Nissan Repair: autochemical product

Question
QUESTION: Good day, Dear expert!

I hope you remember me. I am about skyline engine.
Tell me please what can I do to to repair skyline ( 1994's ) instead  to set another engine in it.
I want to know what I should consider it is need to change engine or no need?

I heard about autochemical products? What about try those autochemic products? Those autochemical products are useful for engine that is disassembled more than once three four times?

Thank you & Regards
Ankhaa

ANSWER: sorry but you don't give me enough information as to what the trouble is . is the car overheating or something ?????????????

---------- FOLLOW-UP ----------

QUESTION: Thank you for reply.

Car sound is not normal that should be, and it is turns off while driving.
In auto services it was 3, 4 times to repair engine and disassembled 3 or 4 times. Those auto services are not good they are just faking, I think and I interested to use autochemical products to repair engine not disassembling. Can you tell me please, it is effective to use autochemical products for 3 or 4 times disassembled engine?

Regards
Ankhaa

Answer
first of all the garage would not be pulling the engine apart as it is time consuming and expensive we would not do it day to day but only if it has damage to the internal components and I am not sure what the auto chemical you are talking about is it some sort of engine sealer we don't use it in the UK so we are not sure what you mean by using auto chemical maybe could you explain in a bit more detail of what this product is many thanks