Sorry about your problem but I have to agree with P E H. It sounds like a lower end knock that is going to take some work to get fixed. The fact the noise is increasing suggests that the damage is done and will only get much worse if you drive it. The more I read stories like this the more I realize that oil hoses are wear items and should be replaced periodically even if they look OK. Cheap insurance.

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LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold