which oil to use in a w124 300td diesel. noisy for the first 5 mins..!

[jgs600]

guys my 1990 300td has 136,000 on the clock and when i got it was nice and quiet on start up and driving. since doing an oil change castrol gtx mineral 10w-40 she now sounds like an old tractor for the first 5 mins or so or until the temp gauge is near 80ish then the engine goes nice and quiet.....!

now does this mean the engine oil is too thick to begin with and thins out when it gets to operating temperature.

am i better off going for something like 5w-40 or what.

any ideas guys would be great.
cheers

 

[krimat2005]

I think your tappets might be worn out. if you want change them go for all 12, you can get them from GSF for about £11-12.