Just completed my Cosworth 4x4 engine With all New seals, o-rings and gaskets etc, including a New cambelt and tensioner. While the engine was out, all 16 tappets was out for a good clean as well.


After the first startup, I have had a droning/grinding noise that appears slowly 30 sec after fired up, and that increases in volume when the engine get's hot.


I have tried to set different tensions to the cambelt, so I can twist the belt 90 degrees when Cold on the longest run, and tested With the same setting when engine is hot. The noise seems to be a bit better when I slack the tension abit, but there is not much between a almost Perfect fitted belt and a flapping belt when I slack it just a little..


The alternator also suffered from two bad bearings, so they have been replaced and are now okay.


Is my camshaft bearings on my last Journey, or do I need to slacken the cam belt even more? It's not whining when reving up, like a to tight cambelt usually should have done IMO. This noise is starting to annoy me.


Here is a video of the noise when engine is hot (and the fans have kicked in twice):

 

It is a strange noise but to me it sounds as though something is rattling outside of the engine not in the engine itself.

 

I can agree With you on that one..


I have mounted some new Collins engine Mounts on the car, because of the old original ones was worn out. The sound was not there before fitting them and the New cam belt and tensioner. The noise can be related to a diesel engine where the engine plastic cover is vibrating and making some resonace sound through the enginebay.


Was out in the garage listening to the noise again, and I can feel and hear the droning noise when I attach a large screwdriver on the front of the turbo/wastegate bracket..

 

I guess it's a twin rib cambelt probaby a Bosch

 

Set your cam belt tension when the engine is at operating temperature. It will be loose when cold which is correct

 

Cotina; The cambelt is from Gates and tensioner is a INA one, both from Burton.


Turbosystems; I have set the tension on cambelt when engine is at operating temp now, can twist the cambelt 80-90 degrees. When engine has Cooled Down, the belt is loose, as you mention. When firing it up again when Cold, I can hear a bit of flapping noise from the cambelt until it starts to get warm, and it's stops flapping. I find it difficult to adjust it from not flapping when Cold and not be to tight when warm. Just leave it like this, as long as it doesnt rub or hit anything when flapping?


And regarding the droning noise, it all seems to be sourced down to resonace going through the enginebay/exhaust due to New uprated/stiff engine Mounts. The noise is gone on lower revs at idle and on higher idle, and appears on some different revs and loads while driving..

Thanks for help/tip!