Loud cracking noise - rotational with rev's

You are not that far from Wales surely there are loads of garages round there versed in servicing the tratter community... I don't think you will have trouble finding one if you don't take the job on yourself.

Right then.. paranoid follow up! I'll pop pics in my buuld thread of it going back together and all that boring stuff you've all seen before rather than post in here.

Truck is now back together, but i have potential issues i want to run past all of you as the paranoia has set in already.

To recap the coolant lashed itself all over the floor. Strip down saw the P gasket was the culprit and in a really bad state. Also 90% of all the fins were missing from the rad and the Y peice from expansion tank to thermostat housing/top left of rad wasn't flowing properly. Keen eyes may have spotted more at this point of course.

New parts i have fitted;
Re-con original rad - been stipped recored and painted and is the original copper/brass item with metal oil cooler not an alu/plastic job.
New P gasket
New waterpump and gasket
New thermostat
New Y peice hose (original from LR)
Recently a new aux belt and tensioner which is what started this thread in the first place.

The cambelt is due, to make this easier i'll be pulling the rad again for space, knowing this i have used normal water and some prestone mix with both antifreeze to make a flush through juice.

In the back waiting i have 6 litres of blue coolant and 6 litres of distilled water for the end result, meaning i should have 1 litre mixed up left to keep along with my oil etc for top ups if required. I had the prestone stuff left over so used that basically as a coolant flush at this point.

System was filled slowly using both the rad bung and the thermostat bung and heaters on hot for when it ran etc, in my test drive coolant levels didn't drop so fairly confident i've not made a massive air lock. Heater blows through hot as it has from day one.. i guess i'm just a luckier one here.. OR the system is just getting too hot full stop.

While i was waiting for various parts over bank holiday weekend, between work etc i degreased what i could off the block and surrounding parts this included cleaning out my intake and intercooler and fitting new boost pipes while im at it. The EGR has been blanked but the fuel pump is standard at this point and not fiddled with.

I have noticed a leak on my inlet/exhaust gasket so could this be a potential cause to my issues im about to describe? Was thinking something like binding brakes to make things work harder too but clutch down rolling down the road or just releasing handbrake and the truck isnt grabbing or sticking so to speak.

Before coolant spat itself my guage starts below the white line and builds its way up to about 1/3rd of the guage. Bit more driving and she goes to about half way. The fan is working fine btw and really no idea how others run with it off?

Anyway.. i get on the motorway and within a minute at 55mph im 2/3rd on temp guage and creeping for the red, i have to slow to 50mph to keep it from moving or wait for a lorry to overtake and i can reduce the load a bit at 55 and follow him.

This sucked! Then the coolant went.. so i thought i had some closure.. i had an issue that had presented itself.

With the bits i've replaced i'm surprised it went that well to be honest. That day i did see an orange and black 90 in the outside lane absolutely tanking it.. i was smiling thinking lucky bastard!

So.. all parts fitted and truck started! No sign of a water leak out the back of the block and coolant levels stayed good. I did also top up the oil before i started her because of re-filling the oil cooler and after running for a few mins i switched off and checked it all again.

So.. guage moved up to about 2/3 going up the street on 20mph road, out to roundabout and upto 30 road and im sat at half. Bear in mind im not reving the hell out of it and i'd say using about 50% throttle.. was on a test run not a race. Got my way down into town after a bit of stop start but say 20 mins into my journey on the return loop my temp guage was once again on the rise!

I thought again maybe this air sound which initially thought was a boost leak is actually the inlet maybe getting starved of air and thus working harder?

Got back home and needle was at 2/3 maybe closer to 80% on the dial and i havent got over 30mph the whole run nor did i put my foot down. I didnt have the revs as high as say it would be at 60mph on the motorway. Worth saying at this point i wasnt labouring the engine either.. just in cruise status.

Soo.. parked up.. all dry and coolant levels fine and flowing water to expansion tank.

Im really not confident at this point i'll be able to hit a motorway or a "longer drive" without an issue cropping up. If some of you drive without your fan and i've replaced all these bits something is a miss.

Any thoughts/suggestions helpful as always.. sorry its a long one but tried to give details i could remember.

Oh.. popped in a new air filter too at this point. Oil is about 4k old from paperwork.

Thanks again

Mark

Edit:to add - when i pulled up the coolant wasn't boiling or steaming away. Is there an easy way to test the guage incase its jumping 1/2/3 as i describe?

My 300 sits at bang on half way and is rock steady. Even hauling it's lardy backside on full power up a 9000ft climb in the Alps.

You either need a new thermostat because yours is lazy, or much more likely you have an airlock somewhere.

Park on a hill if you can pointing up hill and fill as follows...

Expansion cap off, rad bung off thermostat bung off.

Fill expansion tank slowly until half full OR until rad bung overflows (depends on how steep hill is!) Fit expansion cap, fill through rad bung until rad full if needed, fit rad bung.

SLOWLY fill the thermostat housing. It will take some time! keep going eventually it will full up. get as much in as you can. Put the bung in.

Open the expansion tank and see - you will have between almost empty and half full. Top to half full refit cap

Start engine.

There is a small pipe off the side of the stat housing going to the Y connector - if you pull this off with the engine running it should give you a stream of coolant (probably frothy at first starting.) if this is blowing coolant from the waterpump you are fine.

I will check levels again. I did fill as slowly as i could and through all the bungs as you've suggested amd that leaves my res about half full.

I am on thermostat number 2 as well, first one was ok but changed seeing as i was doing everything else.

I'll pull the Y hose (brand new so we know thats good) and see if its flowing nicely. I did however see movment in the coolant in the res so im guessing it is fine.

Checked levels.. same journey tonight amd the needle stayed just below half the whole way. However.. fuel guage is pinned to full right now.. do all the guages etc share a common ground somewhere? Might have an issue there and engine actually operating ok. New secondary set of guages are on my christmas list though! Done with these ones already. Looking at the durite ones as seem to be the o.e.m looking guage to go for.

Well - it does perhaps sound like that there may be a gauge fault then.... sadly no idea on defender electrics.