poke" A/K/A/ Pandora's box.

Good luck and keep me informed what happens.

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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